Baseline Goniometer Plastic 6 Inch Arm Length Use this goniometer during physical therapy assessments and treatments to evaluate the flexibility and movement of joints such as the knee elbow shoulder and hip. By measuring the range of motion and the joint s axis of motion with a protractor-like scale and two arms one fixed and one moveable you can track progress during rehabilitation identify limitations or abnormalities and tailor treatment plans accordingly. 1 Goniometer 6 Inch Arm Length