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Young Warren B.; Pryor, John F.; Wilson, Greg J.
Journal of Strength and Conditioning Research: November 1995
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ABSTRACTThis study compared a countermovement jump (CMJ) and drop jumps performed according to 3 objectives: maximum jump height (DJ-H), minimum contact time (DJ-t), and maximum jump height/contact time ratio (DJ-H/t). Subjects (N = 17 males) performed all 4 jump conditions on a contact mat/computer system that recorded the contact and flight times. DJ-H produced significantly greater jump height/contact time at all drop heights than DJ-H/t. DJ-H/t produced significantly greater jump height, longer contact time, and greater jump height/contact time at all drop heights than DJ-t. CMJ and best height in DJ-H height and best DJ-H/t performance was low. As DJ drop height increased, so did the jumps resulting in heel-ground contact. DJ characteristics are similar to CMJ when jump height is the only objective. But when DJ contact time is shortened, the imposed stretch loads probably increase and different qualities are required for successful jumps.

This study compared a countermovement jump (CMJ) and drop jumps performed according to 3 objectives: maximum jump height (DJ-H), minimum contact time (DJ-t), and maximum jump height/contact time ratio (DJ-H/t). Subjects (N = 17 males) performed all 4 jump conditions on a contact mat/computer system that recorded the contact and flight times. DJ-H produced significantly greater jump height/contact time at all drop heights than DJ-H/t. DJ-H/t produced significantly greater jump height, longer contact time, and greater jump height/contact time at all drop heights than DJ-t. CMJ and best height in DJ-H height and best DJ-H/t performance was low. As DJ drop height increased, so did the jumps resulting in heel-ground contact. DJ characteristics are similar to CMJ when jump height is the only objective. But when DJ contact time is shortened, the imposed stretch loads probably increase and different qualities are required for successful jumps.

© 1995 National Strength and Conditioning Association