ANATOMY LC4c The Muscular System Upper & Lower Limb PDF

UNIVERSITY OF NORTHERN PHILIPPINES ANATOMY LC4c MUSCULAR SYSTEM: Upper & Lower COLLEGE...

UNIVERSITY OF NORTHERN PHILIPPINES ANATOMY LC4c MUSCULAR SYSTEM: Upper & Lower COLLEGE OF MEDICINE, BATCH 2026 Limb Transcribers: Achacoso, Acosta, Ammiyao, Anulacion, Avecilla, Busaing Dr. De Grano | Nov 2022 Editors: Abrero, Almeron, Anaper COURSE OUTLINE I. AXIO-APPENDICULAR MUSCLES A. Anterior Axio-Appendicular Muscles B. Posterior Axio-Appendicular Muscles C. Scapulohumeral Muscles D. Rotator Cuff Muscles E. Poland Syndrome II. THE ARM A. Anterior Compartment Muscles of the Arm B. Posterior Compartment Muscles of the Arm III. THE FOREARM A. Anterior Compartment of the Forearm B. Posterior Compartment of the Forearm C. Elbow Tendinitis IV. THE HAND A. Lateral Group Thenar B. Medial Group Hypothenar V. THE HIP AND THIGH A. Gluteals B. Anterior Compartment of the Thigh C. Medial Compartment of the Thigh D. Posterior Compartment of the Thigh VI. THE LEG A. Anterior Compartment of the Leg Figure 1. Anterior Axio-appendicular Muscles B. Lateral Compartment of the Leg C. Superficial Posterior Compartment of the Leg Table 1. Muscles of the anterior wall of the axilla (spinal segments in bold are the major D. Deep Posterior Compartment of the Leg segments innervating the muscle) E. Compartment Syndrome Muscle Origin Insertion Innervatio Main Action VII. THE FOOT n A. Intrinsic Muscles of the Foot Pectoralis Clavicular head: Lateral hip of Lateral and Adducts and B. Plantar Muscles: First and Second Layer Major anterior surface intertubercul medial medially rotates C. Plantar Muscles: Third and Fourth Layer of medial half ar sulcus of pectoral humerus; draws VIII. DISEASES AND DISORDERS OF THE MUSCULAR SYSTEM of clavicle humerus nerves; scapula Sternocostal clavicular anteriorly and I. AXIO-APPENDICULAR MUSCLES head: anterior head (C5, inferiorly A. Anterior Axio-Appendicular Muscles surface of C6), and Acting alone,  There are four axio-appendicular muscles (thoraco-appendicular or sternum, sternocost clavicular head pectoral muscles) move the pectoral girdle: superior six al head flexes humerus o Pectoralis Major costal (C7, C8, T1) and sternocostal o Pectoralis Minor cartilages, and head extends it o Subclavius aponeurosis of from flexed o Serratus Anterior external position  These muscles produce powerful adduction and medial rotation of the oblique muscle arm when acting together, your pectoralis major in particular. The Pectoralis 3rd-5th ribs near Medial Medial Stabilizes two parts of the pectoralis major can also act independently: the minor their costal border and pectoral scapula by clavicular head of the pectoralis flexes the humerus, and the cartilages superior nerve (C8, drawing it sternocostal head extends it back from the flexed position. surface of T1) inferiorly and  To test the clavicular head of pectoralis major, the arm is abducted at coracoid anteriorly 90°; the individual then moves the arm anteriorly against resistance. If process of against thoracic acting normally, the clavicular head can be seen and palpated. scapula wall  To test the sternocostal head of pectoralis major, the arm is abducted Sub-clavius Junction of 1st Inferior Nerve to Anchors and at 60° and then adducted against resistance. If acting normally, the rib and its surface of the subclavius depresses sternocostal head can be seen and palpated. costal cartilage middle third (C5, C6) clavicle  By testing the serratus anterior, you also test the function of the long of clavicle thoracic nerve. The hand of your outstretched limb is pushed against a Serratus External Anterior Long Protracts scapula wall. If the muscle is acting normally, several digitations of the muscle anterior surfaces of surface of thoracic and holds it can be seen and palpated. lateral parts of medial nerve (C5, against thoracic 1st - 8th ribs border of C6, C7) wall; rotates scapula scapula B. Posterior Axio-Appendicular Muscles  Superficial and intermediate groups of extrinsic shoulder muscles attached the superior appendicular skeleton to the axial skeleton  Superficial posterior axio-appendicular (extrinsic shoulder) muscles: o Trapezius o Latissimus dorsi Page 1 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Table 2. Superficial posterior axio-appendicular (extrinsic shoulder) muscles. Muscle Origin Insertion Innervation Main Action Trapezius Medial third of Lateral third Spinal Descending superior nuchal of clavicle; accessory part elevates; line; external acromion nerve (CN XI) ascending part occipital and spine of (motor fibers) depresses; and protuberance; scapula and C3, C4 middle part nuchal spinal nerves (or all parts ligament; (pain and together) spinous proprioceptive retracts processes of fibers) scapula; C7-T12 descending vertebrae and ascending parts act together to rotate glenoid cavity superiorly Latissimus Spinous Floor of Thoracodorsal Extends, dorsi processes of intertubercu nerve (C6, C7, adducts, and Figure 2. Posterior Axio-appendicular Muscles inferior 6 lar sulcus of C8) medially thoracic humerus rotates C. Scapulohumeral Muscles (Intrinsic Shoulder Muscles) vertebra, humerus;  Similar to the muscles that position the pectoral girdle thoraco-lumbar raises body  Muscles that cross the shoulder joint and move the humerus bone of fascia, iliac towards arms the arm crest, and during  Include both axial and scapular muscles inferior 3 or 4 climbing.  