Responsiveness and Validity of Weight-Bearing Test for Measuring Loading Capacity in Patients With Triangular Fibrocartilage Complex Injury

Abstract

Context: Weight-bearing test (WBT) is a noninvasive quantitative test which has been used recently to determine loading capability of the individuals. The aim of this study was to strengthen the evidence for using the WBT test for measuring weight-bearing capacity of the upper-extremity with the specific objective of examining the internal and external responsiveness and concurrent validity of the test in patients with triangular fibrocartilage complex injury. Design: Single-group repeated measures. Methods: Internal responsiveness was assessed using effect size statistics. The correlation coefficient was used to examine external responsiveness by testing 5 hypotheses regarding predefined correlations between the changes in the measurements. Concurrent validity was evaluated by analyzing correlations between the WBT and other measurements. Thirty-one patients with triangular fibrocartilage complex injury were included for the analysis of the concurrent validity. Eighteen patients who completed all measurements at baseline and at 3-month follow-up enrolled for the responsiveness analysis. Measurements included the WBT, pain intensity, grip strength, and upper extremity functional level. Results: The WBT test was able to detect statistically significant changes in weight-bearing capacity between baseline and follow-up (P = .0001). The effect size of the WBT was large. Three out of 5 hypotheses (60%) were confirmed, a good correlation was found between changes scores of the WBT and grip strength (r = .478; P < .05). There were significant correlations between the WBT and other measurements (r value range from −.401 to .742; P < .05). A higher correlation was found between the WBT and grip strength (r = .742; P = .0001). Conclusions: The responsiveness and concurrent validity of the WBT test confirmed that it is able to measure change in weight-bearing capacity in patients with triangular fibrocartilage complex injury.