Measurement Properties of a Test Battery to Assess Postural Orientation During Functional Tasks in Patients Undergoing Anterior Cruciate Ligament Injury Rehabilitation
Visual rating of postural orientation during functional tasks may be a valuable tool to track rehabilitation progress following anterior cruciate ligament (ACL) injury. A valid test battery assessing postural orientation as a separate construct is lacking.OBJECTIVES:
To evaluate measurement properties of a test battery to assess postural orientation in patients with ACL injury.METHODS:
The content validity of functional tasks was assessed by expert focus group discussions. Fifty-one patients (45% women) with ACL injury performed 9 functional tasks of varying difficulty. Interpretability, internal consistency, interrater reliability, and measurement error were assessed for segment-specific postural orientation errors (POEs), within-task POEs, and total POE score. Postural orientation errors were scored on video on an ordinal scale from 0 (no POEs) to 3 (major POEs).RESULTS:
Stair ascent, deep squat, and crossover hop for distance were excluded in focus group discussions. Postural orientation errors in some tasks were excluded due to floor effects. The mini-squat and drop jump were excluded due to poor internal consistency (α≤.184). Interrater reliability values for segment-specific POEs and within-task POEs yielded fair to almost perfect agreement (κ = 0.429–0.875) and almost perfect agreement for total POE score (intraclass correlation coefficient = 0.842), without systematic differences between raters. The smallest detectable changes were 0.7 and 5 points for groups and individuals, respectively.CONCLUSION:
The final test battery (single-leg mini-squat, stair descent, forward lunge, single-leg hop for distance) of 4 POEs (foot pronation, medial knee-to-foot position, hip joint POEs, and trunk segment POEs) demonstrated good measurement properties in people with ACL injury.