Author(s) :

David Melamed, Konstantinos.

Volume/Issue :

Abstract :

Anterior cruciate ligament (ACL) injuries are among the most common orthopedic injuries, with approximately 250,000 cases occurring annually in the US. Surgical reconstruction (ACLR) followed by extensive rehabilitation is the standard treatment for athletes returning to sport (RTS). Despite the length and intensity of rehabilitation, between 20-40% of patients sustain a subsequent ACL tear. This raises concerns regarding the adequacy of current RTS decision-making criteria. Arthrogenic muscle inhibition (AMI), a neuromuscular impairment characterized by reduced voluntary activation of the quadriceps following joint injury, has emerged as a potential contributor to persistent deficits after ACLR. However, AMI is rarely directly assessed within RTS batteries. This systematic review evaluated the role of AMI in RTS outcomes following ACLR. Of 3490 PubMed studies identified, 35 were included in the review. Literature consistently reports associations between AMI and reduced quadriceps activation, neuromuscular asymmetries, altered gait mechanics, and kinesiophobia, all factors associated with increased risk of reinjury. Yet, RTS protocols still rely primarily on time since surgery, limb symmetry indices, and psychological readiness measures, with limited assessment of underlying neuromuscular inhibition. These findings suggest that AMI may represent a contributing neuromuscular factor influencing multiple domains used to determine RTS readiness. However, the evidence is predominantly associative, and direct links between AMI and reinjury outcomes remain limited. Future research should focus on developing reliable and feasible methods for assessing AMI and evaluating whether incorporating such assessments into RTS batteries improves prediction of reinjury risk and functional outcomes.