title: VALIDATION OF TWO CLINICAL MEASURES OF CORE STABILITY.
abstract: BACKGROUND
  Emerging evidence suggests poor core stability is a risk factor for low back and lower extremity injuries in athletes. Recently the trunk stability test (TST) and unilateral hip bridge endurance test (UHBE) were developed to clinically assess core stability. Although these and other clinical tests of core stability exist, how well they assess core stability when compared to biomechanical measures of isolated core stability has not been thoroughly evaluated.
  
  
  OBJECTIVE
  The purposes of this study were to 1) determine concurrent validity of two novel clinical core stability assessments (TST and UHBE), and 2) assess relationships between these assessments and the trunk endurance and Y-Balance tests. The authors' hypothesized that the TST and UHBE would be highly correlated to the lab-based biomechanical measure of isolated core stability. Also, the TST and UHBE would be moderately correlated with each other, but not with the trunk extensor endurance and Y-Balance.
  
  
  METHODS
  Cross-Sectional design.
  
  
  METHODS
  Twenty healthy active individuals completed the TST (recorded number of errors), UHBE (s), trunk extensor endurance (s), Y-Balance (% leg length) test (YBT), and biomechanical test of core stability.
  
  
  RESULTS
  Correlational analyses revealed a small, non-significant association between TST and biomechanical measures (rs = 0.2 - 0.22), while a moderate, significant relationship existed between UHBE and biomechanical measures (rs = -0.49 to -0.56, p < 0.05). There was little to no relationship between TST and UHBE (r = -0.07 to - 0.21), or TST and extensor endurance (r = -0.18 to -0.24). A moderate, significant association existed between TST and two reach directions of the YBT (r = -0.41 to -0.43, p < 0.05).
  
  
  CONCLUSIONS
  Study data support the utility of UHBE as a clinical measure of core stability. The poor relationship between the TST and biomechanical measures, combined with observation of most control faults occurring in the lower extremity (LE) suggest the TST may not be an appropriate clinical test of core stability.
  
  
  METHODS
  Level 3.
authors.affiliation: Physical Therapy & Rehabilitation Sciences Department, Drexel University, Philadelphia, PA, USA.
authors.forename: Courtney M
authors.initials: CM
authors.lastname: Butowicz
authors.forename: D David
authors.initials: DD
authors.lastname: Ebaugh
authors.affiliation: Division of Physical Therapy, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Noehren
authors.affiliation: Physical Therapy & Rehabilitation Sciences Department, Drexel University, Philadelphia, PA, USA.
authors.forename: Sheri P
authors.initials: SP
authors.lastname: Silfies
keywords: athletic injuries; core stability; neuromuscular control