Table 4.

Step-Down Test Protocol

Each individual must wear shorts that enable the evaluator to observe their knee position throughout the entire SDT. They are instructed to stand barefoot with both legs shoulder width apart and parallel to each other with arms positioned at their side on a standardized step that is 20-25 cm high. They are then asked to transition to a single leg-stance on the unaffected leg with the non-stance knee extended out from the step and foot in dorsiflexion. The stance leg is positioned so that the toes are even with the front edge of the step. While maintaining a straight trunk, individuals are then instructed to bend their knee on the stance leg until the heel of the contralateral leg touches the floor. Without putting weight on the heel, they must return to the starting position at a rate of 1 squat per 2 seconds. After completion of each repetition the participants will return to their original standing position before beginning the next repetition. Individuals will perform the SDT a total of 3 times. They will then complete 3 repetitions on the affected side. A single investigator will demonstrate the entire test performance before the participation of an individual.

The evaluator assessed the overall test performance of the individuals affected side. Along with an overall impression, each repetition was graded as “positive” or “negative” for the five criteria listed below. For the individual to pass, the evaluator must first grade the overall impression of test performance as passing. Second, a total of 4 out of the 5 specific criteria must be negative for deviation. A passing grade of at least 1 out of the 3 tests are needed for evaluation. Therefore, failing 2 out of 3 tests still elicits a passing assessment.

Scoring Criteria Overall impression (balance, balance or acceleration provided by heel contact, gross arm deviation, ability to perform test) 1. Trunk movement (forward lean, lateral rotation, lateral flexion, thoracic rotation) 2. Posture of the pelvis (tilt or rotation) 3. Posture of the hip joint (adduction or internal rotation) 4. Posture of the knee (knee valgus or tremor) 5. Depth of squat (inability to contact heel to ground)

SDT – step-down test