Biomechanical studies suggest performance on a drop vertical jump (DVJ) can predict anterior cruciate ligament (ACL) injury and should be targeted during rehabilitation after ACL reconstruction. A clinically feasible tool would be advantageous for quantitatively evaluating performance and change in DVJ following therapy. Such a tool should be developed by a panel of experts to establish consensus on the usefulness of the tool, and to verify that essential components are included.
PURPOSE: The purpose of the present study was to establish consensus on the content and scoring of a Clinician Rated DVJ Scale for use during rehabilitation after ACL reconstruction.
METHODS: Using a Delphi process, 20 experts on the risk factors, prevention, treatment and/or biomechanics of ACL injury, anonymously critiqued the proposed Clinician Rated DVJ Scale, using Likert-scales and written feedback. Three-to-five rounds were planned a priori as termination criteria, with the requirement of 75% agreement on items after the final round.
RESULTS: Nine researchers and eleven clinicians including physical therapists, athletic therapists and orthopaedic surgeons participated. Response rates were 55%, 85% and 70% for rounds two, three and four, respectively. After rounds one and two, the scale was revised to include only the components that ≥ 61% of experts agreed upon. After round three, only two components had ≤ 75% agreement, and these were refined for round four. After round four, ≥ 92% agreement was achieved. Final items on the scale include a rating of knee valgus collapse (No to Extreme), and other undesirable movements including evidence of lateral trunk lean, insufficient trunk flexion, insufficient knee flexion and limb-to-limb asymmetry. A scale from 0 (No knee valgus collapse and no undesirable movements) to 9 (Extreme knee valgus collapse ± undesirable movements) is included for each leg to monitor change throughout rehabilitation.
CONCLUSIONS: The Delphi process resulted in adequate agreement on the content and scoring of the Clinician Rated DVJ Scale to support its preliminary use as a measurement tool for functional testing throughout rehabilitation following ACL injury and/or reconstruction. A Beta version of the scale will be subsequently piloted.