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THE EFFECTS OF ANKLE POSITIONAL STRENGTH
TRAINING ON STRENGTH AND PASSIVE JOINT POSITION
SENSE

presented by

DANA GABRIELLE CORTESE

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THE EFFECTS OF ANKLE POSITIONAL STRENGTH TRAINING ON STRENGTH
AND PASSIVE JOINT POSITION SENSE

By

Dana Gabrielle Cortese

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE
Department of Kinesiology

2004

ABSTRACT
THE EFFECTS OF ANKLE POSITIONAL STRENGTH TRAINING ON STRENGTH
AND PASSIVE JOINT POSITION SENSE
By

Dana Gabrielle Cortese

Objective: To compare positional strength training and traditional strength training
techniques on the ankle joint, assessing changes in muscular strength and passive joint
position sense (PJ PS). Subjects: Seventeen healthy, physically active college students
participated in the study. Subjects were randomly assigned to one of two groups,
positional strength training (5 females, 4 males) and traditional strength training (5
females, 3 males). Measurements: Pro-test and posttest isokinetic strength and PJPS
measures were acquired using an isokinetic dynamometer. Plantar flexion/dorsiflexion
and inversion/eversion strength were measured at 30°/s and 180°/s. Plantar flexion PJPS
was assessed at three target angles 20°, 30°, and 40°. Inversion PJPS was assessed at
three target angles 5°, 10°, and 20°. Results: No significant interaction was found
between strength training group and time for isokinetic strength. A Significant main
effect for plantar flexion, inversion, and eversion strength was revealed for all subjects
regardless of training group. No significant interaction between strength training group
and time was discovered for PJ PS. Conclusions: Positional strength training did not
result in greater improvement in ankle strength and passive joint position sense in
comparison to traditional strength training. The positional and traditional training groups

exhibited comparable strength gains and passive joint position sense measures.

I would like to dedicate this Master’s Thesis to my family and let them know that I have
finally found my way home. Thank you for your love and support.
I believe in myself. . .because you believe in me.

If you wake up with the sunrise, and all your dreams are still as new
And happiness is what you need so bad
The answer lies with you

Led Zeppelin

iii

ACKNOWLEDGEMENTS

I would like to take this opportunity to thank my committee members for their
guidance and wisdom, which they have bestowed upon me. I truly appreciate your
support and encouragement over the years and I am grateful to have had the opportunity
to collaborate with three amazing educators and mentors. You have provided me an
environment to grow and develop as a scholar in my field and have inspired me to
continue my education and quest for knowledge.

In addition, I would also like to thank all of the subjects who volunteered to
participate in my research. Thank you for your time and dedication each week to
complete the strength training. Your efforts and competitive spirits made my research
enjoyable and a success.

To my fellow graduates, I would like to say thank you for your support and
assistance; being together has really helped me to endure. Thank you for always lending

and ear and being an excellent audience.

I would also like to thank my family and friends for your encouragement and your

faith in me. Thank you for your love and unwavering support. I love you!

TABLE OF CONTENTS

LIST OF TABLES ............................................................................................................ vii

LIST OF FIGURES ......................................................................................................... viii
CHAPTER 1

INTRODUCTION ............................................................................................................... 1

Statement of the Problem ......................................................................................... 3

Statement of the Purpose ......................................................................................... 3

Significance .............................................................................................................. 4

Research Hypothesis ................................................................................................ 4

Delimitations ............................................................................................................ 4

Limitations ............................................................................................................... 4

Assumptions ............................................................................................................. 5
CHAPTER 2

REVIEW OF LITERATURE .............................................................................................. 6

The Ankle Joint ........................................................................................................ 7

Talocrural Joint ............................................................................................ 7

Subtalar Joint ............................................................................................... 9

Distal Tibiofibular Joint ............................................................................... 9

Mechanism of Injury .............................................................................................. 10

Chronic Ankle Instability ....................................................................................... 10

Mechanical Instability ................................................................................ 10

Functional Instability ................................................................................. ll

Proprioception ................................................................................ 1 1

Mechanoreceptors .......................................................................... 12

Joint Position Sense ....................................................................... 12

Strength .......................................................................................... 13

Neuromuscular Control .................................................................. l4

Postural Control ............................................................................. l4

Rehabilitation ......................................................................................................... 15

Benefits of Strength Training ................................................................................. 15
CHAPTER 3

METHODS ........................................................................................................................ 17

Subjects .................................................................................................................. 18

Instrumentation ...................................................................................................... 1 8

Defined Variables .................................................................................................. 18

Materials ................................................................................................................ 19

Protocol .................................................................................................................. 19

Positional Strength Training ...................................................................... 20

Traditional Strength Training .................................................................... 20

Weight Training Progression ..................................................................... 21

Isokinetic Strength Testing ........................................................................ 21

Passive Joint Position Sense ...................................................................... 22
Statistical Analysis ................................................................................................. 23
CHAPTER 4
RESULTS ................................................................................................................ 24
Passive Joint Position Sense Results ...................................................................... 25
Isokinetic Strength Results .................................................................................... 28
CHAPTER 5
DISCUSSION .................................................................................................................... 33
Passive Joint Position Sense .................................................................................. 34
Isokinetic Strength ................................................................................................. 36
Clinical Implications .............................................................................................. 38
Considerations for Future Research ....................................................................... 4O
APPENDICES ................................................................................................................... 41
Appendix A: Materials ........................................................................................... 42
Appendix B: Informed Consent Form ................................................................... 44
Appendix C: Instructional Tutorial ........................................................................ 48
Appendix D: Strength Training Position ............................................................... 50
Appendix E: Strength Training .............................................................................. 52
Appendix F: Isokinetic Strength Testing ............................................................... 54
Appendix G: Passive Joint Position Sense Testing ................................................ 56
BIBLIOGRAPHY .............................................................................................................. 58

vi

TABLE 1

TABLE 2

TABLE 3

TABLE 4

LIST OF TABLES

Descriptive Table for the Means of the Interaction of Training
Group and Time on Inversion Passive Joint Position Sense .................... 26

Descriptive Table for the Means of the Interaction of Training
Group and Time for Plantar Flexion Passive Joint Position Sense ............ 27

Descriptive Table for the Means of the Training Group and
Time for Isokinetic Strength ...................................................................... 3O

Descriptive Table for the Means of the Main Effect of Time on
Strength Variables ...................................................................................... 32

vii

FIGURE 1

FIGURE 2

FIGURE 3

FIGURE 4

FIGURE 5

FIGURE 6

FIGURE 7

FIGURE 8

FIGURE 9

FIGURE 10

FIGURE 1 1

FIGURE 12

FIGURE 13

FIGURE 14

FIGURE 15

FIGURE 16

LIST OF FIGURES

Means ( i 1 SD) for Passive Joint Position Sense Target Angles
5 Degrees, 10 Degrees, 20 Degrees. (n = 17). (P = .05). ............................... 26

Means ( i 1 SD) for Passive Joint Position Sense Target Angles
20 Degrees, 30 Degrees, 40 Degrees. (n = 17). (P = .05) .............................. 27

Means ( i 1 SD) for Eversion/Inversion Isokinetic Peak Torque Variables
EV 30°/s, INV 30°/s, EV 180°/s, INV 180°/s. (n = 17). (P = .05) ................. 29

