Segal Neil, Davis Maria D, Mikesky Alan E
Department of Rehabilitation Medicine, University of Kansas, Kansas City, KS, USA.
Department of Orthopaedics & Rehabilitation, University of Iowa, Iowa City, IA, USA.
Geriatr Orthop Surg Rehabil. 2015 Sep;6(3):160-7. doi: 10.1177/2151458515583088.
Greater quadriceps strength has been associated with lower risk of symptomatic knee osteoarthritis (OA) in older adults. However, factors that confer elevated risk of knee OA (eg, sedentary lifestyle, obesity, and knee injury) also contribute to a reduced tolerance of resistance training programs at ≥60% 1-repetition maximum (1RM). Therefore, the current study assessed whether concurrent application of blood flow restriction (BFR) to low-load resistance training is an efficacious and tolerable means of improving quadriceps strength in men at risk of symptomatic knee OA.
Men older than age 45, with a history of knee injury or elevated body mass index (BMI), were randomized to low-load resistance training (30% 1RM) either with or without concurrent BFR. Isotonic double-leg press strength and isokinetic knee extensor strength were assessed before and after 4 weeks of training 3 times/wk. Knee pain (Knee Osteoarthritis Outcome Score) was assessed for tolerance.
Of the 42 men (mean age 56.1 ± 7.7 years) who were randomized, 41 completed the program. There were no significant intergroup differences in age, BMI, knee pathology, or muscle strength at baseline. Although leg press 1RM improved in both control and BFR groups, there were no significant intergroup differences in primary or secondary measures of muscle strength. The BFR was not associated with worsening of knee pain, but there was a significant improvement in knee pain in the control group.
In comparison with training without BFR, addition of BFR to 30% 1RM resistance training for 4 weeks did not confer significantly greater increases in leg press or quadriceps strength in older men with risk factors for symptomatic knee OA.
股四头肌力量增强与老年人症状性膝关节骨关节炎（OA）风险降低相关。然而，导致膝关节OA风险升高的因素（如久坐不动的生活方式、肥胖和膝关节损伤）也会导致对≥60% 1次重复最大值（1RM）的抗阻训练计划的耐受性降低。因此，本研究评估了在低负荷抗阻训练中同时应用血流限制（BFR）是否是改善有症状性膝关节OA风险男性股四头肌力量的有效且可耐受的方法。
年龄超过45岁、有膝关节损伤史或体重指数（BMI）升高的男性被随机分为低负荷抗阻训练组（30% 1RM），一组同时进行BFR，另一组不进行。在每周3次、为期4周的训练前后，评估等张双腿推举力量和等速膝关节伸展力量。评估膝关节疼痛（膝关节骨关节炎结局评分）以确定耐受性。
在随机分组的42名男性（平均年龄56.1±7.7岁）中，41名完成了该计划。基线时，两组在年龄、BMI、膝关节病理或肌肉力量方面无显著组间差异。尽管对照组和BFR组的腿举1RM均有所改善，但在肌肉力量的主要或次要指标上，两组间无显著差异。BFR与膝关节疼痛加重无关，但对照组的膝关节疼痛有显著改善。
与不进行BFR的训练相比，在有症状性膝关节OA风险因素的老年男性中，在30% 1RM抗阻训练中添加BFR进行4周训练，在腿举或股四头肌力量增加方面并没有显著更大的效果。
