College of Health Sciences

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Browsing College of Health Sciences by Subject "ACL"

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    Do muscle strength deficits of the uninvolved hip and knee exist in young athletes before anterior cruciate ligament reconstruction?
    (SAGE, 2017) Hannon, Joseph; Wang-Price, Sharon; Goto, Shiho; Garrison, J. Craig; Bothwell, James M.
    Background: Muscle strength of the involved limb is known to be decreased after injury. Comparison with the uninvolved limb has become standard of practice to measure progress and for calculation of limb symmetry indices (LSIs) to determine readiness to return to sport. However, some literature suggests strength changes in the uninvolved limb also are present after lower extremity injury. Purpose: To examine the uninvolved limb strength in a population of adolescent athletes after an anterior cruciate ligament (ACL) injury and compare strength values with those of the dominant limb in a healthy control group. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 64 athletes were enrolled in this study, including 31with injured ACLs (mean age, 15.6 ± 1.4 years) and 33 healthy controls (mean age, 14.9 ± 1.9 years). The median time from injury to testing was 23 days for the ACL-injured group. Participants underwent Biodex isokinetic strength testing at 60 deg/s to assess quadriceps and hamstring strength. Isometric hip strength (abduction, extension, external rotation) was measured using a handheld dynamometer. The muscle strength of the uninvolved limb of the ACL-injured group was compared with that of the dominant limb of the healthy control group. Results: The results showed a significant difference in quadriceps muscle strength between the 2 study groups (P < .001). Isokinetic quadriceps strength of the uninvolved limb in the ACL group was significantly decreased by 25.5% (P < .001) when compared with the dominant limb of the control group. Conclusion: The results of this study demonstrate a decreased isokinetic strength of the quadriceps muscle in the uninvolved limb after ACL injury as compared with healthy controls. Consideration should be taken when using the uninvolved limb for comparison when assessing quadriceps strength in a population with an ACL injury.
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    Effectiveness of a 6-week injury prevention program on kinematics and kinetic variables in adolescent female soccer players: A pilot study
    (University of Puerto Rico Medical Sciences Campus, 2010-03) Ortiz, Alexis; Trudelle-Jackson, Elaine; McConnell, Keegan; Wylie, Stephanie
    BACKGROUND: Incidence of knee injuries in female soccer players is 2-6 times that of male counterparts. The objective was to determine whether an injury prevention program incorporated into the athlete’s regular soccer practice is effective for improving landing mechanics. METHODS: Two competitive adolescent female soccer teams (n = 30) participated in the study. One team served as the control group while the other team participated in a 6-week injury prevention program. Muscle strength, muscle length, and 3-dimensional kinematics and kinetics during a single legged drop jump and single legged squat task were measured pre and post-intervention. A 2 x 2 repeated measures multivariate analyses of variance (MANOVA’s) were used to compare strength and flexibility measures as well as knee joint kinematics and kinetics. Significant multivariate results were followed with appropriate univariate analyses. RESULTS: Quadriceps strength increased significantly (p=.004) following the injury prevention program while other strength and flexibility measurements were unchanged. Differences in knee joint angles and moments during the drop jump and squat tasks showed varied results with a tendency for improvement in the intervention group. CONCLUSIONS: Flexibility and strength do not appear to be affected by a short injury prevention program. Knee joint injury predisposing factors improved minimally but did not reach statistical significance with a short injury prevention program integrated as warm-up into soccer practice. Further research with a larger sample size is needed to explore the effectiveness of such programs.