The Truth About Shoulder Impingement

Understanding the biomechanics behind shoulder impingement exercises will reveal why shoulder impingement is an outdated diagnosis. Shoulder impingement, now known as subacromial pain syndrome (SAPS), involves pain under the acromion, a part of your shoulder. It does not specify the mechanism behind the pain.

There can be many reasons why pain develops in this area. A physical therapist is a movement expert and can help determine the source of the pain. It is our expertise that can determine the source of the pain from a diagnosis that is nowhere near pinpointing when is wrong with the shoulder. Shoulder impingement exercise prescription from a PT restores shoulder and scapular mobility and builds back rotator cuff strength for pain alleviation. Not only that, it also restores your function without resorting to outdates treatments like shoulder decompression surgery. This post addresses why shoulder impingement is an outdated diagnosis and what can now be done to relieve shoulder pain from what looks like shoulder impingement.

**This is not medical advice. Please consult your medical provider for more information.

Understanding Subacromial Pain Syndrome

Shoulder impingement has become an outdated diagnosis. Now, it is often referred to as subacromial pain syndrome (SAPS). SAPS is an umbrella term for pain under the acromion. The acromion is a small part at the top of your shoulder blade. The area we often feel pain in is between the acromion and the top of your humerus (arm bone). This pain can come from a plethora of issues, including inflammation, irritation from overuse, weakness, and poor movement form.

Pain in this area can be a dull ache or an intense sharp pain. Most of the time, it affects us lifting our arms overhead, hence commonly referred to as shoulder impingement. Physical therapy can be very helpful for this issue with emphasis on shoulder impingement exercises working to address the deficits present. These shoulder impingement exercises play a crucial role in managing subacromial pain syndrome and can offer both pain relief and restore your shoulder function.

Why Shoulder Impingement is No Longer An Accepted Diagnosis

To understand why shoulder impingement is no longer an accepted diagnosis, we first have to learn how it came to be. Back in 1972, Charles Neer, an orthopedic surgeon, published a paper on a surgery he developed. This surgery is what is known as the acromioplasty (subacromial decompression surgery). This is when the acromion is shaved down to create more space. This surgery was used to correct what we know as shoulder impingement. Neer’s methods greatly influenced the orthopedic medical field for decades to come. However, these methods were based solely on theory.

The acromioplasty surgery was based off of the theory that the supraspinatus tendon gets impinged under the acromion as the arm is raised overhead. Studies now show us otherwise. Not only is the tendon no longer able to be compressed under the acromion at 90 degrees of arm elevation, but this meta-analysis also shows that subacromial decompression surgery is no better than placebo surgery! Lets take a more in depth look at why shoulder impingement is outdated.

The Biomechanics of the Shoulder When We Move Our Arms

Let’s review what goes on inside the body when we raise our arms up and overhead. When dealing with shoulder impingement, it has been long understood that when you lift your arm up, the subacromial space reduces. This loss in space makes it easier for the supraspinatus tendon to get “impinged” under the acromion. Shoulder impingement is many times accompanied by a painful arc of around 60-120° of elevation. Many studies have reviewed the impact of humeral elevation on the subacromial space for this very reason.

This particular study reviewed the literature around this very topic to summarize all of the findings. It was found that with measuring the actual distance from the acromion to the humerus, the minimal difference between these landmarks was found within the range of 70-120° of humeral elevation. This goes along with the original impingement theory in regards to the painful arc. However, this did not account for where the rotator cuff tendons are located as the arm is being raised overhead.

When looking at where the rotator cuff tendons are as your are moving your arm, it was found that the RTC (rotator cuff) tendons are closest to the coracoacromial arch at much lower levels of elevation than previously theorized. The supraspinatus tendon was found to be closest to the acromion, on average, at ~42° of elevation. On top of that, a couple of studies found that the RTC tendons actually came into contact with the coracoacromial arch in asymptomatic individuals.

So what does all of this mean? Based off of these findings, “impingement” would be happening all day long, no matter what you do. Due to the RTC tendons passing close to the coracoacromial arch at <90° of elevation, something as simple as reaching for a glass of water on the table would theoretically cause pain. This also suggests that individuals with a painful arc may be experiencing pain from something other than “impingement.” The shoulder complex is just that… complex. There are a multitude of reasons why pain could be present and where it could be coming from.

If Shoulder Impingement Isn’t the Problem, Then What is Causing My Pain?

