1. Exercise Science
The Muscular System

2. Agonist and Antagonist
responsible formain movmenet
Antagonist
Acts in opposition to specific movements generated by the agonist
Returns the limb to initial position
Antagonistic pairs
Needed in body because muscles can only exert a pulling force and can’t push themselves back in original position

4. Movement
Agonist
Antagonist
Knee Flexion
Hamstrings
Quadriceps
Medial Shoulder Rotation
Pectoralis Major
Infraspinatus
Shoulder Rotation & Elevation
Trapezius
Lattissimus Dorsi
Hip Extension
Gluteus Maximus
Iliopsoas
Trunk Extension
Erector Spinae
Rectus Abdominus
Plantar Flexion
Gastrocnemius
Tibialis Anterior
Wrist Flexion
Wrist Flexors
Wrist Extensors
Forearm Supination
Supinator
Pronator (teres/quadratus)
Dorsi Flexion
Shoulder Abduction
Anterior Deltoid
Latissimus Dorsi
Shoulder Adduction/Rotation
Deltoid/Trapezius
Thigh Flexion
Iliacus
Hip Extension & Adduction
Adductor Magnus
Gluetus Medius & Psoas
Trunk Rotation
External Obliques
Adducts/Lateral Rotation of Arm
Supraspinatus
Retracts Scapula
Rhomboids
Serratus Anterior
Neck Flexion
Sternocleidomastoid

5. Principles of Muscle Action
Muscle must cross a joint to act directly on that joint
How a muscle crosses a joint will affect the action
When muscles shorten, it exerts on equal pull on origin & insertion – whichever offers less resistance is the one which will move

6. Origin = the end that stays fixed
Insertion = the end that moves

7. Muscles of the Neck Sternocleidomastoid Origin: clavicle & sternum
Insertion: mastoid process (temporal bone behind ear)
Function: flex & rotate head side to side

8. Spinalis Origin: cerical & thoracic vertebrae
Insertion: cervical and thoracic vertebrae above
Function: extend & laterally flex spine

9. Muscles of the Abdomen Rectus Abdominus
Origin: pubic crest & pubic symphysis
Insertion: xiphoid process & inferior ribs
Function: trunk flexion; also expiration, defecation & childbirth

10. External Obliques/Transverse Abdominus
Origin: lower 8th rib
Insertion: iliac crest, linea alba & pubis
Function: flex & rotate vertebral column, compress abdomen during forced expiration

11. Muscles Acting on the Upper Limb
Pectoralis Major
Origin: clavicle, sternum, coastal cartilage of 1st to 6th rib, external oblique muscle
Insertion: intertubercular groove
Function: internal rotation, adduction & flexion of arm

12. Latissimus Dorsi
Origin: lumbar & 7th thoracic vertebrae, iliac crest, down to the sacrum
Insertion: back of humerus at floor of interturbercular groove
Function: adductor, extensor and internal rotator of the arm

13. Muscles of the Rotator Cuff
Supraspinatus
Origin: posterior scapula
Insertion: greater tubercle of humerus
Function: stabilize shoulder joint, abducts shoulder
Infraspinatus
Function: stabilize shoulder joint, laterally rotates shoulder

14. Teres Minor Subscapularis Origin: Lateral border of scapula
Insertion: greater tubercle of humerus
Function: stabilzes, laterally rotates shoulder
Subscapularis
Origin: anterior scapula
Insertion: lesser tubercle of humerus
Function: stabilize, rotates humerus medialy

15. * S.I.T.S.

16. Muscles that Position the Scapula
Trapezius
Origin: occipital bone down to the 12th vertebrae
Insertion: spine of the scapula, acromion & clavicle
Function: important lateral neck muscles
Acting alone: tilt the head side to side
Together: neck extension

17. Rhomboid Major and Minor
Origin: T2-T5 (major), C7-T1 (minor)
Insertion: scapula (major), scapular spine (minor)
Function: adduction & retraction of scapula, downward rotation of scapula

18. Levator Scapulae Origin: 4 upper cervical vertebrae near base of skull
Insertion: scapula
Function: elevates & rotates scapula

20. Serratus Anterior Origin: first 8-9 ribs Insertion: scapula
Function: upward rotation & abduction or protraction of scapula

21. Pectoralis Minor Origin: 3rd, 4th, 5th rib Insertion: scapula
Function: elevates ribs, depress & protracts scapula

22. Scapular Muscles that Move Humerus
Deltoid
Origin: clavicle, acromion, spine of of scapula
Insertion: humerus (deltoid tuberocity)
Function: medially rotates shoulder, abducts arm, extends & laterally rotates arm

23. Teres Major Origin: scapula
Insertion: intertubercular groove of humerus
Function: medial rotator, adductor, extends humerus at the arm

