Modulation of grasping forces during object transport.

Subjects held an instrumented object in a tripod grasp and moved it in the horizontal plane in various directions. The contact forces at the digits were measured and the grip force was decomposed into 2 components: a manipulating force responsible for accelerating the object and a grasping force responsible for holding the object steady. The grasping forces increased during the movement, reaching a peak near the time of peak velocity. The grasping forces also exhibited directional tuning, but this tuning was idiosyncratic for each subject. Although the overall grip forces should be modulated with acceleration, the load force did not vary during the task. Therefore the increase in the grasping force is not required to prevent slip. Rather, it is suggested that grasping force increases during translational motion to stabilize the orientation of grasped objects.

[1]  M. Arbib.  Coordinated control programs for movements of the hand , 1985 .

[2]  Kiyoshi Nagai,et al.  Analysis of multi-fingered grasping and manipulation , 1990 .

[3]  Christine L. MacKenzie,et al.  Opposition space and human prehension , 1990 .

[4]  Tsuneo Yoshikawa,et al.  Manipulating and grasping forces in manipulation by multifingered robot hands , 1987, IEEE Trans. Robotics Autom..

[5]  K. J. Cole,et al.  Sensory-motor coordination during grasping and manipulative actions , 1992, Current Biology.

[6]  J. Flanagan,et al.  Coupling of grip force and load force during arm movements with grasped objects , 1993, Neuroscience Letters.

[7]  J R Flanagan,et al.  The Role of Internal Models in Motion Planning and Control: Evidence from Grip Force Adjustments during Movements of Hand-Held Loads , 1997, The Journal of Neuroscience.

[8]  K. J. Cole,et al.  Wrist action affects precision grip force. , 1997, Journal of neurophysiology.

[9]  R S Johansson,et al.  Sensory input and control of grip. , 1998, Novartis Foundation symposium.

[10]  R. Johansson,et al.  Control of Grip Force When Tilting Objects: Effect of Curvature of Grasped Surfaces and Applied Tangential Torque , 1998, The Journal of Neuroscience.

[11]  Mitsuo Kawato,et al.  Internal models for motor control and trajectory planning , 1999, Current Opinion in Neurobiology.

[12]  R S Johansson,et al.  Control of fingertip forces in multidigit manipulation. , 1999, Journal of neurophysiology.

[13]  J. F. Soechting,et al.  Factors influencing variability in load forces in a tripod grasp , 2002, Experimental Brain Research.

[14]  J. F. Soechting,et al.  Two virtual fingers in the control of the tripod grasp. , 2001, Journal of neurophysiology.

[15]  R. Johansson,et al.  Encoding of Direction of Fingertip Forces by Human Tactile Afferents , 2001, The Journal of Neuroscience.

[16]  Andrew M. Gordon,et al.  Coordination of fingertip forces in object transport during locomotion , 2003, Experimental Brain Research.

[17]  R. Johansson,et al.  Coordinated isometric muscle commands adequately and erroneously programmed for the weight during lifting task with precision grip , 2004, Experimental Brain Research.

[18]  R. Johansson,et al.  Somatosensory control of precision grip during unpredictable pulling loads , 1992, Experimental Brain Research.

[19]  R. Johansson,et al.  Visual size cues in the programming of manipulative forces during precision grip , 2004, Experimental Brain Research.

[20]  R. Johansson,et al.  Programmed and triggered actions to rapid load changes during precision grip , 2004, Experimental Brain Research.

[21]  M. T. Wallace,et al.  Visual, auditory and somatosensory convergence in output neurons of the cat superior colliculus: multisensory properties of the tecto-reticulo-spinal projection , 2005, Experimental Brain Research.