Infraspinatus Pain: 6 Possible Causes

What is Infraspinatus Pain?

Infraspinatus pain is common and is most often caused by overuse or repetitive movements of the shoulder and arm.[1] It is also related to further disability if range of motion and strength continue to be impaired, affecting sleep and activities of daily living.[2]

The infraspinatus is a muscle in the shoulder and is one of the four muscles which comprise the rotator cuff. The infraspinatus and rotator cuff muscles help stabilise your shoulder and help move your arm smoothly.

You can find your infraspinatus muscle at the back of your shoulder. It attaches between the top of your humerus (arm bone) and your scapula (shoulder blade). It helps rotate your arm outwards (also called external rotation) and lift your arm overhead.

What are the symptoms of infraspinatus pain?

The symptoms of infraspinatus pain include:

• Shoulder pain

• Shoulder blade pain

• Shoulder weakness

• Reduced range of motion

• Difficulty putting weight on the affected side

• Trouble sleeping on the affected shoulder

• Pain with daily activities

• A ‘catching’ or ‘grinding’ sensation when the arm is moved.

What causes infraspinatus pain?

Infraspinatus pain is often caused by overuse or repetitive movements of the shoulder and arm. It is commonly experienced by athletes who complete repetitive overhead movements, such as swimmers or gymnasts, and people in painting or building occupations. Infraspinatus pain is more common in older people.

Infraspinatus pain has many potential causes, ranging from a minor strain to a complete tear. Sometimes, infraspinatus pain results from something simple and will resolve with rest. However, infraspinatus pain might also result from an injury or a more severe issue.

The following are some of the causes of infraspinatus pain:

1. Infraspinatus tear

In some cases, the shoulder can be overloaded by lifting, reaching, or pushing motions, resulting in a tear in the infraspinatus muscle.[3]

There are two different types of infraspinatus tears:

• A partial tear - This occurs when part of the muscle is torn, but not completely. It is usually a result of repetitive activities or ageing.

• A complete tear (or full-thickness tear) - This occurs when the muscle is torn all the way through. This is usually a result of an acute incident, such as a fall or an accident. People with an acute injury may experience sudden pain and weakness in the arm.

A doctor can use specific tests to assess and diagnose the different infraspinatus tears and recommend the appropriate treatment.

2. Infraspinatus tendinopathy

Infraspinatus pain can also be caused by tendinopathy. Tendinopathy is an overuse injury of the muscle. Symptoms may develop when the load on the muscles (by repetitive throwing or reaching overhead) exceeds the strength of the muscles. Over time, this can cause shoulder stiffness, dull aching pain, and a loss of shoulder movement.[4] It may also result in difficulty completing everyday activities. Symptoms can be worsened by weakness, bony spurs, or poor sporting technique.

Overhead athletes, such as tennis players or gymnasts, are particularly susceptible to shoulder tendinopathy due to the repetitive stress caused by the specific movements in their sport.

3. Infraspinatus impingement

Impingement occurs when the space between a muscle and the bones in the shoulder narrows, resulting in muscle compression. This can be particularly evident when the arm is lifted. A weakness in the rotator cuff muscles, shoulder dysfunction, poor posture, and repeated overhead activities can increase the risk of infraspinatus impingement.

The main symptoms of infraspinatus impingement include a catching or grinding sensation, pain when the arm is lifted, and stiffness. Pain can become persistent and can impact everyday activities, such as reaching overhead or getting dressed.

4. Bursitis

The bursa is a fluid-filled sac in the shoulder joint that reduces friction between the humerus and tip of the shoulder blade. Bursitis occurs when the bursa becomes inflamed due to repeated stress on the shoulder or overuse.

Symptoms include swelling and pain when the shoulder is moved. This can affect the movement of the shoulder, particularly during pushing motions or reaching overhead.5

5. Pinched nerve

The infraspinatus muscle is innervated by the suprascapular nerve. If this nerve gets pinched, it can cause pain in the infraspinatus muscle.

In rare cases, symptoms can include radiating or shooting pain in the shoulder region, shoulder weakness, and even muscle wasting.

A pinched nerve can develop over time with overuse or due to shoulder dysfunction. It can also be caused by trauma, such as an accident.

6. Trigger Points

A trigger point has been described as a tender area in a muscle that can cause intense or radiating pain when specifically pressed or ‘triggered.’ Not all medical professionals agree that trigger points genuinely exist.

