Wrist & Hand Muscles

The wrist and hand are very complex parts of the body, with many bones, tendons and muscular structures enabling us  to use them. See more about the muscles in the wrist and hand, their uses, and how to strengthen and stretch them.

Flexor Pollicis Longus

Flexor Pollicis Longus Muscle

The word pollicis refers to the thumb and so the flexor pollicis longus is the long muscle which flexes the thumb!

Origin - Middle anterior surface of the radius.  

Insertion - Base of the distal phalanx of the thumb.  

Actions - Flexion of the thumb.
Flexion of the wrist.

Innervation - Anterior interosseous nerve.  

Daily uses - Gripping something tightly.

Example strengthening exercises - Wrist flexion using a dumbbell.

Example stretches - Wrist flexor stretch.  

Related muscles - Extensor pollicis longus. Flexor digitorum superficialis.

Flexor Digitorum Superficialis

Flexor Digitorum Superficialis Muscle

Flexor Digitorum Superficialis is sometimes also known as Flexor Digitorum Sublimis. It is one of the wrist flexor muscles found in the palm side of the forearm and wrist.

Origin - Medial epicondyle of the humerus.
Medial coronoid process.
Radial tuberosity. 

Insertion - Splits into 4 tendons which insert to the sides of the middle Phalange of the four fingers. 

Actions - Flexion of the wrist.
Flexion of the fingers. 

Innervation - Median nerve. 

Daily uses - Making a fist. 

Example strengthening exercises - Wrist flexion using a dumbbell. 

Example stretches - Wrist flexor stretch.

Related muscles - Flexor carpi ulnaris. Flexor carpi radialis. Flexor pollicis longus.

Flexor Carpi Ulnaris

Flexor Carpi Ulnaris Muscle

Flexor carpi ulnaris is one of the wrist flexor muscles of the front (palmar) aspect of the forearm. It also helps extensor carpi ulnaris to ulnar deviate the wrist.

Origin - Medial epicondyle of the humerus.

Insertion - Base of the 5th metacarpal.
Pisiform and hook of hamate. 

Actions - Flexion of the wrist.
Ulnar deviation (adduction) of the wrist. 

Innervation - Ulnar nerve. 

Daily uses - Pulling rope towards you. 

Example strengthening exercises - Wrist flexion using dumbbells. 

Example stretches - Wrist flexor stretch.

Related injuries - Golfers elbow. 

Related muscles - Flexor carpi radialis. Extensor carpi ulnaris.

Flexor Carpi Radialis

Flexor Carpi Radialis Muscle

Flexor Carpi Radialis crosses the elbow joint and so is also a weak elbow flexor.

Origin - Medial epicondyle of the humerus.

Insertion - Base of the 2nd and 3rd metacarpals.  

Actions - Flexion of the wrist.
Radial deviation of the wrist.  

Innervation - Median nerve.  

Daily uses - Pulling rope towards you.  

Example strengthening exercises - Wrist flexion using a dumbbell.

Example stretches - Wrist flexor stretch.  

Related injuries - Golfers elbow.  

Related muscles - Flexor carpi ulnaris. Flexor digitorum superficialis.

Extensor Pollicis Longus

Extensor Pollicis Longus Muscle

The tendon of Extensor Pollicis Longus can be seen on the radial side of the wrist, at the base of the thumb where it forms the lower border of the 'anatomical snuffbox' a triangular shape between two tendons.

Origin - Upper posterior surface of the ulna.

Insertion - Base of the distal phalanx of the thumb.

Actions - Extension of the wrist.
Extension of the thumb. 

Innervation - Posterior interosseous nerve. 

Daily uses - Releasing your grip on an object. 

Example Strengthening Exercises - Wrist extension using a dumbbell. 

Example Stretches - Wrist extensor stretch. 

Related muscles - Flexor Pollicis Longus.

Extensor Digitorum

Extensor Digitorum Muscle

Extensor Digitorum Communis is sometimes simply referred to as Extensor Digitorum. It is one of the extensor muscles of the wrist, found in the forearm.

Origin - Lateral epicondyle of the humerus.

Insertion - Splits into 4 tendons which insert to the bases of the 2nd and 3rd Phalanges of the four fingers. 

Actions - Extension of the wrist.
Extension of the fingers.

Innervation - Posterior interosseous nerve. 

Daily uses - Pulling the hand back and straightening the fingers to wave. 

Example strengthening exercises - Wrist extension using a dumbbell. 

Example stretches - Wrist extensor stretch. 

Related injuries - Tennis elbow. 

Related muscles - Extensor carpi ulnaris. Extensor carpi radialis brevis. Extensor carpi radialis longus. Extensor pollicis longus.

Extensor Carpi Ulnaris

Extensor Carpi Ulnaris Muscle

Extensor carpi ulnaris is located on the back (dorsum) of the forearm amongst the other wrist extensors. This is the only muscle responsible for ulnar deviation (moving the hand sideways in the direction of the little finger).

Origin - Lateral epicondyle of the humerus

Insertion - Base of the 5th metacarpal (dorsal side).

Actions - Extension of the wrist
Ulnar deviation (adduction) of the wrist.

Innervation - Radial nerve.

Daily uses - Accelerating a motorbike.

Example Strengthening Exercises - Wrist extension with a dumbbell

Examples Stretches - Wrist extensor stretch.

Extensor Carpi Radialis Longus

Extensor Carpi Radialis Longus Muscle

Extensor Carpi Radialis Longus is, as the name suggests, the longer of the two extensor carpi radialis muscles as its origin is the ridge above the lateral epicondyle of the humerus, unlike the other wrist extensors which attach to the epicondyle itself.

Origin - Lateral supracondylar ridge of the humerus.

Insertion - Base of the 2nd metacarpal (dorsal side).  

Actions - Extension of the wrist.
Radial deviation (abduction) of the wrist.

Innervation - Radial nerve.  

Daily uses - Typing.  

Example stretches - Wrist extensor stretch.  

Example strengthening exercise - Wrist extension using a dumbbell. 

Related injuries - Tennis elbow.  

Related muscles - Extensor carpi radialis brevis. Extensor carpi ulnaris.

Extensor Carpi Radialis Brevis

The extensor carpi radialis brevis is important in racket sports and golf which require strong wrist extension (movements where the wrist bends backwards).

Origin - Lateral epicondyle of the humerus.

Insertion - Base of the third metacarpal (back of wrist).

Actions - Extension of the wrist
Abduction of the wrist
Weak extension of the elbow.

Innervation - Radial nerve (c6 and c7).

Daily uses - Gripping things.

Example Strengthening Exercises - Tennis elbow wrist flexion exercises.

Example Stretches - Tennis elbow stretch - the elbow is straightened, forearm pronated or rotated inwards and the palm hand pulled downwards.