Chapter 2. Prehension

478 THE GRASPING HAND
Screwdriver, as grasped object, 4-6, 5f, 3 1, and neural network, 398
151-52
prehensile postures, 32f
Screwing object, as dynamic hand movement, and virtual fingers, 34f. 35,377
272t
Silk, as grasped object, 247,249,250f
Secondary dermal papiuae, 209
Simulation techniques, use of, 10
Security, as grasp attribute, 25
Size, of object
Segmental dermatome mapping, of upper limb, and central vision, 179,184
365f
and force applicatim, 263
SELSPOT system, for tracking movements, 123 and grasp type, 51,52f, 53,169, 173
Semiotic constraints on grasping, 3 16
and grasping, 58,59,142,154
Sensorimotor adjustments
and kinematic landmarks, 154
in deceleration phase, 147-48
and maximum aperture, 152
in perturbation studies, 157, 158
and pad o sition, 168f. 169-71,17Of,
Sensorimotor level, of mapping, 32Of, 322,
172f,T4
34Of, 341
and palm opposition, 168f. 169-71, 17Of,
Sensorimotor system, and stable grasp, 204
172f. 373
Sensory consequences, 69
and peak aperture. 169, 17Cf
Sensory information
as perceived by neural networks, 86
and grasping, 333
and peripheral vision, 179
as guide for arm, 199
in perhxbation studies, 163,165-67, 167
and hand, 279
and timing of hand closure, 152-53
lack of, and size of peak aperture, 189
and transport component, 154
in motor control of movements, 201,267f, and visual perception, 76-77
268
Skeletal structure, of the upper limb, 351
and object properties, 23 1-34, 233
skin
and phases of prehension, 60
characteristics of, for establishing
and preshaping, 178
stable grasp, 279
restricted, effects of, 178-88
constraints on grasping, 309-10, 313-14
in robotics, 274
dorsal, 208
use by CNS during prehension, 58-59,
elasticity of, 210
228-29
and friction, 209-10,211,212f, 220
Sensory motor contingencies, 69n
layers, 206-9.208f
Sensory systems, of brain, 71f, 73f
load, and deformation, 210
Sequential Network, 132f, 133, 135,136f
mechanical properties of, 210,213-14,
Sequential patterns (of manipulative
222
movement), 27.28
mechanoreceptors, 112,209-10,222-26,
Shape, of object. See also Preshape Schema
223f, 225f
and pad opposition, 261-62,374
as organ, 205-14
and palm opposition, 373
palmar, 208
perception of, 231,232,2331,234
replacement rate, 213
m perturbation studies, 162-63, 165
and stable grasp, 205
and timing of hand closure, 152-53
and stress and strain, 21 1
Shearing force, and object size, 263
surface texture arameters, 213
Shearing velocities, and sweating, 220
and sweating, 2flf, 297f
'Sherry glass response', 57-58, 157,317
viscoelasticity of, 210-11.213
Shoulder
Sliding contacts, 269,272t
degrees of freedom, 354t
slips
innervation, 36%
and cone of friction, 276,278
movement, 357f, 358
and perturbations, 25841
muscles, 361t
resistance to, as analytic measure of
Side opposition. see also Opposition;
grasp, 265,268t
Opposition space; Pad opposition;
slip ratio, 251f, 252,260
Palm oppiclon
and stable grasp, 243
and classification of hand movements,
Snap grasp, 18f
19t, 270,271,371t. 372f
Socio-cultural constraints, on grasping,
and combined grasps, 377,378t
308t, 3 16, 324
definition, 31,32f, 34f, 336,373,375
Soft fingers
and force a lication, 41,239,262,263f
and contact, 236f. 237
grasp, 35,3?44
definition, 237-38,238f
and grasp types. 375-76
and stable grasp, 245-47
(Letters after page numbers: f=figure; n=footnote; t-table.)