Indications

Allen’s Manoeuvre or Allen’s test is used to examine for neurovasular compression (thoracic outlet syndrome, TOS), caused by a cervical rib or anterior scalene muscle syndrome.


Procedure

  1. Patient seated, shoulder abducted to 90° and elbow flexed to 90°.
  2. Examiner palpates radial pulse and asks patient to turn head away from affected side.
Allen's Manoeuvre/test used to examine for thoracic outlet syndrome.

Examiner palpates radial pulse and asks patient to turn head away from affected side.

Modifications

Patient may be instructed to take a deep breath and hold it after the head is rotated to help apply further pressure to the brachial plexus nerve roots and subclavian artery.

Interpretation

Positive AC Shear Test

    Decrease or loss of pulse: neurovasular compression (TOS) from a cervical rib, anterior scalene muscle syndrome.