Means ( _+_ 1 SD) for Plantar Flexion/Dorsiflexion Isokinetic Peak Torque
Variables PF 30°/s, DF 30°/s, PF 180°/s, DF l80°/s. (n = 17). (P = .05) ...... 29

Means ( i 1 SD) for the Main Effect Eversion/Inversion Isokinetic
Peak Torque variables EV 30°/s, INV 30°/s, EV 180°/s, INV 180°/s.
(n = 17). (*P < .05) ........................................................................................ 31

Means ( i 1 SD) for the Main Effect Plantar F lexion/Dorsiflexion
Isokinetic Peak Torque variables PF 30°/s, DF 30°/s, PF 180°/s,

DF l80°/s. (n = 17). (*P < .05) ...................................................................... 31
Leg/Ankle Exerciser ...................................................................................... 43
Subject Position ............................................................................................. 51
Starting Position ............................................................................................. 53
Ending Position .............................................................................................. 5 3
Starting Position ............................................................................................. 53
Ending Position .............................................................................................. 53
Inversion/Eversion Subject Position .............................................................. 55
Plantar Flexion/Dorsiflexion Subject Position .............................................. 55
Inversion/Eversion Subject Position .............................................................. 57
Plantar Flexion/Dorsiflexion Subject Position .............................................. 57

viii

CHAPTER 1

Chapter 1

INTRODUCTION

Lateral ankle sprains are injuries that plague the athletic population. Eighty-five
percent of all ankle injuries occur to the lateral ligaments 1’ 2. Lateral ankle sprains occur
through a forceful mechanism of supination. Supination is defined as the combination of
inversion, plantar flexion, and adduction of the ankle. The injury most often occurs in
jumping and running activities that require a combination of speed and agility, including
dynamic movements of forward propulsion and rapid changes of direction 3’ 4. In
addition, following initial incidence of a lateral ankle sprain, there is an 80% chance of
reoccurrence of injury 5 . As a result, chronic ankle instability or CAI develops 6.

Post injury deficits are evident in both the static and dynamic structures about the
ankle complex 3. Current rehabilitation and prevention programs focus on a variety of
components to restore or maintain fiinctional ankle stability (F AS). The three main
components involved in joint stability are degree of ligament laxity, muscle strength, and
proprioception 2.

One method of rehabilitation that may aid in the restoration of FAS is ankle
positional strength training. Ankle positional strength training is a method of strength
training in which movement is initiated in the position of supination. Positional strength
training places the subject at an angle of 40° of supination. The supination position is
intended to help the subject recognize a potentially dangerous position of supination
which may lead to a lateral ankle sprain and place the structures of the lateral ankle joint

in a stretched position to influence ankle joint mechanoreceptors. Positional strength

training requires the subject to move from a position of supination to a neutral position.
The subject moves from a position where the lateral ankle structures are in a lengthened
or stressed position to a position in which the lateral ankle structures are shorter or
unstressed. The potential of positional strength training to influence muscle strength and
ankle joint mechanoreceptors may lead to an increase in F AS.
Statement of the Problem

Strength training of the muscles that cross the ankle joint is a method used to
develop support about the ankle joint. Some, current strength training protocols do not
incorporate the full range of ankle motion 1. If strength training to develop support of the
ankle joint is conducted through a limited range of motion, the ankle joint and its
surrounding structures, static and dynamic, may not be placed under sufficient stress to
affect desirable changes. Safran et a1. 7 recommend that strength training begin in a
stress-free position of neutral/dorsiflexion and move to a stressful position of plantar
flexion and inversion. The goal of positional strength training is to simulate the position
of injury for lateral ankle sprains, placing the ankle in a starting position of supination
(Le, a combination of plantar flexion, inversion, and adduction) to potentially affect
desirable strength and neuromuscular changes.
Statement of the Purpose

The purpose of this study is to compare positional strength training and traditional
strength training techniques on the ankle joint, assessing changes in muscular strength

and passive joint position sense.

Significance

The majority of traditional strength and proprioceptive training has been
conducted within the mid-range of normal ankle motion. Positional strength training is
performed through an increased range of motion, initiating training in the stressful
position of supination. Positional strength training allows insight into the effects of
placing a joint under increased stress. In addition, the results may provide information
applicable to further rehabilitation or prevention programs for other joints of the body.
Ankle strength training of the muscles that cross the ankle joint is warranted because it
has demonstrated results of increased strength and joint position sense through training "
8' 9. Deficits in strength and joint position sense may predispose an individual to injury.
Research Hypothesis

It is hypothesized that ankle positional strength training would result in greater
improvements in ankle strength and ankle passive joint position sense as compared to
traditional strength training.

Delimitations

1) Passive joint position sense testing for plantar flexion and inversion was performed at
4°/s, whereas the majority of ankle motions are many times faster and more dynamic.

2) Isokinetic strength testing for ankle plantar flexion/dorsiflexion and inversion/eversion
was conducted at two test velocities, 30°/S and l80°/s, whereas dynamic physical activity
occurs in multiple directions and with greater velocity.

Limitations

1) The starting and ending positions for each positional strength training repetition were

identical; and, the path from start to end was variable between subjects.

Assumptions

1) Subjects performed strength testing and strength training with maximal effort.
2) The starting position of ankle positional strength training is the most important

component of the exercise; placing the greater stress on the ankle joint in supination.

CHAPTER 2

Chapter 2

REVIEW OF LITERATURE

The Ankle Joint

To completely understand the common injury of lateral ankle sprains,
comprehension of the ankle complex must be obtained. The ankle joint is comprised of
three articulations: talocrural joint, subtalar joint, and distal tibiofibular joint '0. These
three joints work together to provide ankle rearfoot motion 10. Rearfoot motion can be
defined as triplanar motion, occurring in the sagittal, frontal, and transverse planes '0.
Motion that occurs in the sagittal plane is commonly referred to as dorsiflexion and
plantar flexion. The motion in the frontal plane is referred to as inversion and eversion.
Lastly, the motion that occurs in the transverse plane is referred to as adduction and
abduction ‘0. However, the motion of the rearfoot does not occur in isolated movement
patterns. As stated early, the three joints work together to provide cumulative motions,
also known as pronation and supination. Pronation can be defined as dorsiflexion,
eversion, and abduction. Supination can be defined as plantar flexion, inversion, and
adduction 10.
Talocrural Joint

It is important to examine each joint and its contribution to the ankle complex.

” H. The talocrural joint

The talocrural joint is often considered to be “the ankle joint
primarily allows the motions of dorsiflexion and plantar flexion within the sagittal plane.
During motion of the talocrural joint, accessory motion of the subtalar and tibiofibular

joints are also observed about the oblique axis of the joint 10. For example, in 30° of

plantar flexion, 28° of motion occur in the sagittal plane (plantar flexion), 1° of transverse
plane motion (adduction), and 4° of fiontal plane motion occur (inversion) '0. The
triplanar motion demonstrated about the talocrural joint provides fluid motion and
increased joint stability throughout motion 10.
In addition to the stability provided through osseous configuration, the ligaments
that surround the talocrural joint also play an important role in maintaining joint stability
'0’ '2. Three ligaments laterally support the talocrural joint: anterior talofibular ligament
(ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL) '0’ 12.
The ATP L is an intra-capsular structure that is an average of 7.2 mm wide and 24.8 mm
long 10. As the ankle joint complex moves from a position of dorsiflexion to plantar
flexion, the ATP L becomes taut '2. The primary role of the ATFL is to prevent excessive
anterior displacement of the talus from the talocrural joint and inversion and internal
rotation of the talus on the tibia 10. The ATFL is the most frequently injured ligament of
the lateral complex 10. The CFL is extra-articular and runs from the posterior inferior
aspect of the lateral malleolus to the lateral aspect of the calcaneus '0. Due to the position
and angle of attachment of the CFL, it is most taut in the position of dorsiflexion 10. The
role of CFL is to prevent excessive supination that takes place at the talocrural and
subtalar joints, aiding to restrict inversion and internal rotation of the rearfoot 1°. Lastly,
the PTFL runs from the posterior lateral malleolus to the posterior lateral aspect of the
talus 1°. The PTFL is taut only in extreme angles of dorsiflexion, and, because of this, it

is the least injured lateral ligament of the ankle 12. The primary role of the PTFL is to

prevent both inversion and internal rotation of the talocrural joint '0.

