AT 359
Chapter 22 - The Shoulder Complex

Anatomy:
-Bones
        -Clavicle - weak "S" shaped bone; frequentl fx's - occur in the middle 1/3
        -Scapula - shoulder blade, triangular shaped; very rarely see fx's of scapula
        -Humerus - upper arm bone, very strong bone; rarely see fx's of humerus

-Joints
        -Sternoclavicular Joint (SC joint) - consists of sternum and clavicle; very mobile joint
        -Acromioclavicular Joint (AC joint) - consists of acromion process and clavicle; frequently injured
        -Glenohumeral Joint - ball & socket; unstable joint - rotator cuff and deltoid muscles help stabilize
        -Scapulothoracic Joint - not a true joint, overlooked; scapula is not attached to ribs by ligaments

-Ligaments
        -SC joint - very weak because of bone structure
        -AC joint - anchor clavicle downwards - if torn, clavicle will have step-up deformity
        -GH joint - fairly strong

Shoulder Muscles

-Bursae
            -subacromial - becomes subjected to trauma by overhead activities; commonly injured
            -subcoracoid - very rarely injured

-Nerve Supply
            -C5-T1 provide motor and sensory pathways (brachial plexus)
                    -Axillary (C5, C6)
                    -Musculocutaneous (C5, C6, C7)
                    -Subscapular (C5, C6)
                    -Suprascapular (C5, C6)
                    -Dorsal Scapular (C5)
                    -Pectoral (C5, C6, C7, C8, T1)
                    -Radial (C5, C6, C7, C8, T1)

-Blood Supply
            -Subclavian   →  Axillary  →   Brachial  →  Radial & Ulnar

-Scapulohumeral Rhythm
            -after 30 degrees, the rhythm ratio is 2:1
            -this means that for every 1 degree of movement of scapulothoracic joint, there is 2 degrees of movement of the
             glenohumeral joint
            -with shoulder abduction, scapula does not move until after 30 degrees

-Special Tests

Shoulder Injuries
    -Clavicle fx's
        -most common in mid 1/3 of clavicle where it bends
        -MOI is usually falling on outstretched arm
        -s/s include: severe pain, deformity and crepitus
        -treatment: sling and swathe, go to hospital for xrays

    -Scapular fx's
        -very uncommon in sports setting
        -MOI usually from blunt trauma to the scapula such as a blow to the upper back or falling on it
        -s/s include: severe pain, deformity, crepitus, swelling
        -treatment: arm sling, protect for 6-8 weeks

    -Humerus fx's
        -uncommon in sports but more common that scapular fx's
        -MOI is usually high trauma, but can also be from throwing a ball
        -typically occurs in the mid shaft area
        -will require surgical fixation
        -complications can arise from damage to the brachial artery or epiphyseal plate
      
    -Sternoclavicular sprain
        -MOI is usually fall on outstretched arm
        -if other structures don't absorb force (ie. AC joint, clavicle), the SC joint is the end of the line and will be injured
        -fairly uncommon in sports setting
        -can become displaced (Grade 3) resulting in instability and deformity (dangerous situation)
        -treatment: sling and swathe, evaluation/xray

    -Acromioclavicular sprain
        -usually is referred to as a shoulder separation
        -s/s include: pain, swelling, step-up deformity, loss of ROM and strength, listing towards injured side, holding arm
                -the greater the severity of the sprain, the greater the step-up deformity (piano key test/sign)
        -these will typically cause impingement syndromes because of the hypermobility of the clavicle
        -Grade 3 does not require surgery, but active people should think about having it done
        -treatment:  Kenny/Howard sling, wearing a protective pad upon return to competition

    -Glenohumeral Joint sprain
        -dislocations are the usual injury
                -this can damage the ligaments, as well as the joint capsule and/or rotator cuff muscles
        -MOI is usually force applied to arm in an abducted and externally rotated position
        -s/s: flat-deltoid, lump in armpit, pain, swelling, deformity, spasms
        -1st time dislocations will dislocate again about 80% of the time
        -treatment: stabilize in position found, get to hospital/xrays

    -Shoulder Impingement Syndrome
        -usually affects people with overhead motions
        -affects the supraspinatus tendon, subacromial bursa, and long head of biceps tendon
        -repetitive movements inflame these structures and cause swelling
        -avoid internal rotation/overhead exercises as this will exacerbate injury
        -treatment: rest with limited motion, NSAIDs, RICE

    -Rotator Cuff tears
        -tears are rare in adolescents & young adults
                -partial-thickness tears = rare
                -full-thickness tears = extremely rare
        -most commonly seen in elderly people
        -tendonitis is very common especially among throwers & swimmers
        -s/s: pain at night - can't sleep on that shoulder, pain, swelling, limited ROM, weakness, dead arm feeling
        -treatment: diagnosis should be made through stress tests and MRI arthrogram
        -if torn, surgery is indicated

    -Shoulder Bursitis
        -can be acute or chronic
        -usually affects the subacromial bursa
        -will develop after AC sprains quite often
        -usually requires surgery to remove inflamed tissue (cortisone shots are usually attempted first)
        -treatment: RICE, then ultrasound, NSAIDs, cortisone shots, are sometimes effective

    -Frozen Shoulder (Adhesive Capsulitis)
        -usually found in elderly people
        -MOI is unknown
        -limited movement or immobilization can cause this condition
        -the joint capsule is contracted and thickened along with the rotator cuff muscles being contracted
        -pain and limited ROM will occur on both AROM and PROM
        -main goal is restoring ROM with heat, stretching, exercises, ultrasound

    -Biceps Brachii ruptures
        -occurs with powerful contractions both eccentric and concentric
        -s/s: feels snap, severe pain, deformity (bulge),
        -treatment: apply arm sling, ice, and medical referral
        -does not require surgery unless the victim is a competitive athlete of some sort

    -Bicipital Tenosynovitis
        -common in overhead activities
        -s/s: swelling, crepitus, sticking feeling, pain,
        -treatment: rest, NSAIDs, cryotherapy and ultrasound for inflammation

    -Upper Arm Contusions
        -can develop tackler's or blocker's exotosis over deltoid tuberosity
        -this is a myositis ossificans condition
        -treatment: protect arm with padding, ice and heat when appropriate, NSAIDs

    -Peripheral Nerve Injuries
        -always suspect nerve injuries when there is: constant pain, muscle weakness, paralysis or muscle atrophy
        -MOI is either stretch or contusion - look for history of injury

    -Throwing Mechanics
        -Windup Phase
        -Cocking Phase
        -Acceleration Phase*
        -Deceleration Phase*
        -Follow-Through Phase

        * - most common phases for injuries
        -Acceleration phase is from concentric contractions
        -Deceleration phase is from eccentric contractions

FLEXIBILITY EXERCISES
    -Codman's pendulum
    -Finger walking on wall

Web Sites for further study/learning:
www.ncl.ac.uk~nccc/tutorials/shoulder/ - shoulder anatomy tutorial

www.ccsd.k12.wy.us/cchs_web/cramerfirstaider/fstaider.htm - Cramer First Aider

www.worldortho.com - World Ortho

www.medmedia.com/med.htm - Wheeless' Textbook of Orthopaedics

www.sportsmed.org - American Orthopaedic Society for Sports Medicine

www.medfacts.com - common injuries

www.orthonet.com - OrthoNet