Physically Handicapped Work Capacity Digitized Evaluation Method And Its Application

It is critical for effective use of the disabled human resources to place and accommodate thehandicapped based on their residule work ability. Work ability evaluation of the handicapped provides basictools to the handicapped job design. The handicapped work ability evaluation is multi-dimensional issueincluding medical function evaluation, social cognition and behavior ability evaluation. It is to identify thework competency of the handicapped. However, medical evaluation itself cannot make accurate predictionsfor the work competency. To evaluate the influence of functional impairment on the work ability acomprehensive integration of work and phyisical function should be considered. The high relation of workability variables to the work content is the prerequisite for the reliability and validity of the work ablilityevaluation. It is equally important to deal with complexity of evaluation information. The results shall servethe ergonomic accommodation design of the work system.This thesis proposed a work ability evaluation model for the physically handicapped, who accounts forthe biggest employment percentage in the physical work field in China. Based on the digital humanmodeling and simulation, the thesis built up a virtual work sample simulation by simulate the motion of thephysically handicapped in the virtual environment. With the human and work characteristics as input, themodel output the biomechanical parameters of the work ability. The evaluation results can be shown inmulti-dimensions and provide multi-dimensional information for the ergonomic accommodation.It firstly proposed a conceptual model of work disability to descirbe the work-ability margin. Theinteraction of work requirement and functional disability was used to describe the work disability. AFour-factored model was applied to describe the work requirement while the funcitional disability wasdescribed by phyiscal variables. The interaction of the handicapped with the Four-factored model was usedto represent the work disablity.Then the thesis proposed an analytical model of work disability. The work requirement, workercharacteristics and their interaction are defined in the biomechanical dimension. It further established amotion analysis method specified for the handicapped. The motion analysis method defined the motionelement in3-dimensional chart and the key motion element was thus identified. The quantitative andqualitative integrated method was used to define the values of musculoskeleton and temporal parametersand the work requirement profile was thus formed. The work requirement profile defined a herachialevaluation system. A concave-convex model was established to describe the work disability with the workrequirement profile as the evaluation datum.The thesis then established a handicapped work modelling and simulation method tosimulate the key motion elements related to work disability, which provided a visual analysisplatform for the work disability of the physically handicapped. The body modeling wasrealized on Poser. A function-constrainted motion simulation method is applied to control themotion and posture by calculating the constraints by the physical, functional andphysiological disability.To build up experimental measurement of the work disability variables, the thesisdesigned a ladder climbing experiment to explain how the biomechanical parameters of subjects can be obtained. Further analysis were made on the foot/hand force, force/handseparation, climbing speed and EMG to build up a relational model of the disability on workability. A validated model can output the biomechanical parameters of the work ability withthe input of work and human characteristics parameters.Finally, a digitalized work disability evlauation model was proposed based on the workdisability analysis model and work simulation technique. Ladder climbing task was used toexplain the workability of the model. The measured parameters from the experiment wasinput into the work simulation model in JACK and then compared with the work requirementparameters from JACK. A multi-dimensioned evaluation result of work disability wasvisualized.