Does AS Cause Limited Mobility?

Ankylosing spondylitis (AS) causes chronic inflammation in the joints which may progress and lead to limited mobility.

How does ankylosing spondylitis cause limited mobility?

Most often in people with AS, the inflammation occurs in the spine and in the sacroiliac joints, located between the base of the spine and the pelvis. Some people also experience inflammation in other joints, such as the hips, shoulders, knees, or ankles. The points where tendons and ligaments attach to the joints, called entheses, can also become inflamed and cause tenderness and pain, which is called enthesitis. The chronic inflammation wears away at the bone of the joints. As the body works to replace the lost bone, it can create too much bone in the joint, leading to a fusing of the joint. The entheses and ligaments may also become calcified, called syndesmophytes. Joint fusion immobilizes the joint, causing rigidity or limited mobility.^1-3

Locations and impact of limited mobility

There is wide variation between different people with AS, and not everyone has the same symptoms. The most common joint to be affected in AS is the sacroiliac joint. This can cause low back pain and stiffness, which is worse at night or in the morning and improves with activity.^4,5

AS may progress up the spine to affect the joints between the vertebrae, up to the chest and/or neck.² AS may also affect the joints between the ribs and the spine, or between the ribs and the breastbone. Bony fusion of the vertebrae causes pain and stiffness and can lead to a lack of flexibility in the spine. Some people with AS have difficulty rotating or twisting their spine.⁶ Fusion of the joints between the ribs and spine or between the ribs and the breastbone can make it difficult to fully expand the chest cavity, causing chest pain or difficulty taking deep breaths.⁷

In some people, AS affects the peripheral joints, such as the hips, shoulders, wrists, knees, or ankles. The joint damage is painful and may make daily activities difficult or impossible. Some joints, such as the hip, shoulder, or knee, may be able to be surgically replaced to improve mobility.^2,7

Treating or preventing limited mobility

Effective treatment for AS can reduce pain and stiffness, maintain mobility, and help people engage in their daily activities. Treatment for AS may involve a combination of approaches, including medication, physical therapy, and exercises. In some cases, surgery may be recommended to relieve severe joint damage.²

Medications for AS include^8,9:

• Non-steroidal anti-inflammatory drugs (NSAIDs), which can help relieve pain and inflammation
• Biologic medications, which may help slow or stop the progression of the disease by blocking key processes or compounds involved in the inflammatory response
• Corticosteroids, which may be used for short-term relief of inflammation
• Slow-acting anti-rheumatic drugs (SAARDs), which may help relieve pain and inflammation, especially in those who cannot take biologic medications

Regular exercise is an important part of treatment for AS. People with AS may benefit from working with a physical therapist to address their specific needs. All people with AS should engage in exercises that strengthen the back and neck to maintain or improve posture. Maintaining correct posture is critical, and the spine should be kept straight and erect when sitting or walking. Other exercises that are important for people with AS include deep breathing and aerobic exercises. While physical therapy isn't believed to prevent the progression of the disease, it can minimize the symptoms in certain patients.²