TY - JOUR
T1 - The effects of instruction and hand dominance on grip-to-load force coordination in manipulation tasks
AU - Jin, Xin
AU - Uygur, Mehmet
AU - Getchell, Nancy
AU - Hall, Susan J.
AU - Jaric, Slobodan
N1 - Funding Information:
The study was supported in part by grant from the Serbian Research Fund (# 145 082 ) to S. Jaric.
PY - 2011/10/31
Y1 - 2011/10/31
N2 - The force applied upon a vertically oriented hand-held object could be decomposed into two orthogonal and highly coordinated components: the grip force (GF; the component perpendicular to the hand-object contact area that provides friction) and the load force (LF; the parallel component that can move the object or support the body). The aim of this study was to investigate the underexplored effects of task instruction and hand dominance on GF-LF coordination. Sixteen right-handed subjects performed bimanual manipulation against a horizontally oriented instrumented device under different sets of instructions. The tasks involved exertion of ramp-and-hold or oscillation patterns of LF performed symmetrically with two hands, while the instructions regarding individual actions were either similar (pull with both hands) or dissimilar (pull with one hand and hold with another). The results revealed that the instruction " to pull" leads to higher indices of GF-LF coordination than the instruction " to hold" , as evidenced by a lower GF-LF ratio, higher GF-LF coupling, and higher GF modulation. The only effect of hand dominance was a moderate time lag of GF relative to LF changes observed in the non-dominant hand. We conclude that the instructions could play an important role in GF-LF coordination and, therefore, they should be taken into account when exploring or routinely testing hand function. Additionally, the results suggest that the neural control of GF of the non-dominant hand could involve some feedback mechanisms.
AB - The force applied upon a vertically oriented hand-held object could be decomposed into two orthogonal and highly coordinated components: the grip force (GF; the component perpendicular to the hand-object contact area that provides friction) and the load force (LF; the parallel component that can move the object or support the body). The aim of this study was to investigate the underexplored effects of task instruction and hand dominance on GF-LF coordination. Sixteen right-handed subjects performed bimanual manipulation against a horizontally oriented instrumented device under different sets of instructions. The tasks involved exertion of ramp-and-hold or oscillation patterns of LF performed symmetrically with two hands, while the instructions regarding individual actions were either similar (pull with both hands) or dissimilar (pull with one hand and hold with another). The results revealed that the instruction " to pull" leads to higher indices of GF-LF coordination than the instruction " to hold" , as evidenced by a lower GF-LF ratio, higher GF-LF coupling, and higher GF modulation. The only effect of hand dominance was a moderate time lag of GF relative to LF changes observed in the non-dominant hand. We conclude that the instructions could play an important role in GF-LF coordination and, therefore, they should be taken into account when exploring or routinely testing hand function. Additionally, the results suggest that the neural control of GF of the non-dominant hand could involve some feedback mechanisms.
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U2 - 10.1016/j.neulet.2011.09.059
DO - 10.1016/j.neulet.2011.09.059
M3 - Article
C2 - 21982808
AN - SCOPUS:82455162504
SN - 0304-3940
VL - 504
SP - 330
EP - 335
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 3
ER -