Range of Motion Testing
Range of motion refers to the movement potential of a joint from full extension to full flexion (bending). Range of motion, also known as ROM, is a measure of flexibility involving ligaments, tendons, muscles, bones, and joints, so testing for ROM is essential in determining fitness and in assessing possible damage. Full range of motion indicates that the particular joint has the ability to move in all the directions it is supposed to move.
Reasons for ROM Testing
Flexibility, or lack of it, is an important component of general health. Individuals with full range of motion will generally perform better in their daily and sports activities, and are less likely to suffer injuries. Many factors may contribute to limited ROM and the need for ROM testing. These include:
- Joint swelling and stiffness
- Osteoarthritis
- Rheumatoid arthritis
- Joint injury
- Injury to muscle, tendon or ligament
Medical professionals administering and evaluating the results of ROM testing take into account many variables, including the patient's age, gender, family history, weight and activity level.
Types of ROM Testing
There are three basic types of range of motion: passive, active-assistive and active, defined by the whether, and to what degree, the patient can move the joint voluntarily. Passive ROM exercise is performed by the physical therapist alone, active ROM is performed independently by the patient, and active-assistive ROM may involve the use of bands, straps or other devices, accompanied by verbal directions from the therapist.
Equipment Used for ROM Testing
There are two devices commonly used to measure range of motion.
Goniometer
Apart from physical examination, ROM evaluation is most frequently performed using a device called a goniometer, an instrument that measures the angle at a joint. Goniometers measure range of motion in degrees, from zero to 180 or 360, and come in various shapes and sizes to be used on particular joints.
Inclinometer
Another device used to measure ROM is an inclinometer, usually employed to measure the angle of the cervical, thoracic, or lumbar spine. At times, the inclinometer is used in addition to the goniometer, and at times it replaces it. Sometimes inclinometers are used in pairs. This is known as dual inclinometry.
Even very simple equipment, such as a tape measure, may be used to measure range of motion.
Frequency of ROM Testing
Typically, ROM testing is performed three times. The first time is to establish a baseline, assessing the patient's limitations due to injury or disease, and helping to design a course of rehabilitative treatment.
Midway through the course of treatment, measurements are taken to determine the patient's progress, or whether there is any reduction of strength, possibly as a result of a breakdown in nerve tissue.
A final test is performed at the end of the course of treatment to attempt to determine whether permanent improvement has occurred or whether there is any residual impairment.