Muscles of the Shoulder and Upper Arm Flashcards
Trapezius Origin
Base of skull (occipital bone). Spinous processes of seventh cervical (C7) and all thoracic vertebrae, (T1-T12)
Trapezius Insertion
Lateral third of clavicle. Acromion process. Spine of scapula
Trapezius Action
Upper fibers: Pull the shoulder girdle up (elevation). Helps prevent depression of the shoulder girdle when a weight is carried on the shoulder or in the hand.
Middle fibers: Retract (adduct) scapula
Lower fibers: Depress scapula, particularly against resistance, as when using the hands to get up from a chair.
Upper and lower fibers together: Rotate scapula, as in elevating the arm above the head.
Trapezius Nerve
Accessory X1 nerve. Ventral ramus of cervical nerves, C2, 3, 4.
Trapezius Basic Functional Movement
Ex upper & lower fibers working together: Painting a ceiling
Trapezius Sports that heavily utilize this muscle
Shot put. Boxing. Seated rowing
Trapezius Common problems when muscle isa chronically tight / shortened
Upper fibres: Neck pain or stiffness. Headache
Trapezius Strengthening Exercise
Upper fibers: shoulder press
Middle / lower fibers: Dips
Middle / lower fibers: Chin-ups
Lateral dumbbell raise
Trapezius Self Stretch
Turn head to right and tuck chin in. Pull left shoulder down. Pull head and left shoulder apart from each other.
Levator Scapulae Origin
Transverse processes of the first three or four cervical vertebrae (C1-C4.
Levator Scapulae Insertion
Upper medial (vertebral) border of the scapula (i.e. portion above the spine of the scapula)
Levator Scapulae Action
Elevates scapula. Helps retract scapula. Helps bend neck laterally.
Levator Scapulae Nerve
Dorsal scapular nerve, C4, 5 and cervical nerves C3, 4.
Levator Scapulae Basic Functional Movement
Carrying a heavy bag
Levator Scapulae Sports that heavily utilize this muscle
Shot put. Weight lifting.
Levator Scapulae Common problems when muscle is chronically tight / shortened
Upper fibers: Neck pain or stiffness, headaches
Levator Scapulae Strengthening Exercises
- Shoulder shrugs with dumbbells or barbell
2. Upright rows
Levator Scapulae Self Stretches
- Drop chin to chest and turn chin 45 degrees. Keep spine long
- Use weights to pull down on arms / shoulders
Rhomboids (minor and major) Origin
Spinous processes of the seventh cervical and upper five thoracic vertebrae, (C7-T1???)
Rhomboids (minor and major) Insertion
Medial (vertebral) border of scapula
Rhomboids (minor and major) Nerve
Dorsal scapular nerve, C4, 5.
Rhomboids (minor and major) Basic Functional Movement
Pulling something towards you, such as opening a drawer
Rhomboids (minor and major) Sports that heavily utilize these muscles
Archery. Seated rowing. Wind surfing. Racquet sports.
Rhomboids (minor and major) Common problems when muscles are tight or overstretched
Tight: Soreness or aching between shoulder blades
Overstretched: Rounded shoulders are both symptomatic of, and exacerbated by, overstretched rhomboids (which tend to get overstretched rather than become too tight).
Rhomboids (minor and major) Strengthening exercises
- Seated rowing
- Upright (vertical) rowing
- Lat pull-downs
- Pulley shoulder adduction
Rhomboids (minor and major) Self Stretch
Bring arm across chest opening up scapular position
Serratus Anterior Origin
Outer surfaces and superior borders f upper eight or nine ribs, and the fascia covering their intercostal spaces
Serratus Anterior Insertion
Anterior (costal) surface of the medial border of scapula and inferior angle of scapula
Serratus Anterior Action
Protracts scapula (pulls it forward on the ribs and holds it closely into the chest wall). Rotates scapula for abduction and flexion of arm
Serratus Anterior Nerve
Long thoracic nerve, C5, 6, 7, 8.