Includes: Deltoid, Teres major and the Four rotator cuff muscles ribs (supraspinatus, infraspinatus, teres minor, and subscapularis)  SITS Muscles:  Deep posterior axio-appendicular (extrinsic shoulder) muscles: o Supraspinatus o Levator scapulae o Infraspinatus o Rhomboids o Teres Minor - this provides direct attachment of the appendicular o Subscapularis skeleton to the axial skeleton Table. 4. Scapulohumeral (Intrinsic) Muscles Table 3. Deep posterior axio-appendicular (extrinsic shoulder muscles) Muscle Origin Insertion Innervation Main Action Muscle Origin Insertion Innervation Main Action Deltoid Lateral third Deltoid Axillary nerve Clavicular Levator Posterior Medial border Dorsal Elevates “big of clavicle; tuberosity of (C5, C6) (anterior) part: scapulae tubercles of of scapula scapular scapula and shoulder acromion and humerus flexes and transverse superior to root (C4, C5) rotates its muscle” spine of medially rotates processes of C1- of scapular and cervical glenoid cavity scapula arm C4 vertebrae spine (C3, C4) inferiorly by Acromial (middle nerves rotating part: abducts scapula arm Rhomboid Minor; nuchal Minor: smooth Dorsal Retract Spinal (posterior) major and ligament; triangular area scapular scapula and part: extends minor spinous at medial end nerve (C4, rotate its and laterally processes of C7 of scapular C5) glenoid cavity rotates arm and T1 spine inferiorly; fix Supra- Supraspinatu Superior Subscapular Initiates and vertebrae Major: medial scapula to spinatus s fossa of facet of nerve (C4, assists deltoid in Major: spinous border of thoracic wall scapula greater C5, C6) abduction of arm processes of T2- scapula from tubercle of and acts with T5 vertebrae level of spine to humerus rotator cuff inferior angle muscles Infra- Infraspinatus Middle facet Subscapular Laterally rotates  The Trapezius muscle has a middle part and ascending fibers. spinatus fossa of of greater nerve (C5, arm; and acts  Peeling back the Trapezius muscle reveals the Rhomboid major and Levator scapula tubercle of C6) with rotator cuff scapulae humerus muscles Teres Middle part Inferior facet Axillary nerve Laterally rotates Minor of lateral of greater (C5, C6) arm; and acts border of tubercle of with rotator cuff scapula humerus muscles Teres Posterior Medial lip of Lower Adducts and Major surface of intertubercul subscapular medially rotates inferior angle ar sulcus of nerve (C5, arm of scapula humerus C6) Sub- Subscapular Lesser Upper and Medially rotates scapularis fossa (most tubercle of lower arm; as part of of anterior humerus subscapular rotator cuff, surface of nerves (C5, helps hold head scapula) C6, C7) of humerus in glenoid cavity Page 2 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Note: Bony landmarks includes Acromion and Coracoid process Table 5. Muscles involved in the movement of scapula Movement Muscle Producing Movement Nerve to Muscles of Scapula Elevation Descending part of Trapezius Spinal Accessory CNXI Levator Scapulae Dorsal Scapular Rhomboids Dorsal Scapular Depression Pectoralis major, inferior Pectoral nerves sternocostal head Latissimus dorsi Thoracodorsal Ascending part of Trapezius Spinal Accessory CNXI Serratus anterior, inferior part Long Thoracic Pectoralis minor Medial Pectoral Protraction Serratus anterior Long Thoracic Pectoralis major Pectoral nerves Pectoralis minor Medial pectoral Retraction Trapezius, middle part Spinal Accessory CNXI Rhomboid Dorsal scapular Latissimus dorsi Thoracodorsal Figure 3. Scapulohumeral (Intrinsic) Muscles Upward Trapezius, descending part Spinal Accessory CNXI rotation Trapezius ascending part Serratus anterior, inferior part Long Thoracic Downward Levator scapula Dorsal scapular Rotation Rhomboids Latissimus dorsi Thoracodorsal Pectoralis minor Medial Pectoral Pectoralis major, inferior sternocostal Medial and Lateral Pectoral head nerves E. Poland Syndrome  Uncommon but not rare unilateral congenital anomaly of upper limb development.  The lowest level is the range from agenesis of the pectoralis major (especially its sternocostal part) and pectoralis minor.  Absent anterior axillary fold on the affected side; more inferior nipple.  Because pectoralis major is removed, it results in weakened abduction and extension of the arm and ability to draw the shoulder anteriorly, and lateral rotation of the limb at rest.  