Single-Leg Jump Performance Before and After Exercise in Healthy and Anterior Cruciate Ligament Reconstructed Individuals

• Published in: Journal of sport rehabilitation Vol. 29; no. 7; p. 879
• Main Authors: Bookbinder, Haley, Slater, Lindsay V, Simpson, Austin, Hertel, Jay, Hart, Joseph M
• Format: Journal Article
• Language: English
• Published: United States 01.09.2020
• Subjects: Adolescent; Adult; Anterior Cruciate Ligament Reconstruction - rehabilitation; Exercise Test; Exercise Therapy - methods; Female; Humans; Male; Movement - physiology; Return to Sport; Surveys and Questionnaires; Young Adult; fatigue; knee injury; athlete; limb symmetry
• ISSN: 1543-3072
• DOI: 10.1123/jsr.2019-0159

Many clinicians measure lower-extremity symmetry after anterior cruciate ligament reconstruction (ACLR); however, testing is completed in a rested state rather than postexercise. Testing postexercise may better model conditions under which injury occurs. To compare changes in single-leg performance in healthy and individuals with history of ACLR before and after exercise. Repeated-measures case-control. Laboratory. Fifty-two subjects (25 control and 27 ACLR). Thirty minutes of exercise. Limb symmetry and involved limb performance (nondominant for healthy) for single-leg hop, ground contact time, and jump height during the 4-jump test. Cohen d effect sizes were calculated for all differences identified using a repeated-measures analysis of variance. Healthy controls hopped farther than ACLR before (d = 0.65; confidence interval [CI], 0.09 to 1.20) and after exercise (d = 0.60; CI, 0.04 to 1.15). Those with ACLR had longer ground contact time on the reconstructed limb compared with the uninvolved limb after exercise (d = 0.53; CI, -0.02 to 1.09), and the reconstructed limb had greater ground contact time compared with the healthy control limb after exercise (d = 0.38; CI, -0.21 to 0.73). ACLR were less symmetrical than healthy before (d = 0.38; CI, 0.17 to 0.93) and after exercise (d = 0.84; CI, 0.28 to 1.41), and the reconstructed limb demonstrated decreased jump height compared with the healthy control limbs before (d = 0.75; CI, 0.19 to 1.31) and after exercise (d = 0.79; CI, 0.23 to 1.36). ACLR became more symmetric, which may be from adaptations of the reconstructed limb after exercise. Changes in performance and symmetry may provide additional information regarding adaptations to exercise after reconstruction.