Shoulder Flashcards
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
Terminal Phase (90-180 degrees)
- 2:1 GH:ST movement
- humerus externally rotates 90 degrees
- clavicle: 15 degrees elevation, 30-50 degrees posterior rotation
Shoulder Impingement
- most common disorder of shoulder accounting for 44-65% of all companies of shoulder pain
- impingement= pressure on a tissue found within confined space (subacromial space)
- repetitive impingement may result in soft tissue inflammation (bursitis) or injury (rotator cuff tear)
- sub acromial space is approx 5-8mm
Shoulder Impingement: Clinical presentation
- pain is worse with arm elevation and overhead activities
- pain is typically localized to the anterolateral acromion and frequently radiates to the lateral mid-humerus; pain happening at shoulder radiating down
Types of Pain With Shoulder Impingement
- inflammatory pain: pain at night
- mechanical pain (laying on tissue itself)
- pain with overhead
Causes of Shoulder Impingement
- rotator cuff weakness/pathology
- bicep pathology (SLAP lesion) - superior labrum tear from anterior to posterior
- acromial morphology; abnormalities where you may have more or less rrom
- muscle imbalance (if upward rotators are weak and downward rotators are strong)
- capsular laxity or tightness
- dysfunctional glenohumeral and scapulothoracic kinematics
- degeneration and inflammation of the tendons or bursa
Types of Shoulder Impingement: External
- mechanical encroachment of soft tissue structures (bursa, rotator cuff tendons) between humeral head and acromial arch
Types of Shoulder Impingement: Internal
- encroachment of rotator cuff tendons between humeral head and glenoid rim
1. anterior impingement: entrapment of subscapularis
2. posterosuperior impingement: entrapment of supra- and Infraspinatus
External Impingement:
- subacromial space, bursa and Supraspinatus all in subacromial space
- impingement is inflammation of tendon, this will occupy more space, or inflammation of bursa
- when we go to abduction we get compression of striations in that space
Internal Impingement (anterosuperior)
- subsacpularis, Supraspinatus and with shoulder flexion and internal rotation we get impingement of Supraspinatus between glen drum and head of humerus
- passive test: bring them into these motions and test for sharp pain
Internal Impingement: posterosuperior
- impingement of Infraspinatus between glenoid rim and head of humerus
- from external rotation and abduction like overhead throwing
Supraspinatus tear
- Supraspinatus is the smallest of the 4 RC muscles
- most commonly injured/torn
- poorly vascularized
Why is Supraspinatus Susceptible to Tears?
- impingement: anatomic design of subacromial space
- hypovascularity in distal 1.5cm of tendon–> not blood in there so more susceptible to injury and not good healing
- mechanical disadvantage
- usually preceded by history of inflammation, micro-tearing, muscle weakness, sub scapular dyskinesias (abnormal moving)
- micro-tearing-stress risers > weakness, altered mechanics
Mechanics of Supraspinatus: Action
- initiates abduction (~0-20degrees) until the deltoid can take over
- braces the head of humerus firmly against the glenoid fossa and prevents upward shearing of humeral head-locks down and centres within humerus
- concavity depression -compressive force
Supraspinatus: Mechanically Disadvantaged
- class 3 lever
- force is applied on inside of load sow we have short moment arm and this results in more force than the load and we have to work harder than the weight of the shoulder
- deltoid has long moment arm so force it produces is times by the long distance or lever so it can produce more force
- short moment arm due to insertion of tendon on greater tuberosity (as compared to iteration of deltoid tuberosity lower on the humerus)
Treatment of Supraspinatus Tear: Education
- posture +++- lifting and sitting postures to open up sub-acromial space
- inflammation management (i.e., icing, rest, elevation and NSAIDs)
- avoidance of aggravating positions (i.e., overhead activities, side-sleeping)
Treatment of Supraspinatus Tear: Exercise
- restore ROM
- strengthening of upward rotators (UFT, SA, LFT)
- stretching downward rotators (lev scap, pec minor)
Treatment of Supraspinatus Tear: Manual Therapy
- scapulothroacic mobilizations (upward rotation, retraction, posterior tilt)
- inferior GH glide, if we don’t have glide, we we get impingement so we want to encourage this glide
Treatment of Supraspinatus Tear: Surgery
- acromioplasty
- rotator cuff repair
Glenohumeral Instability: Acute Subsystem
- rotator cuff- centre the head of humerus
