膝关节屈曲角度对主动肌和拮抗肌共同收缩和力矩的影响

目的测试股四头肌进行最大等长收缩时,不同膝关节屈曲角度对股四头肌和腘绳肌收缩时肌电活动和力矩产生的影响。方法10名健康成人在3个不同膝关节角度(分别为30°、60°、90°)下进行膝伸展的最大等长收缩,利用Cybex等速测试系统测试下肢股四头肌产生的力矩,并应用表面肌电仪测试股四头肌和腘绳肌的神经肌电活动。结果在膝关节屈曲60°时,股四头肌的力矩值比其他角度明显增大(P<0.01),但股四头肌在3个屈曲角度时的神经肌电活动差异无统计学意义;而腘绳肌的神经肌电活动在膝关节屈曲90°时最大。结论在特定膝关节角度进行股四头肌和腘绳肌最大等长收缩训练可帮助维持膝关节的稳定性。     

Influence of Lumbar Mobilizations During the Nordic Hamstring Exercise on Hamstring Measures of Knee Flexor Strength,Failure Point,and Muscle Activity: A Randomized Crossover Trial

ObjectiveThe aims of this study were to quantify the effects of spinal mobilization on force production, failure point, and muscle activity of the hamstrings during the Nordic hamstring exercise (NHE), and to explore individual differences in responses.MethodsIn a replicated randomized crossover trial, 24 asymptomatic, recreationally active men (age [mean ± standard deviation]: 27 ± 6 years; body mass: 82 ± 17 kg; height: 181 ± 8 cm) completed 2 standardized intervention trials (L4/5 zygapophyseal mobilizations) and 2 control trials. The failure point of the NHE was determined with 3D motion capture. Peak force, knee flexor torque, and electromyography (EMG) of the biceps femoris were measured. Data analyses were undertaken to quantify mean intervention response and explore any individual response heterogeneity.ResultsMean (95% confidence interval) left-limb force was higher in intervention than in control trials by 18.7 (4.6-32) N. Similarly, right-limb force was higher by 22.0 (3.4-40.6) N, left peak torque by 0.14 (0.06-0.22) N ? m, and right peak torque by 0.14 (0.05-0.23) N ? m/kg. Downward force angle was decreased in intervention vs control trials by 4.1° (0.5°-7.6°) on the side of application. Both peak EMG activity (P = .002), and EMG at the downward force (right; P = .020) increased in the intervention condition by 16.8 (7.1-26.4) and 8.8 (1.5-16.1) mV, respectively. Mean downward acceleration angle changed by only 0.3° (?8.9° to 9.4°) in intervention vs control trials. A clear response heterogeneity was indicated only for right force (Participant × Intervention interaction: P = .044; response heterogeneity standard deviation = 34.5 [5.7-48.4] N). Individual response heterogeneity was small for all other outcomes.ConclusionAfter spinal mobilization, immediate changes in bilateral hamstring force production and peak torque occurred during the NHE. The effect on the NHE failure point was unclear. Electromyographic activity increased on the ipsilateral side. Response heterogeneity was generally similar to the random trial-to-trial variability inherent in the measurement of the outcomes.     

Impact of Exercise on Lower Activity Levels in Children with Acute Lymphoblastic Leukemia: A Randomized Controlled Trial from Turkey

This randomized, controlled experimental study was carried out to determine the effects of an exercise program on both physical parameters and the quality of life of children with acute lymphoblastic leukemia (ALL). A total of 41 children with ALL (20 trial and 21 control cases) at two university hospitals were accepted into the study. Due to the demise of one of the children in the trial group, the study was completed with 19 trial and 21 control patients, a total of 40 children and their parents. Regular and systematic exercise regimens implemented by children with ALL have resulted in improved testing results, enhanced physical performance, and better laboratory results compared with a control group and to children's scores before the initiation of such a program.     

水中运动疗法联合电针对恢复期脑卒中患者下肢肌力和平衡功能的影响

目的:观察水中运动疗法对恢复期脑卒中下肢肌肉力量、痉挛程度及平衡功能的影响。方法:选取62例恢复期脑卒中患者,分为治疗组(水中运动疗法+常规康复治疗+电针治疗)、对照组(常规康复治疗+电针治疗),每组31例。治疗前及治疗6周后,分别采用等速肌力评定、改良Ashworth痉挛量表(MAS)、临床痉挛指数(CSI)、10m最大步行速度测定(MWS)、Berg平衡量表(BBS)对2组患者进行评定。结果:治疗后,2组患者下肢肌肉力量、MWS、BBS评分均较治疗前显著增加(均P0.05),MAS分级评分、临床痉挛指数CSI均较治疗前显著降低(P0.05);治疗后组间比较,观察组下肢肌肉力量、MWS、BBS评分均明显高于对照组(均P0.05),观察组MAS分级评分、CSI指数均低于对照组(均P0.05)。结论:水中运动疗法联合电针疗法可有效提高恢复期脑卒中患者下肢肌力,改善患者平衡功能。