Fukunaga Takumi, Fedge Connor, Tyler Timothy, Mullaney Michael, Schmitt Brandon, Orishimo Karl, McHugh Malachy, Nicholas Stephen
Int J Sports Phys Ther. 2023 Feb 1;18(1):208-214. doi: 10.26603/001c.68073. eCollection 2023.
PURPOSE/HYPOTHESIS: The flexor-pronator mass of the forearm contributes dynamic stability to the medial elbow. Training this muscle group is essential for overhead athletes, however, there is lack of evidence supporting use of training exercises. The purpose of this study was to measure the extent of EMG activity of the flexor pronator musculature during two distinct forearm strengthening exercises using resistance bands. It was hypothesized that two exercises would elicit at least moderate level of muscle activity, but the activation would be different in the pronator versus the flexor muscles.
MATERIALS/METHODS: 10 healthy subjects (all males, age 36±12 years) were included. Surface EMG activity was measured on three muscles of the dominant-side forearm: flexor carpi ulnaris (FCP), flexor digitorum superficialis (FDS), and pronator teres (PT). After measurement of maximal voluntary contraction (MVC) for each muscle, subjects performed wrist ulnar deviation and forearm pronation exercises using elastic band resistance. Resistance was set to elicit moderate exertion (5/10 on the Borg CR10 scale). Order of exercise was randomized and three repetitions of each exercise were performed. Mean peak EMG activity in each muscle across repetitions during the eccentric phase of each exercise was calculated and expressed as a percentage of MVC. Moderate level of activity was defined as 21% of MVC or higher. Peak normalized EMG activity in each muscle was compared using two-way (exercise x muscle) repeated-measures ANOVA with post-hoc pairwise comparisons if a significant interaction was found.
There was an exercise by muscle interaction effect (p<0.001). The ulnar deviation exercise selectively activated FCU (40.3%) versus FDS (19.5%, p=0.009) and PT (21.5%, p=0.022). Conversely, the pronation exercise selectively activated FDS (63.8%, p=0.002) and PT (73.0%, p=0.001) versus FDS (27.4%).
The ulnar deviation and pronation exercises using elastic band resistance studied targeted and activated the flexor-pronator mass musculature. The ulnar deviation and pronation exercises using elastic band resistance are practical and effective means of training the flexor-pronator mass. These exercises can be readily prescribed to athletes and patients as part of their arm care program.
目的/假设：前臂屈肌 - 旋前圆肌团为内侧肘部提供动态稳定性。对于从事过头运动的运动员来说，训练该肌肉群至关重要，然而，缺乏支持使用训练练习的证据。本研究的目的是测量在使用弹力带进行的两种不同的前臂强化练习过程中，屈肌 - 旋前肌肌肉组织的肌电图（EMG）活动程度。研究假设是这两种练习将至少引发中等程度的肌肉活动，但旋前肌与屈肌的激活情况会有所不同。
材料/方法：纳入10名健康受试者（均为男性，年龄36±12岁）。在优势侧前臂的三块肌肉上测量表面肌电图活动：尺侧腕屈肌（FCU）、指浅屈肌（FDS）和旋前圆肌（PT）。在测量每块肌肉的最大自主收缩（MVC）后，受试者使用弹力带阻力进行腕部尺侧偏斜和前臂旋前练习。阻力设定为引发中等强度的用力（Borg CR10量表上为5/10）。练习顺序随机，每种练习进行3次重复。计算每次练习离心阶段各肌肉重复测量的平均峰值肌电图活动，并表示为MVC的百分比。中等活动水平定义为MVC的21%或更高。如果发现显著交互作用，则使用双向（练习×肌肉）重复测量方差分析及事后成对比较来比较各肌肉的峰值标准化肌电图活动。
存在练习与肌肉的交互作用效应（p<0.001）。尺侧偏斜练习选择性地激活了尺侧腕屈肌（40.3%），而指浅屈肌（19.5%，p = 0.009）和旋前圆肌（21.5%，p = 0.022）的激活程度较低。相反，旋前练习选择性地激活了指浅屈肌（63.8%，p = 0.002）和旋前圆肌（73.0%，p = 0.001），而尺侧腕屈肌的激活程度为27.4%。
所研究的使用弹力带阻力的尺侧偏斜和旋前练习针对性地激活了屈肌 - 旋前肌团肌肉组织。使用弹力带阻力的尺侧偏斜和旋前练习是训练屈肌 - 旋前肌团的实用且有效的方法。这些练习可以很容易地作为手臂护理计划的一部分开给运动员和患者。