Latent trigger points only cause pain when pressed. Conversely, active trigger points can cause pain continuously, even without being provoked. Both latent and active trigger points can cause a loss of range of motion and pain.

Trigger points are common in the infraspinatus muscle and can cause infraspinatus pain. A health practitioner can address these trigger points with specific stretches or exercises, massage, dry needling, or pain relief medications.

Other causes of infraspinatus pain

• Arthritis

• Infection

• Fracture

• Gout

• Acute injury

The symptoms of infraspinatus pain may present similarly to other conditions, such as arthritis or infection. Therefore, it is essential to consult a medical professional to obtain a correct diagnosis.

How is infraspinatus pain diagnosed?

A health practitioner, including a doctor or physiotherapist, can perform a history and physical examination to determine the origin of your infraspinatus pain and symptoms.

Your health practitioner might ask about:

• The symptoms in your shoulder

• Any aggravating and easing factors

• When the symptoms started

• Any recent injuries

• Your sports or activities, especially those that involve repetitive movements

• Your family and personal history.

In most cases, they will also do a physical exam to check:

• Which movements cause pain

• The range of motion in the shoulder

• The strength of the muscles in the shoulder

• And other specifics.

They might also perform specific tests to assess the shoulder more closely. In some cases, a doctor might request additional imaging such as an MRI to evaluate the shoulder and surrounding muscles. This can help rule out the more serious causes of the pain. It is essential to get a correct diagnosis before any treatment commences.

How is infraspinatus pain treated?

Treatment will depend on the cause and severity of the pain. It is important to discuss any symptoms with a doctor to obtain the correct diagnosis. A combination of treatment options may be necessary to treat the infraspinatus muscle and alleviate the pain.

The following are some common treatment options:

Rest

As infraspinatus pain is often caused by overuse or repetitive movements, rest can be a beneficial short-term strategy to relieve pain. A doctor or physiotherapist may also recommend avoiding any aggravating activities for a short period.

Heat and ice

Infraspinatus pain may be relieved by applying ice or heat. In the right situation, heat can be helpful before completing stretches or exercises. A cold pack may be more useful when applied after a workout or at the end of the day. It is best to discuss which option may be more beneficial for your condition with your health practitioner.

Massage therapy

Massage therapy can help relieve muscle tension or trigger points in the shoulder muscles that may be contributing to the pain. A qualified massage therapist can target key areas to provide the most benefit.

Exercises and stretches

A physiotherapist is trained to assess, treat, and manage musculoskeletal conditions, such as infraspinatus pain. A physiotherapist can use specific treatments to target your symptoms. Depending on the cause of the pain, exercises and stretches can reduce pain and restore function in the shoulder.

These exercises might include:

• Gentle stretches to help relax any tight muscles in the shoulder.

• Strengthening exercises to build strength in the infraspinatus and rotator cuff muscles. Weights may be added to these exercises as the pain improves.

• Deeper stretches may be used as the pain and function to improve the length and range of the muscles and joints in the area.

NSAIDs

To provide pain relief, a doctor may prescribe non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Nurofen, Advil). This can help make it easier to complete any prescribed exercises.

Steroid injections

Your doctor may suggest steroid injections to target pain and inflammation depending on your specific condition. Steroids can provide short-term pain relief temporarily, but continued injections are not usually recommended due to long-term health consequences.

Surgery

If the infraspinatus muscle is severely injured, such as in an accident or from a fall, your doctor may recommend surgery. In other cases, surgery might also be considered if the infraspinatus pain is persistent or if other conservative treatments have failed. Depending on the original cause or injury, it can take a considerable time to recover after surgery.

Long-term outcomes

The long-term outcomes for infraspinatus pain depend on the cause and severity. Infraspinatus pain can be resolved with rest, stretches and exercises, and pain relief in most cases. However, if the pain is left unaddressed, infraspinatus pain can persist for long periods. It is essential to discuss your symptoms with your doctor or physiotherapist.

A summary of Infraspinatus Pain

• Infraspinatus pain is common in athletes, certain occupations, and older people.

• In most cases, it can be resolved with rest, stretches and exercises from a qualified health practitioner, and pain relief.

• Discussing any symptoms with a health practitioner to rule out more serious causes is important.