Anatomical Locations of the Motor Points of the Biceps Brachii and Brachialis Muscles.

, Kim, Joon Sung; , Kwon, Jeong Yi; , Kang, Sae Yoon; , Park, Jung Won

Original Article

Journal of the Korean Academy of Rehabilitation Medicine 2004;28(6):592-595.

Kim, Joon Sung , Kwon, Jeong Yi , Kang, Sae Yoon , Park, Jung Won

Department of Physical Medicine & Rehabilitation, College of Medicine, The Catholic University of Korea, Korea. wonida@hanmail.net

상완 이두근과 상완근의 해부학적 위치

김준성, 권정이, 강세윤, 박정원

가톨릭대학교 의과대학 재활의학교실

Abstract

Objective
To identify the range of the precise locations of the motor points of biceps brachii and brachialis muscles in relation to bony landmarks.
Method
Nine upper limbs of five male cadavers were dissected. The number and location of the motor points from the musculocutaneous nerve to biceps brachii and brachialis muscles were identified in relation to the bony landmarks. Bony landmarks were coracoid process and lateral epicondyle of the humerus. The length of the arm was defined as the distance from the apex of the coracoid process to the lateral epicondyle of humerus. The locations of the motor points were expressed as the percentage ratio ofthe length from the coracoid process to the motor points in relation to the length of the arm.
Results
First proximal motor points of the long head, short head of biceps brachii, and brachialis were located in 47.5⁑5.6%, 53.0⁑4.6%, 64.3⁑3.4% and second proximal points of them were 51.8⁑2.9%, 57.7⁑3.5%, 68.5⁑4.4% respectively.
Conclusion
The identification of the locations of motor points related to the bony landmarks would increase the accuracy and ease of the motor point blocks to elbow flexors such as biceps brachii and brachialis muscles. (J Korean Acad Rehab Med 2004; 28: 592-595)

Key Words: Biceps brachii muscle, Brachialis muscle, Motor point, Bony landmark