Optimal Pedaling Technique for Sprint Cycling: a Computer Simulation Study

A musculoskeletal model was developed to determine the theoretically optimal pedaling technique (quantified as pedal forces and kinematics) for sprint cycling. Input was a set of stimulation patterns for the eight major muscle groups in the lower extremity, output are the kinematics and forces predicted by a direct dynamics simulation. Stimulation patterns were optimized until maximal average power output was reached. The optimal technique produced 529.1 W in a single limb and was sufficiently similar to typical EMG, pedal force, and kinematic data to conclude that the model is a suitably realistic representation of a cyclist. The optimal pedaling technique was characterized by a raised heel at top dead centre and a large force along the crank at bottom dead centre. In addition, negative torque was produced during the upstroke. These features, traditionally regarded as undesirable, can be explained using properties of the system and the requirement of maximal power output. In a second set of optimizations, weighted combinations of power and technique variables (pedal force and pedal kinematics) were optimized in order to determine the sensitivity of performance to technique. This showed that sprint performance is not very sensitive to pedal kinematics, within a certain range. However, performance decreased by about 7% when an exaggerated 'ankling' technique was used, and by the same amount when the normal component of pedal force was reduced by 37%.