Nick A. Juday

Date of Award


Degree Name

Master of Arts


Human Performance and Health Education

First Advisor

Dr. Mary L. Dawson

Second Advisor

Dr. Roger Zabik

Third Advisor

Dr. Robert Moss

Access Setting

Masters Thesis-Campus Only


Plyometric exercise involves various jumping drills performed to develop strength and power in athletes. The plyometric technique facilitates the neuromuscular system resulting in greater force production when a muscle contracts concentrically. The purpose of this study was to compare the temporal and EMG response of a group of good jumpers with one of poor jumpers. The groups performed a vertical jump and three depth jumps. The jumps were divided temporally into an eccentric, coupling, and concentric phase by four methods. Forty male physical education majors were recruited and then measured for vertical jumping ability. The top 10 jumpers constituted the Good Group and the bottom 10 jumpers constituted the Poor Group. All subjects then performed in a random order a vertical jump and three depth jumps. Dependent variables measured were: (a) time of each phase in the jumps, (b) peak EMG activity for six leg muscles used in the jumps, and (c) the EMG area for six leg muscles used in the jumps. Results indicated that: (a) the groups, Good and Poor, performed similarly with respect to time spent in the phases of the jumps; (b) how the phases were defined affected the phase times and the EMG performance across groups and jumps; ( c) the coupling phase was similar across groups and methods for both peak and area EMG responses; and ( d) the EMG areas were similar for the groups but different for the jumps during the concentric phase of the jumps.

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