1. Chapter 18: The Shoulder Complex

2. The shoulder is an extremely complicated region of the body
Joint which has a high degree of mobility but not without compromising stability
Involved in a variety of overhead activities relative to sport making it susceptible to a number of repetitive and overused type injuries
Movement and stabilization of the shoulder requires integrated function of the rotator cuff muscles, joint capsule and scapula stabilizing muscles

3. Anatomy

4. Functional Anatomy Sternoclavicular (SC) joint
Clavicle articulates with manubrium of the sternum
Weak bony structure but held by strong ligaments
Fibrocartilaginous disk between articulating surfaces
Shock absorber and helps prevent displacement forward
Clavicle permitted to move up and down, forward and backward and in rotation
Clavicle must elevate 40 degrees to allow upward rotation of scapula and thus shoulder abduction

5. Functional Anatomy Acromioclavicular (AC) Joint
Lateral end of clavicle with acromion process of scapula
Weak joint and susceptible to sprain and separation
AC ligament, CC ligament, & thin fibrous capsule
Posterior rotation of clavicle as arm elevates
Must rotate approx. 50 degrees for full elevation to occur

6. Functional Anatomy Coracoacromial arch
Arch over the GH joint formed by coracoacromial arch, acromion and coracoid process
Subacromial space: area in between CA arch and humeral head
Supraspinatus tendon, long head biceps tendon, and subacromial bursa
Subject to irritation and inflammation as a result of excessive humeral head translation or impingement from repeated overhead activity

8. Glenohumeral (GH) Joint
Ball and socket, synovial joint in which round head of humerus articulates with shallow glenoid fossa of scapula
stabilized slightly by fibrocartilaginous rim called the Glenoid Labrum
Humeral head larger than glenoid fossa
At any point during elevation of shoulder only 25 to 30% of humeral head is in contact with glenoid
Statically stabilized by labrum and capsular ligaments
Dynamically stabilized by deltoid and rotator cuff muscles

9. Scapulothoracic (ST) Joint
Not a true joint, but movement of scapula on thoracic cage is critical to joint motion
Scapula capable of upward/downward rotation, external/internal rotation & anterior/posterior tipping
In addition to rotating other motions include scapular elevation and depression & protraction (abduction) and retraction (adduction)

10. ST Joint
During humeral elevation (flexion, abduction and scaption) scapula and humerus must move in synchronous fashion
Often termed scapulohumeral rhythm
Total range 180°: GH joint, 60° of scapular mvmt
Ratio of 2:1, degrees of GH movement to scapular movement after 30 degrees of abduction and 45 to 6 degrees of lfexion
Maintain joint congruency
Length-tension relationship for numerous muscles
Adequate subacromial space

11. Scapulohumeral rhythm
During humeral elevation
Scapula upwardly rotates
Posteriorly tips
Externally rotates
Elevates
& Retracts
Alterations in these movement patterns can cause a variety of shoulder conditions

14. Stability of shoulder joint
Instability often the cause of many specific shoulder injuries
During movement essential to maintain position of humeral head relative to glenoid
Likewise it is essential for glenoid to adjust its position relative to moving humeral head, while maintaining stable base

15. Rotator cuff muscles along with long head of the biceps provide dynamic stability
control the position of humeral head
Prevent excessive displacement or translation of humeral head relative to glenoid
Co-activation of rotator cuff muscles function to compress humeral head into glenoid for stability, as well as depress humeral head
counteracts contraction of deltoid which is elevating humeral head
Imbalance between muscle components will create abnormal GH mechanics and injury

16. Scapular stability and mobility
Scapular muscles play critical role in normal function of shoulder
Produce movement of scapula on thoracic cage
Dynamically position glenoid relative to moving humerus
levator scap & upper trap=scap elevation
middle trap & Rhomboids=scap retraction
Lower trap=scap retraction, upward rotation and depression
Pec minor=scap depression
Serratus anterior=scap abduction and upward rotation
Only attachment of scapula to thorax is through these muscles

