MOBILE WAD

GENERAL INFORMATION

The “mobile wad” refers to a group of three muscles on the forearm’s lateral side. These muscles are involved in wrist extension and radial deviation and play a key role in forearm stability and grip strength. The mobile wad muscles are essential for tasks requiring fine motor control, such as writing, gripping and lifting objects.

ORIGIN

The muscles of the mobile wad originate from the lateral epicondyle of the humerus:

• Brachioradialis: Originates from the lateral supracondylar ridge of the humerus.
• Extensor Carpi Radialis Longus: Originates from the lateral supracondylar ridge of the humerus.
• Extensor Carpi Radialis Brevis: Originates from the lateral epicondyle of the humerus.

INSERTION POINT

The mobile wad muscles insert into various bones of the wrist and hand:

• Brachioradialis: Inserts into the lateral surface of the distal radius, just above the wrist.
• Extensor Carpi Radialis Longus: Inserts into the base of the second metacarpal, allowing wrist extension and radial deviation.
• Extensor Carpi Radialis Brevis: Inserts into the base of the third metacarpal, aiding in wrist extension and radial deviation.

MAJOR ARTERIES

The following arteries supply the mobile wad muscles:

• Radial Artery: Supplies oxygenated blood to the lateral side of the forearm, including the brachioradialis and extensor carpi radialis muscles.
• Posterior Interosseous Artery: Provides blood to the deeper muscles of the posterior forearm, including parts of the extensor carpi radialis.

NEURAL INNERVATION

The mobile wad muscles are innervated by:

• Radial Nerve: Provides motor and sensory innervation to the brachioradialis and extensor carpi radialis muscles, controlling wrist extension and forearm stability.

TRIGGER POINT

Trigger points can develop in the mobile wad muscles, particularly the brachioradialis and extensor carpi radialis, leading to pain in the forearm, wrist and elbow. These trigger points often result from repetitive strain, overuse, or poor posture during activities like typing or gripping.

CONCENTRIC FUNCTION

The mobile wad muscles contract concentrically to produce movements such as:

• Wrist Extension: Extends the wrist, aiding in lifting, pushing and stabilising the hand during various tasks.
• Radial Deviation: Moves the wrist towards the thumb side, helping with side-to-side movements of the hand.
• Forearm Flexion: The brachioradialis assists in flexing the forearm, helping with activities requiring elbow bending.

ECCENTRIC FUNCTION

The mobile wad muscles also play an essential role in controlling movements through eccentric contractions:

• Wrist Flexion Control: Eccentrically controls wrist flexion during the lowering phase of pushing or gripping tasks, preventing over-flexion.
• Radial Deviation Control: Eccentrically slows the movement when the wrist moves toward the ulnar side, maintaining wrist stability.

ISOMETRIC FUNCTION

The mobile wad muscles stabilise the wrist and forearm during static activities:

• Grip Stability: Maintains wrist extension and radial deviation during isometric gripping tasks, such as holding tools or equipment.
• Forearm Stability: The brachioradialis helps stabilise the forearm during static tasks like carrying or lifting objects.

RELATED MUSCLES SCIENTIFIC NAMES

• Brachioradialis: Assists in forearm flexion, contributing to grip strength and stabilising the forearm during dynamic tasks.
• Extensor Carpi Radialis Longus: Extends the wrist and aids in radial deviation, providing stability during wrist movements.
• Extensor Carpi Radialis Brevis: Works with the extensor carpi radialis longus to extend and radially deviate the wrist, offering support during lifting and gripping activities.
• Flexor Carpi Radialis: A synergist in radial deviation, balancing wrist movements with the extensor muscles.
• Extensor Digitorum: Assists in extending the wrist and fingers, complementing the action of the mobile wad muscles.

ANTAGONIST

• Flexor Carpi Ulnaris: Opposes the extensor carpi radialis by flexing and ulnarly deviating the wrist, counteracting wrist extension and radial deviation.
• Pronator Teres: Opposes the brachioradialis by pronating the forearm, working against forearm flexion and supination.
• Flexor Carpi Radialis: Flexes and radially deviates the wrist, acting as a synergist but also opposing wrist extension provided by the extensor carpi radialis muscles.

COMMON INJURIES

• Lateral Epicondylitis (Tennis Elbow): An overuse injury commonly affecting the mobile wad muscles, particularly the extensor carpi radialis brevis, leading to pain and inflammation around the elbow.
• Radial Tunnel Syndrome: Compression of the radial nerve can lead to pain and weakness in the mobile wad muscles, affecting wrist extension and grip strength.
• Extensor Tendonitis: Inflammation of the tendons, particularly in the extensor carpi radialis, caused by repetitive strain, leading to pain in the wrist and forearm.
• Forearm Strain: Overuse of the mobile wad muscles can lead to muscle strain, causing pain and discomfort during wrist extension or gripping.
• Wrist Sprain: Involves overstretching or tearing of ligaments in the wrist, affecting the function of the extensor carpi radialis and brachioradialis.

EXERCISES

• Wrist Extensions: Strengthens the extensor carpi radialis muscles by extending the wrist upward against resistance, improving wrist stability and control.
• Radial Deviations with Resistance: Hold a small weight or resistance band and move the wrist towards the thumb side, strengthening the extensor carpi radialis and improving wrist stability.
• Reverse Wrist Curls: Targets the extensor carpi radialis longus and brevis by curling the wrist upward with resistance, building endurance in the forearm.
• Brachioradialis Curls: Involves curling a dumbbell or resistance band with a neutral grip, strengthening the brachioradialis and improving forearm flexion.
• Grip Strengtheners: Engages the brachioradialis and extensor carpi radialis muscles by squeezing a soft ball or hand grip, improving grip strength and forearm endurance.

STRETCHES

• Wrist Extensor Stretch: Extending the arm and gently pulling the fingers downward, stretching the extensor carpi radialis muscles and relieving tension.
• Forearm Stretch: Involves stretching both the flexor and extensor muscles by extending the wrist in both directions, improving flexibility in the mobile wad muscles.
• Brachioradialis Stretch: Stretch the brachioradialis by extending the forearm and gently rotating the wrist, relieving tightness in the forearm.
• Radial Deviation Stretch: Stretches the mobile wad muscles by pulling the wrist towards the pinky side, relieving tightness and improving range of motion.
• Reverse Wrist Stretch: This is performed by flexing the wrist and pulling it gently with the opposite hand, balancing the tension between the flexor and extensor muscles.