Muscle injuries are highly prevalent in military training, physical exercise and daily activities, which are mainly classified into contusion, strain and laceration. Among them, contusions and strains account for more than 90% of all cases, while lacerations are relatively rare. Muscle contusion refers to mechanical damage of muscle fibers caused by direct blunt impact of external force, occurring frequently in both athletic and non-athletic trauma. It may lead to muscle dysfunction, swelling, atrophy, contracture, and a higher risk of recurrent injury. Trauma rehabilitation medicine has long focused on exploring effective strategies to accelerate muscle repair and achieve complete functional recovery. The core challenge is to develop feasible clinical interventions that can enhance cell proliferation while inhibiting fibrosis. At present, the mainstream clinical management follows the RICE principle: rest, ice compression, compression bandaging and elevation. Cold compress is applied within 24 hours after injury, while hot compress is adopted after 24 hours.

SD rats (mixed gender, 220 g)
Modeling method: The gastrocnemius muscle was fully exposed. A weight was dropped in free fall from a fixed height with constant mass to strike the medial muscle belly of the right lower limb gastrocnemius with a single impact, so as to establish a stable blunt muscle contusion model.
Evaluation index: HE staining

Gastrocnemius muscle HE staining