VISUAL FEEDBACK ARRAY TO ACHIEVE REPRODUCIBLE LIMB DISPLACEMENTS AND VELOCITIES IN HUMANS.

Precise and reproducible feedback is important for studies on motor control, the adaptive responses to exercise training and the limits of human neuromuscular performance. For this purpose, a custom instrumentation array was previously developed to provide human subjects with visual feedback on their contractile durations and limb velocities during knee extension exercise. The array consisted of two columns, each with 14 high-visibility light emitting diodes. One array column provided the subject with the target cadence of position change while the complementary array provided an indication of the actual rate of displacement achieved by the subject. The array design has been improved to include an onboard microcontroller-based signal generator to generate the desired protocol cadence and also the ability to easily customize and 'lock in' desired protocol parameters. The array allows for custom settings to provide feedback on the concentric and eccentric activation periods during exercise. It can also be used in clinical settings to track the active or passive ranges of motion during rehabilitation.