This study aimed to compare time-to-boundary and sample entropy during a single-leg balance task between individuals with chronic ankle instability (CAI), lateral ankle sprain copers, and healthy controls. Twenty-two participants with CAI, 20 lateral ankle sprain copers, and 24 healthy controls performed a single-leg balance task during an eyes-closed condition. Participants with CAI exhibited lower time-to-boundary values compared with lateral ankle sprain copers and healthy controls. However, we did not find differences in sample entropy variables between cohorts. A decrease in time-to-boundary values in participants with CAI indicated that CAI may constrain the ability of the sensorimotor system to maintain the center of pressure within the boundaries of the base of support. However, the regularity of the center of pressure velocity time series appears not to be altered in the CAI cohort in this study.
Masafumi Terada, Megan Beard, Sara Carey, Kate Pfile, Brian Pietrosimone, Elizabeth Rullestad, Heather Whitaker and Phillip Gribble
Megan Q. Beard, Samantha A. Boland and Phillip A. Gribble
Decreased hip strength is often present in patients with chronic overuse lower extremity injuries. The hand-held dynamometer (HHD) can be used in a clinical setting to quantify hip strength; however, reliability of the device remains unclear. The purpose of this study was to determine the interexaminer and intersession reliability of a HHD when measuring isometric hip abduction (HABD) and external rotation (HER) strength, both with and without a fixed strap. The HHD had good to high reliability regardless of examiner, session, or stabilization when measuring HABD (ICC = 0.885–0.977) and HER (ICC = 0.879–0.958) isometric strength. HHD is an appropriate instrument for measuring isometric hip strength.
Ryan S. McCann, Kyle B. Kosik, Masafumi Terada, Megan Q. Beard, Gretchen E. Buskirk and Phillip A. Gribble
The Star Excursion Balance Test (SEBT) and Functional Movement Screen (FMS) are functional performance measures capable of predicting lower-extremity injury risk. While suboptimal SEBT and FMS performances are influenced by multiple factors, the contribution of hip strength and flexibility to these tests is mostly unknown. Examination of hip strength and flexibility influences on the SEBT and FMS may direct clinicians to better methods of correcting functional deficits.
Determine the relationships of isometric hip strength and hip passive range of motion (PROM) with functional performance measures.
Athletic training facility.
43 NCAA Division I women’s soccer players (19.65 ± 1.12 y; 166.93 ± 3.84 cm; 60.99 ± 4.31 kg) volunteered.
Data Collection and Analysis:
All participants were tested bilaterally in the SEBT; the deep squat, in-line lunge, hurdle step, and straight leg raise, comprising a lower-extremity FMS (FMS-LE); hip internal and external rotation PROM; and isometric hip extension strength (HEXT). The mean of the 3 averaged, normalized SEBT scores was used as a composite score. Pearson product moment correlations assessed relationships of SEBT and FMS-LE scores with PROM and HEXT. Significance was set a priori at P < .05.
Pearson correlations revealed anterior (ANT) SEBT scores had a low negative association with HEXT (r = –0.33,P = .004) and a low positive association with hip internal rotation PROM (PROM-IR) (r = .43,P = .003). All other correlations were negligible.
Flexibility training aimed at PROM-IR may contribute to improved ANT scores. Targeting HEXT and hip external rotation PROM are likely not preferred means of correcting deficits in SEBT and FMS-LE performance.