Why Does My Teres Minor Hurt? Causes and Relief

Teres minor pain typically stems from one of a handful of causes: a muscle strain or tendon injury from overhead activity, compression of the nerve that supplies the muscle, myofascial trigger points, or even a problem in the neck that sends pain signals to the back of the shoulder. The teres minor is a small but important muscle in the rotator cuff, and because it sits in a crowded neighborhood of tendons, nerves, and blood vessels, pinning down exactly why it hurts can be surprisingly tricky.

What the Teres Minor Actually Does

The teres minor is the smallest of the four rotator cuff muscles. It runs from the outer edge of your shoulder blade to the top of your upper arm bone, and its main job is to rotate your arm outward and help stabilize the ball-and-socket joint of the shoulder. Every time you reach behind your head, cock your arm back to throw, or rotate your arm away from your body, the teres minor is working. Research using elastography has shown that the teres minor’s stiffness changes with different rotation angles, reflecting how much load the muscle handles across different arm positions.¹ Because it shares so much of its workload with the infraspinatus (its larger neighbor), isolated teres minor problems are less common than issues affecting the supraspinatus or subscapularis. When the teres minor does become the primary source of pain, the causes tend to fall into a few distinct categories.

Muscle Strain and Tendon Tears

Like any muscle, the teres minor can be strained by a sudden forceful movement or torn by acute trauma. A hard throw, a fall onto an outstretched arm, or an awkward catch during a sport can overload the muscle-tendon unit. Acute strains range from mild fiber damage that heals on its own in a few weeks to partial or full-thickness tendon tears that need more serious intervention. Isolated teres minor tears are uncommon, and the handful documented in the literature are typically treated either with rest and rehabilitation or with arthroscopic repair, depending on the extent of damage. One case report described a patient who underwent successful arthroscopic repair of an isolated teres minor tear and returned to full pre-injury function afterward.²

Repetitive overhead activity is probably the more common culprit. Swimmers, baseball pitchers, tennis players, and people who work with their arms overhead for extended periods subject the teres minor to repeated eccentric loading, where the muscle is lengthening while it contracts. Over time, this can produce micro-damage that accumulates faster than the body can repair it, leading to tendinopathy or chronic strain. The pain is usually felt deep in the back of the shoulder, sometimes radiating slightly down the arm, and it tends to worsen during overhead movements or external rotation against resistance.

Quadrilateral Space Syndrome

One of the less well-known causes of teres minor pain is quadrilateral space syndrome, sometimes called QSS. The quadrilateral space is a small anatomical tunnel on the back of the shoulder, bordered by the teres minor above, the teres major below, the long head of the triceps on one side, and the upper arm bone on the other. Running through this narrow gap are the axillary nerve and the posterior humeral circumflex artery. When something compresses those structures inside the space, it produces QSS.³

Because the axillary nerve supplies the teres minor, compression here directly affects the muscle. People with QSS typically feel a vague, poorly localized ache in the back of the shoulder that gets worse with overhead activity. Over time, if the nerve compression continues, the teres minor can actually atrophy, meaning the muscle wastes away and loses its bulk. This is a sign that the nerve has been compromised for a while. In chronic cases, QSS can be debilitating and may ultimately require surgery.⁴

QSS is considered rare, but it may be underdiagnosed because its symptoms overlap with more common shoulder problems like rotator cuff tendinopathy or impingement. It tends to show up in athletes who do a lot of overhead work. Fibrous bands within the quadrilateral space are frequently the cause of the compression; in a small surgical series of overhead athletes, fibrous bands entrapping the axillary nerve were found in three of four shoulders, and all patients returned to full overhead activity about twelve weeks after decompression surgery.⁵

Myofascial Trigger Points

If your teres minor pain is a deep, dull ache that seems to radiate beyond where the muscle sits, trigger points could be responsible. Trigger points are hyperirritable knots within a taut band of muscle that produce local tenderness and often refer pain to other areas. Teres minor trigger points characteristically send pain to the immediate area over the muscle on the back of the shoulder and sometimes into the upper arm. They can also produce a sensation of deep soreness that feels disproportionate to any injury you can remember.

