אימונים Surface Electromyographic Activation Patterns and Elbow Joint Motion During a Pull-Up

[Mike Bikov]

J Strength Cond Res. 2010 Nov 9. [Epub ahead of print]
Surface Electromyographic Activation Patterns and Elbow Joint Motion During a Pull-Up, Chin-Up, or Perfect-Pullup™ Rotational Exercise.

Youdas JW, Amundson CL, Cicero KS, Hahn JJ, Harezlak DT, Hollman JH.

Program in Physical Therapy, Mayo Clinic, Rochester, Minnesota.
Abstract

Youdas, JW, Amundson, CL, Cicero, KS, Hahn, JJ, Harezlak, DT, and Hollman, JH. Surface electromyographic activation patterns and elbow joint motion during a pull-up, chin-up, or Perfect-Pullup™ rotational exercise. J Strength Cond Res 24(12): 3404-3414, 2010-This study compared a conventional pull-up and chin-up with a rotational exercise using Perfect·Pullup™ twisting handles. Twenty-one men (24.9 ± 2.4 years) and 4 women (23.5 ± 1 years) volunteered to participate. Electromyographic (EMG) signals were collected with DE-3.1 double-differential surface electrodes at a sampling frequency of 1,000 Hz. The EMG signals were normalized to peak activity in the maximum voluntary isometric contraction (MVIC) trial and expressed as a percentage. Motion analysis data of the elbow were obtained using Vicon Nexus software. One-factor repeated measures analysis of variance examined the muscle activation patterns and kinematic differences between the 3 pull-up exercises. Average EMG muscle activation values (%MVIC) were as follows: latissimus dorsi (117-130%), biceps brachii (78-96%), infraspinatus (71-79%), lower trapezius (45-56%), pectoralis major (44-57%), erector spinae (39-41%), and external oblique (31-35%). The pectoralis major and biceps brachii had significantly higher EMG activation during the chin-up than during the pull-up, whereas the lower trapezius was significantly more active during the pull-up. No differences were detected between the Perfect·Pullup™ with twisting handles and the conventional pull-up and chin-up exercises. The mean absolute elbow joint range of motion was 93.4 ± 14.6°, 100.6 ± 14.5°, and 99.8 ± 11.7° for the pull-up, chin-up, and rotational exercise using the Perfect·Pullup™ twisting handles, respectively. For each exercise condition, the timing of peak muscle activation was expressed as a percentage of the complete pull-up cycle. A general pattern of sequential activation occurred suggesting that pull-ups and chin-ups were initiated by the lower trapezius and pectoralis major and completed with biceps brachii and latissimus dorsi recruitment. The Perfect·Pullup™ rotational device does not appear to enhance muscular recruitment when compared to the conventional pull-up or chin-up.

PMID: 21068680 [PubMed - as supplied by publisher]​

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