Development of a three-dimensional static biomechanical model for the prediction of hand exertion capability and its application to cart pushing and pulling /
A new three-dimensional whole-body biomechanical model has been developed to predict maximum isometric hand exertion capability under strength, stability, and foot/floor friction constraints. The strength constraints ensure that the moments created by the predicted hand exertion at the joints do no...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=736583371&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | A new three-dimensional whole-body biomechanical model has been developed to predict maximum isometric hand exertion capability under strength, stability, and foot/floor friction constraints. The strength constraints ensure that the moments created by the predicted hand exertion at the joints do not exceed the functional strength of the joints. The stability constraints ensure that the exertion does not cause the person to lose their balance. The friction constraints ensure that the person does not slip while performing the predicted exertion. An objective function must be formulated to mathematically define the type of exertion. Sequential quadratic programming has been used to solve the resulting nonlinear programming problem. Inputs to the model include posture, anthropometry, strength capability, and coefficient of static friction at the foot/floor interface. The minimum forces needed to push or pull a 4-wheel cart from a stationary state were measured under different conditions. The objective was to develop a relationship that can be used to estimate the minimum push/pull forces from parameters that can be measured easily such as cart weight, wheel diameter, floor material, and wheel orientation. A knowledge-based system for the design of manual materials handling tasks based on the psychophysical guidelines of Snook and Ciriello (I 99 1) was developed. The outcome was a tool called the Maximum Acceptable Weights and Forces Associate, MAWFA. The system was evaluated by ten domain experts. All of them reported its desirability and usefulness. A lab study was conducted to measure the three-dimensional hand forces people exert to initiate a cart push, pull, and 90' right turn and the postures they assume for two cart loads: 73 kg and 181 kg, and three handle heights: knuckle, elbow, and shoulder heights. The laboratory-measured hand force exertions were compared to the minimum forces needed to push/pull the cart under the same conditions, to the maximum hand forces predicted by the three-dimensional hand force exertion capability biomechanical model (3DHFEC), and to the psychophysical initial push/pull force limits. The Three-Dimensional Static Strength Prediction Program TM was used to estimate lower back loading. Lumbar lateral shear and torsion were also estimated for the turning tasks. |
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| Item Description: | Vita. "Major Subject: Industrial Engineering". |
| Physical Description: | xvii, 234 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 189-201. |