1. Muscle Groups of the: 1. Axilla 2. Scapular Region 3. Rotator Cuff 4. Arm 5. Forearm Flexors Forearm Extensors Gluteal Region Thigh Leg Abdomen Back Exercise SciencePSE 4U

2. Pectoralis Major Description: A large fan shaped muscle – covers upper portion of chest, forms anterior of axillary fold Origin: Clavicle, sternum, and ribs 1-7 Insertion: Crest of greater tubercle of humerus Action: Flexes, adducts and medially rotates arm Group 1Muscles of the Axilla

3. Pectoralis Minor Description: A flat thin muscle directly beneath and obscured by the pectoralis major. Forms anterior wall of Axilla Origin: Anterior surface of ribs 3-5 Insertion: Coracoid process of the scapula Action: Depresses the scapula and elevates ribs 3-5 Group 1Muscles of the Axilla

4. Serratus Anterior Description: Forms medial wall of axilla. Serrated or sawtooth appearance. Lies deep to scapula and beneath & inferior to pectoral muscles on lateral rib C1 Origin: Outer surface of ribs1-9 Insertion: Entire length of vertebral border of the scapula Action: Stabilizes, abducts and rotate the scapula upward Group 1Muscles of the Axilla

5. Subscapularis Description: Forms part of posterior wall of axilla; a “rotator cuff” muscle Origin: Subscapular fossa Insertion: Lesser tubercle of the humerus Action: Extends and medially rotates the arm, stabilizes shoulder joint. Group 1Muscles of the Axilla

6. Teres Major Description: A thick rounded muscle found inferior to the teres minor. Helps form posterior wall of axilla Origin: Axillary border of scapula Insertion: Lesser tubercle of the humerus Action: Adducts, extends and medially rotates the arm Group 1Muscles of the Axilla

7. Latissimus Dorsi Description: A broad flat, triangular muscle of the lower back (lumbar region). Forms part of posterior wall of axilla Origin: Spinous processes of T7-T12 and L1-L5, the sacrum, iliac crest, and ribs 10-12 Insertion: Intertubercular groove of the humerus Action: Extends, adducts and medially rotates the arm; pulls shoulder inferiorly Group 1Muscles of the Axilla

8. Trapezius Description: A flat triangular muscle, upper fibers run downward to scapula, middle fibers run horizontally to scapula, lower fibers run superiorly to scapula Origin: Occipital bone, the ligamentum nuchae, and the spinous processes of C7-T12 Insertion: Lateral 1/3 of clavicle and the spine of the scapula Action: Abducts and extends head, rotates and adducts scapula Group 2Muscles of the Scapular Region

9. Levator Scapulae Description: Thick strap like muscle located at back & side of the neck, deep to trapezius; Origin: Transverse processes of C1-C4 Insertion: Superior angle of scapula Action: Elevates scapula, and rotates and abducts neck Group 2Muscles of the Scapular Region

10. Rhomboid Major Description: A rectangular shaped muscle lying deep to trapezius and inferior to levator scapulae. Inferior to rhomboideus minor. Origin: Spinous processes of T1-T4 Insertion: Inferior, vertebral border of the scapula Action: Adducts, stabilizes and rotates the scapula Group 2Muscles of the Scapular Region

11. Rhomboid Minor Description: A rectangular shaped muscle lying deep to trapezius and inferior to levator scapulae Origin: Spinous processes of C6-C7 Insertion: Superior, vertebral border of the scapula Action: Adducts, stabilizes and rotates the scapula Group 2Muscles of the Scapular Region

12. Deltoid Description: Responsible for roundness of shoulder Origin: Clavicle, acromion process, and spine of the scapula. Insertion: Deltoid tuberosity of the humerus Action: Abducts, flexes, extends medially, and laterally rotates the arm Group 2Muscles of the Scapular Region

13. Group 3Muscles of the Rotator Cuff Consists of 4 muscles a) Supraspinatus b) Infraspinatus c) Teres Minor d) Subscapularis (mnemonic S.I.T.S. - they sit on the shoulder) *If any of the rotator cuff muscles is damaged due to strain or bad mechanics, the consequences are serious for arm/shoulder actions

14. Supraspinatus Description: Named for its location on posterior aspect of scapula Origin: Supraspinous fossa of the scapula Insertion: Greater tubercle of the humerus by a common tendon with Infraspinatus and Teres Minor Action: Abducts arm and stabilizes the shoulder Group 3Muscles of the Rotator Cuff

15. Infraspinatus Description: Partially covered by deltoid & trapezius Origin: Infraspinous fossa of the scapula Insertion: Greater tubercle of the humerus by common tendon with Supraspinatus & Teres Minor. Action: Extends, laterally rotates arm and stabilizes the shoulder Group 3Muscles of the Rotator Cuff

16. Teres Minor Description: Small, elongated muscle that lies inferior to infraspinatus Origin: Axillary border of the scapula. Insertion: Greater tubercle of the humerus by common tendon with supraspinatus & infraspinatus Action: Same action as infraspinatus muscle (Extends, laterally rotates arm and stabilizes the shoulder) Group 3Muscles of the Rotator Cuff

