Musculoskeletal System Module muscles of the upper limb 1 Dr. Mohammed Elfatih Elbadri MBBS, MSc , HDEM, orthopedic surgery resident AUW, School of medicine , batch 25 3/26/2019 2 Muscles of the Upper Arm The muscles of the upper arm are concerned with the movements at the shoulder and elbow joints on the frontal axis and, therefore, are situated on the anterior (three flexors) and posterior (one extensor) surfaces of the upper arm and attach to the bones of the forearm AUW, School of medicine , batch 25 3/26/2019 3 Arm Compartments Anterior Compartment (3 muscles) Flexors of forearm and arm Posterior Compartment (1 muscle) Extensor of forearm and arm AUW, School of medicine , batch 25 3/26/2019 4 Anterior compartment Brachialis Coracobrachialis Biceps brachii Long head Short head AUW, School of medicine , batch 25 3/26/2019 5 AUW, School of medicine , batch 25 3/26/2019 6 Biceps brachii(musculocutaneous n.) Origin: Short head: coracoid process Long head; glenoid fossa Insertion: Proximal radius Action: Flexes elbow supinates AUW, School of medicine , batch 25 3/26/2019 7 Brachialis (musculocutaneous n.) Origin: Humeral shaft Insertion Proximal ulna Action: flexes elbow AUW, School of medicine , batch 25 3/26/2019 8 Coracobrachialis Which muscle is NOT a flexor of the elbow? The Coracobrachialis makes up part of the mass of the upper arm but doesn’t actually cross the joint (scapula to humerus only). AUW, School of medicine , batch 25 3/26/2019 9 Coracobrachialis Origin: coracoid process Insertion: Humerus Flexion and adduction of humerus. Musculocutaneous nerve AUW, School of medicine , batch 25 3/26/2019 10 AUW, School of medicine , batch 25 3/26/2019 11 AUW, School of medicine , batch 25 3/26/2019 12 Posterior compartment (Radial Nerve) Elbow extensors (Triceps brachii) Long head Medial head Lateral head AUW, School of medicine , batch 25 3/26/2019 13 (Triceps brachii) Origin: Long Head: Glenoid Fossa Medial & Lateral Heads: Posterior surface of humeral shaft Insertion: Olecranon process of ulna Action: Extends elbow AUW, School of medicine , batch 25 3/26/2019 14 AUW, School of medicine , batch 25 3/26/2019 15 AUW, School of medicine , batch 25 3/26/2019 16 AUW, School of medicine , batch 25 3/26/2019 17 The topography of the upper arm Radial canal is located behind the humerus. It is bounded by the radial groove of the humerus in the front and by the triceps brachii in the back. The canal has a spiral path. The radial canal begins on the medial surface of the arm between the medial and lateral heads of the triceps brachii and exits on the lateral surface of the arm between the brachialis and brachio-radialis. AUW, School of medicine , batch 25 3/26/2019 The topography of the upper arm The canal gives passage to the radial nerve and a. profunda brachii. Medial bicipital groove lies medially between the biceps brachii and brachialis; it transmits the main neurovascular bundle of the upper arm. Lateral bicipital groove resides laterally between the biceps brachii and brachialis; it gives passage to the cephalic vein. 19 Forearm Muscles The muscles of the forearm are separated into two groups according to position and function: the anterior group is composed of flexors and pronators, the posterior group is composed of extensors and supinator. Each group consists of a superficial and deep layers. Cross elbow, wrist and finger joints Movement of hand and fingers Proximally are fleshy Distally have long tendons Flexor and extensor retinacula “wristbands” Keep tendons from jumping outwards when tensed AUW, School of medicine , batch 25 3/26/2019 20 Forearm Muscles Anterior compartment Superficial and Deep layers Flexors of hand and fingers Most flexors have common origin on medial epicondyle Contains 2 pronator muscles Posterior compartment Superficial and Deep layers Extensors of hand and fingers Most extensors have common origin on lateral epicondyle Contains a supinator muscle AUW, School of medicine , batch 25 3/26/2019 21 Anterior Compartment of Forearm Muscles Nerves Superficial Flexor digitorum superficialis Median Flexor carpi radialis Median Pronator teres Median Palmaris longus Median Flexor carpi ulnaris Ulnar Deep Pronator quadratus Median Flexor pollicis longus Median Flexor digitorum profundus Ulnar (med 1/2), Median (lat 1/2) AUW, School of medicine , batch 25 3/26/2019 Superficial Layer 22 Flexor carpi radialis Median n. Origin: Medial epicondyle of humerus Insertion: Base of 2nd & 3rd metacarpals