What is the correct use of a goniometer?

After joint injury or surgery the physical therapist often uses a goniometer to measure the range of motion at the beginning of therapy and periodically that should show improvement in range of motion. The word goniometer is derived from the Greek terms gonia and metron, which mean angle and measure, respectively.

A goniometer is usually made of plastic and is often transparent. Occasionally goniometers are made of metal. There are two "arms" of the goniometer: the stationary arm and the moveable arm.