More severe forms: breast hypoplasia (evident in childhood by the lack of nipple), absence of two or four rib segments (possible lung herniation) and additional development deficiencies in the free limb Figure 4. Deltoid Muscle  Functional disability is similar to that experienced by someone who had undergone Radical Mastectomy (removal of breast including pectoral D. Rotator Cuff Muscles muscle due to advanced breast cancer)  the “SITS” muscles  Main function: during all movement of the shoulder joint or glenohumeral is to hold the humeral head in the glenoid cavity of the scapula. Figure 6. Left, Poland’s Syndrome. Right, Normal. Figure 5. Rotator Cuff Muscles Figure 7. Musculature of Poland Syndrome Page 3 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano II. THE ARM Biceps Long head— Radial Musculocuta Powerful  Region of the upper limb between the shoulder and the elbow brachii supraglenoid Tuberosity neous nerve flexor at the  The superior aspect of the arm communicates medially with the axilla. tubercle of (C5, C6) forearm at Inferiorly, there are a number of important structures that pass between the scapula; the elbow arm and the forearm through the cubital fossa which is positioned just Short head— joint and anterior to the elbow joint. apex of supinator of coracoid the forearm;  Divided into two compartments by medial and lateral intermuscular septa process accessory which passed from each side of the humerus to the outer slip of the deep flexor of the fascia that surrounds the limb. arm at the glenohumera l joint Brachia- Anterior Tuberosity Musculocuta Powerful lis aspect of of the ulna neous nerve flexor of the humerus (C5, C6); forearm at (medial and small the elbow lateral contribution joint surfaces) and by the radial adjacent nerve (C7) intermuscular to lateral septae part of the muscle B. Posterior Compartment Muscle of The Arm o Elbow extensor and pronators o Triceps brachii o Anconeus Figure 8. Muscle compartments of the arm Table 7. Muscle of the posterior compartment of the arm A. Anterior Compartment Muscles of The Arm Muscle Origin Insertion Innervation Function  Elbow flexors and supinators Triceps Long head – infraglenoid Olecranon Radial Nerve Extension of the brachii tubercle of scapula; of ulna (C6, C7, C8) forearm at the  Principal flexors Medial Head – posterior elbow joint; long o Coracobrachialis surface of humerus, head can also o Biceps brachii (above grove of medial extend and adduct o Brachialis nerve); the arm at the Lateral Head – posterior shoulder joint surface of humerus, (below groove of medial nerve) Anconeus Lateral epicondyle of Olecranon Radial Abduction of humerus and nerve the ulna in proximal (C6,C7, C8) pronation; posterior (via branch accessory surface of to medial extensor of the ulna head of elbow joint triceps brachii) Figure 9. Coracobrachialis, biceps brachii and brachialis muscle Table 6. Muscles of the anterior compartment of the arm Muscle Origin Insertion Innervation Function Coraco- Apex of Linear Musculocuta Flexor of the brachialis coracoid roughering neous nerve arm at the process on (C5, C6, C7) glenohumera midshaft of l joint humerus on medial side Figure 10. Trapezius muscle Page 4 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano III. THE FOREARM  SUPINATE AND PRONATE o Supinator muscle supinates the forearm o Biceps brachii supinates the forearm o Pronator teres and pronator quadratus pronate the forearm  MOVE THE WRIST JOINT, HAND, AND FINGERS o Muscles in the forearm move the hand at the wrist and/ or the fingers. o Extrinsic muscles of the wrist and hand originate on the forearm, not the wrist or hand. o Tendons of the forearm muscles typically are surrounded by tendon (synovial) sheaths and held adjacent to the skeletal elements by strong fascial structures. o At the wrist, the deep fascia of the forearm form thickened, fibrous bands termed RETINACULA. A. ANTERIOR (FLEXOR) COMPARTMENT OF THE FOREARM  Muscles occur in three layers: Superficial, Intermediate and Deep  Associated with: o Movements of the wrist joints o Flexion of the fingers including the thumb and pronation  All muscles in the anterior compartment of the forearm are innervated by the median nerve, except for the FLEXOR CARPI ULNARIS MUSCLE and the medial half of the FLEXOR DIGITORUM PROFUNDUS MUSCLE, which are innervated by the ulnar nerve  SUPERFICIAL LAYER o Flexor carpi ulnaris o Palmaris longus o Flexor carpi radialis o Pronator teres Table 8. Superficial layer of muscles in the anterior compartment of the forearm Muscle Origin Insertion Innervation Function Flexor carpi Humeral head- Pisiform bone, Ulnar nerve Flexes and adducts the ulnaris --medial and then via (C7, C8, T1) wrist joint epicondyle of pisohamate and humerus; pisometacarpal ligaments into Ulnar head---- the hamate and olecranon and base of Figure 11. Superficial layer of forearm muscles. A. Superficial muscles (flexor reti posterior metacarpal V naculum not shown). B. Flexor carpi ulnaris muscle. border of ulna Palmaris Medial Palmar Median Flexes wrist joint; longus epicondyle of aponeurosis of nerve (C7, because the palmar  INTERMEDIATE LAYER humerus hand C8) aponeurosis anchors o Flexor Digitorum superficialis the skin of the hand, contraction of the Table 9. Intermediate layer of muscles in the anterior compartment of the forearm muscle resists shearing Muscle Origin Insertion Innervatio Function forces when gripping. n Flexor carpi Medial Base of Median Flexes and abducts the Flexor Humero-ulnar Four tendons, Median Flexes proximal radialis epicondyle of metacarpals II nerve (C6, wrist digitorum head--medial which attach to nerve (C8, interphalangeal joints humerus and III C7) superficialis epicondyle of the palmar T1) of the index, middle, Pronator Humeral head- Roughening on Median Pronation humerus and surfaces of the ring, and a little finger, teres --medial lateral surface, nerve (C6, adjacent margin middle can also flex epicondyle and midshaft of C7) of coronoid phalanges of the metacarpophalangeal adjacent radius process; radial index, middle joints of the same supra- head—oblique ring and little fingers and the wrist epicondylar line of radius fingers joint ridge; Ulnar head— medial side of coronoid process - All four muscles in the superficial layer-the flexor carpi ulnaris, palmaris longus, flexor carpi radialis, and pronator teres-have a common origin from the medial epicondyle of the humerus, and, except for the pronator teres, extend distally from the forearm into the hand Page 5 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Figure 13. Deep layer of Forearm Muscle B. POSTERIOR (EXTENSOR) COMPARTMENT OF THE FOREARM  ACTIONS: o Movement of the wrist joints o Extension of the fingers and thumbs and supination  INNERVATION: Radial Nerve Figure 12. Intermediate layer of forearm muscles.  Is composed of extensors just like in your upper arm  DEEP LAYER o Flexor digitorum profundus o Flexor pollicis longus o Pronator quadratus o ACTION: Flex radiocarpal joint and fingers, pronate forea Table 10. Deep layer of muscles in the anterior compartment of the forearm Muscle Origin Insertion Innervation Function Flexor Anterior and Four tendons, Lateral half by Flexes distal digitorum medial surfaces which attach to median nerve interphalangeal profundus of ulna and the palmar (anterior joints of the anterior medial surfaces of the interosseous index, middle half of distal phalanges nerve); medial ring and little interosseous of the index, half by ulnar fingers; can also membrane middle, ring, and nerve (C8, T1) flex little fingers metacarpophala ngeal joints of the same fingers and the wrist joint Flexor Anterior surface Palmar surface of Median nerve Flexes pollicis of radius and base of distal (anterior interphalangeal longus radial half of phalanx of interosseous joint of the interosseous thumb nerve) (C7, C8) thumb; can also membrane flex metacarpophala ngeal joint of the thumb Pronator Linear ridge on Distal anterior Median nerve Pronation quadratus distal anterior surface of radius (anterior surface of ulna interosseous nerve) (C7, C8) Figure 14. Posterior surface of the forearm. Superficial muscles. Page 6 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano  SUPERFICIAL LAYER o Extensor digitorum o Extensor digiti minimi o Extensor carpi ulnaris - ACTION: Extension at wrist joint - All have a common origin from the supraepicondylar ridge and lateral epicondyle of the humerus except for the brachioradialis and anconeus which extend as tendons into the hand. Table 11. Superficial Layer of Muscles in the posterior compartment of the forearm Muscle Origin Insertion Innervation Function Extensor Lateral Four tendons, Posterior Extends the digitorum epicondyle of which insert interosseous index, middle, humerus and via extensor nerve (C7,C8) ring, and little adjacent hoods into the fingers; can intermuscular dorsal aspects also extend septum and of the bases of the wrist deep fascia the middle and distal phalanges of the index, middle, ring and little fingers Extensor Lateral Extensor hood Posterior Extends the digiti minimi epicondyle of of the little interosseous little finger humerus and finger nerve (C7, C8) adjacent intermuscular septum together with extensor digitorum Extensor Lateral Tubercle on Posterior Extends and carpi ulnaris epicondyle of the base of interosseous adducts the humerus and the medial nerve (C7, C8) wrist Figure 15. Superficial layer of muscles in the posterior compartment of the forearm Left- posterior side of Brachioradialis muscle (anterior view) Right- Superficial muscles (posterior view) border of ulna metacarpal V  DEEP LAYER  LATERAL GROUP o Supinator o Brachioradialis o Abductor pollicis longus o Extensor carpi radialis longus o Extensor pollicis brevis o Extensor carpi radialis brevis o Extensor pollicis longus  Surgically, they are referred to as MOBILE WAD OF HENRY. o Extensor indicis It is a group of your radial muscles that flex your elbow and  ACTION: Extend at wrist joints and fingers, and supinate they can be retracted as a unit during surgery but in some forearm books, they are included as part of your posterior  Except for the supinator muscle, all these deep layer muscles compartment already. originate from the posterior surface of the radius, ulna, and interosseous membrane and pass into the thumb and Table 12. Superficial layer (Lateral Group) of muscles in the posterior compartment of fingers. the forearm  Three of these muscles-the abductor pollicis longus, Muscle Origin Insertion Innervation Function extensor pollicis brevis, and extensor pollicis longus emerge Brachio- Proximal part of Lateral Radial nerve Accessory from between the extensor digitorum and the