17. Subscapularis Description: A large triangular muscle, and the only muscle in the group located on the anterior surface of the scapula Origin: Subscapular fossa of the scapula Insertion: Lesser tubercle of the humerus Action: Medially rotates humerus and stabilizes the shoulder. Group 3Muscles of the Rotator Cuff

18. Triceps Brachii Description: Large fleshy muscle and the only muscle of posterior compartment of the arm Origin: Long head= Infraglenoid tuberosity of the scapula Lateral and medial heads= posterior surface of humerus Insertion: Olecranon process of the ulna Action: Extends the forearm and arm, and adducts the arm Group 4Muscles of the Arm

19. Coracobrachialis Description: A small cylindrical muscle. Origin: Coracoid process of the scapula Insertion: Medial shaft of the humerus Action: Flexion & adduction of the humerus Group 4Muscles of the Arm

20. Brachialis Description: Strong muscle that is immediately deep to the biceps brachii Origin: Anterior, distal humerus Insertion: Coronoid Process of the ulna Action: Flexion of the forearm Group 4Muscles of the Arm

21. Anconeus Description: A short triangular muscle closely associated with distal end of triceps Origin: Lateral epicondyle of the humerus Insertion: Olecranon process of the ulna Action: Extends the forearm Group 4Muscles of the Arm

22. Pronator Teres Description: A two headed muscle Origin: Medial epicondyle of the humerus and the coronoid process of the ulna Insertion: Middle shaft of the radius Action: Pronates and weakly flexes the forearm Group 5Forearm Flexors

23. Flexor Carpi Radialis Description: Runs diagonally across the forearm; midway, its fleshy belly is replaced by a flat tendon that becomes cordlike at wrist Origin: Medial epicondyle of the humerus Insertion: 2nd and third meta carpals Action: Flexes & abducts the hand; aids in flexion and pronation of forearm. Powerful flexor of wrist Group 5Forearm Flexors

24. Flexor Carpi Ulnaris Description: Most medial muscle of this group; two headed Origin: Medial epicondyle of humerus; olecranon process; posterior surface of ulna Insertion: Pisiform, hamate & 5th metacarpal Action: Flexes & adducts the hand; powerful flexor of wrist Group 5Forearm Flexors

25. Gluteus Maximus Description: Largest and strongest, most superficial of gluteal muscles; forms bulk of buttock mass; fibers are thick & coarse. Origin: Lateral surface of ilium, sacrum and coccyx Insertion: Lateral condyle of tibia by lateral fascia and gluteal tuberosity of the femur Action: Extends, abducts, and laterally rotates the thigh Group 7Muscles of the Gluteal Region

26. Gluteus Medius Description: Thick muscle largely covered by gluteus maximus and sits on top of gluteus minimus Origin: Outer ilium, between the posterior & the anterior gluteal lines Insertion: Greater trochanter of the femur Action: Abducts & medially (internal) rotates the thigh Group 7Muscles of the Gluteal Region

27. Gluteus Minimus Description: Smallest and deepest of the gluteus muscles Origin: Outer (external) ilium, between the anterior and the inferior gluteal lines Insertion: Greater trochanter of the femur Action: Abducts and medially (internally) rotates the thigh; same action as the gluteus medius Group 7Muscles of the Gluteal Region

28. Sartorius Description: A superficial anterior muscle of the thigh. It derives its name from the latin word sartor meaning “to mend”. Origin: Anterior superior iliac spine Insertion: Medial surface of the tibia Action: The sartorius acts across two joints: Flexes and laterally rotates the hip and flexes the knee Group 7Muscles of the Gluteal Region

29. Quadratus Femoris: Description: Short thick muscle; most inferior of lateral rotator muscles, extends laterally from pelvis Origin: Ischial Tuberosity Insertion: Shaft of the femur just below the greater trochanter Action: Laterally rotates the thigh and stabilizes hip joint Group 7Muscles of the Gluteal Region

30. Sartorius Description: A superficial anterior muscle of the thigh. It derives its name from the latin word sartor meaning “to mend”. Origin: Anterior superior iliac spine Insertion: Medial surface of the tibia Action: The sartorius acts across two joints: Flexes and laterally rotates the hip and flexes the knee Group 8Muscles of the Thigh Anterior Compartment

31. IIiopsoas Description: A composite of two closely related muscles: iIiacus and psoas major Origin: Psoas major – the transverse processes and bodies of T12 and L1-L5 IIiacus – iliac fossa and sacrum Insertion: Lesser trochanter of femur Action: Flex the thigh; flex the trunk on the femur Group 8Muscles of the Thigh Anterior Compartment

32. Rectus Femoris Description: Superficial, straight muscle of the anterior thigh; longest head and only muscle of the group to cross the hip joint Origin: Anterior inferior iliac spine Insertion: Tibial tuberosity, via the patella and the patellar ligament Action: Extends the leg (knee) and flexes the thigh Group 8Muscles of the Thigh

33. Vastus Lateralis Description: Forms lateral aspect of thigh Origin: Greater trochanter and the lateral lip of the linea aspera of the femur Insertion: Tibial tuberosity, via the patella and the patellar ligament Action: Extend the leg (knee) Group 8Muscles of the Thigh

