Effects of a Knee Ligament Injury Prevention (KLIP) Exercise Program on Impact Forces in Females

Publication Date


Type of Culminating Activity


Degree Title

Master of Science in Exercise and Sport Studies



Major Advisor

Chad Harris


Ronald P. Pfeiffer


Mark DeBeliso


Previous research has suggested high impact forces generated during landings contribute to noncontact ACL injuries. The purpose of this was to study examine peak vertical impact forces (Fp) and rate of force development (RFD) following a nine-week plyometric based KLIP program in college age females. Twenty-eight females (mean age = 24.0 ± 4.0 yr.) subjects were assigned into control (N=14) and treatment (N=14) groups. Treatment subjects attended KLIP sessions twice a week for nine weeks (18 sessions) and control subjects received no intervention. KLIP was comprised of several combinations of jump/hop maneuvers that progressed in difficulty and intensity. Ground reaction forces generated during a step-land protocol and vertical jump height were assessed at study onset and termination. Subjects in the treatment group averaged 16.7 KLIP sessions, representing 93% compliance. Significant reductions in Fp (p=0.0004) and RFD (p=0.0743) were observed in the treatment group. There were no significant differences in vertical jump height between groups. Our results indicate nine-weeks (18 sessions) of KLIP training altered landing strategies to lower Fp and RFD. These changes are considered conducive to a reduced risk of knee injury while landing.

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