Subtalar Joint

The subtalar joint allows for motion of pronation and supination. This joint is formed by
the articulation between the talus and the calcaneus. The subtalar joint can be further
divided into an anterior and a posterior joint separated by the sinus tarsi and canalis tarsi
'0. The anterior joint lies farther medial and has a higher center of rotation than the
posterior joint. As a result, rotation about the oblique axis is altered 10. Rotation about
the subtalar oblique axis results in a 42° upward tilt and a 23° medial tilt, as compared to
the perpendicular axis of the foot '0.

The support of the subtalar joint is provided by three groups of lateral ligaments:
deep ligaments (cervical and interosseous), retinacula, and peripheral ligaments 10. First,
the deep ligaments cross through the canalis tarsi and are often referred to as the “crutiate
ligaments” of the subtalar joint ‘0. The cervical ligament primarily resists supination,
while the interosseous ligament is taut throughout the motions of pronation and
supination. Second, the inferior exterior retinacula (IER) supports the lateral aspect of
the subtalar joint. Third, the peripheral ligaments of the subtalar joint are the CFL, lateral
talocalcaneal ligament (LTCL), and fibulotalocalcaneal ligament (FTCL) 10. The CFL, as
previously stated, aids in restricting inversion and internal rotation of the calcaneus. The
other two ligaments, LT CL and F TCL, both aid in preventing excessive supination '0.
Distal T ibiofibular Joint

The distal tibiofibular joint is a syndesmosis joint that is stabilized by the
interosseous membrane and the anterior and posterior inferior tibiofibular ligaments '0.

The syndemosis joint is necessary to provide the structure of the talocrural joint,

providing stability between the tibia and the fibula 10.

Mechanism of Iniufl

Lateral ankle sprains occur in a variety of athletic venues, especially soccer,
basketball, and volleyball 4. Ankle injuries most often result during forward propulsion,
jumping, and/or cutting activities 4. The mechanism of injury can be more specifically
described as a sudden traumatic supination. As a consequence of traumatic supination,
structures of the ankle complex are compromised and injury results.

Chronic Ankle Instability

Chronic ankle instability (CAI) occurs when an individual sustains recurrent ankle
injuries. There are two main theories related to the cause of CA1, mechanical instability
(MI) and functional instability (Fl) '0. Mechanical instability can be defined as ligament
laxity or ligament elongation or rupture 14. In addition to changes in ligament integrity,
joint arthokinematics may be compromised and degenerative joint changes may occur '0.
F I as defined by Freeman is simply a “feeling of giving way” ‘4. Further explanation was
offered by Hertel et a1. '0 who stated that F1 was a result of impaired proprioception and
sensation, impaired neuromuscular firing patterns, impaired postural control, and Strength
deficits. In the following section, the components of MI and F1 will be examined in
detail.

Mechanical Instability

One indicator MI is the extent of ligament damage that has occurred about the
ankle complex ‘0. The ligaments about the ankle joint serve three major functions:
provide proprioceptive information for proper joint function, prevent excessive joint
motion, and act as a guide to direct motion 12. In addition, the ankle ligaments provide

neurologic feedback that directly mediates reflex muscle stabilization about the joint '5.

10

In the presence of ligament laxity, ligament function is compromised and the ankle is
predisposed to further injury '0.

Joint arthrokinematics may become compromised following a lateral ankle sprain
'0. As demonstrated by Bemier et a1. 14, unstable ankles exhibited increased degrees of
inversion just before heel strike during normal walking. In addition, Hertel ‘0 discovered
instances of hypomobility in the talocrural joint which leads to a diminished range of
dorsiflexion. As a result, the ankle will be able to invert and internally rotate more easily
10. In subsequent research, altered arthrokinematics were also discovered in the posterior
glide of the talus '0. Both findings support the alteration of proper arthrokinamatics.
Dorsiflexion requires an anterior roll of the talus accompanied by a posterior glide of the
talus.
Functional Instability

The four major components that encompass Flare deficits in proprioception and
sensation, diminished strength, impaired neuromuscular firing, and poor postural control.
Proprioception

The concept of proprioception can be defined as awareness of posture, movement,
and changes in equilibrium, as well as, the knowledge of position, weight, and resistance
to objects in relation to the body 16. Proprioception encompasses the sensation of joint
movement (kinesthesia) and joint position sense (I PS) 15. Proprioceptive input is
provided to the central nervous system (CNS) by mechanoreceptors found in the skin,
muscles, joints, ligaments, and tendons. In addition, visual and vestibular centers also

contribute afferent information to the CNS regarding body position and balance ‘5.

Mechanoreceptors

Muscle mechanoreceptors include muscle spindle afferent neurons that are able to
detect muscle length and provide a unidirectional signal of joint movement 17. Excitation
of muscle afferents, through muscle vibration, results in sensations of joint movement
and position 17. Muscle spindles function to measure muscle stretch over a large range of
muscle fiber length '5 . In addition, there are mechanoreceptors specific to muscle
tendons, known as golgi tendon organs (GTO) 15. The GTO serves as a protective
mechanism recruited when muscle contraction forcefully pulls on the tendon ‘5 .

Joint mechanoreceptors include both large, rapidly conducting axons, and small
diameter afferents, with slow conducting axons 17. The rapidly conducting afferents are
also known as Group 2 afferents, of which there are two main groups - the Ruffmi
afferents! and the Paciniforrn afferents 17. The Ruffinin afferents are found mainly in the
“flexion” side of the joint, the side of the joint that is stretched when the joint is extended
17. Ruffini afferents are considered limit detectors, excited only during extreme extension
rotations 17. The Paciniforrn afferents are stimulated by pressure or compression and are
activated by tensile loading of the surrounding joint capsule 17. The slow conducting
afferents are also known as the Group 3 and 4 afferents. These afferents appear to be
related to pain rather than proprioception 17.

Joint Position Sense

JPS has been found to decrease following a trauma to the lateral ankle complex.
Recent research has found a decrease in sensory input from joint receptors, leading to
abnormal body positioning '5. In addition, a 6-week strength training intervention

conducted by Docherty et al. 1 revealed increased dorsiflexion and eversion strength and

12

improved inversion and plantar flexion J PS. Results of the study indicated that deficits
were present in both strength and J PS and that both components could be positively
affected through strength training 1.
Strength

Conceptually, muscle strength is essential to maintain functional ankle stability. As
discussed previously, the mechanism of injury for a lateral ankle sprain places the ankle
joint in a compromised position of supination. The strength of the lateral ankle
musculature, specifically the peroneus longus and brevus, allow the ankle to resist the
supination movement, specifically guarding against inversion 10. Tropp '8 supported this
concept through experimentation on ankle eversion strength. The findings demonstrated
a significant difference in muscle peak torque production for pronation between ankles
with and without functional instability. The results indicating strength deficits are
directly related to functional instability of the ankle 18. Recent research disputes these
findings by demonstrating no eversion strength deficits in the functionally unstable ankle
19-21.

