Comparison of Joint Angles and Muscle Activations between Simulated Stair-climbing Machine and General Ladder

The purpose of this study was to compare the joint angles and muscle activations between simulated stair-climbing machine and general ladder. Twelve male healthy undergraduate students (aged 23.7±0.4 yrs, height 172.17±2.45 cm, weight 68.92±3.35 kg) were randomly assigned into the stair-climbing simulation machine and general ladder at two ladder angles (75 and 90 degrees) using a repeated measures design. A 300 Hz high-speed camera was used to record the climbing movements for the analysis of joint angles, and surface electromyography was used to collect the major muscle activations. After a paired t test, the results of kinematics showed that there were no significant differences in all joint angles of the upper and lower limbs between simulated stair-climbing machine and general ladder at the 75 degree ladder angle. Furthermore, no significant differences in most of the joint angles of the upper and lower limbs were recorded between both at the 90 degree ladder angle. The results of muscle activations showed that there were significant differences in some of the muscles between the simulated stair-climbing machine and general ladder at the 75 and 90 degrees ladder angles. Moreover, muscle activations during climbing the stair-climbing machine were generally smaller than those during climbing the general ladder. In conclusion, although the muscle activations had some differences between climbing the stair-climbing simulation machine and general ladder groups, climbing movements of upper and lower extremities were almost the same.