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Ergon expert - a knowledge-based system for the analysis and design of manual materials handling (Ergon expert - ein wissensbasiertes system zur analyse und gestaltung von lastenmanipulationen) (in German)
ABSTRACTS
whereas among the middle-aged and oldest men the manual workers tended to have the poorest performance. Good self-rated health and the intensity of physical exercise during leisure were positively associated with muscle strength in the youngest and middleaged groups whereas in the oldest group the most important variable was home gymnastics. The multivariate structural equation models of isometric strength differed somewhat among the age groups and in these models the abovementioned variables accounted for 3343% of the variance in isometric strength within the age groups. The results illustrated the most important factors associated with isometric strength in samples of men of different ages and also provided suggestions as to how these determinants might influence comparisons between different age groups in respect of muscle strength. 24.2.12 (128453) Viljanen, T, Viitasalo, J T and Kujala, U M 'Strength characteristics of a healthy urban adult population' Eur J Appl Physiol Occup Physiol Vol 63 No 1 (1991) pp 43-47 (27 refs) A random sample of 778 subjects representing ages 25, 35, 45 and 55 years were studied for the amount of habitual physical activity, their anthropometric structure, vertical jumping height, trunk extension and flexion torques and dynamic endurance fitness of trunk extension and flexion. The proportion of subjects who were habitually physically active did not change systematically with age. The highest number of physically inactive subjects was found in men and women in the 35year age group. The results in all the tests used to assess the strength characteristics were statistically significant when related to sex (p < 0.001) and in all, except the relative maximal isometric torque of trunk extension, when related to age (p < 0.001). Everyday physical activity was related to the variation in vertical jumping height (p < 0.001), as well to the dynamic endurance fitness (p < 0.001) of trunk extension and flexion. The decline in vertical jumping height and dynamic endurance fitness of trunk extension and flexion fitness was found to start at earlier ages than that of relative maximal isometric trunk extension and flexion torques. Dynamic endurance fitness of trunk flexion showed a more pronounced decline with age than trunk extension fitness. 24.2.13 (128943) Jager, M and Hecktor, K 'Ergon Expert - a knowledge-based system for the analysis and design of 132
manual materials handling' (Ergon Expert - ein Wissensbasiertes System zur Analyse und Gestaltung von Lastenmanipulationen) (in German) ZArbwiss Vol 45 No 4 (1991) pp 216-222 (27 refs) Ergon Expert implemented on a personal computer is a modular knowledge-based system for the analysis and design of typical manual materials handling tasks. Directives relating to occupational safety, somatometric data as well as biomechanical, energetic and psychophysical methods are considered in the evaluation. A user-friendly interface coordinates the input of the required parameter data and provides additional information and graphical output of the results. Numerous help procedures have been developed to facilitate utilization of the system by a wide usership. 24.2.14 (128963) Soderberg, G L (ed)
Selected topics in surface electromyography for use in the occupationalsetting: expert perspectives National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA, DHHS (NIOSH) Publication No. 91-100 (1992) 179 pp Surface electromyography (EMG) is a technique whereby voltage-measuring electrodes attached to the surface of the skin are used to detect and/or infer various phenomena relating to muscular contractions. The development of sophisticated electronic instrumentation has permitted the use of surface EMG in most areas of ergonomics research and analysis involving muscle activity. Despite the increasing diversity of applications, there was, at the inception time of this project, no reference work available which provided basic instruction and information on the interpretation and applications of surface EMG. It is this need which the present volume begins to address, through the use of expert perspectives. 24.2.15 (128965) Taylor, N A S, Sanders, R H, Howick, E I and Stanley, S N 'Static and dynamic assessment of the Biodex dynamometer' Eur J Appl Physiol Occup Physiol Vol 62 No 3 (1991) pp 180-188 (10 refs) The validity and accuracy of the Biodex dynamometer were investigated under static and dynamic conditions. Static torque and angular position output correlated well with externally derived data (r = 0.998 and r > 0.999, respectively). Three subjects performed maximal voluntary knee extensions and flexions at angular velocities from 60 to 450°s-1. Using linear accelerometry,
high-speed filming and Biodex software, data were collected for lever arm angular velocity and linear accelerations, and subject-generated torque. Analysis of synchronized angular position and velocity changes revealed the dynamometer controlled angular velocity of the lever arm to within 3.5% of the pretest value. Small transient Velocity overshoots were apparent on reaching the set velocity. High-frequency torque artefacts were observed at all test velocities, but most noticeably at the faster speeds, and were associated with lever arm accelerations accompanying directional changes. application of resistive torques by the dynamometer, and limb instability. Isokinematic torques collected from ten subjects (240,300 and 400°s-~) identified possible errors associated with reporting knee extension torques at 30° of flexion. As a result of tissue and padding compliance, leg extension angular velocity exceeded lever arm angular velocity over most of the range of motion, while during flexion this compliance meant that knee and lever arm angles were not always identical, particularly at the start of motion. Nevertheless, the Biodex dynamometer was found to be both a valid and an accurate research tool: however, caution must be experienced when interpreting and ascribing torques and angular velocities to the limb producing motion.
