1 - Shoulder Flashcards
What are the bony landmarks of the scapula?
Superior angle Inferior angle Medial border Lateral border Acromion Caracoid process
Posterior - infraspinus fossa, supraspinus fossa, spine of scapula, infraflenoid tubercle, acromiol angle
Anterior - subscapula fossa, superior notch, supraglenoid tubercle, glenoid cavity, infraglenoid tubercle
What bones make up the shoulder girdle?
Humerus
Scapula
Clavicle
Name the joints of the shoulder girdle
Glenohumeral joint
Acromioclavicular joint
Sternoclavicular joint
What are the bony landmarks of the humerus?
Head of humerus Greater tubercle Lesser tubercle Inter tubercular groove Crest of greater tubercle Crest of lesser tubercle Deltoid tuberosity Lateral epicondyle Medial epicondyle Lateral condyle Medial condyle Radial fossa Capitulum Trochlea Coronoid fossa
Which muscles work to cause shoulder flexion?
Anterior Deltoid
Pectoral is major (Upper fibres)
Deltoid:
Origin Insertion Action When is it used? Exercises? Joints crossed?
O: Lateral 3rd of scapula, acromion border, spine of scapula
I: Deltoid tuberosity
A: all fibres - abduction of shoulder
Anterior fibres - shoulder flexion, medial rotation, horizontal adduction
Posterior fibres - shoulder extension, lateral rotation, horizontal abduction
W: anything OH, scratching your head, Chang a light bulb, high fiving
E: Lat raises, shoulder press (variations), straight arm raise, straight arm pushdown
J: Glenohumeral, acromio-clavicular
Infraspinatus
Origin Insertion Action When is it used? Exercises Joints crossed
O: Infraspinatus fossa/medial border
I: Greater tubercle (posterior to supraspinatus)
A: lateral rotation, shoulder extension, horizontal abduction
W: sticking chest out, driving (pull), opening curtains, opening a door
E: Reverse flyes, 90/90’s,lateral external rotation
Supraspinatus
Origin - supraspinus fossa
Insertion - greater tubercle of humerus
Found deep to the trapezius’ upper fibres and its muscle belly runs underneath the acromion to its insertion.
It assists the deltoid with abduction of the shoulder and is the only muscle of the group not to be involved in shoulder rotation.
Subscapularis
Origin
Insertion
Action
Origin - Subscapularis fossa of the scapula
I - lesser tubercle of the humerus
A - assists in medial rotation of the humerus. also stabilises the head of the humerus in the glenoid cavity
W- would be used when reaching your arm around to scratch your back
Teres Minor
Origin
Insertion
Action
When
Origin - upper two thirds of the lateral border of the scapula
I - greater tubercle of the humerus
A - laterally rotate the humerus, assists in shoulder adduction, stabilises the head of the humerus in the glenoid cavity
W - driving, fanning a smoke filled room, starting a lawnmower cord, opening a door
Small muscle squeezed between the infraspinatus and teres major.
Teres Major
Origin
Intersection
Action
When
Origin - inferior angle and lower third of lateral border of the scapula
I - crest of the lesser tubercle of the humerus (anterior)
A - adducts the shoulder, medially rotates the shoulder, assists in shoulder extension
W - being placed into handcuffs, scratching your back, driving (cruising), rowing exercises
The teres major is known as the Lats little helper as it is a complete synergistic to the Lats. Although it shares a name with the teres minor, it completes an opposite action. Teres minor laterally rotates whereas the teres major medially rotates.
Coracobrachialis
Origin
Insertion
Action
When
O - coracoid process of the scapula
I - medial surface of the mid-humeral shaft
A - flex the shoulder, Adduct the shoulder
W - reaching around your face to scratch your opposite ear, completing s bench press, blocking something in front of your face
Pectoralis Minor
Origin
Insertion
Action
When
Origin - third, fourth and fifth ribs
I - medial surface of the coracoid process of the scapula
A - depresses the scapula, abducts the scapula and Downwardly rotates the scapula.
It’s fibres run perpendicular to the pectoralis majors fibres. During aerobic activity, the pec minor helps to elevate the rib cage for inhalation.
Rhomboid Major
O - spinous process of T2-5
I - medial border of the scapula
A - medially/Downwardly rotates the scapula, adducts the scapula and elevates the scapula
W - sticking out your chest, shrugging your shoulders when uncertain, squeezing through a tight space
Rhomboid Minor
Origin
Insertion
Action
When
O - spinous processes of C7-T1
I - upper portion of the medial border across from the spine of the scapula
A - medially rotates/Downwardly rotates the scapula, adducts the scapula, elevates the scapula
W - when sticking your chest out, squeezing through a small space, shrugging your shoulders when uncertain
