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.