Effects of saddle height on knee forces of recreational cyclists with and without knee pain
Background: Low saddle height has been empirically linked to increased compressive force at the patellofemoral joint and to the development of overuse knee pain.
Research question: How changes in saddle height would affect patellofemoral and tibiofemoral forces of cyclists with and without knee pain.
Type of study: Cross-sectional.
Methods: Sixteen cyclists without knee pain and eight cyclists with knee pain performed four 2-minute submaximal cycling trials using their preferred saddle height, two saddle heights (high and low) eliciting ±10° change in knee flexion angle, in relation to their preferred saddle height, and a saddle height eliciting 25° knee flexion at the 6 o´clock crank position. Workload (3.04 ±0.78 W/kg) was consistent and pedalling cadence was visually controlled at 90 rpm for every trial. Right pedal forces and joint kinematics recorded during all trials enabled calculation of patellofemoral and tibiofemoral forces using a musculoskeletal model.
Results: Changes in saddle height did not substantially affect patellofemoral and tibiofemoral forces when comparing cyclists with and without knee pain. Compared to the low saddle height there were larger anterior tibiofemoral forces at optimal (35% without pain, 51% pain) and high saddle heights (76% without pain, 92% pain).
Conclusions: Bicycle saddle height can probably be set within a large range of knee motion (i.e., ~44-65° determined during dynamic cycling at the 3 o'clock position) to minimise possible detrimental effects of large patellofemoral and tibiofemoral forces.
Keywords: bicycle configuration, joint kinetics, joint kinematics, knee flexion angle
Autor / Fonte:Dr Rodrigo Rico Bini, Professor Patria A Hume. International SportMed Journal, Vol.15 No.2, June 2014, pp.188-199.