Smith Miriam J, Hoffman Nolan J, Jose Argell J San, Burke Louise M, Opar David A
School of Behavioural and Health Sciences, Australian Catholic University, Melbourne, VIC, Australia.
Sports Performance, Recovery, Injury and New Technologies (SPRINT) Research Centre, Australian Catholic University, Melbourne, VIC, Australia.
Sports Med. 2025 Mar;55(3):569-596. doi: 10.1007/s40279-025-02174-w. Epub 2025 Jan 24.
Following anterior cruciate ligament (ACL) injury, quadriceps muscle atrophy persists despite rehabilitation, leading to loss of lower limb strength, osteoarthritis, poor knee joint health and reduced quality of life. However, the molecular mechanisms responsible for these deficits in hypertrophic adaptations within the quadriceps muscle following ACL injury and reconstruction are poorly understood. While resistance exercise training stimulates skeletal muscle hypertrophy, attenuation of these hypertrophic pathways can hinder rehabilitation following ACL injury and reconstruction, and ultimately lead to skeletal muscle atrophy that persists beyond ACL reconstruction, similar to disuse atrophy. Numerous studies have documented beneficial roles of nutritional support, including nutritional supplementation, in maintaining and/or increasing muscle mass. There are three main mechanisms by which nutritional supplementation may attenuate muscle atrophy and promote hypertrophy: (1) by directly affecting muscle protein synthetic machinery; (2) indirectly increasing an individual's ability to work harder; and/or (3) directly affecting satellite cell proliferation and differentiation. We propose that nutritional support may enhance rehabilitative responses to exercise training and positively impact molecular machinery underlying muscle hypertrophy. As one of the fastest growing knee injuries worldwide, a better understanding of the potential mechanisms involved in quadriceps muscle deficits following ACL injury and reconstruction, and potential benefits of nutritional support, are required to help restore quadriceps muscle mass and/or strength. This review discusses our current understanding of the molecular mechanisms involved in muscle hypertrophy and disuse atrophy, and how nutritional supplements may leverage these pathways to maximise recovery from ACL injury and reconstruction.
前交叉韧带（ACL）损伤后，尽管进行了康复训练，股四头肌萎缩仍会持续，导致下肢力量丧失、骨关节炎、膝关节健康状况不佳以及生活质量下降。然而，对于ACL损伤和重建后股四头肌肥大适应性出现这些缺陷的分子机制，我们了解甚少。虽然抗阻运动训练可刺激骨骼肌肥大，但这些肥大途径的减弱会阻碍ACL损伤和重建后的康复，并最终导致骨骼肌萎缩持续至ACL重建之后，类似于废用性萎缩。许多研究已证明营养支持（包括营养补充）在维持和/或增加肌肉质量方面的有益作用。营养补充可能通过三种主要机制减轻肌肉萎缩并促进肥大：（1）直接影响肌肉蛋白质合成机制；（2）间接提高个体更努力锻炼的能力；和/或（3）直接影响卫星细胞的增殖和分化。我们认为营养支持可能会增强对运动训练的康复反应，并对肌肉肥大的分子机制产生积极影响。作为全球增长最快的膝关节损伤之一，需要更好地了解ACL损伤和重建后股四头肌缺陷所涉及的潜在机制以及营养支持的潜在益处，以帮助恢复股四头肌的质量和/或力量。本综述讨论了我们目前对肌肉肥大和废用性萎缩所涉及分子机制的理解，以及营养补充剂如何利用这些途径来最大程度地从ACL损伤和重建中恢复。
