Bones of the Appendicular Skeleton: The Hand

Overview

• Each hand consists of 27 bones, making a total of 54 bones for both hands.
• The bones are categorized into:
  • 8 carpal bones (wrist)
  • 5 metacarpals (palm)
  • 14 phalanges (fingers)

Identifying Right and Left Hand

• The anterior side is the palm side.
• The posterior or dorsal side is the back of the hand.
• Recognize orientation to distinguish between left and right hand.

Carpal Bones

• Proximal Row (thumb side to other side):
  • Scaphoid: Long bone on the lateral side.
  • Lunate: Crescent moon shape in particular view.
  • Triquetrum: Three-sided bone.
  • Pisiform: Sits on top of the triquetrum.
• Distal Row (thumb side to other side):
  • Trapezium: Next to the metacarpal of the thumb.
  • Trapezoid: Small bone next to the trapezium.
  • Capitate: Large bone along the middle finger.
  • Hammate: Has a hook, helps to remember it with "H" in both words.

Metacarpals

• Numbered 1 to 5 from thumb to little finger.
  • Metacarpal 1: Metacarpal of the thumb.
  • Metacarpal 2: Index finger.
  • Metacarpal 3: Middle finger.
  • Metacarpal 4: Ring finger.
  • Metacarpal 5: Little finger.

Phalanges

• Each finger generally has 3 phalanges: proximal, middle, and distal.
• The thumb has only 2 phalanges: proximal and distal.
• Phalanx is singular, phalanges is plural.
  • Proximal Phalanx: Nearest the metacarpal.
  • Middle Phalanx: Middle bone in fingers (absent in thumb).
  • Distal Phalanx: Tip of the finger.

Common Challenges

• Students often confuse the anterior (palm) view with the posterior (back) view, making it difficult to correctly identify left and right hands.