Muscles and Muscle Actions Upper Body Flashcards
Rhomboids
- between shoulder blades
- crosses shoulder girdle
- retracts scapula
- downwordly rotates scapula
- origin- spinour process of cervical and thoracic vertebrae c7, t1-t5
- insertion medial border scapula
Rhomboids
- between shoulder blades
- crosses shoulder girdle
- retracts scapula
- downwordly rotates scapula
- origin- spinour process of cervical and thoracic vertebrae c7, t1-t5
- insertion medial border scapula
Serratus anterior
- Sides of ribs
- crosses shoulder girdle
- protraction
- upwardly rotates scapula
- origin- outer surfaces of first 8 or 9 ribs
- insertion anterior surface of medial border fo scapula
Serratus Anterior
- Sides of ribs
- crosses shoulder girdle
- protraction
- upwardly rotates scapula
- origin- outer surfaces of first 8 or 9 ribs
- insertion anterior surface of medial border fo scapula
Levator scapulae
- back of neck
- crosses shoulder girdle
- moves scapula relative to ribcage
- elevated scapula
- assists in downward roation of scapula
- insertion laterally flexes the neck
Levator
- back of neck
- crosses shoulder girdle
- moves scapula relative to ribcage
- elevated scapula
- assists in downward roation of scapula
- insertion laterally flexes the neck
origin- transverse process of cervical vertebrae
insertion- media border of scapula between superior angle and root of spine od scapula
Pectoralis Minor
- front of chest beneath pec major
- crosses shoulder girdle (moves scapula relative to ribcage)
- pulls shoulder girdle forwards (protraction)
- downwardly rotates scapula (works as synergist with rhomboids)
- origin 3,4 5th ribs
insertion- coracoid process of scapula
- stabilizes shoulder girdle
- holds scapula forwards during pushing actions
- often becomes too short and tight which pulls shoulder blade forwards and down
Pectoalis Minor
- front of chest beneath pec major
- crosses shoulder girdle (moves scapula relative to ribcage)
- pulls shoulder girdle forwards (protraction)
- downwardly rotates scapula (works as synergist with rhomboids)
- origin 3,4 5th ribs
insertion- coracoid process of scapula
- stabilizes shoulder girdle
- holds scapula forwards during pushing actions
- often becomes too short and tight which pulls shoulder blade forwards and down
Trapezius
- between shoulder blades
- crosses shoulder girdle (moves scapula relative to ribcage)
- upper fibers raise shoulder girdle (elevation)
- middle fibers pull shoulder girdle back (retraction)
- lower fibers pull shoulder girdle down (depression)
whole muscle upwardly rotates scapula (synergist with seratus anterior)
origin- cranium, c7 and thoracic vertebrae
Different fiber directions for upper, middle and lower trapezius allow it to create force in 3 different directions
Trapezius
- between shoulder blades
- crosses shoulder girdle (moves scapula relative to ribcage)
- upper fibers raise shoulder girdle (elevation)
- middle fibers pull shoulder girdle back (retraction)
- lower fibers pull shoulder girdle down (depression)
whole muscle upwardly rotates scapula (synergist with seratus anterior)
origin- cranium, c7 and thoracic vertebrae
Different fiber directions for upper, middle and lower trapezius allow it to create force in 3 different directions
Pectoralis Major
Chest
crosses shoulder
horizontal flexion/adduction of arm
medial rotation of arm (draws arm inward)
arm adduction
lift arm forwards (flexion)
origin- clavicle, sternum and cartilage of ribs 1-6
inserts humerus
different fiber directions allow arm to move in different directions
Pectoralis Major
Chest
crosses shoulder
horizontal flexion/adduction of arm
medial rotation of arm (draws arm inward)
arm adduction
lift arm forwards (flexion)
origin- clavicle, sternum and cartilage of ribs 1-6
inserts humerus
different fiber directions allow arm to move in different directions
Latissimus Dorsi
back
crosses shoulder
draws arm back and down (extension)
draws arm down and to side (adduction)
turns arm inwards (medial rotation)
assists in depression of scapula (through action on humerus)
origin- thoracolumbar fascia from c7-c12, lumbar vertebrae and iliac crest, lower 4 ribs and angle of scapula
insertion humerus
Latissimus dorsi
back
crosses shoulder
draws arm back and down (extension)
draws arm down and to side (adduction)
turns arm inwards (medial rotation)
assists in depression of scapula (through action on humerus)
origin- thoracolumbar fascia from c7-c12, lumbar vertebrae and iliac crest, lower 4 ribs and angle of scapula
insertion humerus
Teres Major
back, just beneath shoulder blade
crosses shoulder
draws arm down into the side (adduction)
draws arm back and down (extension)
turns arm inwards (medial rotation)
origin- inferior angle of scapula
insertion -humerus