When we analyze the complex nature of the shoulder, it becomes evident that the traditional theory related to shoulder impingement is outdated. If this is the case, and you are experiencing pain when reaching overhead, then what is causing your pain? What is the diagnosis?

If you ask me, getting the diagnosis is part of the problem. Everyone wants to know what the diagnosis is. I get it. In a way, it helps to explain what is going on. It helps to identify the specificity of an issue. For example, many people experience shoulder pain and find out they have a rotator cuff tear. The diagnosis of the rotator cuff tear tells you what the problem is and gives you a reason for having pain. Here is the contradiction around this—lots of people who have rotator cuff tears are asymptomatic, meaning they don’t have pain or any other symptoms. Why do we search for a diagnosis if we have no problem with it?

Here is another example as to why I don’t love searching for a diagnosis. A shoulder diagnosis can be difficult to pin down. A lot of times, you end up getting a diagnosis for your shoulder pain that still doesn’t specify what is going on. Things like subacromial pain syndrome or rotator cuff syndrome don’t specify anything. They are umbrella terms for non-specific shoulder pain. In other words, its a diagnosis that means you have shoulder pain, but uncertain where it is coming from.

Using a Functional and Movement-Based Approach

There are better ways, in my opinion, to explain shoulder pain and that is to use a functional approach. As a physical therapist, it is my job to help educate others as to why they are experiencing pain. Based off of the information I collect in an evaluation, I emphasize what factors may be missing when looking at how the shoulder works. Is there adequate strength in the muscles of the rotator cuff and with the supporting and surrounding musculature? Is there a range of motion limitation? Are there muscle imbalances contributing to poor glenohumeral or scapulothoracic movement? Sometimes, pain comes from muscle imbalances or movement coordination issues. There doesn’t always have to be something specific, like shoulder instability or a bicep tear.

In fact, in most cases, there is not a specific injury or trauma that occurs. A lot of pain is insidious in nature, meaning that it comes on with apparently no reason. Muscle imbalances and overuse injuries tend to be the most common reason for this. We may not realize it, but sometimes we do something that we don’t do often and we overdo it. It may not be apparent at first, but your shoulder will let you know later. Something like cleaning up the garage over the weekend or volunteering one day at the food bank could set something off in the shoulder. Without realizing it, you are asking too much of your shoulder muscles than what they can keep up with. They only have so much gas in the tank. If you use it all up, you got nothing left to give.

A key strategy for pain relief and fostering your shoulder health is to ensure a gradual increase in activity. It takes careful management of the load you are placing on your shoulder. This approach not only supports your shoulder’s complexity, but also addresses the potential muscle imbalances that could also be contributing to your shoulder pain. This steers clear of the older “shoulder impingement” treatment paradigm.

What “Shoulder Impingement Exercises” Should I Be Doing?

When dealing with shoulder impingement, or subacromial pain syndrome (SAPS), as it is now recognized as, shoulder impingement exercises should address the deficits you have. Dealing with a mobility limitation in your shoulder? You should be working on range of motion exercises into the direction(s) you are limited in. Feeling weakness or muscular fatigue in your shoulder or arm? You should be incorporating some strength training for your shoulder. It is important to focus on the muscles and muscle groups that are weaker. If you train a muscle group that is already strong and ignoring the weaker areas, you won’t see any improvement. The goal is to limit muscle imbalances. Here is a simple list of ideas to get your started on your journey to pain relief and better shoulder function:

• Rotator Cuff Strengthening: These exercises are vital in rehabilitating the shoulder and restoring shoulder health. They target the four muscles of the rotator cuff that support your shoulder joint, ensuring they can handle the daily demands placed on them.
• Mobility Exercises: Enhancing the range of motion through mobility exercises can significantly improve function if you are limited by range of motion deficits. They work to lubricate the shoulder joint, improve soft tissue extensibility, and reduce stiffness that contributes to discomfort and limitations in movement.
• Postural Correction Exercises: Poor posture can be a contributing factor to shoulder pain. It can also limit how well you can lift your arms overhead. Improving posture will help with overall shoulder health, as well as other areas of the body.

Key Considerations When Exercising

One of the biggest things to consider when starting an exercise program when addressing pain is to listen to your body. If SAPS is something you are dealing with, rest and long periods of movement are not what would be recommended. You want to move your shoulder and arm to keep everything mobile and the shoulder joint lubricated.

