Recovery of Muscle Strength and Knee Function After Sports-Related Injuries in Young Athletes: A Systematic Review
L.F.D. Coutinho, C.H.D. CoutinhoObjectives:
Sports-related knee injuries are one of the leading causes of absence from sport among young athletes and are frequently associated with prolonged deficits in muscle strength and functional limitation. Despite their clinical relevance, evidence regarding the trajectory of strength and functional recovery after such injuries remains fragmented, hindering the standardization of rehabilitation protocols. This study aims to systematically review the scientific literature on the progression of thigh muscle strength and knee function in young athletes following sports-related knee injuries, identifying recovery patterns and associated factors.
Methods:
A systematic review was conducted in accordance with the PRISMA 2020 guidelines, with searches performed in PubMed, Scopus, Web of Science, and Consensus.app databases (2010–2025). Longitudinal and cohort studies involving young individuals ≤26 years old with sports-related knee injuries were included. Outcomes assessed included quadriceps and hamstring muscle strength, function, pain, and return to sport.
Results:
Analysis of seven studies revealed residual strength deficits (10–15%) persisting up to 24 months after injury, regardless of injury type (ACL, meniscal, or mixed). Muscle strength showed no strong correlation with functional performance. Arthrogenic muscle inhibition and psychological factors significantly influenced recovery. Persistent deficits were associated with an increased risk of early-onset osteoarthritis.
Conclusion:
Knee injuries in young individuals result in long-lasting deficits in strength and function, requiring prolonged, multidimensional rehabilitation focused on neuromuscular control, psychosocial support, and prevention of joint degeneration. Continuous monitoring should be maintained even after return to sport.