The mobile wad (or mobile wad of Henry) is a group of the following three muscles found in the lateral compartment of the forearm:
[Baek 2004, pp 508–509]
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brachioradialis
The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by ...
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extensor carpi radialis brevis
In human anatomy, extensor carpi radialis brevis is a muscle in the forearm that acts to extend and abduct the wrist. It is shorter and thicker than its namesake extensor carpi radialis longus which can be found above the proximal end of the exten ...
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extensor carpi radialis longus
It is also sometimes known as the "wad of three",
[Biel 2019, p138] "lateral compartment",
[DuParc 2003, 55–030–A-10] or "radial group"
[Platzer 2004, p 164] of the forearm.
Function
These three muscles act as flexors at the elbow joint.
[Note: The extensor carpi muscles are so named because they extend at the ]carpus
In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal ...
, not at the elbow.
The extensor carpi radialis brevis and longus are both weak flexors at the elbow joint. Brevis moves the arm from ulnar abduction to its mid-position and flexes dorsally. Longus is a weak pronator in the flexed arm and a supinator in the outstretched arm. At the carpal joints longus acts in dorsiflexion with the
extensor carpi ulnaris
In human anatomy, the extensor carpi ulnaris is a skeletal muscle located on the ulnar side of the forearm. The extensor carpi ulnaris acts to extend and adduct at the carpus/wrist from anatomical position.
Being an extensor muscle, extensor carp ...
and in radial abduction with the
flexor carpi radialis
In anatomy, flexor carpi radialis is a muscle of the human forearm that acts to flex and (radially) abduct the hand. The Latin ''carpus'' means wrist; hence flexor carpi is a flexor of the wrist.
Origin and insertion
The flexor carpi radialis is ...
. These two muscles are called "fist clenchers" because they must be slightly flexed dorsally during clenching to permit maximal flexion.
Brachoradialis is inserted distally on the radius end therefore, unlike the previous two muscles, only acts on the forearm. It brings the forearm into midposition between supination and pronation, and in this position it acts as a flexor. In slow movements and in the supinated forearm it has a minimal flexor action.
Notes
References
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External links
Description at orthopaediccare.net
{{Muscles of upper limb
Muscles of the upper limb