24.2.16 (128985) Veeger, H E J, Van der Woude, L H V and Rozendal, R H 'A computerized wheelchair ergometer. Results of a comparison study' Scand J Rehab Med Vol 24 No 1 (1992) pp 17-23 (21 refs) To determine the validity of propulsion simulation on a stationary wheelchair ergometer, nine male able-bodied subjects performed submaximal exercise tests on the ergometer and on a motordriven treadmill. Oxygen uptake, ventilation and stroke parameters were equal for both devices, but heart rate was lower and trunk movement was less for the ergometer test. Analysis of forces and power output on the ergometer indicated that power output was equal for both wheels. The ratio between applied forces and the effectively directed force component was approximately 80%. Also, a small torque was applied by the hand on to the hand-rim surface which contributed to the total propulsion torque around the axle. It is concluded that the ergometer is capable of simulation of wheelchair propulsion, although the different trunk motion may necessitate sufficient wheelchair propulsion experience. Force analysis results are discussed.
,\pplied Ergonomics
whereas among the middle-aged and oldest men the manual workers tended to have the poorest performance. Good self-rated health and the intensity of physical exercise during leisure were positively associated with muscle strength in the youngest and middleaged groups whereas in the oldest group the most important variable was home gymnastics. The multivariate structural equation models of isometric strength differed somewhat among the age groups and in these models the abovementioned variables accounted for 3343% of the variance in isometric strength within the age groups. The results illustrated the most important factors associated with isometric strength in samples of men of different ages and also provided suggestions as to how these determinants might influence comparisons between different age groups in respect of muscle strength. 24.2.12 (128453) Viljanen, T, Viitasalo, J T and Kujala, U M 'Strength characteristics of a healthy urban adult population' Eur J Appl Physiol Occup Physiol Vol 63 No 1 (1991) pp 43-47 (27 refs) A random sample of 778 subjects representing ages 25, 35, 45 and 55 years were studied for the amount of habitual physical activity, their anthropometric structure, vertical jumping height, trunk extension and flexion torques and dynamic endurance fitness of trunk extension and flexion. The proportion of subjects who were habitually physically active did not change systematically with age. The highest number of physically inactive subjects was found in men and women in the 35year age group. The results in all the tests used to assess the strength characteristics were statistically significant when related to sex (p < 0.001) and in all, except the relative maximal isometric torque of trunk extension, when related to age (p < 0.001). Everyday physical activity was related to the variation in vertical jumping height (p < 0.001), as well to the dynamic endurance fitness (p < 0.001) of trunk extension and flexion. The decline in vertical jumping height and dynamic endurance fitness of trunk extension and flexion fitness was found to start at earlier ages than that of relative maximal isometric trunk extension and flexion torques. Dynamic endurance fitness of trunk flexion showed a more pronounced decline with age than trunk extension fitness. 24.2.13 (128943) Jager, M and Hecktor, K 'Ergon Expert - a knowledge-based system for the analysis and design of 132
manual materials handling' (Ergon Expert - ein Wissensbasiertes System zur Analyse und Gestaltung von Lastenmanipulationen) (in German) ZArbwiss Vol 45 No 4 (1991) pp 216-222 (27 refs) Ergon Expert implemented on a personal computer is a modular knowledge-based system for the analysis and design of typical manual materials handling tasks. Directives relating to occupational safety, somatometric data as well as biomechanical, energetic and psychophysical methods are considered in the evaluation. A user-friendly interface coordinates the input of the required parameter data and provides additional information and graphical output of the results. Numerous help procedures have been developed to facilitate utilization of the system by a wide usership. 24.2.14 (128963) Soderberg, G L (ed)