extensor carpi radialis lateral surface of (C5,C6) before flexor of radialis brevis tendons of the superficial layer and pass into supraepicondylar distal end of division into elbow joint the thumb. ridge of humerus radius superficial and when forearm  Two of the three "outcropping" muscles (abductor pollicis and adjacent deep branches is mid longus and extensor pollicis brevis) form a distinct muscular intermuscular pronated bulge in the distal posterolateral surface of the forearm. septum  All muscles of the deep layer are innervated by the posterior Extensor Distal part of Dorsal Radial nerve Extends and interosseous nerve which is a continuation of a deep branch carpi lateral surface of (C6, C7) abducts the of your radial nerve. radialis supraepicondylar base of before division wrist longus ridge of humerus metacarpal II into superficial Table 13. Deep layer of muscles in the posterior compartment of the forearm and adjacent and deep Muscle Origin Insertion Innervation Function intermuscular branches Supinator Superficial part- Lateral Posterior Supination septum lateral epicondyle surface of interosseous Extensor Lateral epicondyle Dorsal Deep branch Extends and of humerus , radius nerve (C6, C7) carpi of humerus and surface of of radial nerve abducts the radial collateral superior to radialis adjacent base of (C7,C8) before wrist and anular the anterior brevis intermuscular metacarpals penetrating ligaments; deep oblique line septum II and III supinator part –supinator muscle crest of the ulna Page 7 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Abductor Posterior Lateral side of Posterior Abducts pollicis surfaces of ulna base of interosseous carpometacarp longus and radius (distal metacarpal I nerve (C7, C8) al joint of to the thumb; attachments of accessory supinator and extensor of the anconeus), and thumb intervening interosseous membrane Extensor Posterior surface Dorsal surface Posterior Extends pollicis radius (distal to of base of interosseous metacarpophal brevis abductor pollicis proximal nerve (C7, C8) angeal joint of longus) and the phalanx of the the thumb; can adjacent thumb also extend the interosseous carpometacarp Figure 17. Fascial compartments of the arm membrane al joint of the thumb C. ELBOW TENDINITIS/TENDINOSIS OR LATERAL EPICONDYLITIS Extensor Posterior Dorsal surface Posterior Extends  “Tennis elbow” pollicis surfaces of ulna of base of interosseous interphalangea  Musculoskeletal condition that may follow repetitive use of longus (distal to distal phalanx nerve (C7, C8) l joint of the superficial extensor muscle of the forearm. abductor pollicis of the thumb thumb; can  Pain over the lateral epicondyle and radiates down the posterior longus) and the also extend surface of the forearm. adjacent carpometacarp  People with tendinitis often feel pain when they open a door or lift a interosseous al and glass. membrane metacarpophal  Repeated forceful flexion and extension of the wrist strain the angeal joints of attachment of the common extensor tendon producing inflammation the thumb of the periosteum of the lateral epicondyle (Lateral Epicondylitis). Extensor Posterior Extensor Posterior Extends index  This condition is seen in tennis players. indicis surfaces of ulna hood of index interosseous finger (distal to finger nerve (C7, C8) extensor pollicis longus) and the adjacent interosseous membrane Figure 18. Elbow tendinitis/ tendinosis or Lateral Epicondylitis IV. THE HAND A. LATERAL GROUP THENAR (4)  *Thenar group –mainly for thumb o Opponens pollicis o Abductor pollicis brevis o Adductor pollicis o Flexor follicis brevis  Action: Flex, abduct, adduct and oppose the thumb o The three thenar muscles are associated with the opposition of the thumb to finger and with the delicate movement of the thumb, and are responsible for the prominent swelling of the thenar eminence on the lateral side of the thumb on the base of the thumb. o Thenar muscles are innervated by the specific reoccurrence branch of median nerve. Table 14. Thenar Muscles Muscle Origin Insertion Innervation Function Opponens Tubercle of Lateral margin Recurrent Medially pollicis trapezium and and adjacent branch of rotates thumb flexor palmar surface median nerve retinaculum of metacarpal I (C8, T1) Figure 16. Deep layer of muscles in the posterior compartment of the forearm. Page 8 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Abductor Tubercles of Proximal Recurrent Abducts pollicis scaphoid and phalanx of the branch of thumb to brevis trapezium and extensor hood median nerve metacarpophal adjacent flexor of thumb (C8, T1) angeal joint retinaculum Flexor Tubercle of the Proximal Recurrent Flexes thumb pollicis trapezium and phalanx of the branch of at brevis flexor thumb median nerve metacarpophal retinaculum (C8, T1) angeal joint B. MEDIAL GROUP HYPOTHENAR (3)  *Hypothenar group – supports the little fingers o Opponens digiti minimi o Abductor digiti minimi o Flexor digiti minimi brevis  Action: Flex, Abduct and oppose the thumb o Hypothenar muscles contribute to the swelling in the medial side of the palm at the base of the little finger. o