Lifting strengths decrease with the extent of squat postures

Article type: Research Article

Authors: Lee, Tzu-Hsien

Affiliations: Associate Professor, Department of Management and Information Technology, Southern Taiwan University of Technology, No. 1, Nan-Tai Street, Yung-Kang 710, Tainan, Taiwan. Tel.: 886 6 2533131 ext. 4126; Fax: 886 6 2422029; E-mail: thlee@mail.stut.edu.tw

Abstract: The objective of this study was to examine the effects of different squat postures on maximum static lifting strengths. Ten experienced healthy male lifters were examined on their maximum static two-handed lifting strengths and associated elbow, shoulder, trunk, knee and ankle postural angles at three exertion heights (25 cm, 34 cm and 43 cm) and five lifting postures (stoop posture and light, medium, deep, and full squat postures). A two-factor factorial repeated measures design was used for analyzing the strength data. The results indicated lifting strength decreased with the extent of squat posture. All five investigated postural angles were highly correlated with lifting strength. Overall stepwise regression revealed that knee angle had most influence on lifting strength. Additionally, The regression equations for lifting strength developed on the knee angle demonstrated satisfactory linear relationship between lifting strength and knee angle for individuals. This paper clearly shows that lifting posture needs to be standardized in lifting strength tests.

Keywords: static strength, squat lifting, postural angle

DOI: 10.3233/BMR-2004-173-404

Journal: Journal of Back and Musculoskeletal Rehabilitation, vol. 17, no. 3-4, pp. 105-109, 2004