TY - JOUR
T1 - Electromyographic analysis of the thumb
T2 - A study of isometric forces in pinch and grasp
AU - Cooney, William P.
AU - An, Kai Nan
AU - Daube, Jasper R.
AU - Askew, Linda J.
N1 - Funding Information:
From the Department of Orthopedics, Mayo Clinic and Mayo Foun-dation, Rochester, Minn. Supported in part by Grant No. 249 from the Orthopedic Research and Education Foundation and by Research Grant AM-17172 from the National Institutes of Health, Public Health Service. Received for publication Nov. 29, 1982; accepted in revised form July 3, 1984. Reprint requests: W. P. Cooney ill, M.D., Mayo Clinic, 200 First St. SW, Rochester, MN 55905.
PY - 1985
Y1 - 1985
N2 - An electromyographic study of thumb muscles was performed on eight subjects by means of integrated polyelectromyography and simultaneous recordings of isometric flexion-extension, abduction-adduction, and prehensile pinch and grasp of the thumb. The integrated electromyographic signal proved to be an excellent index of thumb muscle activity, with a linear relationship found at low to middle levels of muscle strength. To facilitate understanding of thumb function, thumb muscles can be classified as primary or secondary on the basis of electrical potential activity. In isometric flexion, the flexor pollicis longus (FPL) was primary, whereas in extension, the extensor pollicis longus (EPL) and abductor pollicis longus were primary. In adduction, the adductor pollicis and EPL were primary and the FPL was secondary. In abduction, the abductor pollicis brevis and opponens pollicis were primary. The adductor pollicis, opponens pollicis, and FPL were nearly equal during pinch and grasp, with significant electrical activity increasing with greater force requirements. The first dorsal interosseous and EPL contributed secondarily in both pinch and grasp. When surgeons consider tendon transfers for nonfunctioning thumb muscles, the primary muscles should be replaced first to best restore pinch and grasp strength.
AB - An electromyographic study of thumb muscles was performed on eight subjects by means of integrated polyelectromyography and simultaneous recordings of isometric flexion-extension, abduction-adduction, and prehensile pinch and grasp of the thumb. The integrated electromyographic signal proved to be an excellent index of thumb muscle activity, with a linear relationship found at low to middle levels of muscle strength. To facilitate understanding of thumb function, thumb muscles can be classified as primary or secondary on the basis of electrical potential activity. In isometric flexion, the flexor pollicis longus (FPL) was primary, whereas in extension, the extensor pollicis longus (EPL) and abductor pollicis longus were primary. In adduction, the adductor pollicis and EPL were primary and the FPL was secondary. In abduction, the abductor pollicis brevis and opponens pollicis were primary. The adductor pollicis, opponens pollicis, and FPL were nearly equal during pinch and grasp, with significant electrical activity increasing with greater force requirements. The first dorsal interosseous and EPL contributed secondarily in both pinch and grasp. When surgeons consider tendon transfers for nonfunctioning thumb muscles, the primary muscles should be replaced first to best restore pinch and grasp strength.
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U2 - 10.1016/S0363-5023(85)80106-4
DO - 10.1016/S0363-5023(85)80106-4
M3 - Article
C2 - 3980932
AN - SCOPUS:0022303531
VL - 10
SP - 202
EP - 210
JO - Journal of Hand Surgery
JF - Journal of Hand Surgery
SN - 0266-7681
IS - 2
ER -