Postural stability and isokinetic strength do not predict knee
valgus angle during single-leg drop-landing or single-leg squat in elite male
rugby union players
Affiliations: [a] Neuromuscular Research Laboratory, Department of
Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| [b] Training Laboratory, School of Sports Medicine,
Università degli Studi di Firenze, Florence, Italy
Note: [] Corresponding author: J.S. Akins, Neuromuscular Research
Laboratory, Department of Sports Medicine and Nutrition, University of
Pittsburgh, 3830 South Water Street, Pittsburgh, PA 15203, USA. E-mail: jsa14@pitt.edu
Abstract: BACKGROUND: Knee injuries have been identified as the most common
injury in rugby. Knee valgus has been identified as a risk factor for ligament
injuries in athletes and predictors of knee valgus may assist in the design of
knee injury prevention programs. PURPOSE: The purposes of this study were
to use postural stability (PS) and strength measures to predict knee valgus
angle during dynamic tasks, identify relationships between PS and strength, and
compare measures between positions. METHODS: Participants presenting
positive during a gluteal dysfunction screening exam were enrolled.
Participants performed PS, isokinetic strength, and biomechanical assessments.
Stepwise multiple linear regression analyses were performed to identify
predictors of knee valgus. Correlation coefficients identified relationships
between PS and strength, and independent t-tests compared forwards and backs. RESULTS: Backs had significantly (p< 0.05) better PS and greater
strength as compared to forwards. Hip abduction strength was correlated
(r=− 0.52–−0.71, p< 0.05) with all eyes open static PS measures.
Regression analysis failed to identify predictors of knee valgus angle. CONCLUSION: Although PS and strength were not multivariate
predictors of knee valgus in male rugby players, bivariate correlations suggest
that hip abduction strength training may be beneficial for enhancing PS.
