Appendicular Skeleton & Joint Movements

Pectoral Girdle & Upper Limb

The pectoral girdle and upper limb are essential components of the appendicular skeleton, providing support and facilitating a wide range of movements.

• Clavicle: Connects the sternum and scapula, acting as a strut to stabilize the shoulder.

• Scapula: Includes the scapular spine, acromion, coracoid process, and glenoid cavity, serving as attachment points for muscles and articulation with the humerus.

• Humerus: The head fits into the glenoid cavity; contains greater/lesser tubercles and condyles for muscle attachment and articulation with the forearm.

• Radius & Ulna: The radius is on the thumb side (lateral), and the ulna is on the pinky side (medial); the olecranon process forms the elbow.

• Hand: Composed of carpals (8), metacarpals (5), and phalanges (14).

Pelvic Girdle & Lower Limb

The pelvic girdle and lower limb support body weight and enable locomotion.

• Coxal Bone: Formed by the fusion of the ilium, ischium, and pubis; the acetabulum forms the socket for the femur head.

• Femur: The head fits into the acetabulum; features trochanters and condyles for muscle attachment and articulation with the tibia and patella.

• Tibia & Fibula: The tibia is the main weight-bearing bone; the fibula is thinner and lateral.

• Foot: Composed of tarsals (7), metatarsals (5), and phalanges (14).

Major Joints & Ligaments

Joints and ligaments provide stability and allow movement between bones.

• Knee: Includes the ACL (anterior cruciate ligament), PCL (posterior cruciate ligament), MCL (medial collateral ligament), LCL (lateral collateral ligament), menisci, and patellar tendon.

• Hip: The acetabulum, labrum, iliofemoral, ischiofemoral, and pubofemoral ligaments stabilize the joint.

• Shoulder: Stabilized by the glenohumeral capsule, acromioclavicular (AC) joint, and ligaments.

Movements at Synovial Joints

Synovial joints allow a variety of movements essential for daily activities and athletic performance.

• Flexion / Extension / Hyperextension: Decreasing or increasing the angle between bones (e.g., bending and straightening the elbow).

• Abduction / Adduction / Circumduction: Movement away from or toward the midline; circumduction is a circular motion combining flexion, extension, abduction, and adduction.

• Supination / Pronation: Rotational movement of the forearm (supination: palm up; pronation: palm down).

• Inversion / Eversion: Movements of the sole of the foot inward (inversion) or outward (eversion).

• Dorsiflexion / Plantarflexion: Upward (dorsiflexion) or downward (plantarflexion) movement of the foot at the ankle.

• Internal (medial) / External (lateral) rotation: Rotation toward or away from the midline of the body.

Study Tips

Effective study strategies can enhance understanding and retention of anatomical concepts.

• Use 3D anatomy apps (such as Complete Anatomy or Visible Body) to visualize structures.

• Label blank bone diagrams to reinforce spatial relationships.

• Practice identifying bones on your own body to connect theory with practice.

• Relate movement terms to real-life actions for better recall.