Relevant Hand Anatomy

The hand anatomy includes three parts

• wrist or carpus
• palm or metacarpus
• fingers or phalanges

To know about the anatomy of the carpus click here.

To know about the anatomy of the fingers click here.

On this page we will know about the metacarpus.

The metacarpus consists of 5 bones called the metacarpal bones. Each metacarpal bone consists of three parts

• base that articulates with the bones of the wrist forming the wrist joint
• a middle portion called the shaft
• a head that articulates with the corresponding finger forming the metacarpo-phalangeal joint

The metacarpal bones are numbered 1 to 5 starting from the thumb to the little finger respectively.

These bones provide attachment to the palmar and dorsal interossei muscles that are responsible for side to side movement of the fingers.

Towards the little finger are a group of muscles that from a prominence on the palm called the hypothenar eminence (mount of moon). These muscles are

• palmaris brevis is a small muscle located below the skin whose function is to enhance the wrinkles on the palm improving grip
• abductor digiti minimi moves the little finger outwards
• flexor digiti minimi brevis flexes the little finger at the metacarpo-phalangeal joint
• opponens digiti minimi flexes the little finger at the metacarpo-phalangeal joint and rotates it laterally so as to deepen the hollow of the palm and bringing the little finger opposite to the thumb

Towards the thumb are a group of muscles that from a prominence on the palm called the thenar eminence (mount of venus). These muscles are

• abductor pollicis brevis is a thin muscle located below the skin whose function is to bring the thumb at 90 degrees to the palm
• adductor pollicis moves the thumb close to the thumb and is very useful in gripping (holding a motorcycle handle)
• flexor pollicis brevis flexes the thumb at the metacarpo-phalangeal joint
• opponens pollicis flexes the thumb at the metacarpo-phalangeal joint and rotates it medially so as to deepen the hollow of the palm and bringing the thumb towards the little finger

The lumbrical muscles are 4 muscles that arise from the tendon of flexor digitorum profundus muscle which is responsible for flexing the distal inter-phalangeal joint. The lumbrical muscles attach to the extensor expansion. Hence they are the only muscle to join a flexor tendon to a extensor tendon. Function of these muscles is to extend the inter-phalangeal joints.

At the back of the hand are the tendons of the extensor digitorum muscle that is responsible for extension of the fingers at all their joints.

I hope the information provided was helpful. If you have any query about hand anatomy you can ask me at the contact me page.

This page was last updated on 6th February 2009.

Hand anatomy includes wrist and fingers. So look at the folowing pages...

Finger Anatomy

Wrist Anatomy

Other causes of hand pain...

Rolando Fracture

Bennett Fracture

Hand Infection

Dupuyteren Contracture

Compartment Syndrome

Hand Injury

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