These knots tend to develop in muscles that are overworked, held in shortened positions for long periods, or subjected to sustained postures like hunching at a desk. The teres minor, because of its small size and the high demands placed on it during repetitive arm movements, is a common site for these trigger points to form. Treatment typically involves direct pressure on the knot, stretching, or dry needling, a technique where a thin needle is inserted into the trigger point to release it. Research on dry needling of active trigger points in the teres minor has shown improvements in pain intensity and shoulder rotation range of motion.

When the Pain Is Actually Coming from Your Neck

Sometimes what feels like teres minor pain does not originate in the shoulder at all. The nerve roots that exit the lower cervical spine, particularly at the C5 and C6 levels, supply sensation and motor function to the shoulder area. When a disc herniation, bone spur, or other spinal issue compresses these nerve roots, the pain can radiate into the posterior shoulder in a pattern that mimics rotator cuff pathology. A study examining patients with C5-C6 radiculopathy found that a substantial proportion also had rotator cuff lesions detected on shoulder MRI, highlighting how often the two conditions coexist and complicate diagnosis.⁶

The clinical challenge is that you can have both a neck problem and a shoulder problem at the same time, and each can amplify the other’s symptoms. If you have teres minor area pain alongside neck stiffness, tingling in the arm or hand, or pain that changes with head position, your clinician may need to evaluate the cervical spine as well as the shoulder to sort out what is driving the symptoms.

How Teres Minor Problems Are Diagnosed

Doctors use specific physical examination maneuvers to test whether the teres minor is functioning normally. One of the most well-known is the hornblower’s sign, which is tested by placing your arm in a specific externally rotated position and seeing if you can hold it there against resistance. Research found that the hornblower’s sign had perfect sensitivity and high specificity for detecting irreparable teres minor degeneration.⁷ For massive rotator cuff tears involving the teres minor, a separate study found that the most accurate clinical test was an external rotation lag sign greater than 40 degrees, which achieved perfect sensitivity and a specificity above 90%.⁸

These tests are mainly designed to detect significant structural damage like large tears or advanced degeneration. For milder problems such as tendinopathy, strain, or trigger points, the physical exam is often more about reproducing the pain pattern and ruling out other structures. Your clinician will test external rotation strength, palpate the muscle directly, and may check neighboring structures to see if the infraspinatus, deltoid, or long head of the triceps could be contributing.

When imaging is needed, MRI is the most common choice because it can show tendon tears, muscle atrophy, and fatty infiltration of the teres minor, which suggests chronic denervation. Ultrasound is another option and has the advantage of being dynamic, meaning you can move the arm during the exam. Cadaver research has confirmed that ultrasound can reliably identify the teres minor insertion and detect tears of the muscle-tendon unit.⁹ For suspected quadrilateral space syndrome, MRI may show selective fatty atrophy of the teres minor, and angiography or MR angiography can reveal compression of the posterior humeral circumflex artery during arm positioning.

Conservative Relief Strategies

Most teres minor pain responds well to conservative treatment, and surgery is rarely the first step. The initial approach typically includes rest from aggravating activities, ice or heat (whichever feels better to you), and anti-inflammatory medication if appropriate. Beyond that, targeted rehabilitation is where the real progress happens.

A rehab program for teres minor pain focuses on several goals:

External rotation strengthening: Because the teres minor’s primary job is external rotation, progressive strengthening of this movement helps restore the muscle’s capacity and resilience. Resistance bands or light dumbbells with the elbow bent at your side are the standard starting point.
Posterior shoulder stretching: Gentle cross-body stretches and sleeper stretches can relieve tightness in the teres minor and the posterior capsule of the shoulder.
Scapular stabilization: Weakness or poor control of the muscles that move the shoulder blade can shift more load onto the rotator cuff, including the teres minor. Exercises targeting the lower trapezius and serratus anterior help redistribute forces more evenly.

Scapular stabilization deserves special attention because abnormal scapular movement, known as scapular dyskinesis, is an often-forgotten contributor to shoulder pain. The scapula needs to rotate, tilt, and glide in coordination with the arm during overhead movement; when it does not, the rotator cuff muscles have to compensate, and the teres minor can be one of the muscles that pays the price.¹⁰ If your teres minor pain is related to overhead activity, a physical therapist will almost certainly evaluate how your shoulder blade moves and build scapular exercises into your program.

For trigger point-driven pain, manual therapy techniques like deep tissue massage or dry needling can provide relatively fast relief. Foam rolling the posterior shoulder is harder to do effectively because of the muscle’s small size and location, but a lacrosse ball pressed against a wall can approximate the pressure a therapist would apply. Trigger point treatment works best when combined with stretching and strengthening rather than used as a standalone fix.

