Hip abduction-adduction strength and one-leg, hop tests: Test-retest reliability and relationship to function in elite ice hockey players

Study Design: Single group, test-retest. Objectives: To determine: (1) hip abduction and adduction torques during co ncentric and eccentric muscle actions, (2) media[ and lateral one-leg hop d istances, (3) the test-retest reliability of these measurements, and (4) th e relationship between isokinetic measures of hip muscle strength and hop d istances in elite ice hockey players. Background: The skating motion used in ice hockey requires strong contracti ons of the hip and knee musculature. However, baseline scores for hip stren gth and hop distances, their test-retest reliability, and measures of the e xtent to which these tests are related for this population are not availabl e. Methods and Measures: The dominant leg of 27 men (mean age 20 +/- 3 yrs) wa s tested on 2 occasions. Hip abduction and adduction movements were complet ed at 60 degrees . s(1) angular velocity with the subject lying on the non- test side and the test leg moving vertically in the subject's coronal plane . One-leg hops requiring jumping from and landing on the same leg without l osing balance were completed in the medial and lateral directions. Results: Hip adduction torques were significantly greater than abduction to rques during both concentric and eccentric muscle actions, while no signifi cant difference was observed between medial and lateral hop distances. Alth ough hop test scores produced excellent ICCs (> 0.75) when determined using scores on 1 occasion, torques needed to be averaged over 2 test occasions to reach this level. Correlations between the strength and hop tests ranged from slight to low (r = -0.26 to 0.27) and were characterized by wide 95% confidence intervals (-0.54 to 0.61). Conclusions: Isokinetic tests of hip abduction and adduction did not provid e a strong indication of performance during sideways hop tests. Although is okinetic tests can provide a measure of muscular strength under specific te st conditions, they should not be relied upon as a primary indicator of fun ctional abilities or readiness to return to activity.