When performing exercises, it is important to know the difference between delayed onset muscle soreness (DOMS) and pain. Pain refers to the injury pain we experience…the body’s defense mechanism that protects us from hurting ourselves. DOMS is exactly what it sounds like…it is muscle soreness that comes after you do something that stresses the body more than it is used to. DOMS can come on after a workout at the gym, helping someone move, or if you just overdid a certain movement over and over again. This phenomenon is okay to experience! It means you challenged your body an appropriate amount. Being sore for a couple of hours all the way up to 48 hours is typical. Anything over 48 hours means you did too much. You should modify how much activity you are doing during your next workout session.

Moreover, avoid overexertion. Incorporating shoulder exercises into your routine should be a gradual process. Rushing into advanced exercises or using too much weight before your shoulder is ready can lead to setbacks. Effective shoulder treatment often requires a tailored approach that respects the body’s current limitations for certain activities.

When to Seek Professional Help

Knowing when to seek professional help can seem confusing at times. We have a tendency to believe that when we feel pain we will give it a day or two and it will go away. That day or two turns into a week and that week turns into multiple weeks. Before we know it, it’s been a few months and we are still dealing with the same pain. Sound familiar?

The body is capable of healing on it’s own over time. But sometimes, it needs a little more assistance. This is when professional guidance may be helpful. If your shoulder pain is getting in the way of you working or performing your daily activities, it could be time to reach out for help. If you have also given your shoulder an adequate time to heal and have tried to troubleshoot on your own with no improvement, you may need to speak with an expert. Another thing to consider is if your pain is getting worse. Pain that gets worse over time should be checked by a medical professional.

If you are uncertain about which shoulder impingement exercises you should be performing, schedule a FREE consult with a physical therapist here! You can also reach out by email with any questions you may have.

Other Articles Related to Shoulder Pain

• Exercises for Shoulder Impingement and Pain Free Movement
• 7 Important Exercises for Shoulder Instability
• Unlock Your Shoulder’s Full Potential with Serratus Anterior Workouts
• Shoulder Strength and Stability: A Beginner’s Guide
• The Difference Between a Rotator Cuff Strain Vs Tear

References

Hunter DJ, Rivett DA, McKiernan S, Snodgrass SJ. Acromiohumeral distance and supraspinatus tendon thickness in people with shoulder impingement syndrome compared to asymptomatic age and gender-matched participants: a case control study. BMC Musculoskelet Disord. 2021;22(1):1004. Published 2021 Dec 1. doi:10.1186/s12891-021-04885-3

Kolk A, Thomassen BJW, Hund H, et al. Does acromioplasty result in favorable clinical and radiologic outcomes in the management of chronic subacromial pain syndrome? A double-blinded randomized clinical trial with 9 to 14 years’ follow-up. J Shoulder Elbow Surg. 2017;26(8):1407-1415. doi:10.1016/j.jse.2017.03.021

Lähdeoja T, Karjalainen T, Jokihaara J, et al. Subacromial decompression surgery for adults with shoulder pain: a systematic review with meta-analysis. Br J Sports Med. 2020;54(11):665-673. doi:10.1136/bjsports-2018-100486

Lawrence RL, Braman JP, Ludewig PM. Shoulder kinematics impact subacromial proximities: a review of the literature. Braz J Phys Ther. 2020;24(3):219-230. doi:10.1016/j.bjpt.2019.07.009

Nazari G, MacDermid JC, Bryant D, Athwal GS. The effectiveness of surgical vs conservative interventions on pain and function in patients with shoulder impingement syndrome. A systematic review and meta-analysis. PLoS One. 2019;14(5):e0216961. Published 2019 May 29. doi:10.1371/journal.pone.0216961

Park SW, Chen YT, Thompson L, et al. No relationship between the acromiohumeral distance and pain in adults with subacromial pain syndrome: a systematic review and meta-analysis. Sci Rep. 2020;10(1):20611. Published 2020 Nov 26. doi:10.1038/s41598-020-76704-z

TL;DR

Shoulder impingement exercises should target exactly what we expect: shoulder impingement. However, this is an outdated diagnosis. Shoulder impingement is now commonly referred to as subacromial pain syndrome (SAPS). Understanding the biomechanics of the shoulder will help tailor an approach to relieve your pain. These exercises should target the muscle imbalances of the shoulder complex, not target shoulder impingement (as this has now been refuted by the research).