EFFECTS OF A 6-WEEK PLYOMETRIC EXERCISE PROGRAM ON LOWER EXTREMITY FORCE PRODUCTION AND JUMP HEIGHT IN ADOLESCENT FEMALE BASKETBALL PLAYERS

J. Sawdon-Bea¹, R. Hill¹, S. Banks¹, J. Roos¹, J. DeYoung¹

Background: Due to the high physical demands of the basketball, lower extremity injuries are common in high school female basketball players. Research has shown that developing power and improving vertical jump height are important aspects of athletic ability and advantageous for female basketball players to compete at a higher level.  Sport specific movements often require an athlete to produce a maximum amount of force over the shortest amount of time. Current research provides evidence suggesting that exercise programs with progressive plyometric training can improve elements of jumping performance, improve strength, and may reduce injury rates among adolescent athletes.  For these reasons, creating evidence informed training protocols targeting these movements is of particular interest to professionals working in performance enhancement or rehabilitation.

Purpose: The purpose of this investigation was 2-fold: to determine the effect of a 6-week pre-season plyometric exercise program on 1) lower extremity force production, and 2) vertical jump height (VJH) in adolescent female basketball players.

Methods: Force production of knee extensors, hip abductors, and hip extensors was measured by one investigator with the hand-held MicroFet3 dynamometer. Intrarater reliability of 0.93 was established prior to testing. A single investigator measured vertical jump height with the MuscleLab Ergotest infrared contact grid using countermovement and depth jumps. The plyometric-based intervention consisted of six exercises performed prior to normal basketball practice twice per week for 6 weeks (six x six). Coaches and team captains led the exercise sessions with investigators attending one practice session per week to monitor form, compliance, and progressions. An exercise log and injury-tracking sheet was provided to the Head Coach.

Results: Seventeen female basketball players completed the study, 13 to 16 years of age (average of 14 years), from a high school Freshman and Junior Varsity basketball team. Statistically significant improvements were observed between pre-test and post-test for both measures of VJH: countermovement and depth jump. Countermovement jump height increased by 12.1% (p =0.003) and depth jump height increased by 12.6% (p =0.003). Measurements of knee extension increased by a mean of 11.7 ft-lb on the right (p =.006) and 14.8 ft-lb on the left (p = .000); hip extension improved by a mean of 3.91 ft-lb on the right (p =.02) and 5.7 ft-lb on the left (p =.003); and hip abduction improved by 1.9 ft-lb on the right (p = .228) and 2.7 ft-lb on the left (p =.032). The only force production measurement that was not statistically significant at post testing was right leg hip abduction. There was a 100% compliance rate with the program.

Conclusion(s): Findings from this research suggest that this Six x Six plyometric training program offers sufficient stimulus to improve lower extremity force production and vertical jump height in adolescent female basketball players.  Further research is needed to compare the plyometric exercise program to a control group.

Implications: It is prudent for clinicians to design efficient and effective training routines to improve athlete performance and reduce injuries. This plyometric exercise program may be a viable option for improving force production and VJH in female adolescent basketball players.

Funding, acknowledgements: No funding sources.

Keywords: plyometrics, force production, vertical jump height

Topic: Sport & sports injuries

Did this work require ethics approval? Yes

Institution: California State University, Fresno

Committee: Committee for the Protection of Human Subjects

Ethics number: #921