Resumen de The effect of different systems of carrying backpacks on muscle activity

Hassan Safikhani, Tengku Fadilah Tengku Kamalden, Saidon Bin Amri, Hamdan Megat

• The purpose of this study is to compare the muscles activity in different systems of carrying the load in students and mountain climbers. EMG activity for TA and LD muscles were recorded with surface electrode while walking with different conditions. 26 young students attended three test sections in three days apart. After warm up subjects walked 10 min on the treadmill without backpack as a normal position in the first day. On the second day subjects walked 10 min with normal backpack, and on third day they walked 10 min with counterbalance load backpack. EMG activity of the TA and LD measured during three conditions of walking. One way analysis of variance (ANOVA) was applied on EMG patterns at muscles. The results indicated that there is a significant difference in TA and LD activities after walking with normal backpack and walking without backpack. There is an also significant difference in TA and LD activities between walking with normal backpack and counterbalance backpack. Results also indicated that there is no significant difference between walking without backpack and walking with counterbalance backpack with p<.856. Findings of this study clearly show the advantage of a counterbalance system for carrying the loads. In addition to these, the reduction of muscle activity is a considerable kinematic and ergonomic benefit of carrying load in such backpacks.