- scapular stabilizers- hold shoulder blade in place so it is not moving around on humerus
Glenohumeral Instability: Passive Subsystem
- bony congruence- dent glenoid or humerus labrum; cartilage ring helps deepen socket
- ligaments
- capsules
Glenohumeral Instability: Neural Subsystem
- musculotendinous receptors
- ligamentous receptors
Shoulder Instability
- most dislocated joint- most mobile
- shoulder can exit joint and it stays out and needs to be put back into socket
- subluxation- it comes out and in in a fast movement
- involves separation of humerus from glenoid
- ## described as position of humeral head relative to glenoid fossa
Shoulder Instability: epidemiology
- younger (20-30 years)
- male:female (9:1)- males more likely to participate in risky sports or high contact sports
- older (60-80) years, females: males 3:1 when older)
Types of Shoulder Instability: TUBS
- T: traumatic
- U: unilateral with
- B: Bankart lesion, requiring
- S: surgery
- results from traumatic injury and effects the side that got impacted and can include lesion
Types of Shoulder Instability: AMBRI
- A: atraumatic
- M: multidirectional instability
- B: bilateral
- R: requiring rehab and/or
- I: inferior capsular shift
- some people can self dislocate both arms without trauma and can dislocate anterior or posterior, etc. they require rehab, not surgery. would rather strengthen and stabilize it, it is hyper-mobile
TUBS vs AMBRI
- can be overlap
- ligamentous lax patients with traumatic injuries (both)
- rehab would predominately be TUBS, AMBRI; people have learned to deal with it on their own
Hil-Sach’s/Bankart Lesion
- dislocation, we bang off rim of glenoid and it causes it to break (displaced bankers lesion and broken rim of labrum)
- can also get hill sach lesion where we dent the head of the humerus from dislocation
- want an x ray
- may need surgery to fix
- also gives prognosis indicator if they will injure themselves again
Tubs- Types (traumatic) Anterior*
- most dislocations are anterior: 95%
- MOI: abduction plus external rotation and extended arm
- less commonly trauma to posterior humerus
Tubs- Types (traumatic) Posterior
- rare: 2-4% of dislocations
MOI: - direct: large force at anterior shoulder directed posteriorly (seizure)- can happen from seizure where person falls and floor makes them dislocate posteriorly
Indirect: flexion + abduction and internal rotation ( falling into a board in a hockey game and makes us fly backwards)
Tubs- Types (traumatic) Inferior
- very rare
MOI: sudden forceful shoulder abduction +/- loading arm in hyperabduction
example; sliding in hockey after getting cross checked and falling on stomach and boards pushing you
OR handstand where you spring with arms overhead causing inferior glide
Anterior Instability- Arthrokinematics
EXTERNAL ROTATION
- shoulder at rest, anterior and posterior capsule.
- ER causes tightness of anterior capsule.
- we see convex move on concave and we have anterior glide because there is a posterior roll.
- Abd +Ext; have excessive anterior glide which can cause sprain or rupture of structures limiting anterior translation and head of humerus will go anterior inferior
osteokinematics
posterior rotation
Anthrokinematics
- posterior roll
- anterior glide
External Rotation and Abduction Injury
- Abduction + ER force= excessive anterior glide which will sprain the supporting anterior capsule/ ligaments and the head of the humerus will dislocate/sublux anteriorly
Anterior Instability: clinical presentation
- serve pain with all movements, limited ROM
- palpable humeral head in axilla (deltopectoral space)- can see deformity and see it poke out
- arm often held in adduction and external rotation
- cannot move arm at all, pain but also too scared to move it
potential neurovascular compromise
- check distal pulses
- axillary nerve palsy
Associated Injuries with Anterior Instability
- dislocations
- fractures (greater or lesser tuberosity, proximal humerus, distal clavicle, AC separation, Bankart and Hill Sach lesions)
- Labral tear- Bankart lesion without bony part
- rotator cuff tear (higher incidence in older patients)
- axillary nerve injury- supplies posterior shoulder
- brachial plexus injury (described as dead arm, quickly stretched brachial plexus where it shuts things off and they cannot feel their arm)
- vascular injury
Anterior Instability Treatment: Reduction/Immobilization
- reduction ASAP
- immobilization of GH joint (sling)
- maintain ROM of ST joint, elbow, wrist
- joint went through a lot so give it time to rest ~7-10 days
Anterior Instability Treatment: Rehab
- ++++
- rotator cuff strengthening (so it doesn’t happen again)
- proprioception/joint position sense re-training
