Effects of saddle height, pedaling cadence, and workload on joint kinetics and kinematics during cycling.

CONTEXT It is not clear how noncyclists control joint power and kinematics in different mechanical setups (saddle height, workload, and pedaling cadence). Joint mechanical work contribution and kinematics analysis could improve our comprehension of the coordinative pattern of noncyclists and provide evidence for bicycle setup to prevent injury. OBJECTIVE To compare joint mechanical work distribution and kinematics at different saddle heights, workloads, and pedaling cadences. DESIGN Quantitative experimental research based on repeated measures. SETTING Research laboratory. PATIENTS 9 healthy male participants 22 to 36 years old without competitive cycling experience. INTERVENTION Cycling on an ergometer in the following setups: 3 saddle heights (reference, 100% of trochanteric height; high, +3 cm; and low, -3 cm), 2 pedaling cadences (40 and 70 rpm), and 3 workloads (0, 5, and 10 N of braking force). MAIN OUTCOME MEASURES Joint kinematics, joint mechanical work, and mechanical work contribution of the joints. RESULTS There was an increased contribution of the ankle joint (P=.04) to the total mechanical work with increasing saddle height (from low to high) and pedaling cadence (from 40 to 70 rpm, P<.01). Knee work contribution increased when saddle height was changed from high to low (P<.01). Ankle-, knee-, and hip-joint kinematics were affected by saddle height changes (P<.01). CONCLUSIONS At the high saddle position it could be inferred that the ankle joint compensated for the reduced knee-joint work contribution, which was probably effective for minimizing soft-tissue damage in the knee joint (eg, anterior cruciate ligament and patellofemoral cartilage). The increase in ankle work contribution and changes in joint kinematics associated with changes in pedaling cadence have been suggested to indicate poor pedaling-movement skill.