The Relationship Between A Measure Of Dynamic Balance And A Movement Assessment

Abstract

The Star Excursion Balance Test (SEBT) is a valid and reliable dynamic balance test commonly used to identify functional deficits associated with lower extremity injury. Movement assessments are also used clinically to identify risk factors for injury. Predictive factors for decreased SEBT performance are unknown and identification of such factors would provide clinically useful information for injury prevention. It is hypothesized that postural deviations observed during a movement assessment would be contributing factors to dynamic balance deficits. PURPOSE: To determine the relationship between dynamic balance and a movement assessment in an effort to identify risk factors for decreased SEBT performance. METHODS: A single group study was performed in a university clinical setting with 47 division-I track and field athletes (male=25, female=22; age, 20.8±1.2 years; mass, 71.3±15.7 kg; height, 176.3±9.3 cm). All subjects underwent the SEBT (anteromedial, medial, posterior reach directions) and a movement assessment consisting of a single-leg and an overhead squat. Correlation (rpb) coefficients were calculated to determine the relationship between normalized SEBT reach distances and dichotomously scored movement assessment scores indicating the presence/absence of postural deviations at four kinetic chain checkpoints (foot/ankle, knee, lumbo-pelvic-hip complex, shoulder/c-spine). Inter-tester reliability of the movement assessment was also determined using percent agreement. RESULTS: A negative relationship reflecting a medium effect size was found between SEBT posterior reach and forward falling of the arms during the overhead squat (r = -.23, p = .03). Anteromedial SEBT reach was negatively correlated with rounding of the low back during the overhead squat (r = -.24, p = .02). Using squats as a movement assessment demonstrated fair to good percent agreement amongst raters (r =.76 - .99). CONCLUSION: We demonstrated that postural deviations in the proximal kinetic chain during an overhead squat are associated with decreased SEBT performance. These results provide some evidence for proximal chain involvement in decreased dynamic balance scores and lower extremity injury risk and support the incorporation of the proximal chain into clinical injury assessment and prevention efforts.