Stemcelldoc's Weblog

February 1, 2009

Rotator Cuff Signs: Empty Can Test

The supraspinatus is the most commonly injured rotator cuff  muscle.  It originates from the shoulder blade passes laterally beneath acromion and attaches onto the humerus.supraspinatus-lateral1supraspinatus

The supraspinatus  stabilizes the shoulder joint and allows one to raise their arm in a plane similar to a jumping jack.

The empty can test assesses the supraspinatus for instability and the presence of tears.  The test is conducted as follows:


The patient raises his arm to 90 degrees and angles the arm forward 30 degrees at the shoulder joint.  The shoulder is then internally rotated as if pouring a can on the floor.  Resistance is applied looking for weakness or pain. The test is positive if there is significant pain or weakness or resistance.

Rotator cuff tears which do not response to physical therapy can be treated with expanded stem cells.  At Regenexx patients use their own stem cells to repair damaged tendons, ligaments, bones and cartilage.

January 31, 2009

Rotator Cuff Sign

Rotator cuff tears often result in pain over the front and outer aspect of the shoulder.  The  pain maybe  increased when pushing upwards on the shoulder  or reaching forward. Weakness may also be reported. Unfortunately pain and weakness do not make the diagnosis of a tear in the rotator cuff.

Park et. al., demonstrated that to best way to diagnose full-thickness rotator cuff tears on physical examination is when the painful arc test, the drop-arm sign, and weakness in external rotation were all positive.  These are known as the rotator cuff signs.

The painful arc test is positive if the patient has pain when raising their arm from their side upward beyond the level of their shoulder.


The drop-arm sign is the inability of a patient to hold the arm up at or above the shoulder against gravity.  Please click video for a demonstration of this test.

Weakness in external rotation exam starts with patient seated.  The elbows are flexed at 90°, thumbs turned up, and the arm rotated internally 20°. The patient is then asked to externally rotate the arm against resistance.  If there is weakness or fatigue with external rotation the test is positive.  See example:weakness-with-external-rotation1

Surgery is a common treatment of tears in the rotator cuff.  An alternative is the use of stem cells to regenerate damaged tendons, ligaments and degenerative cartilage.  Regenexx enables a patient to use their own stem cells to regenerate tears in the rotator cuff without surgery, anesthesia or extensive rehabilitation.

%d bloggers like this: