TY - JOUR
T1 - In vivo determination of the direction of rotation and moment-angle relationship of individual elbow muscles
AU - Zhang, L.
AU - Butler, J.
AU - Nishida, T.
AU - Nuber, G.
AU - Huang, H.
AU - Rymer, W. Z.
PY - 1998/10
Y1 - 1998/10
N2 - The direction of rotation (DOR) of individual elbow muscles, defined as the direction in which a muscle rotates the forearm relative to the upper arm in three-dimensional space, was studied in vivo as a function of elbow flexion and forearm rotation. Electrical stimulation was used to activate an individual muscle selectively, and the resultant flexion-extension, supination-pronation, and varus-valgus moments were used to determine the DOR. Furthermore, multi-axis moment-angle relationships of individual muscles were determined by stimulating the muscle at a constant submaximal level across different joint positions, which was assumed to result in a constant level of muscle activation. The muscles generate significant moments about axes other than flexion-extension, which is potentially important for actively controlling joint movement and maintaining stability about all axes. Both the muscle DOR and the multi axis moments vary with the joint position systematically. Variations of the DOR and moment-angle relationship across muscle twitches of different amplitudes in a subject were small, while there were considerable variations between subjects.
AB - The direction of rotation (DOR) of individual elbow muscles, defined as the direction in which a muscle rotates the forearm relative to the upper arm in three-dimensional space, was studied in vivo as a function of elbow flexion and forearm rotation. Electrical stimulation was used to activate an individual muscle selectively, and the resultant flexion-extension, supination-pronation, and varus-valgus moments were used to determine the DOR. Furthermore, multi-axis moment-angle relationships of individual muscles were determined by stimulating the muscle at a constant submaximal level across different joint positions, which was assumed to result in a constant level of muscle activation. The muscles generate significant moments about axes other than flexion-extension, which is potentially important for actively controlling joint movement and maintaining stability about all axes. Both the muscle DOR and the multi axis moments vary with the joint position systematically. Variations of the DOR and moment-angle relationship across muscle twitches of different amplitudes in a subject were small, while there were considerable variations between subjects.
UR - http://www.scopus.com/inward/record.url?scp=0032190227&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032190227&partnerID=8YFLogxK
U2 - 10.1115/1.2834754
DO - 10.1115/1.2834754
M3 - Article
C2 - 10412441
AN - SCOPUS:0032190227
SN - 0148-0731
VL - 120
SP - 625
EP - 633
JO - Journal of Biomechanical Engineering
JF - Journal of Biomechanical Engineering
IS - 5
ER -