17. Prevention of Shoulder Injuries
Proper physical conditioning is key
Develop body and specific regions relative to sport
Strengthen through a full ROM
Focus on rotator cuff muscles in all planes of motion
Be sure to incorporate scapula stabilizing muscles
Enhances base of function for glenohumeral joint

18. Warm-up should be used before explosive arm movements are attempted
Contact and collision sport athletes should receive proper instruction on falling
Protective equipment
Mechanics versus overuse injuries

19. Throwing Mechanics
Instruction in proper throwing mechanics is critical for injury prevention

20. Windup Phase Cocking Phase Acceleration
First movement until ball leaves gloved hand
Lead leg strides forward while both shoulders abduct, externally rotate and horizontally abduct
Cocking Phase
Hands separate (achieve max. external rotation) while lead foot comes in contact w/ ground
Acceleration
Max external rotation until ball release (humerus adducts, horizontally adducts and internally rotates)
Scapula elevates and abducts and rotates upward

21. Deceleration Phase Follow-Through Phase
Ball release until max shoulder internal rotation
Eccentric contraction of ext. rotators to decelerate humerus while rhomboids decelerate scapula
Follow-Through Phase
End of motion when athlete is in a balanced position

22. Assessment of the Shoulder Complex
History
What is the cause of pain?
Mechanism of injury?
Previous history?
Location, duration and intensity of pain?
Crepitus, numbness, distortion in temperature
Weakness or fatigue?
What provides relief?

23. Observation Elevation or depression of shoulder tips
Position and shape of clavicle
Acromion process
Biceps and deltoid symmetry
Postural assessment (kyphosis, lordosis, shoulders)
Position of head and arms
Scapular elevation and symmetry
Scapular protraction or winging
Muscle symmetry
Scapulohumeral rhythm
Insert 18-6

24. Recognition and Management of Specific Injuries
Clavicular Fractures
Cause of Injury
Fall on outstretched arm, fall on tip of shoulder or direct impact
Occur primarily in middle third (greenstick fracture often occurs in young athletes)
Signs of Injury
Generally presents w/ supporting of arm, head tilted towards injured side w/ chin turned away
Clavicle may appear lower
Palpation reveals pain, swelling, deformity and point tenderness

25. Clavicular Fractures (continued)
Rehab concerns
Closed reduction - sling and swathe, immobilize w/ figure 8 brace for 6-8 weeks
Possible involvement of AC and SC joints
Clavicle insertion for deltoid, upper trap & pec major
Provide stability and neuromuscular control to shoulder complex
Must be addressed in rehab
Removal of brace should be followed w/ joint mobilization of clavicle, isometrics and use of a sling for 3-4 weeks
AROM & PROM
Occasionally requires operative management

27. Fractures of the Humerus
Cause of Injury
Humeral shaft fractures occur as a result of a direct blow, or fall on outstretched arm
Proximal fractures occur due to direct blow, dislocation, fall on outstretched arm
Care
Immediate application of splint, treat for shock and refer
Athlete will be out of competition for 2-6 months depending on location and severity of injury
Progressive ROM exercises as tolerated
PRE exercises of shoulder & elbow after 4-6 weeks
Maintain strength of elbow, forearm and wrist musculature

28. Sternoclavicular Sprain
Cause of Injury
Indirect force, blunt trauma (may cause displacement)
Care
PRICE, immobilization
Immobilize for 3-5 weeks followed by graded reconditioning
Strengthen muscles in range that does not put further stress on joint
Low grade joint mobilizations after inflammation is controlled
Restore normal mechanics of shoulder complex

29. Acromioclavicular Sprain
Cause of Injury
Result of direct blow (from any direction), upward force from humerus, fall on outstretched arm
Signs of Injury
Grade 1 - point tenderness and pain w/ movement; no disruption of AC joint
Grade 2 - tear or rupture of AC ligament, partial displacement of lateral end of clavicle; pain, point tenderness and decreased ROM (abduction/adduction)
Grade 3 - Rupture of AC and CC ligaments with dislocation of clavicle; gross deformity, pain, loss of function and instability