Action: Flexes wrist; abducts hand AUW, School of medicine , batch 25 3/26/2019 23 Superficial Layer Palmaris longus Median n. Origin: Medial epicondyle of humerus Insertion: Palmar aponeurosis Action: Flexes wrist AUW, School of medicine , batch 25 3/26/2019 24 Superficial Layer Flexor carpi ulnaris Ulnar n. Origin: Medial epicondyle of humerus Insertion: Pisiform and base of 5th metacarpal Action: Flexes wrist; adducts hand AUW, School of medicine , batch 25 3/26/2019 25 Superficial Intermediate Layer Flexor digitorum superficialis Median n Origin: Medial epicondyle of humerus Insertion: Middle phalanges nof fingers 2-5 Action: Flexes wrist and middle phalanges AUW, School of medicine , batch 25 3/26/2019 26 Superficial Layer Pronator teres Median n. Origin: Medial condyle of humerus Coronoid process of ulna Insertion: Lateral radius (midshaft) Action: Pronates forearm AUW, School of medicine , batch 25 3/26/2019 27 Pronation: Opposite of supination Medial rotation of the arm so palm faces inferiorally Relaxed position Ulna and Radius are crossed AUW, School of medicine , batch 25 3/26/2019 28 AUW, School of medicine , batch 25 3/26/2019 29 Deep Layer Flexor pollicis longus Median n Origin: Anterior surface of radius Insertion: Distal phalanx of thumb Action: Flexes distal phalanx of thumb AUW, School of medicine , batch 25 3/26/2019 30 Deep Layer Flexor digitorum profundus Median n Origin: Anteromedial surface ulna Insertion: Distal phalanges of fingers 2-5 Action: Flexes distal phalanges AUW, School of medicine , batch 25 3/26/2019 31 Posterior Compartment of Forearm Muscles Nerves Superficial Brachioradialis Radial Anconeus Radial Extensor carpi radialis longus & brevis Radial Extensor digitorum Radial Extensor carpi ulnaris Radial Extensor digiti minimi Radial Deep Supinator Radial Abductor pollicis longus Radial Extensor pollicis longus + brevis Radial Extensor indicus Radial AUW, School of medicine , batch 25 3/26/2019 32 Superficial Extensor carpi radialis brevis Radial n. Origin: Lateral epicondyle of humerus Insertion: Base of 3rd metacarpal Action: Extends and abducts wrist AUW, School of medicine , batch 25 3/26/2019 33 Superficial Extensor digitorum minimi Radial n. Origin: Lateral epicondyle of humerus Insertion: Distal phalange of little finger Action: Extends little finger AUW, School of medicine , batch 25 3/26/2019 34 Superficial Extensor digitorum Radial n. Origin: Lateral epicondyle of humerus Insertion: Distal phalange of fingers 2-4 Action: Extends fingers and wrist; abduct fingers AUW, School of medicine , batch 25 3/26/2019 35 Deep Extensor indices Radial n. Origin: Posterior surface of distal ulna Insertion: Extensor expansion of index finger Action: Extends index finger AUW, School of medicine , batch 25 3/26/2019 36 Deep Extensor pollicis longus Radial n. Origin: Dorsal shaft of radius and ulna Insertion: Base of distal phalanx of thumb Action: Extends thumb AUW, School of medicine , batch 25 3/26/2019 37 Deep Extensor pollicis brevis Radial n. Origin: Dorsal shaft of radius and ulna Insertion: Base of proximal phalanx of thumb Action: Extends thumb AUW, School of medicine , batch 25 3/26/2019 38 Deep Abductor pollicis longus Radial n. Origin: Posterior surface of radius and ulna Insertion: Base of 1st metacarpal Action: Abducts and extends thumb AUW, School of medicine , batch 25 3/26/2019 39 The topography of the forearm The cubital fossa is bounded by the brachialis above below it is bounded by the brachioradialis (laterally) and pronator teres (medially). Within the borders of the cubital fossa there are two grooves located on each side from the brachialis — medial cubital groove and lateral cubital groove AUW, School of medicine , batch 25 3/26/2019 40 The topography of the forearm The ulnar groove of the forearm lies between the flexor carpi ulnaris and flexor digitorum superficialis. It transmits the ulnar nerve, artery, and vein. AUW, School of medicine , batch 25 3/26/2019 41 The topography of the forearm The median groove of the forearm resides in the lower part of the forearm between the flexor carpi radialis and flexor digitorum superficialis. It contains the median nerve. AUW, School of medicine , batch 25 3/26/2019 42 The topography of the forearm The radial groove runs between the flexor carpi radialis and brachioradialis. It transmits the radial artery , vein, and nerve. AUW, School of medicine , batch 25 3/26/2019 43 Thank you AUW, School of medicine , batch 25 3/26/2019.