1. Most patients assume a slumped posture in sitting with weight bearing just behind the ischial tuberosities. Lateral flexion of the trunk generally occurs to the involved side.


Thoracic kyphosis and lumbar lordosis occur with accompanying stretch weakness to the back extensors and shortening to the rectus abdominals. Generally patients forward flex at the level of the trunk where the ribcage ends.


2. Because muscles stabilizing the ribs are also flaccid there is a lack of ribcage stability.

1. Gravity pulls the scapula into downward rotation.



2. The client's posture of forward trunk flexion reinforces scapular downward rotation and promotes elevation of the scapula on the thorax.



3. Sternocleidomastoid becomes tightened leading to altered line of pull of the AC and SC joints.



4. Orientation of the Glenoid Fossa changes so that instead of facing upward, forward and outward it orients downward. This compromises the structural stability of the gleno-humeral joint.



5. Tipping and winging of the scapula results.

1. The rotator cuff usually has low tone and lacks the functional movement needed to stabilize the humeral head in the glenoid fossa.



2. Gravity exerts a downward pull on the head of the humerus.



3. The biomechanics of dynamical glenohumeral joint movement are lost.



4. Because the arm is positioned frequently in internal rotation, adduction and a few degrees of extension, the latissimus dorsi and the pectoralis major become shortened. The results in stretch weakness to the external rotators of the rotator cuff (teres minor and subscapularis).



5. Subluxations can then occur (see following).

1. Mechanical factors causing inferior subluxation
   
   
   1. Superior part of the GH joint capsule is initially normally taut. Because the muscles that cause the head of the humerus to glide inferiorly in the glenoid are weak, mobility of the gleno-humeral joint into flexion and abduction is impaired. The superior portion of the joint eventually becomes stretched secondary to gravitational forces. As the capsule is stretched, stability is then provided by the coracohumeral ligament (Jenson 1975).
   
   
   
   2. Over stretching of the superior capsule of the GH joint (above) leads to decreased stability of the glenohumeral joint.
   
   
   
   3. Mal-alignment of the glenoid fossa occurs secondary to scapular downward rotation.
   
   
   
   4. The scapula fails to lie flat on the chest wall (tipping).
   
   
2. Dynamic factors causing inferior subluxation
   
   
   1. The rotator cuff becomes overstretched and cannot seat the head of the humerus, glide it inferiorly during abduction, or provide external rotation during abduction movements.
   
   
   
   2. Overstretching of the serratus anterior, upper and lower trapezius with shortening of the levator scapulae compromises the clients ability to upwardly rotate the scapula and to maintain proper glenoid position.
   
   
   
3. Results of inferior subluxation
   
   
   1. The humerus falls into internal rotation and hyperextension.
   
   
   
   2. Pectorals, latissimus, teres major and anterior capsule of the GH joint become shortened.
   
   
   
   3. There is a resultant loss of external rotation at the GH joint and accompanying stretch weakness of the rotator cuff.
   
   
   
   4. Brachial Plexus Injuries: As head of humerus moves inferiorly it encounters teres major......as this muscle stretches and loses elasticity pressure is placed on the brachial plexus/brachial artery. The most frequently injured cord is the lateral cord which innervates the rotator cuff.
   
   
   
4. Attempted arm movement with the joint in this position CAUSES:
   
   
   1. Poor mechanics
   
   
   
   2. Impingement of:
      1. Supraspinatus tendon - leading to pain and inability to function
      
      
      
      2. Long head of the biceps - leading to tendinitis, pain, and a position of elbow flexion and supination, secondary to pain.
      
      
      
      3. Sub acromial bursa - leading to bursitis and pain.
      
      
      
      4. The rest of rotator cuff - As elevation or abduction at the gleno-humeral joint occurs the head of the humerus is "jammed" into the acromion process and impingement occurs.

1. In clients who tend to sublux anteriorly the scapula usually lies elevated due to tightness/recruitment of the upper trapezius and levator without stabilization by the lower trap and the serratus anterior.



2. Gleno-humeral extension occurs from tightness of the latissimus dorsi so that the distal end of the humerus falls behind the GH joint with pressure anteriorly on the head of the humerus.