Similarly, the strength of the dorsiflexors may play an important role in resisting
the compromising position of plantar flexion. In ankles with a greater degree of plantar
flexion and a smaller degree of dorsiflexion to plantar flexion ratio endured a higher
incidence of lateral ankle sprains 11' Furthermore, the anterior drawer test, utilized to
determine ATFL laxity, demonstrated increased excursion with increasing degrees of
plantar flexion 4. The results of this study revealed increasing plantar flexion relates to
decreasing joint stability. In addition, the results implicate that increasing angles of

plantar flexion lead to decreasing joint stability.

13

Neuromuscular Control

Motor control of an extremity is dependent upon afferent sensory and
proprioceptive mechanoreceptors, as well as, efferent reflexive and voluntary muscle
responses 22. Muscle response aids in neuromuscular control and is also a component of
dynamic muscular support. Muscle latency can be defined as the time from onset of an
inversion moment to the first motor response 4. Current research has examined muscle
latency, specifically of the peroneal musculature. The peroneus longus has been shown

1. 13, conducted a

to react significantly later in unstable than in stable ankles 4. Vaes eta
study investigating muscle response to sudden ankle supination in unstable versus stable
ankles. The results of the experiment revealed muscular response occurring at 40 degrees
of supination in unstable ankles and at 32 degrees of supination in stable ankles '3.
Moreover, the latency of the peroneus longus and brevis musculature was found to
increase with increasing angles of plantar flexion '3.
Postural Control

Postural control is the ability to maintain balance of the entire body during
locomotion or perturbation 23. Postural control is influenced by three components: visual
input, vestibular input, and somatosensory input 6. Balance can be achieved through two
strategies, the ankle strategy and the hip strategy 6. The ankle strategy is used in response
to small, slow horizontal perturbations and the forces used to move the body’s center of
mass occur at the ankle 6. The hip strategy is used in response to larger, faster
perturbations and the forces used to move the center of mass occur at the hip 6. Normal
balance strategy consists of a combination of the ankle and hip strategies 6. In the

absence of normal postural control strategies, a fall or lateral ankle sprain may occur 23.

l4

Rehabilitation

The main goal of a rehabilitation program is to restore function. In the beginning
stages of rehabilitation of a lateral ankle sprain, the two main objectives are to regain
range of motion and strength 7. Strength training should begin in a position of relatively
low stress and neutral dorsiflexion, and progress to a position of increased stress with
inversion and plantar flexion 7. Safran et al. 7stated, “It is critical to train the athlete in
this position as it is the position of injury”. The majority of strength training protocols
that are implemented following lateral ankle sprains involve rubber tubing exercises
executed within the mid range of available motion 8’ 24. In addition, free weight exercises
of the ankle and calf raises are also used to promote ankle strength gains.

Once range of motion and strength begin to increase, proprioceptive training can
be initiated 7. Ankle disc training, BAPS board, is a common method of proprioceptive
rehabilitation. The BAPS board can be utilized in a seated non-weight bearing position
and then progressed from partial to full weight bearing 24. The BAPS board, when
performed in the weight bearing position, aids in re-establishing neuromuscular control
25.

Ultimately, in the progression to functional activity, exercise programs should
move from open kinetic chain (OKC) exercises to closed kinetic chain exercises (CKC).
In the CKC exercises, activity is conducted under the stress of body weight, which proves
to be more closely related to functional demands placed on the ankle joint 21.

Benefits of Strength Training
If strengths deficits are not present in functionally unstable ankles, then, why

implement strength training protocols in rehabilitation programs? This is a pertinent

15

question that remains to be answered. What are the benefits gained by strength training
musculature that crosses the ankle joint? In a study conducted by Docherty et a1 ‘, it was
determined that strength training can alter motor recruitment, resulting in selective
activation of antagonist muscles, and their motor units, and antagonist coactivation.
Furthermore, recent findings suggest that strength training can play a dual role of
increasing both strength and joint position sense 1. In addition, Blackburn et a1. 8
demonstrated that proprioception and muscular strength contribute to balance and joint
stability in similar manners. The results of their intervention demonstrated that
enhancement of proprioception and strength are equally effective in promoting joint

stability and the reciprocal maintenance of balance 8.

l6

CHAPTER 3

l7

Chapter 3

METHODS

Subjects

Seventeen healthy and physically active college students (10 females, 7 males,
mean age = 24.2 years, mean height = 170.03 cm, mean weight = 72.5 kg) volunteered to
participate as subjects. All subjects signed a consent form approved by Michigan State
University Institutional Review Board. Subjects were excluded form participation if they
had suffered a recent head injury, presented with vestibular deficits, or suffered a lower
limb injury within the last year.

Instrumentation

An isokinetic dynamometer (Biodex Inc., Shirley, NY) was utilized to measure
strength in the directions of ankle plantar flexion/dorsiflexion and ankle
inversion/eversion. The isokinetic dynamometer was also used to evaluate passive joint
position sense (PJPS) for the motions of ankle plantar flexion and ankle inversion.
Defined Variables
Peak Torque — Maximum torque production during one set of isokinetic strength testing,

measured in Newtons (N).

Average Peak Torque - Calculated average of individual peak torques produced during
the three sets of ten repetitions

isokinetic strength testing, measured in Newtons (N).

EV 30°/s — Average eversion peak torque (N) at 30°/s

INV 30°/s — Average inversion peak torque (N) at 30°/s

18

EV 180°/s — Average eversion peak torque (N) at l80°/s

INV 180°/s — Average inversion peak torque (N) at 180°/S

PF 30°/s — Average plantar flexion peak torque (N) at 30°/s

DF 30°/s — Average dorsiflexion peak torque (N) at 30°/S

PF l80°/s -— Average plantar flexion peak torque (N) at 180°/s

DF 180°/s - Average dorsiflexion peak torque (N) at 180°/s
Degrees of Relative Error — Used as a measure of joint position sense, calculated as angle
from the designated target angle, measured in degrees.
Materials

A leg/ankle exerciser (Elgin Exercise Equipment Corp., Lombard, IL) was used
for ankle positional strength training and ankle traditional strength training (Appendix A).
Athletic tape was used to designate the exercise starting and stopping positions. Plate
weights were utilized for the strength training progression.
Protocol

A 4-week strength training intervention program was cOnducted. Subjects were
randomly assigned to one of two strength training groups, positional and traditional
training. The positional training group consisted of 9 subjects (5 females, 4 males). The
traditional training group consisted of 8 subjects (5 females, 3 males).

The subjects read and signed the consent form prior to participation (Appendix
B). During the initial training session, an instructional lesson was implemented; the
tutorial included instructions regarding proper foot positioning and fastening and exercise

range of motion (initial ankle positioning and final ankle positioning) (Appendix C). In

19

addition, prior to participation each subject performed a pre-test to develop a baseline
strength and PJPS measure.

