Knee extensor strength and hop test performance following anterior cruciate ligament reconstruction

TY - JOUR

T1 - Knee extensor strength and hop test performance following anterior cruciate ligament reconstruction

AU - Barfod, Kristoffer W

AU - Feller, Julian A

AU - Hartwig, Taylor

AU - Devitt, Brian M

AU - Webster, Kate E

N1 - Copyright © 2018 Elsevier B.V. All rights reserved.

PY - 2019/1

Y1 - 2019/1

N2 - BACKGROUND: Knee extensor strength and single limb hop for distance have been suggested as useful measures to evaluate readiness to return to sport after anterior cruciate ligament (ACL) reconstruction. The aim of the study was to examine the association between knee extensor strength and single leg hop for distance following ACL reconstruction and to determine the proportion of patients with knee extensor strength symmetry deficits at six and 12 months.METHODS: From December 2013 to December 2015 69 patients aged 14 to 45 undergoing primary ACL reconstruction were recruited. Isokinetic concentric knee extensor strength testing and single limb hop for distance were performed six and 12 months postoperatively. Satisfactory knee extensor strength was defined as a leg symmetry index (LSI) ≥85%.RESULTS: At six months 27.5% (19/69) of patients had recovered satisfactory knee extensor strength in the injured leg, improving to 46.4% (32/69) at 12 months. Recovery of satisfactory strength was associated with hopping distance. Hop symmetry was achieved considerably faster than knee extensor symmetry, with 66.7% (46/69) of patients demonstrating satisfactory hopping symmetry at six months, 89.9% (62/69) at 12 months. Recovery of hopping distance was not associated with knee extensor strength.CONCLUSIONS: Single leg hop test cannot be used as a surrogate measure for knee extensor strength as no association was found between hop tests and knee extensor strength. Less than one in three patients at six months and one in two at 12 months had recovered satisfactory knee extensor strength.

AB - BACKGROUND: Knee extensor strength and single limb hop for distance have been suggested as useful measures to evaluate readiness to return to sport after anterior cruciate ligament (ACL) reconstruction. The aim of the study was to examine the association between knee extensor strength and single leg hop for distance following ACL reconstruction and to determine the proportion of patients with knee extensor strength symmetry deficits at six and 12 months.METHODS: From December 2013 to December 2015 69 patients aged 14 to 45 undergoing primary ACL reconstruction were recruited. Isokinetic concentric knee extensor strength testing and single limb hop for distance were performed six and 12 months postoperatively. Satisfactory knee extensor strength was defined as a leg symmetry index (LSI) ≥85%.RESULTS: At six months 27.5% (19/69) of patients had recovered satisfactory knee extensor strength in the injured leg, improving to 46.4% (32/69) at 12 months. Recovery of satisfactory strength was associated with hopping distance. Hop symmetry was achieved considerably faster than knee extensor symmetry, with 66.7% (46/69) of patients demonstrating satisfactory hopping symmetry at six months, 89.9% (62/69) at 12 months. Recovery of hopping distance was not associated with knee extensor strength.CONCLUSIONS: Single leg hop test cannot be used as a surrogate measure for knee extensor strength as no association was found between hop tests and knee extensor strength. Less than one in three patients at six months and one in two at 12 months had recovered satisfactory knee extensor strength.

KW - Adolescent

KW - Adult

KW - Anterior Cruciate Ligament Injuries/physiopathology

KW - Anterior Cruciate Ligament Reconstruction

KW - Female

KW - Follow-Up Studies

KW - Humans

KW - Knee Joint/physiopathology

KW - Male

KW - Middle Aged

KW - Movement/physiology

KW - Muscle Strength/physiology

KW - Postoperative Period

KW - Prospective Studies

KW - Sports

KW - Young Adult

U2 - 10.1016/j.knee.2018.11.004

DO - 10.1016/j.knee.2018.11.004

M3 - Journal article

C2 - 30554909

SN - 0968-0160

VL - 26

SP - 149

EP - 154

JO - The Knee

JF - The Knee

IS - 1

ER -