Bones of the Forearm & Hand

Supinator muscle

Binds to the proximal part of the ulna at the interosseus membrane

Trapezoid

Bone of the wrist that is medial to the trapezium and lateral to the capitate. It is also distal to the scaphoid and proximal to the second metacarpal.

Scaphoid

Bone that articulates with radius and forms floor of anatomical snuffbox. Also articulates with the Trapezium, Trapezoid Capitate, and Lunate bones. Most commonly fractured bone (by falling on extended hand)

Hamate

Bone that articulates with triquetral, lunate, and capitate bones on its proximal end and with the fourth and fifth metacarpal on its distal end. This bone is commonly fractured especially amongst amateur golfers.

Triquetral

Bone that is directly medial to lunate bone. It also articulates with the cartilage (ligament) that connects the wrist bones to the ulnar head. The triquetral is one of the more commonly fractured carpal bones.

Pisiform

Bone that is embedded in the tendon of the flexor carpi ulnaris muscle and increases the movement of the arm by allowing the tendon of this muscle to move over it. Is placed directly ventrally to triquetral bone.

Lunate carpal

Bone that is in between Scaphoid & Triquetral bones. Forms articular surface with scaphoid to articulate with the radius bone. It is a commonly dislocated carpal bone.

Trapezium

Bone that lies on radial side of the hand & articulates with the scaphoid on the proximal end and the first metacarpal (of the thumb) on it's distal end. Forms a saddle-looking joint with both articulations.

Ulna

Bone that's on the pinky side. Articulates with the triquetrum, lunate and scaphoid bones at the carpal articular surface.

Ulnar Styloid process

Bottom connection of Ulna -> ulnar collatoral ligament attaches

Radial Styloid Process

Cone-like surface that borders the carpal bones laterally

Medial carpal articular surface

Connects the radius of the forarm and the lunate bone of the wrist.

Lateral carpal articular surface

Connects the radius of the forearm and the scaphoid bone of the wrist.

Sesamoid bones

Develop in certain tendons and are found where tendons cross the ends of long bones in the limbs; they protect the tendons from excessive wear and often change the angle of the tendons as they pass to their attachments. (clincially oriented anatomy, P. 21)

First distal phalanx

Distal phalanx of the thumb (outermost bone of thumb)

Radius

Fovea of the radius articulates with the capitulum of the humerus at the proximal end of the radius.

Hamulus

Hook-like projection that extends out of the palmar side of the hamate bone. Flexor retinaculum binds to hamate at the hamulus.

Interosseus membrane

Membrane between ulna and radius that forms a fibrous joint

First proximal phalanx

Proximal phalanx of the thumb. Articulates with the first metacarpal on the proximal end and the first distal phalanx on its distal end.

Distal radioulnar joint

The distal joint between the radius and ulna

Second intermediate phalanx

The first of 4 intermediate phalanxes of the hand. The thumb has no phalanx. (proximal phalanx of pointer finger)

Second distal phalanx

The second of 5 distal phalanxes of the hand. (distal phalanx of pointer finger)

Second metacarpal

The second of 5 metacarpals of the hand that form the palm. (metacarpal of pointer finger)

Second proximal phalanx

The second of 5 proximal phalanxes of the hand. (proximal phalanx of pointer finger)

Humerus

Articulates with scapula (proximal) @ glenohumeral joint, Ulna (distal) @ trochlea of humeroulnar joint , & Radius (distal) @ capitulum of humeroradial joint