Morphology and Anabolic Response of Skeletal Muscles Subjected to Eccentrically or Concentrically Biased Exercise

Redox signaling‑mediated muscle atrophy in ACL injury: Role of physical exercise (Review)

Muscle atrophy frequently occurs in patients with anterior cruciate ligament (ACL) injury, despite active participation in muscle strengthening programs. Without appropriate countermeasures such as exercise and pharmacological interventions, the atrophy may worsen. At the cellular and molecular levels, various protein synthesis‑related pathways and redox‑dependent molecules regulate processes associated with atrophy by activating or deactivating key signaling pathways. Muscle atrophy and the associated dysfunction can be reversed by physical exercise, which increases protein synthesis, thereby improving muscle strength and function around the ACL. However, the influence of different features of exercise protocols, including exercise type, intensity and duration, as well as the individual capacity of the patient, on the activity of the aforementioned pathways requires further investigation. Additionally, the mechanism by which redox‑sensitive molecules attenuate atrophy in ACL injury remains to be fully understood. The present review discusses exercise, signaling pathways and muscle atrophy in ACL injury, and highlights potential therapeutic strategies. These findings may also have implications for other joint diseases associated with ACL‑related injury.

Eccentric Exercise as a Potent Prescription for Muscle Weakness After Joint Injury

Lengthening contractions (i.e., eccentric contractions) are capable of uniquely triggering the nervous system and signaling pathways to promote tissue health/growth. This mode of exercise may be particularly potent for patients suffering from muscle weakness after joint injury. Here we provide a novel framework for eccentric exercise as a safe, effective mode of exercise prescription for muscle recovery.

Osteochondral Allograft Transplantation in Professional Athletes: Rehabilitation and Return to Play

For the treatment of large chondral and osteochondral defects of the knee, osteochondral allograft transplantation (OCA) is an effective solution with relatively high rates of return to sport. In professional athletes, rehabilitation following OCA is a critical component of the process of returning the athlete to full sports activity and requires a multidisciplinary team approach with frequent communication between the surgical and rehabilitation teams (physical therapists, athletic trainers, coaching staff). In this review, we describe our five-phase approach to progressive rehabilitation of the professional athlete after OCA, which takes into account the biological processes of healing and optimization of neuromuscular function required for the demands of elite-level sport. The principles of early range of motion, proper progression through the kinetic chain, avoidance of pain and effusion, optimization of movement, regimen individuation, and integration of sports-specific activities underlie proper recovery.