A Physical Therapy Guide to Shoulder Impingement

Shoulder impingement may also be referred to as shoulder impingement syndrome, subacromial impingement, or as subacromial pain syndrome. It is a painful shoulder condition that can impact your ability to sleep or use your arm with daily activities, such as reaching in the cupboard or washing your hair.

Since it was first described in 1852, shoulder impingement syndrome has been one of the most common causes of shoulder pain, accounting for 44% to 65% of all shoulder joint complaints.¹

Working with a CityPT physical therapist is a great first step to recovery. Continue reading below to learn more about how and why shoulder impingement develops, what you can do to recover, and steps to prevent its development.

Table of Contents

• Understanding Shoulder Impingement Syndrome
• Symptoms of Shoulder Impingement and Subacromial Pain Syndrome
• What are the Most Common Risks for Developing Shoulder Impingement?
• How to Diagnose Shoulder Impingement
• What to Expect from Physical Therapy
• How Can I Prevent Shoulder Impingement?
• Is It Time to Seek Treatment?

Understanding Shoulder Impingement Syndrome

It may be helpful for you to understand some of the anatomy of your shoulder to understand the nature of subacromial impingement better.

Your shoulder has three bones in it:

• Humerus: The long upper arm bone that includes the "ball" of the shoulder joint.
• Scapula: Also known as the shoulder blade, the outer part serves as the "socket" of your shoulder.
• Clavicle: Known as your collar bone, it forms a joint with the scapula on top of the shoulder.

These three bones also form the three sub-joints that comprise your shoulder. They are:

• In your upper back — the scapula connects with your rib cage via a set of broad, flexible muscles
• In the front — just below where your throat meets your chest, your clavicle connects to your sternum
• Near the outer front part of your shoulder — a hook-shaped protrusion in the scapula, called the acromion, connects with the end of the clavicle

Where is the pain coming from?

Shoulder impingement syndrome tends to involve pain and irritation in the soft structures just below the acromion of the scapula, which is why it is also often referred to as "subacromial impingement." Several structures lie below the acromion:

• Your rotator cuff tendon(s) — a set of muscles and connective tissue that help you to move your humerus within the "socket" of your scapula
• One of the tendons of your biceps muscle
• Your subacromial bursa — a pad-like fluid filled sac
• Various ligaments which help support the shoulder

Sometimes shoulder impingement occurs with an injury to the rotator cuff, and sometimes it happens without any damage to the rotator cuff. Which structures cause the pain is not always clear from imaging or other tests and objective measures.

Time for a new name?

It was once thought shoulder impingement develops due to a lack of space under the acromion. However, when measuring this space, there is little to no difference between people without shoulder pain and those with subacromial pain in multiple studies.²

This new insight — combined with the fact that it is not always possible to identify the exact structure(s) (such as the rotator cuff) causing pain in this region — has led experts to propose an alternate name for this condition.

Thus, many have suggested using the term "subacromial pain syndrome" ³, which may describe more accurately the different causes at play with pain in this part of the shoulder. However, as many people still are more familiar with the term "shoulder impingement," it will be used throughout this article (along with subacromial impingement).

Symptoms of Shoulder Impingement and Subacromial Pain Syndrome

Shoulder impingement syndrome involves pain in the front shoulder region or toward the outer part. Many experience it as a pinching, burning or aching. Some also report shoulder weakness or a sense of stiffness.

You may notice your symptoms in any of the following:

• Reaching your arm overhead or to the side or when lowering from this position
• Rotating your arm inward or reaching across the front of your body with your thumb pointed downward
• Dynamic activities such as throwing
• Sleeping on the involved side

What are the Most Common Risks for Developing Shoulder Impingement?

Typically subacromial impingement develops over time in people who repeatedly perform overhead movements daily. Some risk factors¹ include:

• Repetitive overhead movements, as is common with certain occupations such as painters, that lead to overuse and muscle imbalances
• Overhead athletes, such as swimmers or volleyball players
• Current smokers — this is likely a risk factor due to the adverse effects of smoking on your body's circulation, which can impact joint health and tissue healing.
• Older age — as with many non-traumatic conditions, the risk increases the older you get due to changes in tissue health, including bony abnormalities and the onset of arthritis

How to Diagnose Shoulder Impingement

Certain pain and movement problems can indicate impingement of the subacromial space. Shoulder impingement is diagnosed when your clinician performs a series of tests of different shoulder positions to see if it reproduces your arm pain.

