Week 10

Question 1

Hand-path kinematics

Answer 1

-velocity profile had a typical “bell” shape
-start, accelerate, peak velocity, decelerate, stop
Time to peak velocity- ballistic stage that depends entirely on the motor command (first half of movement)
Time after peak velocity- sensory feedback used to update and improve movement (second half of movement)

Question 2

Grip size

Answer 2

Distance between thumb and index finger
-Max grip aperture- 70% of movement time
-scaled to object size

Question 3

Grip type

Answer 3

Determined by goal, size, and weight of object
-differ by number of fingers and position of thumb
-fingers usually will move together, but individuation can be learned
-many diff ways of classifying grip type

Question 4

Grip force

Answer 4

Generated by muscles of the hand and fingers
-overarching goal: don’t drop the milk!
-amount of force depends on weight of object