- graduated return to sport
Anterior Instability Treatment: Surgery
- anterior capsule stabilization
Risk of Recurrence (Anterior Instability)
- 39% rate of reccurrence after first-time shoulder dislocation risk factors: - age (younger) - male - sporting related dislocations - Hill-Sach's Lesion - Bankart's Lesion
Thoracic Outlet Syndrome (TOS)
- collection of signs and symptoms attributable to compression of the nerves and or blood vessels of the upper extremity as they pass above the first rib and under the clavicle
3 locations of neurovascular compression
- scalene triangle
- costoclavicular space
- subcorocoid space
Types of TOS
- neurogenic
- venous
- arterial
Types of TOS: Neurogenic
- > 90% of all cases
- symptoms are caused by compression of the brachial plexus
- subjective history would report a history of lots of neuropathic pain (burning, tingling)
Types of TOS: Venous
- 3-5% of all cases
- symptoms are caused by compression within subclavian and or axillary veins
Types of TOS: Arterial
- < 3% of cases
- symptoms are caused by ischemia of subclavian artery from compression (usually because of a cervical rib)
Causes of TOS
repetitive stress superimposed on an anatomical abnormality, leading to compression of neurovascular structures
Structure Abnormalities Causing TOS
- cervical rib
- malunion of clavicle or first rib fracture - bone can stick into nerves or arteries in opposite direction
- atypical scalene origin or insertion
- scalene minimus- extra scalene muscle that occupies more space
- hypertrophy of scalene muscles
- callus or fibrosis from prior trauma
- tumor
TOS Clinical Presentation: Neurogenic
- peripheral nerve pain (mot often through the ulnar nerve distribution)
- neck pain
- parethesias (tingling, pins and needles)
- weakness/loss of dexterity
TOS Clinical Presentation: Venous
- arm pain and heaviness
- swelling/cyanosis
- dilated subcutaneous veins
- blood pressure asymmetry between sides (<20 mmHg)
TOS Clinical Presentation: Arterial
- pain in arm and hand due to claudication, worse with activity
- diminished pulse
- coolness/pallor
- numbness
Neurogenic TOS Locations
- ulnar nerve, C7-T1
- inferior bottom part of brachial plexus; when we follow BP we can see how inferior trunk is in the most narrow part of scalene triangle or it can get wedged against first rib or within subarachnoid space
- inferior trunk is more influenced
Neuro Exam (TOS)
motor weakness/atrophy:
- flexor digitorum profundus (ulnar half)
- muscles of the hand (except for LOAF)
- ulnar border of ring finger will be numb, along with weakness of hand and anterior forearm
Special Tests TOS; Vascular
- lots of special tests but they only look at vascular TOS; none to assess neurogenic
- monitor pulse to see if it diminishes in different positions
- military brace test (costoclavicular space)
- wright’s test (subpectoralis minor space)
- adson’s test (inter-scalene space)
TOS-Neurogenic palpation
- distal pulses (radial)
- tinel’s test
- -supraclavicular fossa (brachial plexus)
- cubital tunnel (ulnar)
- carpal tunnel (median)
TOS Neurogenic treatment: Education
- posture ++++ (including scapular mechanics)
- activity modifications (limit repetitive overhead stress, ergonomics)
TOS Neurogenic treatment: manual therapy
- scalene, pectoralis minor stretching
- neuromobilizations (nerve flossing)
- rib, clavicular mobilizations
TOS Neurogenic treatment: exercise
- restore ROM
- strengthening of upward rotators (UFT, SA, LFT)
- stretching downward rotators (Lev scap, pectoralis minor)
TOS Neurogenic treatment: Surgery
- scalenectomy (scalene triangle)
- first rib resection (costoclavicular) - shave off first part of rib
- pec minor tenotomy (subcorocoid)- change anatomy and relocate it
Neuromobilization: Nerves and Stretching
-nerves do not tolerate stretch well as axoplasmic circulation to the nerve is diminished at 23% and occluded at 30% strain
Neuromobilization: Rationale
- restore the dynamic balance between the relative movement of neural tissues and surrounding mechanical interfaces
- this is allowing reduced intrinsic pressure on neural tissue and improving nerve conduction velocity (thus reducing symptoms)
- tensioners vs gliders
Tensioner (Assessment)
- upper limb tension test 3 (ulnar)
- elbow flexion
- wrist/finger extension
- full supination
- scapular depression
- shoulder external rotation
- shoulder abduction to 90 degrees
Slider Treatment
- decrease ulnar nerve tension biases (tension)–>increase ipsilateral neck side bend (slackened)
- decreased contralateral neck side bending (tension) and increase opposite of ulnar nerve tension biases (elbow extension, wrist flexion –slacken)
