Altered movement during single leg hop test after ACL reconstruction: implications to incorporate 2-D video movement analysis for hop tests
Altered movement during single leg hop test after ACL reconstruction: implications to incorporate 2-D video movement analysis for hop tests
Wouter Welling 0 1 2 4 5
Anne Benjaminse 0 1 2 4 5
Romain Seil 0 1 2 4 5
Koen Lemmink 0 1 2 4 5
Alli Gokeler 0 1 2 4 5
0 School of Sport Studies, Hanze University Groningen , Zernikeplein 17, 9747 AS Groningen , The Netherlands
1 Center for Human Movement Science, University Medical Center Groningen, University of Groningen , Antonius Deusinglaan 1, 9713 AV Groningen , The Netherlands
2 Medisch Centrum Zuid , Sportlaan 2-1, 9728 PH Groningen , The Netherlands
3 Wouter Welling
4 Sports Medicine Research Laboratory, Luxembourg Institute of Health , 4 Rue Nicolas Ernest Barblé, 1210 Luxembourg , Luxembourg
5 Département de l'Appareil Locomoteur, Centre Hospitalier de Luxemburg , 4 Rue Nicolas Ernest Barblé, 1210 Luxembourg , Luxembourg
Purpose There is a lack of objective factors which can be used in guiding the return to sport (RTS) decision after an anterior cruciate ligament reconstruction (ACLR). The purpose of the current study was to conduct qualitative analysis of the single leg hop (SLH) in patients after ACLR with a simple and clinical friendly method and to compare the possible difference in movement pattern between male and female patients. Methods Sixty-five patients performed the single leg hop (SLH) test at 6.8± 1.0 months following isolated ACLR. Digital video camcorders recorded frontal and sagittal plane views of the patient performing the SLH. Knee flexion at initial contact (IC), peak knee flexion, knee flexion range of motion (RoM), and knee valgus RoM were calculated. In addition, limb symmetry index (LSI) scores were calculated. Results No differences were found in movement pattern between males and females. Movement analysis revealed that males had a decrease in knee flexion at IC (p= 0.018), peak knee flexion (p= 0.002), and knee flexion RoM (p= 0.017) in the injured leg compared to the non-injured leg. Females demonstrated a decrease in peak knee flexion (p= 0.011) and knee flexion RoM (p= 0.023) in the injured leg compared to the non-injured leg. Average LSI scores were 92.4% for males and 94.5% for females. Conclusions Although LSI scores were > 90%, clinical relevant altered movement patterns were detected in the injured leg compared to the non-injured leg. Caution is warranted to solely rely on LSI scores to determine RTS readiness. Clinical trial registry name and registration The University of Groningen, ID 2012.362. Level of evidence III.
Anterior cruciate ligament; Hop tests; Jump landing; Return to sport; Movement analysis
Introduction
Although an anterior cruciate ligament reconstruction
(ACLR) is considered as a successful procedure [
2
], the rate
of return to sport (RTS) in patients after ACLR is relatively
low [
14
]. Over two-third of patients do not return to their
pre-injury level of sport 1 year after surgery [
2
].
Unfortunately, RTS are associated with ACL re-injury rates reported
between 6–20% [
6, 48, 49, 57
]. The majority of ACL
reinjuries (74%) occur within the first 2 years after RTS [24].
The reason of this high rate of re-injuries after ACLR
is multifactorial [
12
]. One of the contributing factors may
be related movement asymmetries after ACLR, which have
been directly implicated in the risk for ACL-re-injury [
8
].
These deficits may have been present prior to injury and
exacerbated by the surgical procedure. A critical moment
towards the end of an extensive course of rehabilitation is
the clearance by physicians and rehabilitation specialists to
release athletes after ACLR to full RTS [
2, 56
].
To determine the RTS readiness, the most commonly
assessments are clinical, strength, performance-based
functional (like hop testing) and self-reported knee
function [
30
]. It is common to calculate a limb symmetry index
(LSI) defined as the hop test performance of the injured
leg divided by the hop test performance of the non-injured
leg × 100% [
1
]. LSI > 90% are often used as cut-off scores
for RTS [
18, 26
]. Research shows that RTS decisions are
frequently based on subjective criteria [4] and quantitative
analysis of functional tests (distance, time or LSI) [
32, 39
],
while outcomes related to the quality of movement are not
captured [50]. The current method may not be sensitive
enough to detect deficits related to ACL re-injury risk [
18
].
Research suggests that decreased knee flexion angles
will potentially increase the risk of a re-injury, since a more
stiff landing will generated more forces on the ACL [
28
].
Decreased knee flexion compared to the non-injured leg has
been reported for hop tests 7 months after ACLR [
55
]. These
findings may explain the relatively high re-injury rates that
are found in ACLR patients [
5
] and show that the quality of
the movement is essential in ACL rehabilitation [
38, 48
].
Males and females differ in neuromuscular movement
patterns and (...truncated)