FULL VIDEO: Main muscles of the upper limb - Human Anatomy | Kenhub
Kenhub - Learn Human Anatomy・2 minutes read
The tutorial details the main muscles of the Upper Limb, highlighting key muscles in the shoulder, arm, forearm, and hand regions, with a focus on their origins, insertions, and functions. Various muscles are discussed, such as the deltoid, rotator cuff muscles, biceps brachii, triceps brachii, and forearm extensor and flexor muscles, emphasizing their roles in arm and hand movements.
Insights
- The tutorial breaks down the Upper Limb muscles into distinct regions, starting with the shoulder and moving to the forearm and hand, providing a comprehensive understanding of the muscles' origins, insertions, and functions.
- Different compartments in the Upper Limb house specific groups of muscles with unique functions, such as flexors in the anterior forearm and extensors in the posterior forearm, highlighting the intricate balance required for coordinated movements in the Upper Limb.
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Recent questions
What are the main muscles of the Upper Limb?
The main muscles of the Upper Limb are categorized into regions for easier understanding, starting with the shoulder region, followed by the arm, forearm, posterior forearm, and intrinsic hand muscles.
How do the rotator cuff muscles contribute to arm movement?
The rotator cuff muscles, including supraspinatus, infraspinatus, teres minor, and subscapularis, have distinct origins on the scapula and insert onto the head of the humerus, aiding in rotational movements at the shoulder joint.
What are the functions of the biceps brachii and triceps brachii muscles?
The biceps brachii extends over two joints, contributing to movement at the shoulder and elbow joints, while the triceps brachii has three heads and acts at both joints, aiding in arm flexion and extension.
How are the forearm muscles categorized and what are their functions?
Forearm muscles are categorized into anterior and posterior compartments, with superficial and deep layers. The anterior forearm muscles are predominantly flexors, aiding in movements at the elbow, wrist, and digits, while the posterior forearm muscles are extensors, extending the forearm and hand.
What is the unique function of the supinator muscle in the Upper Limb?
The supinator muscle is unique in the Upper Limb as it produces supination of the forearm and wrist at the radio ulnar joints, allowing for rotational movements of the hand and wrist.
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Summary
00:00
Upper Limb Muscles: Shoulder to Hand
- The tutorial focuses on the main muscles of the Upper Limb, breaking them down into regions for easier understanding.
- Starting with the shoulder region, six main muscles are highlighted, originating at the shoulder girdle and attaching to the humerus, allowing arm movement at the shoulder joint.
- The superficial shoulder muscle is the deltoid, named after the Greek letter Delta, with smaller rotator cuff muscles beneath it, aiding in rotational movements.
- The rotator cuff muscles, including supraspinatus, infraspinatus, teres minor, and subscapularis, have distinct origins on the scapula and insert onto the head of the humerus.
- The deltoid muscle is the primary abductor of the arm, while the rotator cuff muscles and teres major contribute to rotational movements at the shoulder joint.
- Moving to the arm, muscles are divided into anterior and posterior compartments, with biceps brachii, coracobrachialis, and brachialis in the anterior, and triceps brachii in the posterior.
- The biceps brachii extends over two joints, contributing to movement at the shoulder and elbow joints, while the triceps brachii has three heads and acts at both joints.
- In the forearm, muscles are categorized into anterior and posterior compartments, with superficial and deep layers, such as pronator teres, flexor carpi radialis, flexor carpi ulnaris, and flexor digitorum superficialis.
- The anterior forearm muscles are predominantly flexors, aiding in movements at the elbow, wrist, and digits, with pronator teres and pronator quadratus working together for pronation.
- The posterior forearm muscles, known as extensor muscles, include brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris.
- These muscles extend the forearm and hand, with radial muscles located laterally and ulnar muscles medially, contributing to various movements in the posterior forearm.
14:47
Posterior Forearm Muscles: Extensors and Supinators
- There are six muscles in the posterior forearm: extensor pollicis longus, extensor pollicis brevis, abductor pollicis longus, extensor indicis, and supinator muscle.
- Muscles of the posterior forearm are primarily extensors, extending the hand at the wrist joint and digits at the metacarpophalangeal and interphalangeal joints.
- Medial and lateral muscles like extensor carpi radialis longus contribute to hand abduction and adduction at the wrist.
- The supinator muscle is unique, producing supination of the forearm and wrist at the radio ulnar joints.
- Intrinsic hand muscles originate and insert within the hand, while extrinsic muscles originate in the arm or forearm and insert onto the hand and digits.
- Intrinsic hand muscles are divided into groups: dorsal and palmar interossei, lumbricals, hypothenar muscles, and thenar muscles.
