A Novel Apparatus to Measure Knee Flexor Strength During Various Hamstring Exercises: A Reliability and Retrospective Injury Study

作者：Hickey Jack T^*; Hickey Peter F; Maniar Nirav; Timmins Ryan G; Williams Morgan D; Pitcher Christian A; Opar David A

来源：Journal of Orthopaedic & Sports Physical Therapy, 2018, 48(2): 72-+.

DOI：10.2519/jospt.2018.7634

• eccentric
• force impulse
• isometric
• muscle
• rate of force development
• strain injury

STUDY DESIGN: Reliability and case-control injury study.
BACKGROUND: Knee flexor strength is a key variable when dealing with hamstring strain injury (HSI), and methodologies of objective measurement of strength are often limited to single exercises.
OBJECTIVES: To establish test-retest reliability of a novel apparatus to measure knee flexor strength during various hamstring exercises, and to investigate whether the measure can detect between-leg differences in male participants with and without history of unilateral HSI.
METHODS: Twenty male participants without and 10 male participants with previous unilateral HSI participated. Isometric knee flexor strength and peak rate of force development (RFD) at 0 degrees/0 degrees, 45 degrees/45 degrees, and 90 degrees/90 degrees of hip/knee flexion were measured, as well as force impulse during bilateral and unilateral variations of an eccentric slider and hamstring bridge, using a novel apparatus. Intraclass correlation coefficient (ICC), typical error, and typical error as a coefficient of variation were calculated for all measures. The magnitudes of between-leg differences within each group were calculated using estimates of effect sizes, reported as Cohen's d and 90% confidence interval (CI).
RESULTS: Moderate to high test-retest reliability was observed for isometric knee flexor strength (ICC = 0.87-0.92) and peak RFD (ICC = 0.88-0.95) across 3 positions and for mean force impulse during the eccentric slider (ICC = 0.83-0.90). In those with prior HSI, large deficits were observed in the previously injured leg compared to the contralateral uninjured leg for mean force impulse during the unilateral eccentric slider (d = -1.09; 90% CI: -0.20, -1.97), isometric strength at 0 degrees/0 degrees (d = -1.06; 90% CI: -0.18, -1.93) and 45 degrees/45 degrees (d = -0.88; 90% CI: -0.02, -1.74), and peak RFD at 45 degrees/45 degrees (d = -0.88; 90% CI: -0.02, -1.74).
CONCLUSION: The novel apparatus provides a reliable measure of isometric knee flexor strength, peak RFD, and force impulse during an eccentric slider, with deficits seen in previously injured hamstrings for these measures.

• 出版日期2018-2