Wrist Extensors- Anatomy and Exercises

Introduction:

The wrist extensor muscles of the hand are located in the back of the forearm and have long tendons connecting them to bones in the hand, where they exert their action.

The wrist extensors includes extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor digitorum (ED), extensor digiti minimi (EDM), extensor carpi ulnaris (ECU) and extensor indicis (EI).

Anatomy:

1. Extensor Carpi Radialis Longus:

Origin:

It originates from lateral supracondylar ridge of humerus.

Insertion:

It inserts on the dorsal surface of the base of the second metacarpal bone.

Nerve Supply:

It is supplied by radial nerve.

Action:

It acts as an extensor of wirst joint and abductor of the hand at the wrist joint.

2. Extensor Carpi Radialis Brevis:

Origin

It originates from the anterior of the lateral epicondyl of the humerus.

Insertion

It inserts on the posterior base of the 3rd metacarpal.

Nerve Supply

It is supplied by deep branch of the radial nerve.

Action

It acts as extensor and abductor of the hand at the wrist joint.

3. Extensor Digitorum:

Origin :

It originates from the lateral epicondyle of the humerus.

Insertion :

It inserts on the extensor expansion of the middle and distal phalanges of 2nd, 3rd, 4th and 5th fingers.

Nerve Supply :

It is supplied by posterior interosseous nerve.

Action :

It extends the hand, wrist and fingers.

4. Extensor Digiti Minimi

Origin :

It originates from the anterior portion of the lateral epicondyle of the humerus.

Insertion :

It inserts on the extensor expansion located at the base of the proximal phalanx of digit V on the dorsal side.

Nerve Supply :

It is supplied by posterior interosseous nerve(C7-C8).

Action :

It acts as extensor of the wrist and the little finger..

5. Extensor Carpi Ulnaris

Origin :

It has 2 heads
Humeral head: It originates from lateral epicondyle of the humerus.
Ulnar head: It originates from the olecranon, posterior surface of ulna, antebrachial fascia.

Insertion :

It inserts on the 5th metacarpal bone.

Nerve Supply :

It is supplied by deep branch of the radial nerve(C7, C8).

Action :

It extends and adducts the wrist.

6. Extensor Indics :

Origin :

It originates from the posterior distal third of ulna and interosseous membrane.

Insertion :

It inserts on the index finger.

Nerve Supply :

It is supplied by posterior interosseous nerve.

Action :

It extends index finger and wrist.

STRETCHING EXERCISE OF WRIST EXTENSORS

1. Forward Wrist stretch :

• Begin with elbow straight.
• With other hand, grasp at thumb side of hand and bend wrist downward.
• To increase the stretch, bend wrist toward small finger.
• Hold end position for 5-10 seconds
• Repeat for 5-6 times

2. Reverse Prayer Stretch :

• Begin backs of hands together in front of body at hip level.
• Slowly bring arms upward.
• Hold end position for 5-10 seconds
• Repeat for 5-6 times

3. Standing Table Stretch :

• Stand at a table with the palms down, fingers flat, and elbows straight.
• Lean the body weight forward.
• Hold this position for 15 seconds.
• Repeat 3 times.

STRENGTHENING EXERCISE OF WRIST EXTENSORS

1. Wrist Circles:

• Sit or stand with the spine erect, shoulders rolled back, and look forward.
• Extend the hands forward at the shoulder level, and fold each palm into a fist.
• Keeping the elbows stationary, turn the wrists to the left, flex them up, turn to the right, and then flex down. Repeat 10 times.
• Reverse the direction and repeat it 10 times.
• 3 sets of 10 reps in each direction

2. Resistance Band Wrist Extensor Exercise :

• Sit on a chair, take a tube resistance band in the right palm, and step on the other end with the right foot.
• Place the right elbow on the right thigh, with the palm facing down.
• This is the starting position. Flex the fist up toward the body.
• Hold this pose for a second.
• Extend the wrist down toward the floor.
• Do this 10 times and then take the resistance band in the left hand and repeat.
• 2 sets of 10 reps with each hand.