Decreased motion in a joint results in decreased ability to use that joint fully. The only way to know if the functional range of motion in a joint is limited is to measure the joint at rest and at the end of the motion. Accomplish this with a goniometer and an assistant or a physical therapist. If the motion is limited and causes decreased function, work to improve motion in the joint.
A joint's range of motion is typically measured using active or functional measurements and passive measurements. Functional measurements of a joint are assessed when the an individual moves the joint and body himself. Pain and the amount of movement are always monitored and noted. Passive motion is when the examiner moves the joint without the assistance of the person being examined.
Range of motion measurements are taken to assess how well a joint functions. Many times these measurements are taken by a physical therapist after an accident or injury to a body part. These functional and passive measurements help the treating physician and therapist monitor the amount of improvement and can help set treatments goals when healing an injured joint.
A goniometer is needed to take measurements of a joint. The goniometer has two arms connected at a protractor. The examiner will place the protractor at the center of the joint then move one of the arms as the person being examined moves her body part. The functional range of motion is taken from the protractor in the form of a measurement of how many degrees of motion the joint allowed. An example of this is knee flexion measurement. The person being examined should start with her leg straight and bring the foot as close to the buttocks as possible. How far she bends her knee would be her functional range of motion of knee flexion.
Comparing to Normal
Measurements should be compared to what is accepted as anatomical normal and the other side of the body if possible. According to Washington State University's Department of Social and Health Services, the following are commonly accepted anatomical measurements: Back-Flexion 90 degrees, extension 25 degrees, lateral flexion 25 degrees. Neck-Flexion 50 degrees, extension 60 degrees, lateral flexion 45 degrees, rotation 80 degrees. Hip-Flexion 100 degrees, extension 30 degrees, adduction 20 degrees, abduction 40 degrees. Knee-Flexion 150 degrees. Shoulder-Flexion 150 degrees, extension 50 degrees, adduction 30 degrees, abduction 150 degrees. Elbow-Flexion 150 degrees, extension 0 degrees. Forearm-Pronation 80 degrees, supination 80 degrees. Ankle-Dorsiflexion 20 degrees, plantarflexion 40 degrees, inversion 30 degrees, eversion 20 degrees. Wrist-Flexion 60 degrees, extension 60 degrees, ulnar deviation 30 degrees, radial deviation 20 degrees.
If there is a decrease in functional range of motion, pain or odd sensation with motion of a joint, see a medical physician to discuss options to improve motion and decrease pain.