Biomechanical Analysis of Upper Extremity for Manual One-handed Lifting Tasks

• Main Authors: Chih-Yu Hsiao, 蕭志宇
• Other Authors: Cheng-Lung Lee
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/62913524585938627811

碩士 === 朝陽科技大學 === 工業工程與管理系碩士班 === 97 === People sometimes use single hand to lift objects at worksites or in daily life due to the environment constraint or object characteristics. The topics of seated horizontal manual lifting and lumbar loads for one-handed lifting task were the main focus in the literature. However, only few studies have been emphasized on the issues of vertical one-handed lifting with erect postures and muscular strain on hand-arm-shoulded system. An experiment was conducted to collect the biomechanical behavior of upper extremities in the laboratory where two 3-component force transducers and EMG system were performed. Fifteen subjects were recruited. The software of Motion Processor developed in the laboratory was used to compute the root mean square and percentage of maximum voluntary contraction (MVC) for the tested muscles. The resultant and peak forces obtained from 3-component force transducers were also calculated and observed. The EMG results showed that there was statistically significant difference between brachioradialis and triceps brachii when the initial lifting location was changed. The decrease about 12% of MVC for brachioradialis was found when the initial lifting location was on the right side of the body. No significant difference for 3-component forces was shown when the lifting patterns were changed. The peak force for one-handed lifting was larger than the average peak values obtained from two-handed lifting. It is recommended that the initial lifting location showed be on the right side of the body and no trunk twisting when lifting is performed. In addition, the object weight showed be decreased to reduce the loads on the hands.