Palpation of the distal interphalangeal (DIP) joint

The examiner places two fingers of one hand on the lateral joint lines and two fingers from the opposite hand at the base of the finger. Pressure is applied from the sides while simultaneously feeling for the distensibility of synovial thickening, excessive joint fluid, or both. The synovial lining of the small joints extends 5 to 6 mm above and below the joint line. An excessive amount of fluid causes the characteristic fusiform shape.