A Study for the Effects of Lifting Position, Age and Gender on Maximum Lifting Strength

다국어 초록 (Multilingual Abstract)

Objective: A laboratory experiment was conducted to investigate the effects of horizontal and vertical distances, age, gender on maximum lifting strengths (MLS) and muscular activities for Korean males and females. Methods: Twenty male and twenty female subjects, in good health, were participated in the experiment. Each subject performed MLS at five different vertical heights (Ankle, Knee, Waist, Elbow and Shoulder height(cm)) and three different horizontal distances (30, 45 and Arm length(cm)). EMG analysis was performed on four different muscles (Trapezius, Deltoid-anterior part, Elector spinae and Wrist flexor). Results: The results of experiment indicated that; for both male and female, magnitude of lifting strengths were affected by both vertical heights and horizontal distances. The average lifting strengths were 282.62N?m for males and 161.50 N?m for females, respectively. Also, average lifting force of females was 57.14% of that of males. This ratio of muscular strength of female vs. male was consistent with previous research revealing that existing guidelines in ergonomics field should be reconsidered with respects to racial and cultural differences. The EMG result showed that activities of trapezius and deltoid muscle tended to increase as a vertical distance increased. Also, activity of deltoid muscle tended to increase according to increasing horizontal distance but that of wrist flexor muscle decreased. Conclusions: Results of this study indicate and recommend that lifting task in industry should be designed with respect to different working conditions as well as racial and cultural differences.

목차 (Table of Contents)

• ABSTRACT
• 1. Introduction
• 2. Method
• 4. Conclusion and Discussion
• References
• Author listings