Reliability and validity of common hip adduction strength measures: The ForceFrame strength testing system versus the sphygmomanometer

Abstract

ObjectivesThe criterion validity of the sphygmomanometer was evaluated, relative to the Force Frame strength testing system. Test-retest reliability was assessed for both hip adduction and abduction strength. DesignTest-retest reliability study and criterion validity study. Participants50 asymptomatic, field-sport athletes. Main outcome measuresMaximal isometric hip adduction and abduction strength were measured. Interclass correlation coefficient(ICC2,1) with confidence intervals were calculated to evaluate reliability of peak strength values. A Pearson product-moment correlation coefficient(r) was calculated to examine criterion validity of the sphygmomanometer as a measure of force when compared to the ForceFrame. ResultsIntra-rater reliability for bilateral adduction testing using both ForceFrame and sphygmomanometer values revealed good-excellent reliability for both the 0° (ICC2.1 = 0.87–0.90) and 45° (ICC2.1 = 0.81–0.91) positions. ForceFrame values revealed good-excellent reliability for 0° abduction position and 45° abduction position. A good-moderate relationship (Pearson's r = 0.63) for 0° adduction position, and poor relationship (Pearson's r = 0.40) for 45° adduction position, were found between adduction squeeze values on ForceFrame and sphygmomanometer. ConclusionExcellent reliability in hip adduction squeeze strength testing for both modes. However, there exists a ‘good to moderate’-‘fair’ relationship between the Force Frame and sphygmomanometer.