Muscles
Intrinsic muscle responsible for abduction of 2nd MP
1st dorsal interosseus
This nerve is responsible for wrist extensors
Radial nerve
An injury to the median nerve requires it
HO with opponens bar
MCP 2 & 3 extension stop
IP extension assist
Distal trimline for the opponens bar
Just proximal to the 1st MP joint
This level of SCI requires only a hand orthosis
C8/T1
Muscles of the thenar eminence
Abductor pollicis brevis, opponens pollicis, flexor pollicis brevis
This nerve is responsible for thumb opposition
Median Nerve
Made from polyester resin and fiberglass
TIRR
MP stop terminates here to maximize lever arm
Just proximal to IP joints
Recommended for C5 SCI
Ratchet wrist driven
Cable driven
External power
Mobile arm support
3 motions the 4th lumbrical performs
MP Flexion, IP extension
Flexor carpi ulnaris
These components are needed to aid in finger extension
Finger Loops
Spring wire
Spring attachment bar
Finger loops should be placed here to allow distal phalanges to be free
Middle phalange
Stanmore Flail Arm Orthosis is recommended for this condition
The insertion of the flexor digitorum superficialis
Base of middle phalanges of digits 2-5
Aids in radial deviation of the wrist
Flexor Carpi Radialis
The MP stop/IP assist is removable to help this
Donning and doffing clothing
Width of MP stop
150% coronal diameter of MP 2-5
Hand Orthosis with MCP 4 & 5 Extension Stop and IP Extension Assist are recommended for this condition
Ulnar nerve lesion @ wrist
3 deep muscles of the anterior forearm
flexor pollicis longus
flexor digitorum profundus
pronator quadratus
Overuse of these two motions cause medial epicondolyitis
Wrist flexion
Forearm pronation
Self-suspending orthosis
IRM
Landmark for proximal trimline of WHO
Bicipital crease
These components are needed for median nerve lesion @ wrist
HO with opponens bar
MCP 2 & 3 extension stop
IP extension assist