Objective We aimed to determine hip and lower-leg muscle strength in people after ACL injury compared with an uninjured control group (between people) and the uninjured contralateral limb (between limbs). Design Systematic review with meta-analysis. Data sources MEDLINE, EMBASE, CINAHL, Scopus, Cochrane CENTRAL and SportDiscus to 28 February 2023. Eligibility criteria Primary ACL injury with mean age 18–40 years at time of injury. Studies had to measure hip and/or lower-leg muscle strength quantitatively (eg, dynamometer) and report muscle strength for the ACL-injured limb compared with: (i) an uninjured control group and/or (ii) the uninjured contralateral limb. Risk of bias was assessed according to Cochrane Collaboration domains. Results Twenty-eight studies were included (n=23 measured strength ≤12 months post-ACL reconstruction). Most examined hip abduction (16 studies), hip extension (12 studies) and hip external rotation (7 studies) strength. We found no meaningful difference in muscle strength between people or between limbs for hip abduction, extension, internal rotation, flexion or ankle plantarflexion, dorsiflexion (estimates ranged from −9% to +9% of comparator). The only non-zero differences identified were in hip adduction (24% stronger on ACL limb (95% CI 8% to 42%)) and hip external rotation strength (12% deficit on ACL limb (95% CI 6% to 18%)) compared with uninjured controls at follow-ups >12 months, however both results stemmed from only two studies. Certainty of evidence was very low for all outcomes and comparisons, and drawn primarily from the first year post-ACL reconstruction. Conclusion Our results do not show widespread or substantial muscle weakness of the hip and lower-leg muscles after ACL injury, contrasting deficits of 10%–20% commonly reported for knee extensors and flexors. As it is unclear if deficits in hip and lower-leg muscle strength resolve with appropriate rehabilitation or no postinjury or postoperative weakness occurs, individualised assessment should guide training of hip and lower-leg strength following ACL injury. PROSPERO registration number CRD42020216793. Data are available in a public, open access repository.

中文翻译：

---

没有虚弱的迹象：前十字韧带损伤后髋部和小腿肌肉力量的系统回顾和荟萃分析

目的 我们的目的是确定 ACL 损伤后患者的臀部和小腿肌肉强度，并与未受伤的对照组（人之间）和未受伤的对侧肢体（四肢之间）进行比较。通过荟萃分析设计系统审查。数据来源 MEDLINE、EMBASE、CINAHL、Scopus、Cochrane CENTRAL 和 SportDiscus 截至 2023 年 2 月 28 日。 资格标准 原发性 ACL 损伤，受伤时平均年龄为 18-40 岁。研究必须定量测量臀部和/或小腿肌肉力量（例如测力计），并报告 ACL 受伤肢体的肌肉力量，并与以下各项进行比较：(i) 未受伤的对照组和/或 (ii) 未受伤的对侧肢体。根据 Cochrane 协作领域评估偏倚风险。结果 纳入 28 项研究（n=23 测量强度≤ACL 重建后 12 个月）。大多数研究检查髋部外展（16 项研究）、髋部伸展（12 项研究）和髋部外旋（7 项研究）强度。我们发现，人与人之间或四肢之间的髋部外展、伸展、内旋、屈曲或踝关节跖屈、背屈方面的肌肉力量没有显着差异（估计范围为比较者的−9% 至+9%）。唯一发现的非零差异是髋部内收（ACL 肢体强 24%（95% CI 8% 至 42%））和髋部外旋强度（ACL 肢体弱 12%（95% CI 6% 至 18%） )) 与随访 > 12 个月的未受伤对照组进行比较，但这两个结果仅来自两项研究。所有结果和比较的证据质量都非常低，并且主要来自 ACL 重建后的第一年。结论 我们的结果并未显示 ACL 损伤后髋部和小腿肌肉出现广泛或显着的肌肉无力，相比之下，通常报道的膝关节伸肌和屈肌的缺陷为 10%–20%。由于尚不清楚髋部和小腿肌肉力量的缺陷是否可以通过适当的康复来解决，或者是否不会出现受伤后或术后无力的情况，因此个体化评估应指导 ACL 损伤后髋部和小腿力量的训练。 PROSPERO 注册号 CRD42020216793。数据可在公共、开放访问存储库中获取。