Thumb Extension

Electrode Placement
Application Instruction by Dr. Lucinda Baker

Electrode placement for isolated thumb extension. The very small negative electrode is placed about two thirds of the way down the forearm over the extensor surface. The positive electrode is over the extensor tendons.

Thumb Extension

Video Instruction
Audio Transcript:

Electrode placement for isolated thumb extension. The very small negative electrode is placed about two thirds of the way down the forearm over the extensor surface. The positive electrode is over the extensor tendons.

Stimulation results in isolated thumb extension, which would be graded three out of five in a muscle grade.

Thumb Extension

Muscle Anatomy

Muscles involved in thumb extension:

Extensor Pollicis Longus
Origin: Middle third of posterior surface of ulna, interosseous membrane
Insertion: thumb, distal phalanx

Thumb Extension

Nerve Anatomy

Nerves involved in thumb extension:

Extensor Pollicis Longus
Nerve innervation: innervated by the posterior interosseous nerve which is a continuation of the deep branch of the radial nerve after it passes through the supinator muscle
Nerve root: C7, C8