Asymmetrical Lower Extremity Loading Early After Anterior Cruciate Ligament Reconstruction Is a Significant Predictor of Asymmetrical Loading at the Time of Return to Sport

Abstract

Objectives: To examine whether asymmetrical lower limb loading early after ACL reconstruction (one month) can predict asymmetrical lower limb loading at the time of return to sport (6 months) and whether other early predictors as knee joint range of motion or maximal isometric strength affect this relationship.Design: Ground reaction forces were measured during a sit to stand task (STS) one month after ACL reconstruction and a vertical countermovement jump (CMJ) 6 months after ACL reconstruction in 58 athletes. Other early post-operative measurements were knee joint range of motion (2 weeks, 1 month and 2 months after surgery) and maximal isometric strength of the knee extensor and flexor muscles (2 months after surgery). Linear regression models were developed using side-to-side limb symmetry index (LSI) of CMJ as the dependent variable.Results: LSI of STS 1 month after surgery was a significant independent predictor of LSI of CMJ 6 months after surgery. After accounting for deficits in knee joint range of motion and LSI of maximal isometric strength (ΔR 2 =0.35 p<0.01), LSI of STS predicted LSI of CMJ (ΔR 2 =0.14 p<0.01). Conclusions:Asymmetrical lower extremity loading one month after ACL reconstruction is an early predictor of asymmetrical lower extremity loading 6 months after surgery.

Neuromuscular Electrical Stimulation Superimposed on Movement Early after ACL Surgery

“…Interventions to counteract quadriceps muscle inhibition, which is an ongoing reflex inhibition of the knee extensor muscles, have to be started as early as possible in the rehabilitation process (4). The lack of activation leads the muscle to a persistent state of atrophy, which may affect further stages of rehabilitation and long term recovery as well as the biomechanics of functional movements (5,6). For example, asymmetrical lower limb loading has been observed during various functional movement tasks and in all phases of rehabilitation following ACL reconstruction (6,7,8,9,10).…”

“…The lack of activation leads the muscle to a persistent state of atrophy, which may affect further stages of rehabilitation and long term recovery as well as the biomechanics of functional movements (5,6). For example, asymmetrical lower limb loading has been observed during various functional movement tasks and in all phases of rehabilitation following ACL reconstruction (6,7,8,9,10). In turn, the lack of loading on the operated limb represents a limitation for quadriceps muscle strength recovery, as the load on the operated limb is an important training stimulus for the recovery of strength (4,11).…”

Effects of early whole-body vibration treatment on knee neuromuscular function and postural control after anterior cruciate ligament reconstruction: A randomized controlled trial

“…Among these factors, the vibration frequency appears to have an important role on the magnitude of the neuromuscular response. An optimal vibration frequency (OVF), which has been defined as the vibration frequency (Hz) at which maximal muscle activation occurs, is always advisable because it potentially produces greater effects on neuromuscular performance in less time (21)(22)(23)(24).…”

Unilateral Discomfort Increases the Use of Contralateral Side during Sit-to-Stand Transfer

“…Asymmetrical loading during STS is reported in people with unilateral impairment, for example, those who underwent transtibial amputation [26], total knee arthroplasty [27], and anterior cruciate ligament reconstruction [28] and in individuals with stroke [29, 30]. It is described in the literature that when individuals with stroke performed the STS with the paretic foot placed behind the healthy foot, they improved the symmetry of their movement [31].…”