TY - JOUR
T1 - Moment arms of the arm muscles at the glenohumeral joint using the tendon excursion method
AU - Itoi, Eiji
AU - Lee, Seok Beom
AU - Berglund, Lawrence J.
AU - Schultz, Fredrick M.
AU - Neale, Patricia G.
AU - An, Kai Nan
N1 - Funding Information:
This study was partly supported by the Mayo Foundation Research Grant 1543-E-97.
PY - 2008
Y1 - 2008
N2 - Muscle moment arm defines the function of the muscle. To date, moment arms of the arm muscles at the glenohumeral joint using the tendon excursion method have not been reported. As the functions of these muscles at the shoulder joint are controversial, this study was undertaken to determine the moment arms of the long and short heads of the biceps (LHB, SHB), the coracobrachialis, and the long head of the triceps muscles. The moment arms were determined in 10 cadaveric shoulders by measuring the tendon excursion when the arm was rotated by 1 radian (57.3°) in 22 different motions. The LHB was a flexor, horizontal flexor, and abductor. The SHB and coracobrachialis were flexors, horizontal flexors, and adductors. The long head of the triceps was an extensor and adductor. Arm rotation significantly affected the function of the LHB only: it was an internal rotator in flexion and an external rotator in abduction. This study clarifies the individual function of the arm muscles at the glenohumeral joint.
AB - Muscle moment arm defines the function of the muscle. To date, moment arms of the arm muscles at the glenohumeral joint using the tendon excursion method have not been reported. As the functions of these muscles at the shoulder joint are controversial, this study was undertaken to determine the moment arms of the long and short heads of the biceps (LHB, SHB), the coracobrachialis, and the long head of the triceps muscles. The moment arms were determined in 10 cadaveric shoulders by measuring the tendon excursion when the arm was rotated by 1 radian (57.3°) in 22 different motions. The LHB was a flexor, horizontal flexor, and abductor. The SHB and coracobrachialis were flexors, horizontal flexors, and adductors. The long head of the triceps was an extensor and adductor. Arm rotation significantly affected the function of the LHB only: it was an internal rotator in flexion and an external rotator in abduction. This study clarifies the individual function of the arm muscles at the glenohumeral joint.
KW - Biceps brachii
KW - Muscle function
KW - Shoulder biomechanics
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U2 - 10.1142/S0218957708001973
DO - 10.1142/S0218957708001973
M3 - Article
AN - SCOPUS:52949084713
SN - 0218-9577
VL - 11
SP - 45
EP - 53
JO - Journal of Musculoskeletal Research
JF - Journal of Musculoskeletal Research
IS - 2
ER -