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Title
Modeling spine shape for the seated posture
Creator
Brodeur, Raymond
Date
1995-12-21
Collection
Ergonomics Research Laboratory Reports
Description
Regression models were developed for predicting spine curvature for a given posture based on the position of the chest and pelvis. The first type of model is highly individualistic, requiring measurement of the subject in several seated postures in order to determine the regression equations between chest position and lumbar spine curvature (most subjects have r2 > 0.8). The second type is a general model based on a large sample of 102 subjects (50 males and 52 females). This regression model...
Show moreRegression models were developed for predicting spine curvature for a given posture based on the position of the chest and pelvis. The first type of model is highly individualistic, requiring measurement of the subject in several seated postures in order to determine the regression equations between chest position and lumbar spine curvature (most subjects have r2 > 0.8). The second type is a general model based on a large sample of 102 subjects (50 males and 52 females). This regression model is less accurate (r2 = 0.62) but is simple to implement.
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Title
The initial position and postural attitude of vehicle operators : H-point and D-point in the pelvis
Creator
Brodeur, Raymond
Date
1995-08-15
Collection
Ergonomics Research Laboratory Reports
Description
Seated posture can be accurately described when the position of the pelvis is accurately measured. The pelvis is one of the most difficult body segments to measure due to the amount of tissue overlaying it and the fact that it is a very private area of the body. To the automobile seat manufacturer, three points on the pelvis are of great importance: H-point (hip joint location) D-point (ischial tuberosity) and ASIS (anterior superior iliac spine). H-point is most important for vehicle...
Show moreSeated posture can be accurately described when the position of the pelvis is accurately measured. The pelvis is one of the most difficult body segments to measure due to the amount of tissue overlaying it and the fact that it is a very private area of the body. To the automobile seat manufacturer, three points on the pelvis are of great importance: H-point (hip joint location) D-point (ischial tuberosity) and ASIS (anterior superior iliac spine). H-point is most important for vehicle packaging, D-point is important for comfort and safety of the occupant and the lap belt is most effective for holding the pelvis in the seat during a crash if it is below the ASIS. This report describes methods developed at the Ergonomics Research Laboratory for measuring pelvic position, using non-invasive methods for locating H-point and D-point. Results from 102 subjects are summarized, describing five points measured on each subject's pelvis and one additional point (H-point) calculated from the measured data.
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Title
The initial position and postural attitudes of driver occupants : anthropometry
Creator
Eppler, Maria
Date
1995-06-19
Collection
Ergonomics Research Laboratory Reports
Description
This report contains a description of all anthropometric measurements of 102 subjects measured in an investigation of driver posture and comfort while operating a 1995 mid-sized vehicle and sitting in a seat buck. The investigation measured twelve anthropometric dimensions with the subject in standing and seated positions as appropriate. The data are divided into baby boomer and pre-baby boomer samples by sex. Subjects were selected to represent the general U. S. population according to age...
Show moreThis report contains a description of all anthropometric measurements of 102 subjects measured in an investigation of driver posture and comfort while operating a 1995 mid-sized vehicle and sitting in a seat buck. The investigation measured twelve anthropometric dimensions with the subject in standing and seated positions as appropriate. The data are divided into baby boomer and pre-baby boomer samples by sex. Subjects were selected to represent the general U. S. population according to age and sex. The dimensions are reported for the total sample as well as the 40 subjects that participated in the driver comfort sutdy. All results were compared to the U. S. Army survey reported by Gordon et al (1989) and lie within ratios of .95 to 1.043 of the Army results.
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Title
The initial position and postural attitudes of driver occupants : experimental protocol
Creator
Reynolds, H. M. (Herbert M.)
Date
1995-05-25
Collection
Ergonomics Research Laboratory Reports
Description
This report contains a description of all instrumentation, tools and procedures used in collecting data for an investigation of driver posture and comfort while operating a 1995 mid-sized vehicle and sitting in a seat buck. The investigation measured anatomical landmarks in three-dimensional space that are used to characterize seated posture with a video anthropometric system installed in the vehicle and a seat buck. It has combined these data with pressure measurements to completely define...