Ultrasound or MRI may also be used to confirm this diagnosis. For most people with otherwise good health with no recent changes to their health history, imaging does not provide any additional information to inform treatment. In those cases, it is safe and effective to proceed with physical therapy.

Imaging tests may be recommended if your physiotherapist or clinician suspects a severe or traumatic rotator cuff tear, rotator cuff tendinitis, or other shoulder injuries. Depending on your health history, an X-ray may also rule out other diagnoses and conditions.

What to Expect from Physical Therapy

Upon your initial evaluation with your CityPT physical therapist, they will ask you about things that increase or relieve your pain and assess your baseline strength and range of motion.

The treatment for subacromial impingement will depend on your daily activities and functional goals.

These treatments may include:

• Use of modalities, such as an ice pack, heat pad, and electrical stimulation (TENS) for short-term pain management
• Advice about modifications to help you with pain-free daily activities as you recover and allow the rotator cuff muscles to heal, such as avoiding a rounded shoulder posture
• Education about your pain and how to recover with becoming pain-free
• Shoulder impingement exercises and manual therapy to help you decrease pain and regain your flexibility and range of motion. Examples include shoulder mobilization, the use of a pulley, and a pain-free upper trapezius and chest stretch.
• Pain-free strengthening exercises for control of your rotator cuff muscles, chest muscles, shoulder blade muscles (scapula), and your neck and upper back (thoracic spine). Examples include isometric strengthening, active shoulder range of motion with a resistance band, rows, and serratus anterior punches
• Progressive strengthening of the shoulder and shoulder blades to target the overhead arm movements, positions, and forces required during your daily life, whether that is painting houses, working as a hairdresser, or throwing a baseball — all with proper shoulder mechanics

Your treatment will include live sessions with your therapist and home exercises for you to perform regularly between your therapy sessions. Your therapist will also discuss exercises to continue with after your last formal treatment session.

Most people with impingement of the subacromial space improve significantly in pain and function with a combination of home exercise and manual hands-on treatment with their physical therapist.

What If Conservative Treatment Doesn't Work?

Subacromial decompression surgery of the rotator cuff tendons (and other affected tissues) was once a standard approach to treat shoulder impingement.

However, most research to date does not support surgery for this condition. Multiple studies do not show any greater benefit of surgery over exercise therapy or placebo surgery, with some showing a greater risk of harm with surgery vs. no surgery.⁴⁵

Thus, if you have not had any benefit from conservative treatment for your subacromial impingement (working with a physical therapist), it is important to discuss risks and benefits with your surgeon or clinician as you consider undergoing a surgical decompression. If you choose surgery, you will likely work with a physical therapist post-operatively.

Besides surgery, other treatments you may consider in consultation with your care team could include:

• Corticosteriod injection
• Other medications for pain relief or to decrease inflammation

One thing to note, as mentioned at the beginning of this article, is that shoulder impingement may occur alongside an injury to the rotator cuff. Many people with rotator cuff injuries can improve their pain and function without surgery. However, you may wish to discuss the pros and cons of rotator cuff surgery with your care team if you need to improve with exercise and manual therapy.

How Can I Prevent Shoulder Impingement?

Research is still underway about which exercises and other preventive measures decrease the risk of developing shoulder impingement. If you want to discuss prevention strategies, consider a session (or more) of physical therapy. Finding a physical therapist specializing in shoulder recovery will be your best bet.

However, some initial studies show that exercises that target the strength and ability to control your rotator cuff and the muscles around your shoulder blade could decrease the risk of a future shoulder injury.⁶ In addition to shoulder strengthening, exercise to promote thoracic — that is, upper back and upper trunk — mobility may be helpful to prevent shoulder injury.⁷

Is It Time to Seek Treatment?

If you have developed some pain in the outer front part of your shoulder — or if you work or compete in an overhead activity — then working with a CityPT physical therapist may be exactly what you need to continue with your sport or occupation without limitation from shoulder pain.

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This guide is intended for informational purposes only. We are not providing legal or medical advice and this guide does not create a provider-patient relationship. Do not rely upon this guide (or any guide) for medical information. Always seek the help of a qualified medical professional who has assessed you and understands your condition.

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