Elbow Orthopaedic Test: Polk's Test

Polk's test, also known as the chair sign test, is a physical examination maneuver used to evaluate for the presence of posterolateral rotatory instability of the elbow joint. This condition can result from injury to the lateral ulnar collateral ligament and can be associated with recurrent dislocation of the elbow joint.

Procedure:

1. Seat the patient in a chair with their affected arm resting on the armrest.
2. Stand behind the patient and grasp their wrist with one hand, while placing the other hand on the patient's proximal forearm.
3. Apply a valgus stress to the elbow joint by pushing the wrist laterally, while simultaneously applying an axial load by pushing down on the forearm.
4. Maintain the elbow flexed at 20-30 degrees and the forearm in pronation during the maneuver.
5. Observe and palpate the joint during the maneuver for any signs of instability, such as a palpable or audible clunk or a sense of apprehension in the patient.
6. Repeat the maneuver on the contralateral side for comparison.

A positive test result is indicated by a palpable and/or audible clunk or apprehension in the patient, which suggests instability or subluxation of the elbow joint.

References:

1. Pollock JW, Brownhill J, Ferreira L, McDonald CP, Johnson J. The posterolateral rotatory instability (PLRI) of the elbow. J Bone Joint Surg Br. 2010;92(1):16-22. doi:10.1302/0301-620X.92B1.22351
2. Magee DJ. Orthopedic Physical Assessment. 6th ed. St. Louis, MO: Elsevier; 2014.