Show moreThis report contains a description of all instrumentation, tools and procedures used in collecting data for an investigation of driver posture and comfort while operating a 1995 mid-sized vehicle and sitting in a seat buck. The investigation measured anatomical landmarks in three-dimensional space that are used to characterize seated posture with a video anthropometric system installed in the vehicle and a seat buck. It has combined these data with pressure measurements to completely define the position of the pelvis (Hpt and Dpt) while the driver is operating a vehicle on the highway. It also took standard anthropometric measurements of each of 102 subjects as well as specialized geometric data on the orientation of the chest and pelvis while measuring the position of the dorsal spines of the vertebrae in the spinal column. Each subject sat in five postures for these measurements of the spinal column. These data will be developed into a model of the human spinal column for seated postures. In addition, measurements were made of each subject while operating the vehicle as well as questionnaires that were used to investigate comfort of the driver.
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Title
The initial position and postural attitudes of driver occupants, posture
Creator
Brodeur, Raymond
Date
1996-06-21
Collection
Ergonomics Research Laboratory Reports
Description
The posture, pressure and subjective responses of forty subjects (20 male, 20 female) were measured during two highway drives. Four video cameras were used to measure targets on each subject in addition to measuring EMG and pressure in the seat cushion and the seat back using pressure mats. Subjective questions were asked at specific time intervals or if the subject adjusted the seat or indicated they were feeling uncomfortable. The goal of this research was to compare the objective...
Show moreThe posture, pressure and subjective responses of forty subjects (20 male, 20 female) were measured during two highway drives. Four video cameras were used to measure targets on each subject in addition to measuring EMG and pressure in the seat cushion and the seat back using pressure mats. Subjective questions were asked at specific time intervals or if the subject adjusted the seat or indicated they were feeling uncomfortable. The goal of this research was to compare the objective measurements to the subjective comfort responses of the subjects. In this report we describe the posture of the subjects during two different highway drive tests. During the fixed back drive, the seatback angle was controlled at a 15o or 30o back angle, in random order, with subjects able to control all adjustments on the 12-way power seats except back angle. During the free comfort drive, subjects had full control over all of the 12 adjustments (6-way power seat, 4-way lumbar support, 2-way back angle). We found that compared to the SAE seat design template, Oscar, all subjects sat with their hip joints significantly forward of the H-point and that the point of maximum deflection (D-point) for the subjects was further forward and with less penetration than that of the design template. Both males and females sat with similar torso-thigh angles as that of the design template, but males sat with a more reclined posture than females and with larger elbow angles. Compared to the design knee angle, both males and females were significantly less than that of Oscar, with males having an even smaller angle than females. Most males had the seat at the full rear-ward position, which was probably a factor in their knee angle. The reclined (30o) seatback angle resulted in the most upright posture, but we strongly suspect that this was maintained with significant muscle activity in order to position the back and head to operate the vehicle.
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Title
The position and postural attitudes of driver occupants, seat position
Creator
Reynolds, H. M. (Herbert M.)
Date
1996-06-21
Collection
Ergonomics Research Laboratory Reports
Description
Subjects representative of the mid-sized automobile market segment in the United States drove a four-door 1995 Chevrolet Lumina on three highway trips. We measured their posture, seat position, muscle activity, pressure distribution and comfort under highway driving conditions. Two identical vehicles were instrumented with video cameras to measure anatomical joint center positions (including H-point and D-point in the pelvis) in three-dimensional space, pressure distribution in the cushion...
Show moreSubjects representative of the mid-sized automobile market segment in the United States drove a four-door 1995 Chevrolet Lumina on three highway trips. We measured their posture, seat position, muscle activity, pressure distribution and comfort under highway driving conditions. Two identical vehicles were instrumented with video cameras to measure anatomical joint center positions (including H-point and D-point in the pelvis) in three-dimensional space, pressure distribution in the cushion and back, and an on-board PC equipped with an A-to-D board that was used to digitize signals from EMG electrodes on the driver's back and all seat position transducers. The seat was a six-way power seat with a power recline and a four-way lumbar support. A technician sat in the back seat operating all measurement equipment and conducting a brief comfort interview at prescribed intervals during the drive. The subjects, obtained from the general population in mid-Michigan, were selected to drive the vehicle without prejudice for halo or marketing effects. This report describes how these subjects used the 12-way power seat in the vehicle to achieve a comfortable or occupant-preferred seat position while operating the vehicle on the highway.
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