All strength training was conducted for the dominant ankle of each subject. Leg
dominance was determined by which leg the subjects prefer to kick a ball. Each subject
began the exercise seated on an adjustable treatment table with the knee at 90° of flexion
and the foot secured to the footplate. The subject’s bare foot was secured to the plate to
avoid accessory motion. The foot was positioned posterior on the footplate with the
calcaneous in the heel cup. Then it was secured with two straps, one across the
metatarsal heads and one across the tarsal metatarsal joints (Appendix D).

Once in the proper position, the subject commenced strength training. The
subject was instructed to move from the designated starting position to the end position,
completing four sets of six repetitions. A one-minute rest period was provided between
each set.

Positional Strength Training

Ankle positional strength training was conducted in a position of supination
(plantar flexion, inversion, and adduction). Ankle strength training began with the
subject positioned in 40° of supination. The subject was then instructed to move the
ankle from supination out to a neutral positioning (Appendix E). The resistance was
provided with plate weights positioned on the front weight plate of the leg/ankle
exerciser. The subject performed four sets of six repetitions, three sessions per week.
Traditional Strength Training

Ankle traditional strengthening was conducted through the motions of plantar

flexion/dorsiflexion. Strengthening began with the foot in plantar flexion and move to a

20

position of dorsiflexion (Appendix E). The resistance was provided with plate weights
positioned on the front weight plate of the leg/ankle exerciser. The subject performed
four sets of six repetitions, three sessions per week.
Weight Training Progression

Weight training was conducted based on 1 RM measures. One RM was
determined through multiple-RM testing. Multiple-RM testing was utilized because the
strength training involved one joint and did not include large muscle areas, minimizing
the possible effects of fatigue 26. Multiple-RM testing was determined based on 10 RM.
Each subject conducted sets of 10 repetitions, increasing the weight after each set.
Subjects were given a 30 second rest period in between each set. Weight increase
commenced when the subject was no longer able to obtain the full 10 repetitions. The
last weight at which the subject was able to complete the full set was determined to be the
10 RM. Once the 10 RM was established, a conversion chart developed by the National
Strength and Conditioning Association was utilized to determine the lRM 26. Strength
training began at 85% of lRM. Weight progression was based on the 2-for-2 rule; 2
additional repetitions performed during 2 consecutive training sessions 26. Weight
increase was conducted in increments of 2.5 lbs.
Isokinetic Strength Testing

Strength testing was conducted on the isokinetic dynamometer. The subject’s
dominant ankle was used for the strength assessment. Inversion/eversion and plantar
flexion/dorsiflexion movement patterns were assessed for peak torque and average peak
torque production (Appendix F). Isokinetic tests were performed at 30° and 180° per

second. Three trials, each consisting of 10 repetitions, were conducted at both test

21

velocities. The subjects were given 10 seconds rest in between trials and one minute rest
was provided between the two test velocities. Subjects were encouraged to demonstrate
their maximum strength throughout all trials and repetitions.
Passive Joint Position Sense

Plantar flexion testing began with the subject’s ankle in a neutral position, with
the shank of the lower extremity perpendicular to the metatarsals. Three target angles
were used to test joint position sense, 20°, 30°, and 40° of plantar flexion. Inversion
testing was conducted with the subject’s ankle in a neutral position, no inversion/eversion
of the ankle joint. Three target angles were used to test joint position sense, 5°, 10°, and
20° of inversion. For each target angle, the subjects were passively moved towards the
target angle at 2° per second. The subject was held at the target position for 10 seconds
and then returned to starting position. The subject remained in the neutral position for 10
seconds and then passive motion was initiated at 4° per second. Subjects were instructed
to hit a stop button when they perceived the target angle. Each subject was tested three
times for joint position sense for each target angle. The testing order for target angles
was randomized for each subject. During the trials, the subject was blindfolded to
eliminate visual input and the air conditioner was turned on to cause an audible
distraction. In addition, instructions emphasized that the subjects should feel the target
position and avoid timing the motion or counting throughout the passive motion

(Appendix G).

22

Statistical Analysis
All statistical analyses were performed with SPSS 10.0 (SPSS Inc., Chicago, IL)

statistical software package. The independent variable was strength training group,
positional strength training or traditional strength training. The dependent variables were
isokinetic strength and PJ PS. A two way repeated measures AN OVA was used to

determine interaction between training group and time for isokinetic strength and PJ PS.

23

CHAPTER 4

24

Chapter 4

RESULTS

Passive Joint Position Sense Results

The results of the two way repeated measures AN OVA revealed no significant
interaction between time and training group for inversion passive joint position sense at 5
degrees, (Positional PRE = 2.9259, POST = 3.4815; Traditional PRE = 2.7917, POST =
2.7083; P = .494) 10 degrees, (Positional PRE = 1.4815, POST = 3.2593; Traditional
PRE = 1.5000, POST = 1.5000; P = .237) or 20 degrees, (Positional PRE = 2.8519,
POST = 2.8889; Traditional PRE = 1.7500, POST = 1.1250; P = .638) (Figure 1). The
descriptive information is depicted in Table 1. Furthermore, the results of the two way
repeated measures AN OVA demonstrated no significant main effect for inversion passive
joint position sense between pre-test and post-test.

The results of the two way repeated measures analysis of variance revealed no
significant interaction between time and training group for plantar flexion passive joint
position sense at 20 degrees (Positional PRE = -2.0370, POST = .8148; Traditional PRE
= -1.9167, POST = -2.1250; P = .062), 30 degrees (Positional PRE = -3.5556, POST = -
1.4074; Traditional PRE = -4.3750, POST = -3.7083; P = .540), or 40 degrees of plantar
flexion (Positional PRE = .4444, POST = 2.8889; Traditional PRE = -.5833, POST = -
.5833; P = .216) (Figure 2). However, the PJPS testing approaches significance at the 20
degrees of plantar flexion at the P = .05. The descriptive information is depicted in Table

2. In addition, the results of the two way repeated measures AN OVA found no

25

significant main effect for plantar flexion passive joint position sense between pro-test
and posttest measures.
Figure 1 Means ( j; 1 SD) for Inversion Passive Joint Position Sense Target Angles

5 Degrees, 10 Degrees, 20 Degrees. (n = 17). (P = .05).

 

Mean Relative Error (deg)

 

 

 

 

 

5 Degrees 10 Degrees 20 Degrees TTTTTT

 

 

 

E! Positional Pre 1111 Positional Post Traditional Pre Traditional Post—l

 

Table 1 Descriptive Table for the Means of the Interaction of Training Group

and Time on Inversion Passive Joint Position Sense

 

 

Mal mam
Pre Post Pre Post
Measure (units) (§D) (§D) (SD) (SD)
5 Degrees 2.9259° 3.4815° 2.7917° 2.7083°

(1.4793) (1.9373) (1.8252) (0.999)

 

10 Degrees 1 .481 5° 3.2593° 1 .5000° 1 .5000°
(2.62) (3.0767) (3.0237) (1.5836)

 

20 Degrees 2.8519° 2.8889" 1 .7500° 1 .1250°
(2.7239) . (2.9297) (4.1125) (2.4165)

 

 

 

 

 

26

Figure 2

Means (: 1 SD) for Plantar Flexion Passive Joint Position Sense

Target Angles 20 Degrees, 30 Degrees, 40 Degrees. (n = 17). (P = .05).