Serratus Anterior Basic Functional Movement
Pushing or reaching forwards for something barely within reach
Serratus Anterior Sports that heavily utilize this muscle
Boxing. Shot put.
Serratus Anterior Common problems when muscle is weak
‘Wined scapula’ (looking like an angel’s wing), especially when holding a weight in front of the body. This is also a feature when the nerve to this muscle is damaged.
Serratus Anterior Strengthening Exercises
- Bench press (including incline)
- Shoulder press
- Press-ups (like push ups)
Serratus Anterior Self Stretch
Sit on chair. Reach one arm behind back of chair. Repeat on other side.
Pectoralis Minor Origin
Outer surface of third, fourth and fifth ribs and fascia of the corresponding intercostal spaces
Pectoralis Minor Insertion
Corocoid process of scapula
Pectoralis Minor Action
Draws scapula forward and downward. Raises ribs during forced inspiration (i.e. it is an accessory muscle of inspiration, if the scapula is stabilized by the rhomboids and trapezius).
Pectoralis Minor Nerve
Medial pectoral nerve with fibers from a communicating branch of the lateral pectoral nerve, C(6), 7, 8, T1.
Pectoralis Minor Basic Functional Movement
Ex: Pushing on arms of chair to stand up.
Pectoralis Minor Sports that heavily utilize this muscle
Racquet sports, e.g. tennis, badminton. Baseball pitching. Sprinting
Pectoralis Minor Common problems when muscle is chronically tight / shortened
Restricts expansion of chest.
Pectoralis Minor Strengthening Exercises
- Bench press
- Dumb-bell flies
- Lat Pull overs
Pectoralis Minor Self Stretches
- Fix arm against a door frame. Step forward keeping your back lengthened, not arched. Raising or lowering arm will stretch different parts of the muscle.
- Stand in middle of open doorway. Arms on each side of door frame. Step forward to open chest.
Pectoralis Major Origin
Clavicular head: Medial half or two-thirds of front of clavicle
Sternocostal portion: Sternum and adjacent upper six costal cartilages.
Pectoralis Major Insertion
Upper shaft of humerus.
Pectoralis Major Action
Adducts and medially rotates the humerus.
Clavicular portion: Flexes and medially rotates the shoulder joint, and horizontally adducts the humerus towards the opposite shoulder.
Sternocostal portion: Obliquely adducts the humerus towards the opposite hip.
The pectoralis major is one of the main climbing muscles, pulling the body up to the fixed arm.
Pectoralis Major Nerve
Nerve to upper fibers: Lateral pectoral nerve, C5, 6, 7
Nerve to lower fibers: Lateral and medial pectoral nerves, C6, 7, 8, T1.
Pectoralis Major Basic Function Movement
Clavicular portion: Brings arm forwards and across the body. as in applying deodant to opposite armpit.
Sternal portion: pulling down from above, such as a rope in bell ringing.
Pectoralis Major Sports that heavily utilize this muscle
Ex: Racquet sports such as tennis. Golf. Baseball pitching. Gymnastics (rings and high bar). Judo. Wrestling.
Pectoralis Major Movements or injuries that may damage this muscle
Indian wrestling and other strength activities that force medial rotation and adduction can damage the insertion of this muscle
Pectoralis Major Common problems when muscle is tight
Rounds the back and restricts expansion of chest, restricting lateral rotation and abduction of the shoulder
Pectoralis Major Strengthening Exercises
- Bench press
- Dumb-bell flies
- Vertical flyes on pec deck machine
- Lat pull-overs
- Dips
Pectoralis Major Self Stretches
- Fix arm against a door frame. Step forward keeping your back lengthened, not arched. Raising or lowering arm will stretch different parts of the muscle.
- Stand in open doorway. Arms out to either side of door frame. Step forward to open chest.
Latissimus Dorsi Origin
A broad sheet of tendon which is attached to the spinous processes of lower six thoracic vertebrae and all the lumbar and sacral vertebrae, (T7 - S5). Posterior part of iliac crest. Lower three or four ribs. Inferior angle of the scapula.
