The aim of the present study was to determine whether changes in ‘posture length’ affect the muscular power produced by the muscles spanning the ankle, knee and hip joints. From a standard inverse dynamics procedure, the computed joint powers therefore provided insight into movement strategies and phenomenon of muscular adaptations to constraints related to ‘posture length’. Our results showed that the preferred knee angle used by the cyclists at the BDC position of the pedal was similar to guidelines from Peveler [1]. However, we noticed few changes of knee flexion between the
four conditions of ‘posture length’. On the contrary, hip angles largely varied from backward posture to forward posture. These results suggest that the optimal fitting of the bicycle should equally depend on recommendations about hip joint angle at the BDC position of the pedal. Otherwise, our results underlined that a forward position allowed to develop larger knee power in comparison to backward posture. Regarding the significance of generated knee joint power on overall pedal power output, we could make the assumption that forward position enhances the performance of the cyclist. However, this also suggests that forward posture could generate strong patellofemoral compression forces and cause knee complaints, e.g. chondromalacia [3, 4]. In addition, several authors demonstrated that backward posture is more comfortable for cyclists, preventing injuries in the low back and the neck [3, 4]. Indeed, this posture implies an anterior pelvic tilt and a more extended posture. This prevents cervical lordosis from becoming too pronounced as a result of exaggerated hyperextension of the neck. These findings corroborate that a balance should be found to both prevent injuries and improve performance in the search for an optimum ‘length posture’ of the cyclist.