3. The head of the humerus then moves anteriorly causing impingement on the long head of the biceps.
   -This biceps impingement can cause elbow flexion and forearm supination common in patients following CVA.

1. The scapula is in a position of downward rotation



2. The scapula is elevated on the chest wall.



3. The humerus is usually positioned in internal rotation (from positioning and tightness of the pectoralis and latissimus dorsi) without rotator cuff strength. It is pulled up under the acromial process.



4. Clients attempt to move their arm with whatever muscles are available. The first to return include the levator scapulae which promotes downward rotation of the scapula.



5. As clients attempt to move their arms over their heads, the deltoid acts usually without rotator cuff innervation. This pulls the head of the humerus up into the superohumeral space causing impingement and pain.



6. Improper weight bearing can also lead to impingement of structures in the superohumeral space and pain.



7. Clients with this condition may need joint mobilization to get an inferior glide of the head of the humerus.



8. If superior subluxation is allowed to continue, the coracohumeral ligament may be torn leading to structural instability of the gleno-humeral joint.

1. Positioning in Bed or in Wheelchair
   
   
   Arm Trays
   
   Lap Trays
   
   Use of a table
   
   Bed Positioning


2. Upper Extremity Weight Bearing
   
   
   Improve trunk Control
   
   Increase motor Control of Arm
   
   Increase Sensory input
   
   Prevent edema/pain
   
   Increase ROM - facilitate inactive muscles


3. Slings


Wear for transfers/gait if there is a greater than 2 finger subluxation inferiorly at the gleno-humeral joint.


4. Joint Mobilization

1. Cognitive problems following head injury. *See appendix A for management ideas.
   
   
   Agitation/Frustration
   
   Poor Emotional Control
   
   Impulsivity and lack of inhibition
   
   Apathy
   
   Depression/Withdrawal
   
   Lack of Insight/ Denial of Disability
   
   Lack of Empathy - Self Centeredness


2. Physical Manifestations of a head injury can vary from very mild to severe. As tone increases in the client following head injury or later stages post stroke the following changes may be seen:
   
   
   1. TRUNK:
      
      
      The first muscles to return after stroke or head injury tend to be levator scapulae, quadratus lumborum and the latissimus dorsi. This can lead to a compromised position of the scapula (discussed above) as well as a hip that (instead of listing downward into gravity) becomes elevated with a posterior rotation.
   
   
   2. UPPER EXTREMITY
      
      Upper extremity: Typical patterns of return are seen in the upper extremity of persons who have head injury. These include:
      
      
      1. Scapula: Downwardly rotated, winging, and/or tipping from the thoracic wall. Scapula is also frequently elevated on the thorax. Gleno-humeral stability is at risk due to poor orientation of the glenoid fossa.
      
      
      
      2. Gleno-humeral Joint: Adduction, extension, and internal rotation occurs from shortening of the pectoralis major and the latissimus dorsi. This can lead to stretch weakness of the rotator cuff. KEEP THE ARM OUT OF INTERNAL ROTATION AS MUCH AS POSSIBLE!!
      
      
      
      3. Elbow: Flexion with pronated forearm largely due to pressure frequently placed on the long head of the biceps. (Ryerson 1995).
      
      
      
      4. Wrist: Usually flexed with ulnar deviation from gravitational forces.
      
      
      
      5. Fingers: Flexed...with severe tone thumb adducts into the palm of the hand and the fingers flex around it.
   
   
   3. LOWER EXTREMITY:
      
      Two patterns are commonly seen in clients following stroke or head injury:
      
      
      1. Flexor pattern:
         
         
         Pelvis: rotated posteriorly and elevated.
         
         Hip: Flexion, External Rotation, Abduction
         
         Knee: Flexion
         
         Ankle: Inversion/Supination/Dorsiflexion
      
      
      2. Extensor Pattern:
         
         
         Pelvis: Posteriorly rotated and may be elevated or depressed.
         
         Hip: Extension/Internal Rotation/Adduction
         
         Knee: Extension
         
         Ankle: Inversion/Supination/Plantar-flexion

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