 

Mean Relative Error (deg)

 

 

 

 

 

20 Degrees

Positional Pre

1111 Positional Post

30 Degrees

E Traditional Pre

40 Degrees
ITraditional PostJ

 

Table 2 Descriptive Table for the Means of the Interaction of Training Group

and Time on Plantar Flexion Passive Joint Position Sense

 

 

 

 

 

 

 

P_os1ion_al m

Pre Post Pre Post

Measure (units) (SD) £0) (SD) (SD)
20 Degrees -2.037° 0.8148° -1.9167° -2.125°
(4.8404) (3.8446) (3.2059) (2.0388)
30 Degrees -3.5556° -1.4074° -4.375° -3.7083°
(5.3671) (3.0631) (3.9378) (4.3441)
40 Degrees 0.4444° 2.8889° -0.5833° -0.5833°
(4.4659) (4.6518) (2.5681) (4.6997)

 

 

27

 

Isokinetic Strength Results

The results of the repeated measures ANOVA demonstrated no significant
interaction between time and training group for isokinetic strength testing (Figure 3, 4).
The descriptive information is shown in Table 3.

A significant main effect was discovered for eversion strength testing at the
velocity of 30°/s (PRE = 15.882, POST = 17.671; P = .047), eversion strength testing at
the velocity of 180°/s (PRE = 9.224, POST = 11.965; P = .000), inversion strength testing
at the velocity of 180°/s (PRE = 10.041, POST = 12.018; P= .011), and plantar flexion
strength testing at the velocity of 180°/s (PRE = 24.694, POST = 31.753; P = .007)
(Figure 5, 6). The descriptive information is shown in Table 4.

The eversion average peak torque increased between pre and post across entire
subject population. In addition, inversion average peak torque increased between pre and
post testing across entire subject population. Lastly, plantar flexion average peak torque

increased between pre-test and post-test across the entire subject population.

28

Figure 3 Means (: 1 SD) for Eversion/Inversion Isokinetic Peak Torque

Variables EV 30°/s, INV 30°/s, EV 180°/s, INV 180°/s. (n = 17). (P = .05).

 

 

25
20‘
Z
o 15 -' \‘N
§10« §§
n.
N
0. \\

 

   
    

      

  

 

 

EV 30°/s |NV30°ls EV180°ls lNV180°ls
I E Positional Pre In Positional Post E Traditional Pre Traditional Post :I

 

Figure 4 Means (: 1 SD) for Plantar Flexion/Dorsiflexion Isokinetic Peak Torque

Variables PF 30°/s, DF 30°/s, PF 180°/s, DF 180°/s. (n = 17). (P = .05).

 

Peak Torque (N)

 

 

 

     

         
 

N

//////

////
W

//

 
 
    

//////%

 

//

PF30°Is DF30°ls PF180°/s DF180°ls

 

I

 

El Positional Pre III Positional Post E Traditional Pre Traditional Post

 

29

 

Table 3 Descriptive Table for the Means of the Training Group and Time for

 

 

 

 

 

 

 

 

 

Isokinetic Strength
Positional Traditional
Pre Post Pre Post
easure (units) (SD) (SD) (SD) LSD)
EV30°ls (N) 16.067 N 17.8 N 15.675 N 17.525 N
(2.842) (5.088) (5.558) (5.088)
INV30°ls (N) 18.133 N 17.878 N 13.438 N 14.913 N
(3.89) (3.497) (5.308) (6.382)
EV180°Is (N) 9.289 N 12.044 N 9.15 N 11.875 N
(1.897) (2.772) (2.796) (2.941)
INV180°Is (N) 10.522 N 13.4 N 9.5 N 10.463 N
(1.877) (3.081) (2.568) (4.358)
PF30°ls (N) 56.233 N 65.667 N 56.037 N 58.65 N
(25.278) (18.355) (26.264) (25.381)
DF30°/s (N) 20.411 N 17.433 N 14.225 N 14.35 N
(13.099) (4.498) (6.359) (6.524)
PF180°ls (N) 25.133 N 33.733 N 24.2 N 29.525 N
(12.411) (8.619) (16.552) (11.732)
DF180°/s (N) 16.389 N 16.356 N 10.3 N 13.888 N
(6.239) (2.688) (5.056) (4.935)

 

 

 

 

 

 

30

 

Figpre 5 Means (i 1 SD) for the Main Effect Eversion/Inversion Isokinetic Peak
Torque Variables EV 30°/s, INV 30°/s, EV 180°/s, INV 180°/s. (n = 17).

(*P<.05).

 

 

 

Peak Torque (N)

     

 

 

   

|NV30°/s EV180°Is lNV180°ls

El Pre-Test In Posttest

EV30°ls

 

 

 

Figure 6 Means (i 1 SD) for the Main Effect Plantar Flexion/Dorsiflexion
Isokinetic Peak Torque variables EV 30°/s, INV 30°/s, EV 180°/s,

INV 180°/s. (n = 17). (*P<.05).

 

 

Peak Torque (N)

 

 

 

PF30°IS DF3 I °/s PF180°Is DF180°Is

 

 

 

31

Table 4 Descriptive Table for the Means of the Main Effect of Time on

 

 

 

 

 

 

 

 

 

Strength Variables
Pre Post
eaeure (units) (SD) (SD)
EV30°Is (N) 15.882 N 17.671 N
(4.195) (4.928)
lNV30°ls (N) 15.924 N 16.482 N
(5.073) (5.125)
EV180°ls (N) 9.224 N 11.965 N
(2.286) (2.763)
INV180°/s (N) 10.041 N 12.018 N
(2.219) (3.916)
PF30°ls (N) 56.141 N 62.365 N
(24.925) (21 .525)
DF30°ls (N) 17.500 N 15.982 N
(10.706) (5.591)
PF180°ls (N) 24.694 N 31.753 N
(14.039) (10.102)
DF180°ls (N) 13.524 N 15.194 N
(6.361) (3.985)

 

 

 

 

32

 

CHAPTER 5

33

Chapter 5

DISCUSSION

The results of this study support the null hypothesis. Positional strength training
did not result in greater improvement in ankle strength and passive joint position sense.
The positional and traditional training groups exhibited comparable strength gains and
passive joint position sense measures.

Passive Joint Position Sense

The study revealed no significant interaction between strength training group and
time for passive joint position sense. The positional and the traditional training groups
did not differ in degrees of relative error post testing.

In contrast, research conducted by Elis et a1. 9 demonstrated an increase in plantar
flexion and dorsiflexion PJPS following a six-week rehabilitation program. This program
consisted of a combination of 12 different strength and proprioceptive exercises. This
disparity in PJPS results may be due to the instrumentation used in testing. This study
utilized a custom built device, consisting of a footplate and a Penny & Giles goniometer
9. The passive movement was controlled manually, allowing for variable speeds during
testing. This subject provided a verbal cue to stop passive movement when they felt
replication of the testing position, relying on reaction of the practitioner to cease passive
movement. In the current study, the isokinetic dynamometer was used for PJPS testing,
which provided a more direct measure of PJPS. The speed of passive movement was
regulated and a trigger given to the subject stopped passive movement.

