The test-retest reliability of an inclined squat strength test protocol

Functional testing of the lower extremity is supported as a good predictor for successful return to premorbid activity. However, current reliable functional tests may be too strenuous for a patient in the acute stage of recovery. A functional testing protocol utilizing an inclined sliding board apparatus was evaluated for test-retest reliability. Thirty-five subjects (ages = 18-25, mean = 20.49 +/- 1.71) with no known knee pathologies were tested. Subjects performed a 20-second test for squat repetitions and a 50-squat repetition test for time, executing a single leg squat in an inclined position on the sliding board apparatus. The test was repeated 1 week later. The intraclass correlation coefficient equaled 0.80 for the 50-repetition timed test and 0.89 for the 20-second repetition test. The results indicate an acceptable test-retest reliability for the inclined sliding board apparatus protocol. We advocate the use of this testing protocol for the purpose of evaluating functional ability during the early stages of rehabilitation of lower extremity conditions.