Arthrogenic Muscle Inhibition: Best Evidence, Mechanisms, and Theory for Treating the Unseen in Clinical Rehabilitation

Abstract

Context: Arthrogenic muscle inhibition (AMI) impedes the recovery of muscle function following joint injury, and in a broader sense, acts as a limiting factor in rehabilitation if left untreated. Despite a call to treat the underlying pathophysiology of muscle dysfunction more than three decades ago, the continued widespread observations of post-traumatic muscular impairments are concerning, and suggest that interventions for AMI are not being successfully integrated into clinical practice. Objectives: To highlight the clinical relevance of AMI, provide updated evidence for the use of clinically accessible therapeutic adjuncts to treat AMI, and discuss the known or theoretical mechanisms for these interventions. Evidence Acquisition: PubMed and Web of Science electronic databases were searched for articles that investigated the effectiveness or efficacy of interventions to treat outcomes relevant to AMI. Evidence Synthesis: 122 articles that investigated an intervention used to treat AMI among individuals with pathology or simulated pathology were retrieved from 1986 to 2021. Additional articles among uninjured individuals were considered when discussing mechanisms of effect. Conclusion: AMI contributes to the characteristic muscular impairments observed in patients recovering from joint injuries. If left unresolved, AMI impedes short-term recovery and threatens patients’ long-term joint health and well-being. Growing evidence supports the use of neuromodulatory strategies to facilitate muscle recovery over the course of rehabilitation. Interventions should be individualized to meet the needs of the patient through shared clinician–patient decision-making. At a minimum, we propose to keep the treatment approach simple by attempting to resolve inflammation, pain, and effusion early following injury.

Return to sports after ACL injury 5 years from now: 10 things we must do

“…Therefore, increasing neural signalling to skeletal muscle by diverting cortical resources may be advantageous to overcome the inhibition. Eccentric cross-exercise and biofeedback leverage this "send help" strategy and are well suited to enhance muscle function during early recovery from ACLR [87]. Eight weeks of eccentric cross-exercise has facilitated spinal-reflexive and corticospinal excitability, [73] as well as strength [93] of the non-exercised quadriceps.…”

Inhibition of Motor Planning and Response Selection after Anterior Cruciate Ligament Reconstruction

“…So-called priming of motor pathways has been described in numerous populations to date (46), including after ACLR (47)(48)(49)(50). Based on a recent systematic review of neuromodulatory interventions after knee joint trauma (51), eccentric crossed exercise, biofeedback, and motor imagery are all supported for use in this population and mechanically aligned with increasing corticospinal excitability. Although whether these modalities are able to improve LRP area is unknown, clinicians should apply these interventions solely for previously reported clinical benefits when in alignment with patient goals.…”

Weaker Quadriceps Corticomuscular Coherence in Individuals after ACL Reconstruction during Force Tracing

“…Although the effects on CMC are unknown, disinhibitory modalities such as eccentric crossed exercise, biofeedback, and motor imagery can prime motor pathways in this population (45)(46)(47)(48). When in alignment with patient goals, clinicians should apply these interventions solely for previously reported clinical benefits, as well as mechanistic alignment with AMT and gamma CMC impairments (49). Additionally, visual sensory-motor and motor planning processes contribute to the recorded gamma band coherence.…”