When Injections or Surgery Enter the Picture

If conservative treatment is not getting the job done after several months, your doctor may consider a corticosteroid injection. This is most commonly relevant for quadrilateral space syndrome, where reducing inflammation around the compressed nerve can provide substantial relief. In one reported case of QSS, ultrasound-guided corticosteroid injections relieved the patient’s symptoms, and follow-up nerve testing six months later confirmed the axillary nerve was recovering.¹¹

Surgery is reserved for cases that have failed conservative care or where there is clear structural damage. For QSS with identifiable fibrous bands or other compressive lesions, surgical decompression of the quadrilateral space is the standard approach. As mentioned earlier, overhead athletes who underwent this procedure returned to full activity within about three months.⁵ For cases involving isolated teres minor atrophy from nerve branch compression, open surgical release of the fascial tissue around the nerve has also shown encouraging results: patients in one series experienced an average four-point drop in pain scores and meaningful improvements in shoulder function, with no loss of external rotation strength after the procedure.¹²

For isolated tendon tears that do not respond to rehab, arthroscopic repair is an option, though these cases are rare enough that the surgical literature consists mainly of case reports rather than large trials.² Massive rotator cuff tears involving multiple tendons including the teres minor are a different situation entirely and may require more complex surgical reconstruction.

How Sleep Position Plays a Role

If your teres minor pain is worse at night or first thing in the morning, your sleep position may be a factor. Side sleeping puts prolonged compressive pressure on the shoulder underneath you, and research has shown a striking correlation between the side people habitually sleep on and the side where they develop shoulder pain.¹³ The theory is that the weight of the thorax pressing down on a shoulder for hours reduces blood flow and stresses the soft tissues, including the rotator cuff. For something as small as the teres minor, hours of compression could be enough to aggravate an already irritated muscle or tendon.

Practical fixes are simple even if they are hard to sustain: try sleeping on your opposite side or on your back, and consider placing a pillow under or in front of the affected arm to keep the shoulder in a more neutral position. Some people find that a body pillow prevents them from rolling onto the sore side during the night. These adjustments will not fix a torn tendon, but they can meaningfully reduce nighttime aggravation of a muscle that is already inflamed or strained.

Age-Related Changes in Rotator Cuff Blood Supply

If you are over 40 and dealing with teres minor pain that came on gradually without any obvious injury, age-related changes to the rotator cuff’s blood supply may be part of the story. Contrast-enhanced ultrasound research has shown a meaningful decrease in blood flow to the rotator cuff tendons when comparing people younger than 40 to those older than 40.¹⁴ Less blood flow means slower healing, reduced nutrient delivery, and a tendon that is more vulnerable to the accumulation of micro-damage from everyday use.

This vascular decline helps explain why rotator cuff problems become more common with age even in people who are not athletes. The teres minor’s tendon does not get as much research attention as the supraspinatus, which is the rotator cuff muscle most commonly torn, but the same vascular principles apply. A tendon receiving less blood is a tendon that tolerates less load before it starts to break down. For people in this age group, consistent low-load strengthening and maintaining good shoulder mobility are probably the most effective preventive strategies. Waiting until pain appears to start exercising the rotator cuff means the tendon has already been losing ground for years.

Sorting Out Overlapping Shoulder Pain

One of the frustrating realities of teres minor pain is that it rarely announces itself with a neon sign. The posterior shoulder is densely packed with muscles, tendons, and nerves that share overlapping territories. Pain in the area where the teres minor lives could be coming from the infraspinatus, the posterior deltoid, the posterior capsule of the joint itself, or the axillary nerve. Even experienced clinicians sometimes need imaging or diagnostic injections to confidently isolate the teres minor as the source.

If your shoulder pain is vague and diffuse rather than sharp and localized, a broader evaluation is usually more helpful than zeroing in on one muscle. A physical therapist or orthopedic specialist can assess your overall shoulder mechanics, scapular control, cervical spine, and rotator cuff function as an integrated system. Sometimes the teres minor hurts not because something is wrong with it specifically, but because it is being overloaded by weakness or dysfunction somewhere else in the chain. Fixing the root cause rather than just chasing the site of the pain is what leads to lasting improvement.