Latissimus Dorsi Insertion
Twists to insert into the intertubercular sulcus (bicipital groove) of humerus, just below the shoulder joint.
Latissimus Dorsi Action
Extends the flexed arm. Adducts and medially rotates the humerus (i.e. draws the arm back and inwards towards the body).
Latissimus Dorsi Nerve
Thoracodorsal nerve, C6, 7, 8, from the posterior cord of the brachial plexus.
Latissimus Dorsi Basic Functional Movement
Ex: Pushing on arms of chair to stand up.
Latissimus Dorsi Sports that heavily utilize this muscle
Ex: Climbing. Gymnastics (rings, parallel bars). Swimming. Rowing.
Latissimus Dorsi Strengthening Exercises
- Pull- ups (esp wide grip)
- Lat Pull-downs
- Pull-overs
- Seated rowing
- Pulley shoulder adduction
Latissimus Dorsi Self Stretches
- Reach both arms overhead. Pull right elbow to the left with left hand. Side bending to the left will increase stretch.
- Childs pose
Deltoideus Origin
Clavicle, acromion process and spine of scapula
Deltoideus Insertion
Deltoid tuberosity, situated halfway down the lateral surface of the shaft of the humerus.
Deltoideus Action
Anterior fibers: Flex and medially rotate the humerus.
Middle fibers: Abduct the humerus at the shoulder joint (only aftehr the movement has been initiated by supraspinatus).
Posterior fibers: Extend and laterally rotate the humerus.
Deltoideus Nerve
Axillary nerve, C5, 6, from the posterior cord of the brachial plexus.
Deltoideus Basic Functional Movement
Reaching for something out to the side, or raising the arm to wave.
Deltoideus Sports that heavily utilize this muscle
Javelin. Shot put. Racquet sports. Wind surfing. Weight lifting.
Deltoideus Strengthening Exercises
- Lateral dumb-bell raises (middle fibers)
- Upright rows (mainly middle fibers)
- Bench Press (anterior fibers)
- Shoulder Press (Mainly middle fibers)
- Vertical flyes (anterior fibers
Deltoideus Self Stretches
- Arms behind back. Keep arms and torso straight and slowly bend your knees. Vary by placing back of hands on table (mainly for anterior fibers)
- Raise one arm to shoulder height. Flex the arm across to the other shoulder. Hold the raised elbow with the opposite hand and pull the elbow backward
Supraspinatus Origin
Supraspinous fossa of scapula (hollow above the spine of the scapula).
Supraspinatus Insertion
Greater tubercle at the top of the humerus. Capsule of shoulder joint.
Supraspinatus Action
Initiatyes the process of abduction at the shoulder joint, so that the deltoid can take over at the later stages of abduction.
Supraspinatus Nerve
Suprascapular nerve, C4, 5, 6, from the upper trunk of the brachial plexus
Supraspinatus Basic Functional Movement
Ex: Holding shopping bag away from side of body.
Supraspinatus Sports that heavily utilize this muscle
Baseball. Golf. Racquet sports.
Supraspinatus Movements or injuries that may damage this muscle
Dislocation of the shoulder joint.
Supraspinatus Strengthening Exercises
- Lateral Dumb-bell Raises
2. Seated rowing
Supraspinatus Self Stretches
Raise one arm to shoulder height. Flex the arm across to the other shoulder. Hold the raised elbow with the opposite hand and pull the elbow backward.
Infraspinatus Origin
Middle two-thirds of dorsal surface of scapula, below spine of scapula.
Infraspinatus Insertion
Greater tubercle at the top of humerus. Capsule of shoulder joint.
Infraspinatus Action
As a rotator cuff, helps prevent posterior dislocation of the shoulder joint. Laterally rotates humerus.
Infraspinatus Nerve
Suprascapular nerve, C(4), 5, 6, from the upper trunk of the brachial plexus.
Infraspinatus Basic Functional Movement
Ex: Brushing back of hair.