Selected topics in surface electromyography for use in the occupationalsetting: expert perspectives National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA, DHHS (NIOSH) Publication No. 91-100 (1992) 179 pp Surface electromyography (EMG) is a technique whereby voltage-measuring electrodes attached to the surface of the skin are used to detect and/or infer various phenomena relating to muscular contractions. The development of sophisticated electronic instrumentation has permitted the use of surface EMG in most areas of ergonomics research and analysis involving muscle activity. Despite the increasing diversity of applications, there was, at the inception time of this project, no reference work available which provided basic instruction and information on the interpretation and applications of surface EMG. It is this need which the present volume begins to address, through the use of expert perspectives. 24.2.15 (128965) Taylor, N A S, Sanders, R H, Howick, E I and Stanley, S N 'Static and dynamic assessment of the Biodex dynamometer' Eur J Appl Physiol Occup Physiol Vol 62 No 3 (1991) pp 180-188 (10 refs) The validity and accuracy of the Biodex dynamometer were investigated under static and dynamic conditions. Static torque and angular position output correlated well with externally derived data (r = 0.998 and r > 0.999, respectively). Three subjects performed maximal voluntary knee extensions and flexions at angular velocities from 60 to 450°s-1. Using linear accelerometry,
high-speed filming and Biodex software, data were collected for lever arm angular velocity and linear accelerations, and subject-generated torque. Analysis of synchronized angular position and velocity changes revealed the dynamometer controlled angular velocity of the lever arm to within 3.5% of the pretest value. Small transient Velocity overshoots were apparent on reaching the set velocity. High-frequency torque artefacts were observed at all test velocities, but most noticeably at the faster speeds, and were associated with lever arm accelerations accompanying directional changes. application of resistive torques by the dynamometer, and limb instability. Isokinematic torques collected from ten subjects (240,300 and 400°s-~) identified possible errors associated with reporting knee extension torques at 30° of flexion. As a result of tissue and padding compliance, leg extension angular velocity exceeded lever arm angular velocity over most of the range of motion, while during flexion this compliance meant that knee and lever arm angles were not always identical, particularly at the start of motion. Nevertheless, the Biodex dynamometer was found to be both a valid and an accurate research tool: however, caution must be experienced when interpreting and ascribing torques and angular velocities to the limb producing motion.
24.2.16 (128985) Veeger, H E J, Van der Woude, L H V and Rozendal, R H 'A computerized wheelchair ergometer. Results of a comparison study' Scand J Rehab Med Vol 24 No 1 (1992) pp 17-23 (21 refs) To determine the validity of propulsion simulation on a stationary wheelchair ergometer, nine male able-bodied subjects performed submaximal exercise tests on the ergometer and on a motordriven treadmill. Oxygen uptake, ventilation and stroke parameters were equal for both devices, but heart rate was lower and trunk movement was less for the ergometer test. Analysis of forces and power output on the ergometer indicated that power output was equal for both wheels. The ratio between applied forces and the effectively directed force component was approximately 80%. Also, a small torque was applied by the hand on to the hand-rim surface which contributed to the total propulsion torque around the axle. It is concluded that the ergometer is capable of simulation of wheelchair propulsion, although the different trunk motion may necessitate sufficient wheelchair propulsion experience. Force analysis results are discussed.
,\pplied Ergonomics