The upper limb is a vital part of the human body that enables a range of movements necessary for performing daily activities. It comprises the shoulder, arm, forearm, wrist, and hand and is held in place by a complex array of bones, muscles, nerves, and joints. 

Understanding the intricacies of such structures is very much required for NEET PG aspirants. DocTutorials provides meticulously curated, concept-based material that breaks down intricate subjects such as the upper limb of the human body and its anatomy. 

Keep reading for detailed insight!

What is the Anatomy of the Upper Limb?

The upper limb is a highly mobile, complex structure that supports both powerful movement and dexterous fine motor capabilities. Anatomically, it consists of five main areas: the shoulder, arm, forearm, elbow, and hand—each with its own bones, muscles, nerves, and vascular elements. 

1. Shoulder

The shoulder is the juncture of the trunk and upper limb, supported by the glenohumeral joint of the humerus, scapula, and clavicle. It is stabilised and controlled by superficial muscles such as the deltoid and trapezius and deep rotator cuff muscles: supraspinatus, infraspinatus, teres minor, and subscapularis, recalled by the mnemonic “SITS”.

2. Arm

The arm extends from the shoulder to the elbow and consists of one long bone—the humerus. It is functionally separated into anterior and posterior compartments. The anterior part consists of the coracobrachialis, brachialis, and biceps brachii muscles, whereas the triceps brachii occupies the posterior compartment. 

Innervation is provided by branches of the brachial plexus (C5–T1), and blood supply is through the brachial artery and its branches.

3. Forearm

The forearm is between the wrist and the elbow and is composed of the radius (lateral) and ulna (medial). It helps in supination and pronation due to articulation at the proximal and distal radioulnar joints. 

The muscles of the forearm are divided into anterior (flexor-dominant) and posterior (extensor-dominant) compartments, having superficial and deep layers. Innervation is provided by the radial, ulnar, and median nerves, and arterial supply by branches of the radial and ulnar arteries.

4. Elbow

The elbow is a hinge and pivot joint created by the humerus, radius, and ulna. It performs movements like flexion, extension, pronation, and supination of the forearm. The anterior elbow contains the cubital fossa, an area with dense neurovascular contents supplying the forearm and hand.

5. Hand

The hand is the functionally most complex component of the upper limb, which comprises the wrist (carpus), palm (metacarpus), and fingers (digits). The bones of the carpal include the scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate. There are five metacarpals and 14 phalanges in a proximal, middle, and distal set. 

Additionally, the hand has intrinsic muscles, including the thenar, hypothenar, interossei, lumbricals, palmaris brevis, and adductor pollicis, all of which are essential for fine motor control. Its nerves (median, ulnar, and radial) and arteries are prolongations of the forearm.

What is the Structure and Function of the Upper Limb?

The upper limb consists of 30 bones and starts from the shoulder joint, commonly misrepresented as a ball-and-socket joint—it’s more accurately referred to as a ball-and-saucer joint because of the shallow socket. This structure promotes mobility rather than stability. 

The elbow acts somewhat as a hinge but also enables pronation and supination through the pivot-type articulation between the radial head and the ulna. Meanwhile, the wrist is a condyloid joint permitting movement in more than one direction. 

Planar joints, such as intercarpal and interphalangeal joints, assist dexterity and fine motor functions, in spite of their restricted range of motion.

What are the Common Disorders Associated with the Upper Limb?

There are several types of disorders associated with the upper limbs that can be caused by working in construction, meat or poultry processing, or using computers. These include:

• Carpal tunnel syndrome
• Repetitive strain injury
• Epicondylitis
• Tendonitis

What are the Causes of Upper Limb Disorders? 

Upper limb disorders are frequently encountered in workplace tasks that involve:

• Prolonged repetitive actions, especially when using the same hand or arm movement
• Uncomfortable or awkward working positions
• Sustained or excessive force
• Inadequate work organisation (including workload, job demands, and insufficient breaks)
• Using hand-held power tools for prolonged durations
• Performing a task for an extended period without appropriate rest breaks
• A subpar working environment (including temperature and lighting)

What are the Symptoms of Upper Limb Disorders?

Various types of disorders in the upper limbs of the human body can lead to different symptoms. These include:

• Pain
• Tenderness
• Swelling
• Decreased range of motion
• Stiffness
• Numbness
• Weakness
• Pins and needles

What is the Treatment for Upper Limb Disorders?

Physiotherapy plays a crucial role in treating disorders of the upper limb and can often alleviate symptoms. Treatment options may include:

• Cold or heat therapy
• Mobilisation 
• Massage
• Electrotherapy
• Stretching exercises
• Range of motion exercises
• Strengthening exercises
• Postural advice
• Postural exercises
• Workstation advice

FAQs About the Upper Limb of the Human Body

1. What is the major nerve of the upper limb?

The brachial plexus consists of a network of nerves responsible for controlling the muscles in the shoulder, arm, forearm, and hand. Additionally, these nerves are responsible for sensation throughout the entire upper limb. The brachial plexus nerves originate as “roots” from the spinal cord.

2. What is the blood supply of the upper limb?

When considering arterial supply, the upper limb is supplied by five vessels: the subclavian, axillary, brachial, radial, and ulnar arteries. The axillary, subclavian, and brachial arteries are interconnected, with the brachial artery branching into the radial and ulnar arteries, which then merge in the hand.

3. How many joints are found in the upper limb?

The six main joints of the human upper limb are the sternoclavicular, acromioclavicular, shoulder, elbow, radioulnar, and wrist joints.

4. Which is the largest vein present in the upper limb?

The brachial veins are the largest veins in the human upper limb and are found on both sides of the brachial artery.

5. In what ways do our upper limbs assist us? 

The upper limb has many muscles that aid movement and help us carry out basic activities, like gripping with our hands or raising our arms. They also provide extra stability at the shoulder joint.

Conclusion

Understanding the anatomy, function, and disorders of the upper limb is essential for clinical mastery. For NEET PG students, it can prove to be a determining factor in securing good marks and making accurate diagnoses in clinical settings. DocTutorials makes it easy to grasp such intricate topics through organised, exam-related material developed specifically for students and medical professionals. Through visualisations, concise revision notes, and other NEET PG study materials, DocTutorials allows budding doctors to learn smarter and master subjects like upper limb anatomy and musculoskeletal systems with ease.