Effects of Preoperative Isokinetic Eccentric Training and Whey Protein Isolate Supplement on Quadriceps Strength and Knee Function in Patients with Anterior Cruciate Ligament Rupture.

Objective To explore the effect of preoperative isokinetic eccentric training with or not whey protein isolate supplement before operation on lower limb muscle strength and knee function in patients with anterior cruciate ligament (ACL) rupture. Methods A total of 22 male volunteers aged 18-40 years with ACL rupture were recruited in outpatient service. With randomized block design,subjects were randomly assigned to isokinetic eccentric training (IE) group and isokinetic eccentric training with whey protein isolate supplement (IE+WPI) group. The IE group received isokinetic eccentric training of the injured limb on an isokinetic dynamometer under the guidance of physiatrist in laboratory before operation. There were 3-4 sets per day with 8-10 repetitions for each set,twice a week,with at least one day between sessions. The IE+WPI group were supplied with whey protein isolate 22 g per day on the basis of isokinetic eccentric training,taking breakfast or 30-60 minutes after the training. The intervention lasted for 6 weeks. Isokinetic muscle strength of limbs,the function and laxity of knee,the circumferences of thigh and knee,and the body composition were measured before and after the treatment. Results Compared with baseline,the peak torque (PT) of isokinetic-eccentric contraction (IE group:41.0%,P=0.018;IE+WPI group:46.7%,P=0.008) and the concentric contraction (IE group:29.6%,P=0.018;IE+WPI group:38.9%,P=0.038) of quadriceps in the two training groups significantly increased after isokinetic eccentric training. The Lysholm score increased significantly in IE+WPI group compared with baseline (P=0.018). Conclusions Isokinetic eccentric training before operation for ACL rupture patients can increase the strength of quadriceps and improve the function of knees. Protein isolate supplement can improve such effect.目的 通过观察术前等速离心训练和补充乳清蛋白对前交叉韧带(ACL)断裂患者股四头肌力量及其功能的影响,探讨等速离心运动对ACL断裂患者下肢功能康复的作用。方法招募18~40岁男性ACL断裂志愿者,共入组22例,采用区组化随机数字表法分为等速离心训练(IE)组和等速离心训练+分离乳清蛋白补充(IE+WPI)组。IE组受试者术前在实验室等速生物力学测试训练仪上进行患肢股四头肌等速离心训练,每周2次,每次3~4组×8~10个重复,训练间隔时间至少1 d;IE+WPI组在上述股四头肌等速离心训练基础上每天补充分离乳清蛋白22 g,早餐或运动训练后30~60 min内服用。干预时间6周。干预前后分别检测双侧股四头肌60°/s等速肌力、肌肉量、膝关节功能及松弛度、大腿围度、骨骼肌指数等指标。结果 干预后,IE组和IE+WPI组受试者患侧股四头肌等速离心收缩峰力矩(PT)(41.0%,P=0.018;46.7%,P=0.008)和向心收缩峰力矩(PT)(29.6%,P=0.018;38.9%,P=0.038)均比干预前显著增加。与干预前比较,IE+WPI组Lysholm膝关节评分显著增加(P=0.018)。结论 术前等速离心训练可以显著增加ACL断裂患者股四头肌肌力,并在一定程度上改善膝关节功能,联合补充乳清蛋白效果更佳。.