Infraspinatus Sports that heavily utilize this muscle
Ex: Back hand racket sports
Infraspinatus Movements or injuries that may damage this muscle
Dislocation of the shoulder joint
Infraspinatus Strengthening Exercise
Seated Rowing (limited effect)
Infraspinatus Self Stretches
- Hold doorknob and gently step away from door.
- Raise one arm to shoulder height. Flex the arm across to the other shoulder. Hold the raised elbow with the opposite hand and pull the elbow backward.
Teres Minor Origin
Upper two-thirds of the lateral edge of the dorsal surface of scapula.
Teres Minor Insertion
Back of greater tubercle of humerus. Capsule of shoulder joint.
Teres Minor Action
As a rotator cuff, helps prevent upward dislocation of the shoulder joint. Laterally rotates humerus. Weakly adducts humerus.
Teres Minor Nerve
Axillary nerve, C5, 6, from the posterior cord of the brachial plexus.
Teres Minor Basic Functional Movement
Ex: Brushing Back of hair.
Teres Minor Sports that heavily utilize this muscle
Ex: Back hand racquet sports
Teres Minor Movements or injuries that may damage this muscle
Dislocation of the shoulder joint.
Teres Minor Strengthening exercise
Seated rowing (limited effect)
Teres Minor Self Stretches
- Hold doorknob and gently step away from door
- Raise one arm to shoulder height. Flex the arm across to the other shoulder. Hold the raised elbow with the opposite hand and pull the elbow backward.
Subscapularis Origin
Subscapular fossa (anterior surface of scapula).
Subscapularis Insertion
Lesser tubercle at hte top of the humerus. Capsule of shoulder joint.
Subscapularis Action
As a rotator cuff, stabilizes shoulder joint; mainly prevents the head of the humerus being pulled upwards by the deltoid, biceps brachia and long head of triceps brachia. Medially rotates humerus.
Subscapularis Nerve
Upper and lower subscapular nerves, C5, 6, 7 from the posterior cord of the brachial plexus.
Subscapularis Basic Functional Movement
Ex: Reaching into your back pocket.
Subscapularis Sports that heavily utilize this muscle
Ex: Athletic throwing events. Golf. Racquet sports
Subscapularis Movements or injuries that may damage this muscle
Twisting the arm behind the back, (as in over zealous restraining hold) or struggling to free oneself from that position, may damage the insertion.
Subscapularis Strengthening Exercise
Seated rowing (limited effect)
Subscapularis Self Stretch
Stand near door frame or an outside wall corner. Laterally rotate humerus with elbow bent 90 degree, and anchor hand against door frame.
Teres Major Origin
Lower third of the posterior surface of the lateral border of the scapula.
Teres Major Insertion
Medial lip of intertubercular sulcus (bicipital groove) of humerus (i.e. back of upper shaft of humerus).
Teres Major Action
Adducts humerus. Medially rotates humerus. Extends humerus from the flexed position.
Teres Major Nerve
Lower subscapular nerve, C5, 6, 7, from the posterior cord of the brachial plexus.
Teres Major Basic Functional Movement
Ex: Reaching into your back pocket.
Teres Major Sports that heavily utilize this muscle
Ex: Rowing. Cross-Country skiing.
Teres Major Movements or injuries that may damage this muscle
Sharply jerking the arm forwards, as in throwing a stone to skim it across a lake.
Teres Major Strengthening Exercises
- Seated rowing
- Lat Pull-overs
- Pulley shoulder adduction
Teres Major Self Stretches
- Modified childs pose (hands/arms on chair or stability ball)
- Raise one arm to shoulder height. Flex the arm across to the other shoulder. Hold the raised elbow with the opposite hand and pull the elbow backward.
Biceps Brachii Origin
Short head: Tip of corocoid process of scapula.
Long head: Supraglenoid tubercle of scapula (area just above socket of shoulder joint).
Biceps Brachii Insertion
Radial tuberosity (on medial aspect of upper part of shaft of radius). Deep fascia (connective tissue) on medial aspect of forearm.