30. Care Ice, stabilization, referral to physician
Grades 1-3 (non-operative) will require 3-4 days (grade 1) and 2 weeks of immobilization ( grade 3) respectively
Aggressive rehab is required w/ all grades
Joint mobilizations, flexibility exercises, & strengthening should occur immediately
Progress as athlete is able to tolerate w/out pain and swelling
Padding and protection may be required until pain-free ROM returns
Grade 1 & 2 often treated conservatively while grade 3 may require surgical intervention to reduce separation although often treated w/o surgery also
Grade IV, V & VI- require internal fixation to realign fractured segments

32. Glenohumeral Dislocations
Cause of Injury
Head of humerus is forced out of the joint
Anterior dislocation is the result of an anterior force on the shoulder, forced abduction, extension and external rotation
Occasionally the dislocation will occur inferiorly
Signs of Injury
Flattened deltoid, prominent humeral head in axilla; arm carried in slight abduction and external rotation; moderate pain and disability

33. Care RICE, immobilization and reduction by a physician
Begin muscle re-conditioning ASAP
Use of sling should continue for at least 1 week
Progress to resistance exercises as pain allows

34. Shoulder Impingement Syndrome
Cause of Injury
Mechanical compression of supraspinatus tendon, subacromial bursa and long head of biceps tendon due to decreased space under coracoacromial arch
Seen in over head repetitive activities
Signs of Injury
Diffuse pain, pain on palpation of subacromial space
Decreased strength of external rotators compared to internal rotators; tightness in posterior and inferior capsule
Positive impingement and empty can tests

35. Care Restore normal biomechanics in order to maintain space
Strengthening of rotator cuff and scapula stabilizing muscles
Stretching of posterior and inferior joint capsule
Modify activity (control frequency and intensity)

36. Rotator cuff tear Signs of Injury
Involves supraspinatus or rupture of other rotator cuff tendons
Primary mechanism - acute trauma (high velocity rotation)
Occurs near insertion on greater tuberosity
Full thickness tears usually occur in those athletes w/ a long history of impingement or instability (generally does not occur in athlete under age 40)
Signs of Injury
Present with pain with muscle contraction
Tenderness on palpation and loss of strength due to pain
Loss of function, swelling
With complete tear impingement and empty can test are positive

37. Care RICE for modulation of pain
Progressive strengthening of rotator cuff
Reduce frequency and level of activity initially with a gradual and progressive increase in intensity

38. Shoulder Bursitis Etiology Signs of Injury Management
Chronic inflammatory condition due to trauma or overuse - subacromial bursa
May develop from direct impact or fall on tip of shoulder
Signs of Injury
Pain w/ motion and tenderness during palpation in subacromial space; positive impingement tests
Management
Cold packs and NSAID’s to reduce inflammation
Remove mechanisms precipitating condition
Maintain full ROM to reduce chances of contractures and adhesions from forming

39. Bicipital Tenosynovitis
Cause of Injury
Repetitive overhead athlete - ballistic activity that involves repeated stretching of biceps tendon causing irritation to the tendon and sheath
Signs of Injury
Tenderness over bicipital groove, swelling, crepitus due to inflammation
Pain when performing overhead activities
Care
Rest and ice to treat inflammation
NSAID’s
Gradual program of strengthening and stretching

40. Contusion of Upper Arm Cause of Injury Signs of Injury Management
Direct blow
Repeated trauma could result in development of myositis ossificans
Signs of Injury
Pain and tenderness, increased warmth, discoloration and limited elbow flexion and extension
Management
RICE for at least 24 hours
Provide protection to contused area to prevent repeated episodes that could cause myositis ossificans
Maintain ROM

41. Multi-directional instability
When forces that are generated at GH joint that stabilizing muscles are unable to handle humeral head tends to translate anteriorly and inferiorly
Overtime cause structures to stretch
Increase demands of posterior structures
Eventual breakdown of these tissues

42. MDI rehab considerations
Emphasis on anterior and posterior musculature
Promote neuromuscular control to assist dynamic stability
Patient must be compliant with exercises to avoid instability and/or repetitive subluxations
Surgical intervention is sometimes required to tighten joint capsule