Mobile Wad

What is Mobile Wad

The mobile wad of Henry, commonly known as the mobile wad, is a group of 3 extensor muscles in the forearm. It is usually considered a part of the forearm’s posterior compartment, while some consider it to form a third, lateral compartment of the forearm. 

All 3 muscles in this group are extensors of the hand and wrist. Based on their location and function, other names for the group include the wad of three and the radial group of muscles.

Muscles in the Mobile Wad of Henry & Their Functions

All these muscles originate from the distal side of the humerus and travel down the entire length of the forearm to reach their respective insertion sites.

Name of Muscle	Origin	Insertion	Action
Brachioradialis	Lateral supracondylar ridge of the humerus	Styloid process of the radius	Flexion of the forearm at the elbow
Extensor Carpi Radialis Longus	Lateral supracondylar ridge of the humerus	2nd metacarpal base	Extension and abduction of the hand at the wrist; Flexing the elbow (minor)
Extensor Carpi Radialis Brevis	Lateral epicondyle of the humerus (common extensor tendon)	3rd metacarpal base	Extension and abduction of the hand at the wrist

Interestingly, despite being a part of the posterior compartment and the mobile wad, where all the other muscles work as extensors of the forearm and wrist, the brachioradialis’s primary function is flexing the forearm. In fact, it is one of the primary forearm flexors.

Apart from the above actions, these muscles also help the other posterior forearm muscles in their functions, including stabilizing the elbow (brachioradialis) and strengthening the hand grip (extensor carpi radialis longus and brevis).