A relationship between strength training and joint position sense was also

identified by Docherty et a1. 1, demonstrating improved inversion and plantar flexion J PS

34

following a six-week ankle strength training protocol. Strength training was conducted
with Thera-band tubing in the directions of inversion, eversion, plantar flexion, and
dorsiflexion. The results of the current study may differ from those of Docherty et al. I
because a different component of joint position sense was measured. Docherty et al. '
examined active joint repositioning as opposed to passive joint repositioning. The
mechanoreceptors stimulated during active movement are different from those stimulated
during passive joint movement. Active movement stimulates pacinian corpusles, which
are considered the pure dynamic mechanoreceptors due to their reaction to joint
acceleration and deceleration 27. Passive movement at a slow angular velocity is thought
to stimulate Ruffini endings and GT0 mechanoreceptors 15. Ruffini ending signal static
joint position and GTO respond to increase in tension ‘5.

Joint mechanoreceptors also play a role in joint position sense. Joint
mechanoreceptors are responsible for responding to extremes in range of motion 1. In the
current study, the positional strength training protocol positioned subjects in 40° of
supination and the passive joint position sense testing was conducted in plantar flexion at
a maximum angle of 40° and inversion at a maximum angle of 20°. Thus, even if
positional strength training increased stimulation to the joint mechanoreceptors in
training, the joint mechanoreceptors were not stimulated during testing. The discrepancy
in training stimulation and testing stimulation may be the reason for no increase in
passive joint position sense post positional strength training.

Based on the results obtained for passive joint position sense testing and the
dynamic nature of positional strength training, perhaps a more functional assessment of

joint position sense and proprioception would be warranted. A study conducted by

35

Blackburn et a1. 8 examined the effects of strength, proprioception, and a combination of
strength and proprioception training on balance. Strength training consisted of Thera-
band, free weights, and calf raises. The results revealed individual strength and
proprioception training, as well as combination training, were all equally effective in
achieving balance improvement 8. The improved balance achieved through strength
training reveals an increase in overall proprioception. Proprioception can be defined as
sensation of joint movement or kinesthesia and joint position sense 15. In the current
study, only one component of proprioception was evaluated. Hence, the efficacy of
positional strength training may be better understood by examining overall ankle
proprioception.

Proprioception is an important component in neuromuscular control, contributing
to muscle reflex through alpha motor neuron activation and stimulation of the cortical
pathway ‘5. The muscle spindles respond to the alpha motor neurons producing postural
tone and may lead to an increased response when a muscle is placed on a stretch, yielding
dynamic joint stability '5’ 28. The positional strength training protocol placed the ankle
joint in an increased degree of supination, resulting in increased stress to the lateral ankle
structures. Therefore, the positional strength training may influence overall joint
proprioception.

Isokinetic Strength

The study revealed no significant interaction between strength training group and

time for isokinetic strength. A main effect was demonstrated for isokinetic strength in

the directions of eversion, inversion, and plantar flexion.

36

The results of this experiment support the null hypothesis. The positional training
group did not prove to have a greater impact on eversion strength, as compared to the
traditional training group. The results produced in the positional training group may be
due to the order of muscle recruitment. The complex movement pattern of pronation
(dorsiflexion, eversion, and abduction) may be difficult for subjects to perform. Subjects
recruit the larger, stronger tibialis anterior first and then recruit the smaller peroneal
muscles to more easily execute the complex movement 29. The results of increased
eversion strength for the traditional training group may be equated to the action of the
peroneals as dorsiflexors. The results imply the motion of dorsiflexion requires adequate
peroneal activity.

The findings of increased strength are supported by Docherty et a1. '. They
identified increased eversion strength as a result of a six-week Thera-band strength
training program. This result indicates an increase in strength of the peroneal
musculature and possible subsequent increase in ankle stability. The peroneal muscles
have the ability to alter stiffness of the ankle joint by providing increased muscle stiffness
and greater muscle tone 30. Hence, an increase in peroneal strength altars muscle tone
and may lead to an increase in stability of the ankle joint 30. Based on the effect of
positional strength training on the ankle musculature, future research should examine the
effects of positional strength training on joint stability.

The positional and traditional training groups both exhibited strength gains. The
main effect present reveals that positional strength training is equally effective as
traditional strength training. Positional strength training has proven to increase strength

and may also have additional influence based on the method of training. Theoretically,

37

the positional strength training method has a greater effect on the lateral ankle due to
position of supination. The positional strength training places the lateral capsule, lateral
ligaments, and articular tissue under stress. Pacinian corpuscles are present in these
tissues and are sensitive to acceleration and deceleration movements 27. The stimulation
of these joint afferents may lead to increased awareness to joint movement, for example,
during acceleration of the ankle joint into sudden supination. Increased awareness of
joint acceleration may lead to increased muscle reaction to accelerating motion. Future
research should consider examining positional strength training and its effect on reaction
to a sudden supination movement or muscle latency. Vaes et al. 13 identified a difference
in peroneal latency time between stable and unstable ankles. The latency was assessed
based on response to sudden 50° of supination. The results verified a longer latency time
for unstable ankles and faster acceleration during 50° of supination in the unstable ankles.
The unstable ankles demonstrated a decrease in ability to control the speed of the
injurious moment.
Clinical Implications

The goal of a rehabilitation program is to obtain functional stability. The purpose
of this study was to compare positional and traditional ankle strength training, evaluating
changes in ankle strength and PJPS. Results of positional strength training revealed an
increase in strength and no significant change in PJ PS as measured by degrees of relative
error post training.

Positional strength training proves to be very applicable in a rehabilitation
program. Positional strength training is time and cost efficient. The leg/ankle exerciser

is a low cost training device that only requires plate weights to provide resistance. The

38

simple machine is multi-axial allowing for all ranges of available motion, as well as
movement restrictions if necessary post surgery. Normal movement patterns and sport
activities are multi-axial. Hence, the multi-axial device permits an athlete to train
functionally.

In a rehabilitation program aimed to return an injured athlete to competition, the
athlete must be exposed to stress and perturbation that may be experienced during
participation. Positional strength training is an introductory strengthening exercise that
introduces the ankle to inversion stress experienced during lateral ankle sprains. As the
athlete progresses to more firnctional and sport specific tasks, the same philosophy
remains. Ultimately, the positional strength training follows the S.A.I.D principal of
rehabilitation Specific Adaptations to Imposed Demands. Exposure to supination allows
the ankle complex, including both static and dynamic structures to adapt to increased
lateral stress about the ankle joint.

Overall, muscle weakness post lateral ankle sprain is a controversial issue.
Research, conducted by Kaminski et al. '9, Lentell et al. 20, and McKnight et al. 21,
demonstrates the absence of evertor muscle weakness post lateral ankle sprain or in the
presence of functional ankle instability. Nevertheless, practitioners should continue to
implement strength training exercises because of the potential strength gains and

prospective influence on proprioception.

39

Considerations for Future Research

The current research attempted to examine two methods of strength training,
comparing their effects on strength and passive joint position sense. Suggestions for
future research are:
1) assessment of proprioception

2) assessment of muscle latency

40

APPENDICES

41

APPENDIX A

MATERIALS

42

MATERIALS

 

Figl_lre Leg/Ankle Exerciser

43

APPENDIX B

INFORMED CONSENT FORM

INFORMED CONSENT FORM FOR CLINICAL RESEARCH STUDY
Michigan State University

Title of Project: The Effects of Ankle Positional Strength Training on Strength and
Passive Joint Position Sense.

Primary Investigator: Kavin Tsang, Ph.D., ATC
Department of Kinesiology
105 IM Circle
East Lansing, MI 48824

Secondary Investigator: Dana Cortese, B.S., ATC
Department of Kinesiology
38 IM Circle
East Lansing, MI 48824

This is to certify that I, , have been given the following
information with respect to my participation as a volunteer in a program of investigation
under the supervision of Dr. Kavin Tsang.

