DIMS Lectures Upper Limbs Anatomy PDF

Here is the complete pdf lecture of upper limbs anatomy by Dr. Tahir Malik

Upper Limb Anatomy

The upper limb consists of four major regions:

Shoulder (Pectoral Girdle) – Supports arm movement.
Arm (Brachium) – Contains key muscles responsible for flexion and extension.
Forearm (Antebrachium) – Facilitates wrist and hand movement.
Hand (Manus) – Essential for dexterity and fine motor functions.

Bones of the Upper Limb

The upper limb is supported by a skeletal framework consisting of:

Clavicle: Acts as a strut to keep the arm away from the torso, allowing free movement.
Scapula: Provides attachment sites for multiple muscles involved in shoulder movement.
Humerus: The longest bone of the upper limb, forming the shoulder and elbow joints.
Radius and Ulna: Work together to allow supination and pronation of the forearm.
Carpals, Metacarpals, and Phalanges: Form the wrist, palm, and fingers, supporting precise hand movements.

Joints of the Upper Limb

Shoulder Joint (Glenohumeral Joint)

A ball-and-socket joint providing a wide range of motion.
Stabilized by the rotator cuff muscles and the glenoid labrum.

Elbow Joint

A hinge joint allowing controlled flexion and extension.
Supported by ligaments such as the ulnar collateral ligament.

Wrist and Hand Joints

Metacarpophalangeal (MCP) Joints: Allow grasping and manipulation.
Interphalangeal (IP) Joints: Enable flexion and extension of fingers.

Muscles of the Upper Limb

Shoulder Muscles

Deltoid: Major abductor of the shoulder.
Rotator Cuff Muscles: Provide shoulder stability and rotation.

Arm Muscles

Biceps Brachii: Responsible for elbow flexion and forearm supination.
Triceps Brachii: Extends the elbow.

Forearm Muscles

Flexor Group: Controls wrist and finger flexion.
Extensor Group: Enables wrist and finger extension.

Hand Muscles

Thenar Muscles: Facilitate thumb movement.
Hypothenar Muscles: Control the little finger.

Nerve Supply of the Upper Limb

The brachial plexus supplies the upper limb, with major branches including:

Musculocutaneous Nerve: Controls elbow flexion.
Axillary Nerve: Innervates the deltoid muscle.
Radial Nerve: Enables extension of the wrist and fingers.
Median Nerve: Facilitates fine hand movements.
Ulnar Nerve: Plays a key role in gripping.

Blood Supply of the Upper Limb

Axillary Artery: Supplies the shoulder and upper arm.
Brachial Artery: Main artery of the arm, dividing into:
- Radial Artery (lateral forearm and hand).
- Ulnar Artery (medial forearm and hand).
Palmar Arches: Ensure circulation in the hand.

Clinical Relevance

Common Upper Limb Injuries and Conditions

Fractures:
- Clavicle Fracture: Common in sports injuries and falls.
- Humerus Fracture: Can damage the radial nerve, leading to wrist drop.
- Colles' Fracture: Affects the distal radius, often due to a fall on an outstretched hand.
Nerve Injuries:
- Radial Nerve Palsy: Leads to inability to extend the wrist and fingers.
- Carpal Tunnel Syndrome: Compression of the median nerve, causing numbness in the thumb, index, and middle fingers.
- Ulnar Nerve Injury: Results in claw hand deformity.
Tendon and Ligament Disorders:
- Rotator Cuff Tear: Causes shoulder pain and limited movement.
- Tennis Elbow (Lateral Epicondylitis): Inflammation of the extensor tendons.
- Golfer’s Elbow (Medial Epicondylitis): Affects the flexor tendons.
Circulatory Disorders:

Thoracic Outlet Syndrome: Compression of the subclavian artery or brachial plexus, leading to numbness and arm pain.
Deep Vein Thrombosis (DVT): Can develop in the upper limb, especially after prolonged immobilization.

Fig. Hand Nerves Injuries

Use mnemonic " DR.CUMA " to remember

DR → D for Wrist Drop & R for Radial Nerve

CU → C for Claw Hand & U for Ulnar Nerve

MA → M for Median Nerve & A for Ape Hand

Case Example:

A 30-year-old male presents with wrist drop following a humerus fracture. Examination reveals weakness in wrist extension.

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Diagnosis : Radial Nerve Palsy