24. Elbow Flexors and Extensors
Biceps Brachii
Origin: scapula (coracoid process & supraglenoid tubercle)
Insertion: radial tuberocity
Function: forearm supinator, elbow flexion

25. Brachialis Brachioradialis Origin: lower anterior surface of humerus
Insertion: corocoid process of ulna
Function: elbow flexion
Brachioradialis
Origin: lateral epicondyle of humerus
Insertion: styloid process of radius

26. Triceps Brachii
Origin: posterior humerus & infraglenoid tubercle of scapula
Insertion: olceranon process of the ulna
Function: elbow extension

27. Anconeus Origin: lateral epicondyle of humerus
Insertion: olecranon & superior-posterior ulna
Function: assists triceps in extending forearm

28. Supination and Pronation
Supinator
Origin: lateral epicondyle of humerus
Insertion: lateral radius
Function: supination of forearm

29. Pronator Teres Pronator Quadratus Origin: medial epicondyle of humerus
Insertion: midshaft of radius
Function: pronation of forearm
Pronator Quadratus
Origin: anterior surface of distal ulna
Insertion: anterior surface of distal radius

30. Extrinsic Hand Muscles
ANTERIOR VIEW

31. POSTERIOR VIEW

32. Intrinsic Hand Muscle
Thenar Eminence
Hypothenar Eminence

33. Muscles of the Hip (Posterior)
Tensor Fasciae Latae
Origin: anterior iliac crest
Insertion: iliotibial tract (lateral femur)
Function: flex, abduct & medially rotate thigh

34. Sartorius Origin: anterior superior iliac spine
Insertion: medial tibia
Function: flexion & outward rotation of hip, knee flexion

35. Gluteus maximus Gluteus medius Gluteus minimus
Origin: illium crest, sacrum, coccyx
Insertion: greater trochanter of femur, iliotibial tract
Function: hip extension & external rotation
Gluteus medius
Origin: lateral surface of ilium
Insertion: posterior greater trochanter
Function: hip abduction & internal rotation
Gluteus minimus
Origin: lateral surface of ilum
Insertion: anterior greater trochanter

37. Muscles of the Hip (Anterior)
Iliopsoas (iliacus + psoas major)
Origin: inner ilium
Insertion: lesser trochanter of femur
Function: hip flexion

38. Hip Adductors
Adductor Longus
Adductor Magnus
Adductor Brevis

39. Pectineus Origin: superior ramus of pubis
Insertion: lesser trochanter to linea aspera
Function: hip adduction & flexion

40. Gracilis Origin: inferior ramus of pubis
Insertion: medial tibial condyle
Function: hip adduction, knee flexion

41. Anterior Thigh (Quadriceps)
Rectus Femoris
Origin: anterior inferior iliac spine
Insertion: tibial tuberosity
Function: knee extension & hip flexion
Vastus Lateralis
Origin: linea aspera & greater trochanter
Function: knee extension

42. Vastus Intermedius Vastus Medialis Origin: anterior shaft of femur
Insertion: tibial tuberosity
Function: knee extension
Vastus Medialis
Origin: medial aspect of linea apsera
*Quadriceps = Rectus Femoris, Vastus Lateralis Vastus Intermedius & Vastus Medialis,

43. Posterior Thigh (Hamstring)
Biceps Femoris
Origin: ischial tuberosity & linea aspera
Insertion: head of fibula
Function: knee flexion, hip extension

44. Semimembranosus Semitendinosis Origin: ischial tuberosity
Insertion: medial tibial condyle
Function: knee flexion, hip extension
Semitendinosis
Insertion: proximal part of tibia, below medial condyle
Function: knee flexion, hip extension
*Hamstrings = Biceps Femoris, Semimembranosus & Semitendinosis

45. Extrinsic Foot Muscles
Anterior Compartment
Tibialis Anterior
Origin: anterior shaft of tibia
Insertion: 1st metatarsal (big toe)
Function: dorsi flexion, inversion

46. Posterior Component Gastrocnemius Soleus
*Calf Muscles = Gastrocnemius & Soleus
Gastrocnemius
Origin: lateral & medial conyles of femur
Insertion: calcaneus
Function: plantar flexion, knee flexion
Soleus
Origin: upper tibia & fibula
Function: plantar flexion

47. Tibialis Posterior Popliteus
Origin: posterior surface of tibia & fibula
Insertion: tuberosity of navicular bone
Function: plantar flexion, inversion
Popliteus
Origin: lateral condyle of femur
Insertion: proximal shaft of tibia on posterior side below medial condyle
Function: medially rotates leg

48. Posterior Compartment

49. Extensor hallucus longus
Extensor digitorum longus

50. Flexor Digitorum Longus
Flexor Hallucis Longus

51. Intrinsic Foot Muscles
Flexor Digitorum Brevis
Flexor Hallucis Brevis
Quadratus Plantae