1. Pugpose of the study: The purpose of this study is to compare positional
strength training and traditional strength training techniques on the ankle;
assessing changes in muscular strength and passive joint position sense.

2. Procedures to be followed:

A. If you agree to take part in this research, you will be asked to
complete a 4-week strength training program, positional or traditional
strength training groups. In addition, pre and posttests will be
conducted examining isokinetic strength and passive joint position
sense.

1) Positionpl Strength Training — Ankle positional training is conducted in a
position of supination (plantar flexion, inversion, and adduction). Ankle
strength training begins with the subject positioned in 40° of supination. The
subject is then instructed to move the ankle from supination out to a neutral
positioning. The resistance will be provided with plate weights positioned on
the front weight plate of the leg/ankle exerciser. The subject will complete 4
sets of 6 repetitions.

2) Traditional Strength Training - Ankle strengthening is conducted through
the motions of plantar flexion/dorsiflexion. The subject will perform each
motion in isolation. Strengthening through the motion of dorsiflexion will
begin with the foot in plantar flexion and move to a neutral position. The
resistance will be provided with plate weights positioned on the front weight
plate of the leg/ankle exerciser. The subject will complete 4 sets of 6
repetitions.

Initial Here to Indicate You Have Read This Page

45

3) Weight Training Progression — Weight training is conducted based on 1
RM measures. One RM will be determined through multiple-RM testing.
The subjects 10 RM will be established and converted to 1 RM using a table
constructed by the National Strength and Conditioning Association. Once the
1 RM is determined, strength training will commence at 85% of the subject’s
lRM. Weight progression will based on the 2-for-2 rule; 2 additional
repetitions performed during 2 consecutive training sessions. Weight increase
will be conducted in increments of 2.5 lbs.

4) Isokinetic Strength Testing — Strength testing will be conducted on the
isokinetic dynamometer. The subject’s dominant ankle will be used for the
strength assessment. Plantar flexion/ dorsiflexion and inversion/ eversion
movement patterns will be assessed for peak torque and average peak torque
production. Isokinetic tests will be performed at 30° and 180° per second.
Three trials, each consisting of 10 repetitions, will be conducted at both test
velocities. The subjects will be given 10 seconds rest in between trials and
one minute rest will be provided between the two test velocities.

5) Pisgive Joint Position Seng — Plantar flexion testing will begin with the
subject’s ankle in neutral, with the shank of the lower leg perpendicular to the
metatarsals. Three target angles will be tested, 20°, 30°, and 40° of plantar
flexion. Inversion testing will be conducted with the subject’s ankle in
neutral. Three target angles will be tested 5°, 10°, and 20° of inversion. Next,
the subjects will be passively moved towards the target angle at 2° per second.
The subject is held at the target position for 10 seconds and then returned to
starting position. The subject remains in neutral for 10 seconds and then
passive motion is initiated at 4° per second. The subject is instructed to hit the
stop button when they perceive the target angle. Each angle was tested three
times. During the trials, the subject will be blindfolded to eliminate visual
input and the air conditioner will be turned on to cause an audible distraction.
In addition, instructions emphasize to feel the position and avoid timing the
motion or counting throughout the passive motion.

3. Discomforts and risks:
a. An inherent risk of strength training is enduring muscle damage,
specifically a muscle strain. However, positional strength training
presents a minimal risk of injury due to the nature of the strengthening
protocol. The amount of weight and the speed of training progression will
be determined on an individual basis. In addition, explicit strength
training instructions will be provided to all the participants.
b. In the event of an injury, the secondary investigator will provide first
aid treatment as well as a referral to EMS. The subject assumes all
responsibility and any cost incurred due to participation will be at the
expense of the subject.

Initial Here to Indicate You Have Read This Page

46

4. a. Benefits to the subject:
You will gain valuable knowledge regarding proper strength training

technique.

b. Potential benefits to society:
The results will provide the Athletic Trainer with insight into the effects of

ankle positional strength training. In addition, results will demonstrate the
importance for continuing research in the area of positional training.

5. Alternative procedures which could be utilized:
No alternative to ankle positional strength training currently exists.

6. Time duration of the procedures and study:
Your participation in this experiment will include a 4-week training program.

Three training sessions will be required each week, each session lasting
approximately 10min.

7. Statement of Confidentialig:

Your participation in this research is confidential. Your privacy will be
protected to the maximum extent allowable by law. Only the person in charge
will have access to your identity and to information that can be associated
with your identity. To make sure your participation is confidential, only a
code number will appear on the data collection sheet. Only the researchers
can match your name with your code.

8. Right to ask Questions:
A. You may ask any questions about the research procedures, and the

secondary investigator will answer these questions. Further
questions may be directed to Dr. Kavin Tsang, (517) 353-2010.

B. If you have any questions or concerns regarding your rights as a
study participant, or are dissatisfied at any time with any aspect of
this study, you may contact — anonymously, if you wish — Peter
Vasilenko, Ph.D., Chair of the University Committee on Research
Involving Human Subjects (UCRIHS) by phone: (517) 355-2180,
fax: (517) 432-4503, e-mail: ucrihs@msu.edu, or regular mail: 202
Olds Hall, East Lansing, MI 48824.

C. Your participation is voluntary. You are free to stop participating
at any time, or to decline to answer any specific questions without
penalty.

I have been given the opportunity to ask any questions I may have

and all such questions or inquiries have been answered to my satisfaction.

Subject Signature: Date:

 

47

APPENDIX C

INSTRUCTIONAL TUTORIAL

48

INSTRUCTIONAL TUTORIAL

1. Subject Position

a. Seated upright

b. Knee at 90 Degrees

c. Barefoot secured to the footplate

2. Range of Motion

a. Positional Training

i.

ii.

iii.

iv.

Starting position of supination obtained when tape marks are '
aligned

Ending position obtained when foot is parallel to the floor

Move fi:om starting position to ending position by way of a “J”
motion, a combination motion requiring simultaneous movement
of the foot up and over (Demonstrate motion to the subject)

Subject instructed to replicate “J” motion

b. Traditional Training

i.

ii.

iii.

iv.

Starting position of plantar flexion obtained when tape marks are
aligned

Ending position obtained when foot is parallel to the floor

Move from starting to ending position by way of dorsiflexion and
upward motion (Demonstrate motion to the subject)

Subject instructed to replicate dorsiflexion

49

APPENDIX D

STRENGTH TRAINING POSITION

50

STRENGTH TRAINING POSITION

 

 

Flare 8 Subject Position

51

APPENDIX E

STRENGTH TRAINING

52

STRENGTH TRAINING

Positional Training

   

Figure 9 Starting Position Figpre 10 Ending Position
Traditional Training

 

Figure 11 Starting Position Figure 12 Ending Position

APPENDIX F

ISOKINETIC STRENGTH TESTING

54

ISOKINETIC STRENGTH TESTING

 

 

Figure 14 Plantar Flexion/Dorsiflexion Subject Position

55

APPENDIX G

PASSIVE JOINT POSITION SENSE TESTING

56

PASSIVE JOINT POSITION SENSE TESTING

 

 

Figpre 15 Inversion/Eversion Subject Position

 

Figpre l6 Plantar Flexion/Dorsiflexion Subject Position

57

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58

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