Biceps Brachii Action
Flexes elbow joint. Supinates forearm. (It has been described as the muscle that puts in the corkscrew and pulls out the cork). Weakly flexes arm at the shoulder joint.
Biceps Brachii Nerve
Musculocutaneous nerve, C5, 6.
Biceps Brachii Basic Functional Movement
Ex: Picking up an object. Bring up an object. Bringing food to mouth.
Biceps Brachii Sports that heavily utilize this muscle
Ex: Boxing. Climbing. Canoeing, Rowing.
Biceps Brachii Movements or injuries that may damage this muscle
Lifting heavy objects too suddenly.
Biceps Brachii Common problems when muscle is chronically tight /shortened
Flexion Deformity of elbow (elbow cannot be fully straightened).
Biceps Brachii Strengthening Exercises
- Biceps Curl
- Chin ups
- Lat pull-downs
Biceps Brachii Self Stretches
Arm is held behind you by door frame, table, etc.
Gently turn torso away from object.
Corocobrachialis Origin
Tip of the corocoid process of scapula
Corocobrachialis Insertion
Medial aspect of humerus at mid-shaft
Corocobrachialis Action
Weakly adducts shoulder joint. Possibly assists in flexion of the shoulder joint (but this has not been proven). Helps stabilize humerus.
Corocobrachialis Nerve
Musculocutaneous nerve, C6, 7.
Corocobrachialis Basic Functional Movement
Ex: Mopping the floor.
Corocobrachialis Sports that heavily utilize this muscle
Ex: Golf. Cricket batting.
Corocobrachialis Movements or injuries that may damage this muscle
Suddenly hitting the ground when swinging the bat hard in cricket.
Corocobrachialis Strengthening Exercise
Pulley shoulder adduction
Brachialis Origin
Anterior of lower shaft of humerus.
Brachialis Insertion
Coronoid process and tuberosity of ulna (ie area on front of upper part of shaft of ulna).
Brachialis Action
Flexes elbow joint
Brachialis Nerve
Musculocutaneous nerve, C5, 6.
Brachialis Basic Functional Movement
Ex: Bringing food to the mouth
Brachialis Sports that heavily utilise this muscle
Ex: Baseball. Boxing. Gymnastics.
Brachialis Common problems when muscle is chronically tight / shortened
Flexion deformity of elbow (elbow cannot be fully straightened).
Brachialis Strengthening Exercises
- Biceps curl
2. Chin-ups
Brachialis Self Stretch
Arm is held behind you by door frame, table, etc.
Gently turn torso away from object.
Triceps Brachii Origin
Long head: Infraglenoid tubercle of the scapula (area just below socket of shoulder joint).
Lateral head: Upper half of posterior surface of shaft of humerus.
Medial head: Lower half of posterior surface of shaft of humerus.
Triceps Brachii Insertion
Olecranon process of the ulna (ie upper posterior area of ulna, near the point of the elbow)
Triceps Brachii Action
Extends (straightens) elbow joint. Long head can adduct the humerus and extend it from the flexed position. Stabilizes shoulder joint.
Triceps Brachii Nerve
Radial nerve, C6, 7, 8, T1.
Triceps Brachii Basic Functional Movement
Ex: Throwing objects. Pushing a door shut.
Triceps Brachii Sports tha heavily utilize this muscle
Ex: Basketball or netball (shooting). Shot put. Baseball (pitcher). Volleyball.
Triceps Brachii Movements or injuries that may damage this muscle
Throwing with excessive force.
Triceps Brachii Problems when muscle is chronically tight / shortened
Extension deformity of elbow (elbow cannot be fully flexed); although not very common.
Triceps Brachii Strengthening Exercises
- Bench press
- Press-ups (like Push-ups)
- Dips
- Triceps kick-back
- Overhead Tricep extension
Triceps Brachii Self Stretches
- Arms over head. Keep your head up and elbow as far back as is comfortable, without hollowing your lower back.
- One hand up; the other behind back; hold towel between both hands. Pull hands towards each other. Most effective when the raised elbow is against a wall.
