Paper

Electromyographic study of the m. biceps brachii in movements at the glenohumeral joint
José Furlani

Department of Anatomy of the Instituto de Ciências Biomédicas, University of São Paulo, São Paulo, Brazil

Address of Corresponding Author

Acta Anatomica 1976;96:270-284 (DOI: 10.1159/000144679)

  Key words

• Electromyography
• Muscle
• Biceps brachii
• Glenohumeral joint

  Abstract

Our electromyographic studies on the participation of the m. biceps brachii in the movements of the glenohumeral joint, performed in 30 young adult male volunteers, permit the following conclusions: (1) In the movement of arm flexion, performed against resistance and with extended elbow, both the long and the short heads of the m. biceps brachii were active in all 30 volunteers examined. (2) The same movement of the arm, arm flexion with extended elbow, now without resistance, that is to say performed freely, showed both the long and short heads of the m. biceps brachii active in the majority of cases. (3) In the movements of arm extension, performed freely and against resistance, with extended elbow, and also in the movement of lateral arm rotation with flexed elbow, with and without resistance, the m. biceps brachii was absolutely inactive in all 30 volunteers examined. (4) In the movement of arm abduction, with extended elbow, the element of resistance to the performance showed itself to be important, since without it the m. biceps brachii was absolutely inactive; in the movement performed against resistance both heads of the muscle showed activity in 3 out of the 30 volunteers tested. (5) In the movements of arm abduction with and without resistance, with flexed elbow, the m. biceps brachii was active on occasion. (6) In the movements of arm adduction against resistance, with the elbow either flexed or extended, it was only the short head of the m. biceps brachii which was active, and this in half of the cases examined. (7) In the movements of medical rotation of the arm, with extended elbow, performed freely or against resistance, the long and the short heads of the m. biceps brachii each showed a different behaviour: the long head was always inactive, whereas the short one was seldom active.

Copyright © 1976 S. Karger AG, Basel

  Author Contacts

Prof. José Furlani, Departamento de Anatomia do Instituto de Ciências Biomédicas, Universidade de São Paulo, Caixa Postal 2921, Capital, São Paulo (Brazil)

  Article Information

Received: August 5, 1975
Published online: July 09, 2008
Number of Print Pages : 15