Electromyographic analysis on lower extremity in different cycling seat positions

[[abstract]]Purpose: The purpose of this study was to investigate the Electromyography (EMG) on lower extremity in different cycling seat positions based on different seat tube angles (STA). Methods: Twenty healthy college students (age 24.15 ? 2.13 yrs; height 170 ? 8.58 cm; weight 62.16 ? 2.13 kg) were recruited in this study. Fifteen different cycling seat positions including 3 different heights (90%, 95%, 100% of leg length) and 5 different forward/backward position were investigated. Result: 1. The activation of the Rectus femoris decreased accompanied by increasing seat height; the activation of the Biceps femoris and the Medial Gastrocnemius decreased accompanied by forward seat position. 2. The activation of Tibialis Anterior increased accompanied by the STA increased, but the Medial Gastrocnemius decreased under the same seat height of 95% leg length. According to the questionnaire to our participants, they felt discomfort when the seat was forward and the STA increased. Conclusions: The activation of power extremity was lower when the seat moved forward. Besides, the activation of lower extremity was higher when the STA deceased.