Joint range of motion refers to both the distance a joint can move and the direction in which it can move. There are established ranges that doctors consider normal for various joints in the body.

For example, one study determined a normal knee should ideally be able to flex, or bend, to between 133 and 153 degrees. And a normal knee should also be able to extend so that it’s completely straight.

A reduction in a normal range of motion in any of the joints is known as limited range of motion. Joint range of motion naturally declines as you age, but it can also occur with a number of conditions.

Certain exercises may be helpful for improving and maintaining flexibility in the joints.

Medical conditions

Medical conditions associated with a limited range of motion in the joints include:

  • ankylosing spondylitis, which is a type of arthritis that primarily affects the spine
  • osteoarthritis (OA), which is the most common form of arthritis related to older age and wear and tear of the joints
  • rheumatoid arthritis (RA), an autoimmune form of arthritis caused by your immune system attacking your joints
  • juvenile RA, which is an autoimmune form of arthritis that occurs in children under the age of 16 years
  • cerebral palsy (CP), which is a group of neurological disorders that causes muscle paralysis and loss of body control.
  • Legg-Calve-Perthes disease, which is a disorder that causes the top of the thighbone to die due to lack of blood flow to the joint.
  • sepsis of the hip and other joints, which is a bacterial infection of the joints
  • a congenital form of torticollis, which is a stiff neck associated with muscle spasms
  • syphilis, which is a sexually transmitted infection (STI)

Other causes

Other causes of restricted range of motion include:

See your doctor about any reductions in the normal range of motion of your joints. You should also go to your doctor if you can’t fully straighten or bend one or more joints or if you’re having difficulty moving a certain joint.

People aren’t always aware of their own limited range of motion. You may see a doctor for an unrelated reason and discover that you’re also experiencing a lack of mobility in one or more of your joints.

Your initial appointment will likely consist of a physical examination. This will include an assessment of the affected joints. Your doctor may ask questions about your limited range of motion, such as:

  • When did the problem start?
  • Are you experiencing discomfort?
  • Where is it occurring?
  • Are you having any other symptoms?

Your doctor may also assess the function of your bones, muscles, or nervous system. As a follow-up, your doctor may schedule some tests, such as X-rays of the spine and joints.

Your doctor may recommend a course of physical therapy designed to enhance range of motion.

In some cases, the position of the joint may become permanently fixed. This means you’ll no longer be able to move the joint past a given point. These are known as contracture deformities. Conditions associated with this complication include:

  • cerebral palsy (CP)
  • muscular dystrophy, which is an inherited disease involving muscle weakness
  • Dupuytren’s contracture, which is a thickening of the tissue layer beneath the skin in the hands and wrist
  • Volkmann’s contracture, which is a lack of blood flow to the forearm, causing the muscles in the arm to shorten

Range of motion exercises specifically target joint flexibility. You can do range of motion exercises with a physical therapist. Your doctor or physical therapist can also tell you about exercises that you can easily do at home.

These can help you maintain or improve joint flexibility, which helps with overall freedom and ease of movement.

There are three general categories of range of motion exercises: active, active assistive, and passive.

You can do active exercises without the assistance of another person.

Active assistive exercises rely on your effort and the effort of another person. This other person is often a physical therapist. These exercises are helpful when it’s painful to flex or extend the joint on your own.

Passive exercises rely completely on the effort of the physical therapist or another individual.

These are typical performed when the person receiving treatment isn’t physically able to perform the movement on their own.

Practicing range of motion exercises can greatly increase your flexibility and ease of movement. However, always speak with your doctor before attempting to perform a range of motion exercise for the first time.

Maintaining proper alignment and form are necessary to make sure you don’t injure yourself.