Hypothenar muscles are similar to thenar muscles in names and in organization but unlike the thenar muscles, the hypothenar muscles are innervated by the deep branch of the ulnar nerve. Table 15. Hypothenar Muscle Origin Insertion Innervation Function Opponens Hook of Medial aspect Deep branch Laterally digiti hamate and of metacarpal of ulnar nerve rotates minimi flexor V (C8, T1) metacarpal V Figure 19. Thenar and Hypothenar Muscles retinaculum Adductor Pisiform, the Proximal Deep branch Abducts little  The power grip (palm grasp) refers to forcible motions of the digits acting digiti pisohamate phalanx of of ulnar nerve finger at against the palm; the fingers are wrapped around an object with minimi ligament, and little finger (C8, T1) metacarpophal counterpressure from the thumb—for example, when grasping a cylindrical tendon of angeal joint structure. The power grip involves the long flexor muscles to the digits flexor carpi (acting at the interphalangeal joints), the intrinsic muscles in the palm (acting ulnaris at the metacarpophalangeal joints), and the extensors of the wrist (acting at Flexor Hook of the Proximal Deep branch Flexes little the radiocarpal and midcarpal joints). The “cocking” of the wrist by the digiti hamate and phalanx of of ulnar nerve finger at extensors increases the distance over which the flexors of the fingers act, minimi flexor little finger (C8, T1) metacarpophal producing the same result as a more complete muscular contraction. brevis retinaculum angeal joint Conversely, as flexion increases at the wrist, the grip becomes weaker and more insecure.  In the 5 groups they separated the adductor pollicis—it’s in adductor compartment  Short muscle of the hand: Lumbricals found in the central compartment with the long flexor tendons and interossei, separated by an interosseous compartment between the metacarpals.  Unlike the extrinsic muscles that originate in the forearm insert in the hand and function with the hand, the intrinsic muscles occur entirely in the hand and mainly execute precision movements; they are responsible for the precision grip with the fingers and thumb.  All of the intrinsic muscle of the hand are innervated by deep branch of the ulnar nerve except the three thenar muscles (Abductor pollicis brevis, flexor pollicis brevis and opponens pollicis) and the two lateral muscles, are closer in the thumb part which will be innervated by the median nerve.  This intrinsic muscle is predominantly innervated by spinal cord segment T1 with a contribution coming from C8. Figure 20. Dorsal interossei (palmar view) Page 9 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Lumbricals Tendons of Extensor Medial two by Flex (four flexor hoods of ring, the deep metacarpopha muscles) digitorum middle,and branch of the langeal joints profundus little fingers ulnar nerve; while lateral two extending digital interphalange branches of al joints the median nerve Adductor Transverse Base of Deep branch Adducts pollicis hed- proximal of ulnar nerve thumb metacarpal III; phalanx and (C8, T1) oblique head- extensor hood capitate and of thumb bases of metacarpals II and III V. THE HIP AND THIGH A. Muscles of the Hip and Thigh  Gluteals Figure 21. Palmar interossei (palmar view) o Located in the Posterior pelvis o Extend thigh Opposition: opponens pollicis o Rotate thigh  Occurs at the carpometacarpal joint; “cupping’’ of the palm o Abducts thigh  Anterior Compartment Thigh o Flexes thigh at hip o Extends leg at knee  Medial/Adductor Compartment o Adducts thigh o Medially rotates thigh  Posterior Compartment Thigh o Extends thigh o Flexes leg Figure 22. Palmar movements  So, when you bring the tip of the thumb in contact with the fifth finger, or any with the other fingers involves considerably more movements that can be produced by Opponens pollicis alone. The first four movements of the thumb occur at the carpometacarpal and metacarpophalangeal joints.  Opposition, a complex movement, begins with the thumb in the extended position and initially involves abduction and medial rotation of the 1st metacarpal (cupping the palm) produced by the action of the opponens pollicis at the carpometacarpal joint and then flexion at the metacarpophalangeal joint.  The reinforcing action of the adductor pollicis and FPL increases the pressure that the opposed thumb can exert on the fingertips.  