SI joint pain: 5 possible causes and how physical therapy may help

If you have pain in your lower back, buttock or pelvis, you may wonder whether your sacroiliac (“SI”) joint is involved. SI joint pain can develop for several reasons, including injury, arthritis, pregnancy-related changes and differences in how your body moves.  

Your SI joints connect your sacrum at the bottom of your spine to the two sides of your pelvis. These joints help transfer forces between your upper body and legs. When an SI joint becomes irritated or inflamed, you may feel pain in your lower back or buttock. In some cases, the discomfort can travel into your leg.

Because other hip and lower back conditions can cause similar symptoms, it is important not to assume that every case of lower back or buttock pain comes from your SI joint. A professional evaluation at KC Rehab can help you find the likely source of your symptoms.  

What does SI joint pain feel like?

SI joint pain can affect one or both sides of your body. You may notice symptoms around your lower back, buttock, pelvis or upper leg.  

Your discomfort may become more noticeable when you:

• Stand for a long time

• Walk for extended periods

• Climb stairs

• Shift your weight onto one leg

• Get up from a chair

• Turn or twist your body

• Move from sitting to standing

The exact pattern of your pain can depend on its cause. The following five factors are among the possible causes or contributors to SI joint pain.

1. Injury or trauma

A sudden force can irritate or injure the tissues around your SI joint. Falls, car accidents and twisting injuries are among the events that may contribute to SI joint pain.  

You may also develop symptoms after a movement that places an unexpected load on your pelvis. For example, a quick twist while playing sports or doing yardwork may stress the area.

If your symptoms began after an injury, a physical therapist can assess your movement, strength and mobility to help determine what structures may be involved.

2. Arthritis and joint inflammation

Arthritis and inflammatory conditions can affect your SI joints. Sacroiliitis is inflammation of one or both SI joints, and it can cause pain and stiffness in your lower back and buttocks.  

Certain inflammatory conditions, including forms of spondyloarthritis, may also affect the SI joints.

If inflammation is related to an underlying medical condition, physical therapy may be one part of your care. Your physical therapist may make recommendations like these exercises for lower back arthritis.

3. Pregnancy and postpartum changes

Pregnancy can change the stresses placed on your pelvis. Hormonal and physical changes may affect your joints, including SI joints, while changes in body weight and movement can place different demands on the muscles surrounding your pelvis.

A physical therapist may help you improve strength and movement around your hips, pelvis and core while taking your stage of pregnancy or recovery into account.

4. Differences in movement or body mechanics

Sometimes, SI joint pain may be associated with the way forces travel through your body.

Potential contributors can include:

• Differences in leg length

• Scoliosis

• Changes in walking mechanics

• Muscle weakness

• Reduced hip mobility

• Repeated movements that load one side more than the other

Leg-length differences and scoliosis are among the factors that may contribute to sacroiliac pain.  

That does not mean every movement difference causes pain. Your body can adapt to many differences without symptoms. A physical therapist can evaluate whether a specific movement pattern appears to be contributing to your discomfort.

5. Previous lower back surgery

If you have had spinal fusion surgery, the way forces move through your lower back and pelvis may have changed. This does not mean that everyone who has spinal surgery has SI joint problems. However, if you begin experiencing new pain around your lower back, pelvis or buttock after surgery, tell your health care provider.

How can physical therapy help with SI joint pain?

Physical therapy may help you manage SI joint pain by addressing factors that affect how you move and how much stress is placed around your pelvis.

Your physical therapist may begin by asking about:

• Where you feel pain

• When your symptoms started

• Which activities make them better or worse

• Previous injuries or surgeries

• Your work, exercise and daily activities

Your evaluation may also include tests of your strength, flexibility, range of motion, walking pattern and movement control.

Because SI joint symptoms can resemble other causes of lower back pain, this evaluation is important. Your physical therapist can look at your lower back, hips and pelvis instead of focusing only on the area that hurts.  

Depending on your findings, your treatment plan may include stretching and strengthening exercises. Physical therapy is commonly recommended for SI joint pain, including exercises designed to improve flexibility and strengthen the muscles supporting the area.  

Your treatment may focus on:

• Improving hip and lower-body strength

• Increasing flexibility or mobility

• Improving core control

• Changing movements that aggravate your symptoms

• Gradually returning to activities

• Building a home exercise program

Your physical therapist can also teach you ways to manage your symptoms between appointments and adjust your exercises as your abilities change.

Find out what may be causing your SI joint pain

SI joint pain can result from several different factors, and symptoms in this area can overlap with other hip and lower back conditions. You may have difficulty identifying the cause on your own.

If pain around your lower back, buttock or pelvis keeps returning or limits your daily activities, a physical therapy evaluation can help you better understand what may be contributing to it.

At KC Rehab, your physical therapist can assess your movement, strength and mobility and develop an individualized treatment plan based on your symptoms and goals.

Contact our team today for more information or to schedule an initial appointment.

Frequently asked questions

What is SI joint pain?

SI joint pain is discomfort associated with one or both sacroiliac joints, which connect the bottom of your spine to your pelvis. You may feel pain around your lower back, buttock or pelvis.

Where is SI joint pain usually felt?

You may feel SI joint pain around one side of your lower back, buttock or pelvis. In some cases, discomfort may extend into your upper leg. Other conditions can cause pain in the same areas, so location alone does not confirm an SI joint problem.

What causes SI joint pain?

Possible causes include injury, inflammation, arthritis, pregnancy-related changes, differences in movement and previous lower back surgery. Several factors may contribute at the same time.

What activities can make SI joint pain worse?

Your symptoms may become more noticeable when you stand or walk for long periods, climb stairs, shift your weight onto one leg or move between sitting and standing. Your specific triggers can vary based on the cause of your pain.

Can pregnancy cause SI joint pain?

Pregnancy can contribute to SI joint pain because your body undergoes hormonal, physical and movement changes. These changes can affect the forces placed on your pelvis and the muscles that help support it.

Can arthritis affect your SI joint?

Yes. Arthritis and inflammatory conditions can affect your SI joints. Sacroiliitis, which is inflammation of one or both SI joints, can cause lower back and buttock pain and stiffness.

Can muscle weakness contribute to SI joint pain?

Weakness around your hips, core or lower body may affect the way forces move through your pelvis. However, muscle weakness is only one possible contributor. A physical therapist can determine whether strength is relevant to your symptoms.

How is SI joint pain different from lower back pain?

SI joint pain and other forms of lower back pain can feel similar. Problems involving your spine, hips or surrounding muscles may cause symptoms in the same general area. A physical evaluation can help narrow down the likely source.

What exercises may help SI joint pain?

Your exercise program may include strengthening, stretching, mobility or movement-control exercises. The right exercises depend on what your evaluation shows, so you should avoid assuming that the same program works for every case of SI joint pain.

How can physical therapy help with SI joint pain?

Your physical therapist can evaluate your lower back, hips and pelvis and assess your strength, flexibility and movement. Your treatment plan may include exercises to improve mobility, build strength, improve movement control and help you return to activities that have become uncomfortable.