There are five main types of grasp that the thumb performs: cylindrical grasp, tip pinch,
palmar grasp, spherical grasp, and lateral pinch.
We're all born with the primitive
palmar grasp reflex.
In a study by De Renzi and Barbieri [14], the
palmar grasp reflex was elicited in 21 (66%) of 32 patients with a medial frontal lesion and in 8 (26%) of 30 patients with a lateral frontal lesion.
The crawling, stepping, Moro's, rooting, startle, sucking, and
palmar grasp reflex noted.
The palmar grasp provides the opposition of the palm and the thumb and allows holding bigger and heavier objects such as cans and bottles.
FES pattern activated for the desired grasp was predetermined according to the detected SSVEP (e.g., FES: for palmar grasp as a result of [SSVEP.sub.1]/[f.sub.1]).
The device electrically activates paralyzed muscles by using electrodes that are either implanted within or sutured to the muscles in the hand and the forearm to provide two types of grasping patterns: a
palmar grasp and a lateral pinch.
Four items demonstrated poor reliability: Passive Shoulder Elevation (0.58) and the Reflex section, which includes
Palmar Grasp (0.49), Plantar Grasp (0.67), and Vertical Suspension (0.41).
At 32 weeks, the
palmar grasp should be mostly complete.
This reaction, known as the
palmar grasp reflex, is a throwback to hairier times when babies of our predecessors would have clung to their mothers by gripping on to their body fur.