In pulp-to-pulp opposition, movements of the finger opposing the thumb are also involved. Table 16. Intrinsic group of muscles of the hand. Muscle Origin Insertion Innervation Function Palmaris Palmar Dermis of the Superficial Improves grip brevis aponeurosis skin on the branch of the and flexor medial margin ulnar nerve retinaculum of the hand (C8,T1) Dorsal Adjacent sides Extensor hood Deep branch Abduction of interossei of and base of of ulnar nerve index,middle, (four metacarpals proximal (C8,T1) and ring muscles) phalanges of fingers at the index, metacarpopha middle,and langeal joints Figure 23. Contents of Femur Triangle Gluteals ring fingers Palmar Sides of Extensor Deep branch Adduction of GLUTEALS interossei metacarpals hoods of the of ulnar nerve thumb,index,ri Two Groups (three or thumb,ring (C8,T1) ng,and little 1. Deep group (small muscles): four and little fingers at the  lateral rotators of the femur at the hip joint muscles) fingers and the metacarpopha o Piriformis proximal langeal joints o Obturator Internus, phalanx of o Gemellus Superior, thumb o Gemellus Inferior o Quadratus Femoris Page 22 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Table 17. Deep Group (Small Muscles) of Gluteal Region Muscle Origin Insertion Innervation Main action Piriformis Anterior Superior Branches of Laterally surface of border of anterior rami rotate sacrum; greater of S1, S2 extended thigh sacrotuberous trochanter of and abduct ligament the femur flexed thigh; steady femoral head in acetabulum Obturator Pelvic surface Medial surface Nerve to Laterally internus of obturator of greater obturator rotate membrane trochanter internus (l5,S1) extended thigh and (trochanteric and abduct surrounding fossa) of flexed thigh; bones femur steady femoral head in acetabulum Superior Superior; Medial surface Superior Laterally and ischial spine of greater gemellus; rotate inferior inferior; ischial trochanter same nerve: extended thigh gemelli tuberosity (trochanteric same nerve and abduct fossa) of supply as flexed thigh; femur obturator steady femoral Figure 24. Muscle of the gluteal region internus head in inferior acetabulum Table 18. Superficial Group (Larger Muscles) of Gluteal Region gemellus: Muscle Origin Insertion Innervation Main action same nerve Gluteus Ilium posterior Most fibers Inferior Extends thigh supply as maximus to posterior end in iliotibial gluteal especially from quadratus gluteal line; tract, which nerve (L5, flexed position femoris dorsal surface inserts into S1, S2) and assists in its Quadratus Lateral border Quadrate Nerve to Laterally of sacrum and lateral condyle lateral rotation; femoris of ischial tubercle on quadratus rotate thigh; coccyx; of tibia; some steadless thigh tuberosity intertrochante femoris (L5, stead less sacrotuberous fibers insert on and assists in ric crest of S1) femoral head ligament gluteal rising from femur and in acetabulum tuberosity sitting position. area inferior to Gluteus External Lateral surface Superior Abduct and it medius surface of of greater gluteal medially rotate ilium between trochanter of nerve (L5, thigh; keep pelvis 2. Superficial group (larger muscles) anterior and femur S1) level when  abduct and extend the hip posterior ipsilateral limb is o Gluteus Maximus gluteal lines weight-bearing o Gluteus Medius and advance o Gluteus Minimus opposite o Tensor Fasciae Latae (stabilizes the knee in extension) acting on a (unsupported specialized longitudinal band of deep fascia (the iliotibial tract) that side during its passes down the lateral side of the thigh to attach to the proximal end swing phase). of the tibia in the leg. Many of the important nerves in the gluteal region Gluteus External Anterior Superior Abduct and are in the plane between the superficial and deep groups of muscles. minimus surface of surface of gluteal medially rotate  Many of the important nerves in the gluteal region are in the plane between ilium between greater nerve (L5, thigh; keep pelvis the superficial and deep groups of muscles. anterior and trochanter of S1) level when  Lesser gluteal help stabilize hip to allow fluent bipedal walking inferior gluteal femur ipsilateral limb is lines weight-bearing and advance opposite (unsupported side during its swing phase). Tensor Anterior Iliotibial tract, Superior Abduct and fascia Lata superior iliac which attaches gluteal medially rotate e spine; anterior to lateral nerve (L5, thigh; keep pelvis part of iliac condyle of S1) level when crest tibia ipsilateral limb is weight-bearing and advance opposite (unsupported side during its swing phase). Page 22 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Figure 25. Deep Muscle in the gluteal region (posterior view) Figure 27. Fascia Lata. A. Right limb, anterior view. B. Lateral View Figure 26. Gluteus Maximus Muscle 3. Posterior Pelvis  Tensor Fasciae Latae Figure 28. Tensor fasciae latae. Left gluteal region, lateral view. ANTERIOR COMPARTMENT OF THIGH  All above are innervated by femoral nerve  Contains the anterior thigh muscles, the flexors of the hip and extensors of the knee. 1. Quadriceps femoris  It includes the Rectus femoris, Vastus lateralis, Vastus medialis, Vastus intermedius. Page 22 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano  Quadriceps means “four-headed femoral muscle o It forms the main bulk of the anterior thigh muscles. The large mass in the anterior portion of the thigh of a bodybuilder o Collectively constitutes the largest and one of the most powerful muscles in the body o It covers almost all the anterior aspects and sides of the femur. o Collectively, the quadriceps is a two-joint muscle capable of producing action at both the hip and knee. The quadriceps is the great extensor of the leg so the concentric contraction of your quadriceps, the extension of knees against gravity is important when rising from a sitting or squatting