Muscle Activity Onset Prior to Landing in Patients after Anterior Cruciate Ligament Injury: A Systematic Review and Meta-Analysis

Abstract

Muscle activation during landing is paramount to stabilise lower limb joints and avoid abnormal movement patterns. Delayed muscle activity onset measured by electromyography (EMG) has been suggested to be associated with anterior cruciate ligament (ACL) injury. Therefore, the aim of this systematic review and meta-analysis was to test the hypothesis if ACL-injured patients display different results for muscle onset timing during standard deceleration tasks compared to healthy control participants. PubMed, Embase, Scopus and ScienceDirect databases were systematically searched over the period from January 1980 to February 2015, yielding a total of 1461 citations. Six studies meeting inclusion criteria underwent quality assessment, data extraction and re-computing procedures for the meta-analysis. The quality was rated “moderate” for 2 studies and “poor” for 4. Patients included and procedures used were highly heterogeneous. The tasks investigated were single leg hopping, decelerating from running or walking, tested on a total of 102 ACL-injured participants and 86 controls. EMG analyses of the muscles vastus lateralis, vastus medialis, lateral and medial hamstrings revealed trivial and non-significant standardised mean differences (SMD<0.20; p>0.05) between patients and control participants. Furthermore, no differences were found between the contralateral leg of patients and controls for muscle activity onset of the medial and lateral gastrocnemius (SMD<0.20; p>0.05). Based on 3 studies, the involved legs of ACL-injured patients showed overall earlier muscle activity onset compared to control participants for the medial gastrocnemius (SMD = 0.5; p = 0.05). Similar results were found for the lateral gastrocnemius (SMD = 2.1; p<0.001), with a greater effect size but based only on a single study. We conclude that there are no differences between leg muscles of ACL-injured patients and healthy controls regarding the muscle activity onset during landing. However, current evidence is scarce and weak, which highlights the need for further research in this area.

Ankle perturbation generates bilateral alteration of knee muscle onset times after unilateral anterior cruciate ligament reconstruction

“…This remains unclear based on the retrospective design of our study. While a recent systematic review and meta-analysis ( Theisen et al, 2016 ) suggests that muscle activity onset is not associated with increased ACL injury risk, current evidence is still scarce and weak ( Theisen et al, 2016 ). Future prospective studies should examine whether neuromuscular deficits and altered muscle onsets are present before ACL injuries.…”

Timing of Muscle Activation Is Altered During Single-Leg Landing Tasks After Anterior Cruciate Ligament Reconstruction at the Time of Return to Sport

“…The ACL tears occur soon after the initial ground contact 5,6 and too quickly for reflexive muscular activation (>100 milliseconds) to prevent injuries 7 . Zebis et al (2009) 8 showed that abnormal co-activation of thigh muscles performing side-cutting tasks predisposes for future ACL injury, therefore modulating muscle activity prior to landing seems to be crucial to avoid excessive joint rotations and to protect ACL from dangerous loading 9,10 .…”

“…Considering the electromyographic (EMG) activity prior to landing in ACL reconstructed (ACL-R) subjects, results are controversial in reporting successful or abnormal neuromuscular strategies performing jump-landing tasks 16,17 . A recent review of Theisen et al(2016) 10 describes in details pre-landing muscle activity in ACL injured and reconstructed subjects reviewing the literature from 1980 to 2015. The review underlined the weakness of current evidences on this topic recognizing clinical and methodological heterogeneity, such as the type of graft, time from surgery and level of physical activity as main weak points of existing studies.…”

Predicting post‐operative functional ability from pre‐operative measures in ACL‐injured individuals

“…Nevertheless, while the KOOS was developed for an osteoarthritic population, 2 and the IKDC for a range of knee injuries, 4 they have both been validated in ACL populations 4,34 and are both commonly used in ACLrelated studies. 35 As such, it was important to include them in the current analyses. Furthermore, the KNEES is currently only valid in Danish and therefore its international scope is as yet limited.…”

“…When interpreting our results, the first limitation to consider is that, unlike the KNEES, not all our PROMs are specifically designed for measuring subjective function in ACLd and ACLr patients. Nevertheless, while the KOOS was developed for an osteoarthritic population, and the IKDC for a range of knee injuries, they have both been validated in ACL populations and are both commonly used in ACL‐related studies . As such, it was important to include them in the current analyses.…”