Affiliations: [a] Department of Rehabilitation Medicine, Wonju College of Medicine, Yonsei University, Wonju, Korea | [b] Department of Physical Therapy, College of Medical Sciences, Jeonju University, Jeonju, Korea
Correspondence:
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Corresponding author: Yongwook Kim, Department of Physical Therapy, College of Medical Sciences, Jeonju University, 303 Cheonjam-ro, Wansan-gu, Jeonju, Jeollabuk-do, Republic of Korea. Tel.: +82 63 220 3261; Fax.: +82 63 220 2054; E-mail: [email protected].
Abstract: BACKGROUND:Few studies have reported the contribution of isometric-specific exercise of the biceps brachii muscle to increased strength under manual fixation of the scapula. OBJECTIVE: To investigate the activation amplitude of the biceps brachii (BB), serratus anterior (SA), and upper trapezius (UT) in a supine lying posture based on various exercise conditions. METHODS: The EMG activity of BB, SA, and UT was measured in 25 healthy adults while performing maximal elbow flexion exercise with or without manual stabilization of the scapula in two different loading conditions. RESULTS: Muscle activation of the BB was significantly greater when performed with manual fixation of the scapula under the wrist-loading exercise condition (p< 0.05) but manual fixation of the scapula or absence thereof did not have an effect. Elbow flexion force was significantly increased when applying manual fixation to the scapula in both the hand and wrist-loading exercise conditions (p< 0.05). There were no interaction effects between exercise conditions and manual fixation (with or without) in any of the EMG activation values (p> 0.05). CONCLUSION: Manual stabilization of the scapula is a useful therapeutic technique to increase BB strength. Such an intervention may also be indicated for accurate strength measurement of this muscle.
Keywords: Biceps brachii, manual stabilization, strength training