position. o It's 3x stronger than its antagonistic muscle which will be your hamstrings. o When walking, quadriceps muscles become active during the termination of the swing phase as we prepare the knee to accept the weight. o It is primarily responsible for absorbing the shock of heel strike. o It also functions as fixators during bent knee sports like skiing or tennis and it contracts eccentrically during downhill walking and when descending to stairs. a. Rectus femoris o The rectus femoris received its name because it runs straight down the thigh. Because of its attachments to the hip bone and tibia via the patellar ligament, it crosses two joints; hence, it is capable of flexing the thigh at the hip joint and extending the leg at the knee. o The only part of the quadriceps that crosses the hip joints and as a hip flexor, it acts with and like the Iliopsoas during the pre-swings and initial phases of walking. o The ability of rectus femoris to extend the knee is compromised during flexion but it does contribute to the extension force during the toe-off phase of walking when the thigh is extended. o It is particularly efficient in movements combining knee extension and Figure 29. Muscle of The Quadriceps femoris hip flexion from a position of hip hyperextension and knee flexion, e.g., preparing to kick a soccer ball 2. Sartorius o The rectus femoris is susceptible to injury and avulsion from the o The sartorius, the “tailor’s muscle” anterior inferior iliac spine during kicking, hence the name “kicking o Comes from the word sartus which means “patched and repaired”. muscle.” A loss of function of the rectus femoris may reduce thigh o It is long and ribbon-like flexion strength by as much as 17%. o It passes lateral to medial across the supero-anterior part of the thigh. b. Vastus lateralis (largest) o It lies superficially in the anterior compartment, within its own relatively distinct fascial sheath. It descends inferiorly as far as the medial side of c. Vastus medialis the knee. d. Vastus intermedius o It is the longest muscle in the body, and acts across two joints. The actions of both sartorius muscles bring the lower limbs into the cross- Table 19. Muscles of the anterior compartment of thigh (Quadriceps femoris) legged (sitting position). None of the actions of the sartorius is strong; Muscle Origin Insertion Innervation Main therefore, it is mainly a synergist, acting with other thigh muscles that action produce these movements. Quadriceps femoris Additional Muscle in the Anterior Compartment: Rectus Anterior inferior Via common 3. Iliopsoas femoris iliac spine and tendinous  It is a continuation of the psoas and iliacus muscle. ilium superior to (Quadriceps  Origin: Ilia, sacrum, lumbar vertebrae acetabulum tendon) and Extendin  Insertion: lesser trochanter independent g leg at  Action: flexor of thigh Vastus Greater attachments to knee  Innervation: femoral nerve lateralis trochanter and base of patella; joint: lateral lip of Linea indirectly via Femoral rectus aspera of femur patellar ligament nerve femoris Vastus Intertrochanteric to tibial (L2, L3, L4) also medialis and medial lip of tuberosity; medial steadies Linea aspera of and lateral vasti hip joint femur also attach to tibia and help and patella via iliopsoas Vastus Anterior and aponeuroses intermedius lateral surfaces of (medial and shaft of femur patellar retinacula) Page 22 of 22 [ANATOMY] 1.04 MUSCLAR SYSTEM – Dr. Ana Patricia De Grano Sartorius Anterior Superior part Femoral nerve Flexes, adducts superior iliac of medial (L2, L3) and laterally spine and surface of rotates thigh at superior part tibia hip joint; flexes leg of notch at knee joint, inferior to it (medially rotating leg when knee is fixed) MEDIAL/ADDUCTOR COMPARTMENT OF THIGH 1. Gracilis  Origin: pubis  Insertion: medial tibia  Action: adducts thigh, flex, medial, rotates leg  Innervation: Obturator nerve o Meaning “slender” o It is a long strap-like muscle and it is the most medial muscle of the thigh o It is the most superficial among the adductile group and also weakest member o It is the only one in the group to cross the knee joint as well as the hip joint o It joins with two other two-joint muscles from the other two compartments: Figure 30. Anterior and Posterior view of the Anterior Compartment of the Thigh  Sartorius from the anterior compartment and;  Semitendinosus muscles in the posterior compartment  The iliopsoas, the chief flexor of the thigh, is the most powerful of the hip o Thus, the three muscles are innervated by three different nerves. They flexors with the longest range. Although it is one of the body’s most powerful have a common tendinous insertion known as Pes anserinus. muscles, it is relatively hidden, with most of its mass located in the posterior wall of the abdomen and greater pelvis. Pes anserinus  Its broad lateral part, the iliacus, and its long medial part, the psoas major,  means “goosefoot”. arise from the iliac fossa and lumbar vertebrae, respectively. Thus, it is the  This inserts into the superior part of the medial surface of the thigh. only muscle attached to the vertebral column,