Pushing the limits of human motor control: high-frequency ankle oscillations in expert drummers

This study investigates the neuromechanical characteristics associated with drummers' ability to achieve unilateral ankle oscillations with frequencies up to 10 Hz, surpassing known limits for lower-limb voluntary movements. Eighteen experienced drummers performed rhythmic ankle oscillations across a range of imposed frequencies using a protocol combining motion capture and surface electromyography for trunk and lower limb muscles. Angular kinematics, muscle activation timing, and inter-muscle coordination were quantified to characterize neuromechanical adjustments associated with frequency modulation and to identify factors limiting maximal performance. Drummers exhibited a preferred oscillation frequency of 6.3 Hz (range 5.5 - 7.3 Hz). At this frequency, soleus and tibialis anterior activation durations averaged 56.2 ms and 52.7 ms, respectively, and the latency from dorsiflexion to soleus activation was 48.5 ms. Increasing frequency was associated with shorter activation durations, reduced ankle excursion, and a shift toward plantar flexion. High-frequency performance involved substantial proximal muscle recruitment, particularly at the hip and trunk. Drummers achieving frequencies above 7.5 Hz (n = 6) displayed shorter tibialis anterior activation (34.3 vs. 53.2 ms) and lower tensor fascia latae activation (6.2% vs. 21.0%) compared with others. High-frequency ankle oscillations in expert drummers exhibit neuromechanical features consistent with a constrained oscillatory system, reflecting interactions between limb mechanics, reflex pathways, and coordination constraints. Individual performance differences appear to depend on both distal muscle activation timing and proximal stabilization demands.