The Trendelenburg and single-leg-squat (SLS) tests are purported measures of hip-abduction strength that have not been previously validated.
To correlate isometric hip-abduction strength to frontal-plane hip motion during an SLS and determine the criterion validity of a clinical-observation-analysis method to grade an SLS against 2-dimensional kinematic analysis.
Single-measure, concurrent validity.
Biodynamics research laboratory.
50 uninjured participants.
Main Outcome Measures:
Hip-abduction strength and hip and knee kinematic data during a Trendelenburg test and an SLS.
A weak, positive correlation between hip-abduction strength and hip-adduction angle was found during both the Trendelenburg (r = .22, P = .13) and the SLS (r = .21, P = .14) tests. The observation-analysis method revealed a low sensitivity, .23, and a higher specificity, .86, when compared with the kinematic data.
The usefulness of the Trendelenburg and SLS test in screening hip-abductor strength in a healthy physically active population is limited. The origin of observable deficits during SLS requires further objective assessment.
DiMattia and Livengood are with the Dept of Kinesiology and Health Promotion, College of Education, and Uhl, Mattacola, and Malone, the Dept of Rehabilitation Sciences, College of Health Science, University of Kentucky, Lexington, KY 40536-0200.