The reliability and validity of multidirectional hop tests versus sagittal plane-based hop tests in function of return-to-sport evaluation in patients following anterior cruciate ligament reconstruction

Abstract

Background: Following anterior cruciate ligament reconstruction (ACLR), hop tests are mostly performed in the sagittal plane to evaluate functional performance during the return-to-sport (RTS) decision-making process. However, multidirectional hop tests should be implemented since they could provide a more accurate representation of demands faced during sport- related movements (pivoting/cutting). Objectives: To determine test-retest reliability and discriminant validity of single-leg hop tests in the sagittal, frontal and transversal plane of motion in function of RTS following ACLR. Participants: First, 16 healthy athletes were recruited in order to determine test-retest reliability. Secondly, 13 ACLR patients (ACLG) and 13 control subjects (CG), matched for age, gender, sport and activity level, were recruited for determination of discriminant validity. Measurements: Hop tests were performed in a random sequence: single hop for distance (SH), triple hop for distance (TH), triple medial side hop for distance (TMSH), and 90° medial rotational hop for distance (MRH). Absolute hop distances were measured (cm), with the maximum distance of three repetitions as the outcome measure. Afterwards, limb symmetry indices (LSI's, %) were calculated. Regarding test-retest reliability, intraclass correlation coefficients (ICC's) were evaluated. In order to determine discriminant validity, between-group comparisons were conducted.