Schamroth Test or Schamroth Window Test

This test was originally demonstrated by South African cardiologist Dr Leo Schamroth on himself and is a popular test for clubbing.

When the distal phalanges (bones nearest the fingertips) of corresponding fingers of opposite hands are directly apposed (placed against each other back to back), a small diamond-shaped “window” is normally apparent between the nailbeds.

If this window is obliterated, the test is positive and clubbing is present.