Abstract
Little is known about the contralateral asymmetry in inter-joint coordination after
anterior cruciate ligament reconstruction (ACL-R) during multi-segmental movements.
This study aimed to evaluate inter-joint coordination asymmetry between the injured
(IL) and non-injured leg (NIL) in patients after ACL-R during single-leg jumping.
12 male patients having undergone ACL-R (7.3 months post-surgery) and 12 healthy males
performed maximal vertical single-leg jumps with the right and left leg. The kinematics
of each jump were recorded. The inter-joint coordination between the ankle, knee and
hip joints was assessed by computing the continuous relative phase (CRP) and its variability.
The effect of the group and leg was tested with a mixed linear model. The CRP and
its variability were similar between the dominant and non-dominant leg of the healthy
group. By contrast the CRP of the coupling ankle/knee and ankle/hip was smaller (p<0.01)
for IL in comparison to NIL in the ACL-R group (−30% and −22% respectively). The CRP
variability of the couplings ankle/knee and knee/hip was greater (p<0.05) for IL compared
to NIL (+23% and +40% respectively). In conclusion, the jumping strategy assessed
through the analysis of inter-joint coordination was still affected in ACL-R patients,
which may be a cause of re-injury.
Key words
knee - continuous relative phase - rehabilitation - injury - 2D kinematics
