Biomechanical Measuring Techniques for Evaluation of Workload

Abstract

It is necessary to quantitatively evaluate the workload of workers in order to improve the level of safety and efficiency as well as to prevent workers from musculoskeletal disorders. The purpose of this study is to introduce biomechanical methods that are largely used to quantitatively evaluate workload. The biomechanical methods use kinematics and kinetics to analyze the movement and force of biomechanical body. Motion analysis, joint angle measurement, ground reaction force, mathematical model, and electromyography (EMG) were introduced as a tool or device for biomechanical evaluation. In this study, the special feature of each method was emphasized and important tips for field measurement were summarized. The information and technique disclosed in this summary can be used to evaluate and design the workplace better by effectively control the workload of field workers.

Comparison of the parameters for muscle fatigue evaluation using surface electromyogram in repetitive exercise

“…The parameters for muscle fatigue were calculated for the CPR during a 30 second time window. The RMS was calculated according to equation (1). The power spectrum was determined using Welch's method with a length of 512 samples for each segment [7].…”

“…At work, musculoskeletal disease may happen due to fatigue from repetitive exercise [1]. It is meaningful to assess muscle fatigue of the certain body parts quantitatively [2].…”

Evaluation of the effectiveness of muscle assistive device using muscle fatigue analysis

“…There are three types for the objective assessment of physical workload; questionnaire responses methods and biomechanical methods, physiological methods [2]. Questionnaire responses methods are the subjective evaluation of the subject.…”

“…Another property of sEMG on fatigue, central frequency decreases according the fatigue level. To parameterize this property, we calculate mean frequency (MNF) of sEMG data using the equation(2). For each segment of 20 seconds, power spectrum is calculated and we could calculate MNF.…”