ELECTROMYOGRAPHIC RESPONSES OF BACK MUSCLES DURING LOAD CARRIAGE WALIKNG IN CHILDREN

Youlian Hong and Chi-Kin Cheung.

Department of Sports Science and Physical Education, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.

Eleven primary school boys aged between 9 and 10 years old completed carrying backpack loads of 0%, 10%, 15%, and 20% of their body weight while level walking using natural cadence. Electromyographic signals from the upper trapezius, thoracic erector spinae and lumbar erector spinae were analyzed. Results showed that under the carrying conditions of this study, load significantly influenced the degree of fatigue and muscular activity in upper trapezius, while walking distance significantly influenced degree of fatigue and muscular activity on lumbar erector spinae. This suggested that long distances and heavy loads might lead to low back pain or muscular disorder.