Jump platform exerciser for strengthening the ankle extensors

摘要

An exercise apparatus for strengthening the ankle extensors which includes a platform on which a user jumps repetitively while monitoring the time that he is in contact with the platform and the time that he is out of contact with the platform. In one embodiment, the platform is hinged to a base platform along an edge with a spring and switch in between. The spring holds the platform and base panel slightly apart except when the user is standing on the platform. The switch has two sets of poles, one of which sets activates a circuit for timing the time in contact and the second of which sets activates the time of flight of each jump when the user is out of contact. Monitoring of each period can be performed by any one of several circuits. One circuit includes a clock and display for displaying the current flight or contact time. Another circuit includes structure for presetting target periods for flight and contact times. A respective signal is emitted if actual contact time or flight time exceeds target times respectively. Yet another embodiment measures the total in-contact time for a given number of jumps and the flight time is monitored by controlling jump height to a given value by looking in a mirror as the user jumps.