自行車運動越來越受歡迎，但騎乘姿勢的不良，往往造成更多的運動傷害。適當的騎乘姿勢可以提供更舒適的自行車騎乘，不但可以減少運動傷害，更可以提升運動表現。然而，自行車與人體直接接觸的位置有坐墊位置、手把位置及踩踏位置，此三個位置也是影響人體騎乘姿勢的關鍵位置。目的：針對自行車騎乘時的坐墊、手把及踏板位置進行探討。方法：透過文獻收集、歸納及整理找出最佳的自行車騎乘姿勢。結果：自行車騎乘時的坐墊位置設定為當踏板最低時膝關節屈曲25-35度，手把位置設定為軀幹角度介於30-45度，踩踏位置的最佳位置為踏板的中心軸對齊第一趾骨。建議：目前自行車姿勢調整的最佳方法都採用角度量測方式，在測量時需要花費較多的時間，期望未來能透過人體肢段參數建構更準確、更便利的自行車姿勢調整系統。

Cycling has become one of the world's most popular sports. Poor riding postures may cause injuries. The correct riding posture can reduce cycling injuries and also enhance performance. However, the positions of cycling in direct contact with the human body include the saddle, hand-bar and pedaling positions. They also play important roles in the riding position. The purpose of this study to explore the effect of riding performance on the saddle, hand-bar and pedaling positions during cycling. Reviewing the literature on the saddle, hand-bar and pedaling positions during cycling, this paper tries to summarize and find out the optimal bike riding position. The results are as follows: It has been reported that in the preferred saddle position, the knee angle should be flexed 25-30 degrees when the pedal is at the bottom of the downstroke. In the preferred hand-bar position, the torso should be flexed 30-45 degrees. And in the preferred pedaling position, the first metatarsal head lies are at the center of the pedal. Hopefully, more accurate and convenient bike fitting system by anthropometric analysis can be developed in the future.