A Load and Shift Test | special Test

                                             A Load and Shift Test

 This test is designed to check primary atraumatic instability problems of the glenohumeral joint.
The patient sits with no back support and with the hand of the test arm resting on the thigh.



Ideally, the patient should be sitting in a properly aligned posture

If the patient slouches forward, the scapula protracts, causing the humeral head to translate anteriorly in the glenoid and narrows the subacromial space. For best results, the muscles about the shoulder should be as relaxed as possible. The examiner stands or sits slightly behind the patient and stabilizes

- The shoulder with one hand over the clavicle and scapula With the other hand, 
-the examiner grasp the head of the humerus with the thumb over the posterior humeral head and the fingers over the anterior humeral head 
- The examiner runs fingers along the anterior humerus and the thumb along the posterior humerus to feel where the humerus is seated relative to the glenoid 
- If the fingers dip in" anteriorly as they move medially but the thumb does not, it indicates the humeral head is sitting anteriorly



Normally, the humeral head feels a bit more anterior (I.e., the "dip" is slightly greater anteriorly) when it is properly seated in the glenoid. Protraction of the scapula  the glenoid head to shift anteriorly in the glenoid.
The examiner must be careful with the finger and thumb placement. In the presence of anterior or Posterior pathology, finger and thumb placement may cause pain.

The humerus is then gently pushed anteriorly or posteriorly (most common) in the glenoid if necessary to seat it properly in the glenoid fossa. The seating places the head of the humerus in its normal position relative to the glenoid. This is the "load" portion of the test. If the load is not applied (as in the anterior drawer test), there is no "normal" or standard starting position for the test.



The examiner then pushes the humeral head anteriorly (anterior instability) or posteriorly posterior instability), noting the amount of translation and end feel. This is the "shift" portion of the test.


IMPORTANT POINTS

 With anterior translation, if the head is not centered, posterior translation will be greater than anterior translationtion, giving a false negative test.


If the head is properly centered first, however, with anterior instability present, anterior translation is possible, but posterior translation is virtually absent because of the tight posterior capsule 



Find out translation of shoulder is it normal and abnormal 
and find out grades of shoulder translation 

The load and shift test may also be done in supine lying position

supine lying position 

To test anterior translation, the patient's arm is taken to 45 to 60° scaption (abduction in the plane of the scapula) and in neutral rotation by the examiner holding the forearm near the wrist

 The examiner then place the other hand around the patient's upper arm near the deltoid insertion with the thumb anterior and the fingers posterior feeling the movement of the humeral head in the glenoid while applying an anterior or anteroinferior translation force (with the fingers) or a posterior translation force (with the thumb).

Ideally, the humerus should be "loaded" in the glenoid before starting the test. With the hand holding the forearm, the examiner controls the arm position and applies an axial load to the humerus. During the translationtion movements with the thumb or fingers, the scapula should not move. As the anterior or anteroinferior translation force is applied, the examiner, using the other hand (the one holding the forearm) incrementally, laterally rotates the humerus . This causes greater involvement of the anterior band of the inferior glenoid humeral ligament,
which, if intact, will limit movement so the amount of anterior translation decreases as lateral rotation increases.

 To test posterior translation (posterior instability), the arm is placed in scaption with 45° to 60° of lateral rotation In this case, the thumb pushes the humerus posteriorly, Incrementally, while applying the posterior translation, the examiner medially rotates the arm.
Medial rotation causes the posterior anterior band of the inferior glenohumeral ligament and the posteroinferior capsule to become increasingly tight so that posterior translation decreases as medial rotation increases.