Strict actions of the human wrist flexors: A study with an electrical neuromuscular stimulation method.
In order to elucidate strict actions of the human wrist flexors, motion and force produced by electrical neuromuscular stimulation (ENS) to each of musculus (m.) flexsor carpi radialis (FCR) and m. flexsor carpi ulnaris (FCU) with the prone, semiprone, and supine forearm were studied in ten healthy human subjects. Abduction, extension, adduction, and flexion directions were represented by, respectively, 0°, 90°, 180°, and 270°. ENS to FCR and FCU produced motion in direction of, respectively, 273° (mean) and 265° with the prone, 249° and 232° with the semiprone, and 242° and 229° with the supine forearm to the maximal range. Direction/strength (Nm) of force by ENS to FCR and FCU were, respectively, 298°/1.16 and 239°/1.70 with the prone, 279°/1.30 and 241°/1.62 with the semiprone, and 267°/1.24 and 227°/2.04 with the supine forearm. ENS to FCR exhibited force of 20-29% of maximal flexion and 7-15% of maximal abduction or 1-4% of maximal adduction and that to FCU force of 24-28% of maximal flexion and 15-25% of maximal adduction. The force study results suggest that FCU is a flexor rather than an adductor with every forearm position. FCR should be a flexor rather than an abductor with the prone and semiprone and a flexor with the supine forearm. The action of FCR as the abductor should diminish with supinating the forearm.
Department of Orthopaedic Surgery, Yamagata University School of Medicine, Yamagata, Japan.
Aya
A
Narita
Sagae Orthopedic Clinic, Yamagata, Japan.
Masaaki
M
Sagae
Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.
Katsuhiko
K
Suzuki
Department of Occupational Therapy, Sendai Rehabilitation College, Miyagi, Japan.
Takaaki
T
Fujita
Department of Occupational Therapy, Niigata University of Health and Welfare, Niigata, Japan.
Tasuku
T
Sotokawa
Department of Rehabilitation Medicine, Osaka Medical College, Osaka, Japan.
Haruki
H
Nakano
Department of Physical Therapy, Yamagata College of Medical Arts Sciences, Yamagata, Japan.
Makoto
M
Naganuma
Department of Occupational Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.
Toshiaki
T
Sato
Department of Occupational Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.
Hiromi
H
Fujii
Department of Anatomy and Structural Sciences, Yamagata University School of Medicine, Yamagata, Japan.
Mitsuhiro
M
Nito
Department of Anatomy and Structural Sciences, Yamagata University School of Medicine, Yamagata, Japan.
Wataru
W
Hashizume
Department of Orthopaedic Surgery, Yamagata University School of Medicine, Yamagata, Japan.
Toshihiko
T
Ogino
Department of Anatomy and Structural Sciences, Yamagata University School of Medicine, Yamagata, Japan.
Akira
A
Naito
D000328:Adult; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D005542:Forearm / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D016059:Range of Motion, Articular / Q000502:physiology*; D014953:Wrist / Q000502:physiology*; D014955:Wrist Joint / Q000502:physiology*; D055815:Young Adult
Electrical neuromuscular stimulation; Force; Humans; Motion; Wrist flexor muscles