University of Mount Saint Vincent 4

Carpal Bones

• The carpal bones consist of 8 bones within the wrist:

  • Trapezium

  • Trapezoid

  • Scaphoid

  • Lunate

  • Capitate

  • Hamate

  • Pisiform

Common Injuries

• Scaphoid Bone:

  • Most commonly fractured bone in the human body.

  • Located on the lateral side at the base of the thumb (the pollux).

  • Frequently fractured when a person falls and tries to brace their fall with their hands.

• Lunate Bone:

  • Most commonly dislocated bone.

Tunnels Within the Carpals

• Carpal Tunnel:

  • Contains the median nerve, which can become compressed, leading to carpal tunnel syndrome.

  • Symptoms include numbness, tingling, loss of strength, and dropping objects.

• Tunnel of Guyon:

  • Located between the pisiform and hamate bones.

  • Associated with the ulnar nerve.

Carpal Tunnel Syndrome

• Often results from repetitive wrist movement.

• Commonly seen in certain occupations with high hand usage, such as those in factories (e.g., poultry processing) where repetitive wrist actions can lead to symptoms related to carpal tunnel syndrome.

Hand Anatomy

• The hand consists of:

  • Phalanges: 14 total (with 2 in the thumb (hallux) and 3 in each of the other fingers).

  • Joints:

    • DIP: Distal Interphalangeal Joint

    • PIP: Proximal Interphalangeal Joint

    • MCP: Metacarpophalangeal Joint

Fracture Types

• Boxer's Fracture:

  • Fracture of the second and third metacarpal heads resulting from hitting an object.

• Bar Room Fracture:

  • Fracture of the fourth and fifth metacarpals, often occurring when someone punches a wall or an object without proper technique.

Foot Anatomy

• The foot consists of:

  • Tarsals: 7 in each foot (including the talus and calcaneus).

  • Metatarsals: 5 in each foot.

  • Phalanges: 14 in each foot.

Bone Count

• Hand: 27 bones (8 carpals, 5 metacarpals, and 14 phalanges)

• Feet: 26 bones (7 tarsals, 5 metatarsals, and 14 phalanges)

• Total for both hands: 54 bones.

Arches of the Foot

• The foot features three arches:

  • Medial Longitudinal Arch:

  • Lateral Longitudinal Arch:

  • Transverse Arch:

• Importance of healthy arches:

  • Provide support and act as a springboard.

  • Poor footwear can damage arches, especially high heels.

Orthotics

• Custom orthotics can help support arches and prevent pain, especially in professions that require standing for long periods.

Pelvis Anatomy

• Comprised of the os coxae, which includes:

  • Ilium (most superior)

  • Ischium (most inferior)

  • Pubis (most anterior)

• Pubic Symphysis: fibrous joint between the two pubic bones.

• Sacrum: located superior to the sacrum is L5 vertebra.

• Sacroiliac Joint: where the sacrum connects to the ilium; important for stability and balance.

Differences in Male and Female Pelvis

• Male pelvis has a pubic arch < 90 degrees; Female pelvis > 90 degrees for reproductive purposes.

Femur Anatomy

• The femur is the largest and heaviest bone in the human body, located in the thigh.

  • Head of the femur: articulates with the acetabulum (hip socket).

  • Condyles at the distal end: medial and lateral, crucial for joint articulation at the knee.

Important Landmarks in the Femur

• Greater Trochanter: located laterally.

• Lesser Trochanter: located medially.

Final Reminders

• Pay attention to specific details in anatomy regarding positions, landmarks, and functions of bones and joints.

• Prepare for quizzes and exams by reviewing the axial skeleton, including skull, ribs, sternum, and vertebrae, in detail.