Abstract

Rehabilitation following anterior cruciate ligament (ACL) reconstruction is a critical and core process for restoring normal physiological function of the knee joint, reestablishing joint stability, and facilitating the patient’s return to daily activities and sports. It directly affects the quality of postoperative knee recovery and long-term functional outcomes. Hydrotherapy, leveraging the unique physical properties of water such as buoyancy, resistance, and hydrostatic pressure, serves as a highly advantageous and significant form of rehabilitation intervention after this surgery. The buoyancy of water effectively offsets a portion of body weight, substantially reducing the load borne by the knee joint, thereby minimizing the risk of secondary joint injury during rehabilitation training at its source. Meanwhile, the dynamic resistance of water enables progressive and controllable training of muscle strength around the knee, balance ability, and joint range of motion, adapting to the rehabilitation needs at different postoperative stages. Additionally, hydrostatic pressure acts on the local limb, effectively improving blood circulation around the knee joint and promoting the elimination of metabolic waste, which in turn alleviates common postoperative symptoms such as swelling and pain. As a safe, efficient, and highly adaptable rehabilitation modality, aquatic rehabilitation provides an important biomechanical and exercise physiological theoretical basis for the scientific design of personalized rehabilitation programs following ACL reconstruction. It also strengthens the theoretical foundation for optimizing postoperative rehabilitation pathways in clinical practice and enhancing overall rehabilitation outcomes.