BONES OF THE UPPER LIMB

OVERVIEW

What are the main bone groups of the upper limb?

• Your upper limb comprises two main bone groups: the pectoral girdle and the free part of the upper limb
• The pectoral girdle includes the scapula and clavicle, which connect your limb to the trunk and provide support for your arm mobility
• The free part of the upper limb consists of:
  • The humerus in your upper arm
  • The radius and ulna in your forearm
  • The bones of your hand, including the carpal bones, metacarpals, and phalanges

SHOULDER GIRDLE (PECTORAL GIRDLE)

Components

What are the components of the shoulder girdle?

• Scapula (shoulder blade)
• Clavicle (collarbone)

Scapula

What is the scapula?

• Flat, triangular bone
• Features two broad surfaces with unique borders and angles
• Lateral angle forms the glenoid cavity (socket for the humerus, creating your shoulder joint)

Clavicle

What is the clavicle?

• Articulates medially with the manubrium of the sternum
• Extends laterally to connect with the acromion of the scapula
• Slender, S-shaped bone lying horizontally across your chest
• Functions to keep your shoulder blade in place, allowing your arm mobility

BONES OF THE FREE UPPER LIMB

Humerus

What is the humerus?

• Location: Your upper arm
• Connections:
  • To scapula at your shoulder joint
  • To radius and ulna at your elbow joint
• Features:
  • Longest and largest bone of your upper limb

Radius

What is the radius?

• Location: Thumb side of your forearm
• Features:
  • Large lower end with two joints
  • Joint 1: Articulates with wrist bones
  • Joint 2: Meeting with the ulna

Ulna

What is the ulna?

• Location: Parallel to radius on the lateral side
• Features:
  • Larger at the upper end, forming a substantial portion of your elbow joint
  • Tapers to a smaller lower end
  • Separated from your wrist by a triangular articular disc

Hand Skeleton

What are the sections of the hand skeleton?

• Your hand skeleton has the following sections:
  • Carpal bones: Forming your wrist
  • Metacarpal bones: Forming your palm
  • Phalanges: Your finger bones