Shoulder Flashcards
(86 cards)
what are the four joints at the shoulder complex
- glenohumeral joint
- acromioclavicular joint
- sternoclavicular joint
- scapulothoracic joint
what is the name of the shoulder joint?
- glenohumeral joint
- ball and socket joint
scapulothoracic joint
- important
- physiologic joint
- no synovial joint
- articulation between subscapularis and serratus anterior muscles
- shoulder and rib cage
Rotator Cuff Muscles
SITS- all originate on scapula and insert on humerus
- Supraspinatus (abduction)
- Infraspinatus (external rotation)
- Teres minor (external rotation)
- subscapularis (internal rotation)
Function of Rotator Cuff/Muscles
- centre the head of the humerus within the glenoid fossa
Scapulothroacic Joint - Surface Anatomy
- acromion of scapula should be at T2
- c7 is the first bony bump we often feel
- you can count down 2 processes from c7 to get T2
- scapula should be at height of acromion, if it is higher or lower it is in an abnormal position
- nip line is T4
Points of reference for scapula (vertebral levels)
T2- top of scapula
T3/T4- spine scapula
T7- ending; inferior angle
4 Point Palpation Technique (on right scapula); Left Hand
- thumb on inferior angle of scapula
- index finger on medial end of spine of scapula
- if the thumb on left hand is sticking out or if fourth finger is downward compared to third finger (anterior tilting)
4 Point Palpation Technique (on right scapula); right hand
- thumb on poster-lateral corner of acromion
- index finger on the anterolateral acromion
Scapular Anatomy: superficial
- well defined, you will see trapezius and upper fibres of traps on nearly everyone
- deltoid (anterior, middle and posterior)
Scapular Anatomy; most aggravated?
- levator scapulae and rhomboids.
- levator scapulae tends to get tight on people and often cause headache referral- there is a pressure point that can help
- they carry stress from shoulders and poor ergonomics
- rhomboids become dysfunctional from being too long and stretched out from forward shoulder position
and they are responsible from retracting scapula
what shoulder has the most muscles crossing? how much?
- scapular thoracic joint; 17 muscles attach and across here
6 movements of scapula
- elevation/depression
- protraction/retraction
- upward/downward rotation
muscles involved in scapular elevation
- upper trapezius
- rhomboids
- levator scapulae
muscles involved in scapular depression
- lower trapezius
- lower serratus anterior
muscles involved in scapular protraction (abduction)
- serratus anterior
- pectoralis minor
muscles involved in scapular retraction (adduction)
- trapezius
- rhomboids
muscles involved in upward rotation (lateral) of scapula
- serratus anterior
- upper trapezius
- lower trapezius
muscles involved in downward rotation(medial)
- rhomboids
- levator scapulae
- pectoralis minor
Scapulohumeral Rhythm
- difficult to asses compared to static
- looks at how they all work together
- ## coordinated movements between scapula, humerus and clavicle
Full Range of Motion in Shoulder Complex
Motion in ST joint, GH, AC, and SC joints
Natural Rhythm Ratio
- between GH and ST joints is 2:1
- for every 2 degrees of movement coming from GH joint, 1 degree is coming from ST joint
- ex; 180 degrees abduction= 120 degrees GH abduction + 60 degrees of ST upward rotation
- 60 x 2 is 120 degrees; makes up the 2:1 ratio
Setting Phase: (0-30 degrees GH abduction/felxion)
- scapula is stationary
- all movement is coming from GH joint
- clavicle is 0-5 degrees elevation
- set scapula where it does not move and we have pure movement from GH joint, little elevation of clavicle but humerus does most of the work
Middle Phase: (30-90 degrees)
- 2:1 GH:ST movement- full ROM is 90 degrees from straight vertical to straight horizontal (2/3 movement come from GH)
- clavicle: 15 degrees elevation
- 60 degrees of GH is 30 decrees is ST; increased elevation of clavicle so it can move out of the way while we go overhead