34. Vastus Medialis Description: Forms inferomedial aspect of thigh Origin: Medial lip of the linea aspera of the femur Insertion: Tibial tuberosity, via the patella and the patellar ligament Action: Extends the leg (knee) Group 8Muscles of the Thigh

35. Vastus Intermedius Description: Lies between vastus lateralis and vastus medialis on anterior thigh Origin: Anterior, lateral shaft of the femur Insertion: Tibial tuberosity, via the patella and the patellar ligament Action: Extend the leg (knee) Group 8Muscles of the Thigh

36. Pectineus Description: Short flat muscle; overlies adductor brevis on proximal thigh Origin: Superior ramus of the pubis Insertion: Posterior femur just below the lesser trochanter Action: Adducts and laterally rotates the thigh Group 8Muscles of the Thigh

37. Adductor Longus Description: Most anterior of adductor muscles Origin: Crest and the symphysis of the pubis Insertion: Middle 1/3 of the linea aspera of the femur Action: Adducts and laterally rotates the thigh Group 8Muscles of the Thigh

38. Adductor Brevis Description: Largely concealed by adductor longus and pectineus Origin: Inferior ramus of the pubis Insertion: Upper part of the linea aspera of the femur Action: Adducts and laterally rotates the thigh (femur) Group 8Muscles of the Thigh

39. Adductor Magnus Description: A triangular muscle with a broad insertion; a composite muscle that is part adductor and part hamstring in action Origin: Inferior ramus of the pubis and the ischium Insertion: Most of the length of the linea aspera, and the adductor tubercle of the femur Action: Adducts, flexes, extends and laterally rotates the thigh Group 8Muscles of the Thigh

40. Gracilis Description: Long, thin, superficial muscle of the medial thigh Origin: Symphysis pubis and the pubic arch Insertion: Proximal portion medial tibia just below the condyle Action: Adducts the thigh and flexes the leg Group 8Muscles of the Thigh

41. Biceps Femoris L.H. S.H. Description: Most lateral muscle of the group; arises from two heads Origin: Long head-ischial tuberosity Short head-distal linea aspera Insertion: Head of fibula, and the lateral condyle of the tibia Action: Flexes and laterally rotates the leg (knee), long head extends thigh Group 8Muscles of the Thigh

42. Semitendinosus Description: Lies medial to biceps femoris, quite fleshy; its slendedr tendon begins about 2/3 way down the thigh Origin: Ischial Tuberosity Insertion: Medial, proximal end of the tibia Action: Extends thigh, flexes and medially rotates leg Group 8Muscles of the Thigh

43. Semimembranosus Description: Deep to semitendinosus Origin: Ischial tuberosity Insertion: Medial, proximal end of the tibia Action: Extends thigh, flexes and medially rotates leg Group 8Muscles of the Thigh

44. Tibialis Anterior Description: Superficial muscle of anterior leg; laterally parallels sharp anterior margin of tibia Origin: Lateral tibia Insertion: Medial cuneiform & first metatarsal Action: Dorsiflexes & inverts the foot Group 9Muscles of the LegAnterior Compartment

45. Extensor Digitorum Longus Description: On anterolateral surface of leg; lateral to tibialis anterior Origin: Lateral condyle of the tibia, proximal shaft of the fibula Insertion: Dorsal surface of the phalanges of digits 2-5 Action: Dorsiflexes & everts the foot; extends digits 2-5 Group 9Muscles of the LegAnterior Compartment

46. Extensor Hallucis Longus Description: Deep to extensor digitorum longus & tibialis anterior; narrow origin Origin: Medial shaft of fibula, and interosseous membrane Insertion: Distal phalanx of the hallux (1st digit) Action: Dorsiflexes & inverts foot; extends the hallux Group 9Muscles of the LegAnterior Compartment

47. Gastrocnemius: Description: Superficial muscle of pair; two prominent bellies that form proximal curve of calf Origin: Medial & lateral condyles of the femur Insertion: Calcaneus Action: Flexes the leg and plantar flexes the foot Group 9 Muscles of the LegSuperior Compartment

48. Soleus Description: Deep to gastronemius on posterior surface of calf Origin: Posterior fibula and tibia Insertion: Calcaneus Action: Plantar flexes the foot and important during walking, running & dancing Group 9Muscles of the LegPosterior Compartment

49. Popliteus: Description: Thin, triangular muscle at posterior knee; passes downward & medially to tibial surface Origin: Lateral condyle of the femur Insertion: Proximal portion of the tibia Action: Flexes the leg & rotates it medially to unlock knee from full extension when flexion begins Group 9: Muscles of the LegPosterior Compartment – Deep Muscles

50. External Abdominal Oblique: Description: Largest & most external of the abdominal oblique muscles; fibers run downward & medially; aponeurosis turns under inferiorly forming inguinal ligament Origin: External surface of ribs 5-12 (fleshy strips) Insertion: Linea alba, iliac crest and inguinal ligament Action: Compresses the abdomino pelvis cavity and laterally rotates; aids in lateral flexion Group 10Muscles of the Abdominal Wall