What Is Shoulder Impingement?

Quick Breakdown

Shoulder impingement is one of the most common diagnoses given for shoulder pain, but the term doesn't always describe what's actually causing your symptoms. Rather than simply being a tendon "pinched" beneath a bone, shoulder pain is often influenced by muscle strength, shoulder mechanics, mobility, training loads, and movement patterns. At True Grit Physical Therapy, we perform a comprehensive evaluation to determine why your shoulder hurts so we can treat the underlying cause—not just the diagnosis.

What Is Shoulder Impingement?

Shoulder impingement is a common term used to describe shoulder pain related to the rotator cuff tendons and surrounding tissues, especially during movements like reaching overhead, lifting weights, throwing, or reaching into a cabinet. While the name suggests that a tendon is being trapped or “pinched” between bones, modern research shows that shoulder pain is often more complex than simple compression.

Traditionally, shoulder impingement referred to irritation of the rotator cuff tendons or subacromial bursa beneath the acromion—the bony roof of the shoulder. The idea was that these tissues became compressed as the arm lifted, leading to pain and inflammation.

However, we now understand that many people have changes in this space without experiencing pain, while others experience significant shoulder pain without signs of narrowing on imaging. Because of this, many healthcare providers now use the term rotator cuff-related shoulder pain (RCRSP) instead.

This newer terminology reflects a more accurate understanding of the condition: shoulder pain is often related to how the rotator cuff and surrounding tissues move, function, and tolerate load rather than a single structure being physically “pinched.” This shift has also changed treatment approaches, with a greater focus on improving shoulder strength, movement patterns, and tolerance to activity.

Common Symptoms

People with shoulder impingement or rotator cuff-related shoulder pain often describe:

· Pain reaching overhead

· Pain lifting objects away from the body

· Pain while throwing

· Pain reaching behind the back

· Difficulty sleeping on the affected shoulder

· Weakness

· Pain during pressing exercises

· Pain while putting on a shirt or jacket

Symptoms usually develop gradually, although they may also begin after a sudden increase in activity or repetitive overhead work.

Why Does It Happen?

Shoulder pain rarely has one single cause. Instead, it's often the result of multiple contributing factors working together. These may include:

· Sudden increases in training volume

· Repetitive overhead activity

· Rotator cuff weakness

· Scapular muscle weakness

· Poor muscular endurance

· Limited thoracic spine mobility

· Reduced shoulder mobility

· Movement coordination deficits

· Previous injury

· Inadequate recovery

Think of it like repeatedly driving a car with slightly misaligned tires. One trip isn't a problem. Thousands of miles eventually create wear. Similarly, repetitive loading combined with small movement impairments can gradually irritate shoulder tissues over time.

The Rotator Cuff Does More Than Create Strength

Many people think the rotator cuff simply lifts the arm. Its primary role is actually stability. The four rotator cuff muscles work continuously to keep the ball of the shoulder centered within the socket as the larger muscles generate movement. If these muscles become fatigued or weak, other tissues may be forced to compensate. Over time, this can contribute to pain during overhead activities.

The Shoulder Doesn't Work Alone

The shoulder is part of an entire movement system. Pain may be influenced by:

· The shoulder joint

· The shoulder blade (scapula)

· The thoracic spine

· The cervical spine

· Core stability

· Hip and trunk control

· Overall movement coordination

For example, limited thoracic extension may force the shoulder to work harder overhead. Weakness of the scapular stabilizers may alter how the shoulder blade rotates during elevation. Even lower body deficits can influence throwing mechanics and increase stress on the shoulder. This is why we never evaluate the shoulder in isolation.

Imaging Doesn't Always Tell the Whole Story

One of the biggest misconceptions is that an MRI automatically identifies the source of shoulder pain. In reality, many people without pain have:

· Rotator cuff tears

· Tendinopathy

· Bone spurs

· Labral changes

· Bursal thickening

Especially as we age, these findings become increasingly common. Conversely, someone may have significant shoulder pain despite relatively normal imaging. Imaging provides useful information, but it must always be interpreted alongside your symptoms and physical examination. We treat people—not MRI reports.

Our Evaluation Looks Beyond the Diagnosis

At True Grit Physical Therapy, we don't simply confirm that your shoulder hurts. We determine why it hurts. Our evaluation may include:

· Shoulder range of motion

· Rotator cuff strength testing

· Scapular control assessment

· Muscular endurance testing

· Thoracic spine mobility

· Cervical spine screening

· Functional movement assessment

· Sport-specific or work-specific testing

· Load tolerance evaluation

By identifying the impairments contributing to your symptoms, we can build a treatment plan that addresses the root cause instead of temporarily masking the pain.

How Physical Therapy Can Help

The good news is that most cases of rotator cuff-related shoulder pain improve with conservative treatment. Your rehabilitation may include:

· Manual therapy

· Rotator cuff strengthening

· Scapular stabilization exercises

· Thoracic mobility exercises

· Progressive loading

· Motor control training

· Activity modification

· Sport-specific rehabilitation

· Return-to-throwing or return-to-lifting progressions

The goal isn't simply to eliminate pain. It's to restore your shoulder's ability to tolerate the demands you place on it.

Rest Isn't Always the Answer

Many people stop using their shoulder altogether once pain develops. While temporarily reducing aggravating activities may be helpful, complete rest often leads to additional weakness and reduced tissue capacity. Instead, we typically modify activities while continuing to load the shoulder appropriately. This allows tissues to heal while maintaining strength and function. Movement is often part of the solution—not something to fear.

When Is It Something More Serious?

Although shoulder impingement is common, not every painful shoulder falls into this category. Your evaluation also helps us identify conditions such as:

· Full-thickness rotator cuff tears

· Shoulder instability

· Adhesive capsulitis (frozen shoulder)

· Labral injuries

· Cervical radiculopathy

· Arthritis

· Fractures

· Referred pain from other regions

Recognizing these conditions ensures you receive the most appropriate treatment and referral when necessary.

The Bottom Line

Shoulder impingement is one of the most common explanations for shoulder pain, but the diagnosis alone doesn't explain why your symptoms developed. At True Grit Physical Therapy, we look beyond the label. We evaluate shoulder strength, mobility, muscular endurance, scapular control, thoracic spine mobility, cervical function, and movement mechanics to identify the true contributors to your pain. Because our goal isn't simply to stop your shoulder from hurting. It's to help your shoulder move better, tolerate more, and get you back to lifting, throwing, working, and living with confidence.