Do you get a pinching sensation or nagging pain in your shoulder? Is this aggravated when your arms are above your head? You may be suffering from a subacromial impingement or shoulder impingement.
This article answers what a shoulder impingement is, what causes them, the common signs and symptoms of a shoulder impingement, what you can do to help yourself, how your physiotherapist or osteopath can assist you and how long until your subacromial impingement gets better.
Time poor? Watch this short video with Dr Abbey Davidson (Osteopath) on subacromial impingement:
What is subacromial impingement?
In simple terms a sub acromial impingement or shoulder impingement refers to the pinching of the rotator cuff tendons or bursa between boney surfaces of the shoulder during movement. If this occurs repetitively inflammation and damage to these structures increases.
The subacromial space is the space between the acromion (part of the scapula or shoulder blade) and the humerus (arm bone) where several muscle tendons and bursa pass through. In subacromial impingment these tendons and bursa can be compressed between these two boney surfaces repetitively; resulting in inflammation and micro tears in tendons.
What is shoulder impingement?
Shoulder impingement is the informal name for a subacromial impingement. It is sometimes also known as Swimmer’s shoulder or throwers shoulder.
How common is subacromial impingement?
Subacromial impingement is super common accounting for up to 44-65% of all shoulder pain! Subacromial impingment is so common that is the second most common complaint after low back pain. Subacromial Impingement can occur at any age but people in their 60’s being are the most common.
What is in the subacromial space?
The following structures travel through the subacromial space:
- Subacromial bursa (the biggest bursa in the body)
- Supraspinatus muscle tendon
- Infraspinatous muscle tendon
- Subscapularis muscle tendon
- Teres minor muscle tendon
- Long Head biceps muscle tendon
It is common in a subacromial impingement that more than one of these structures to become inflamed or effected by the impingement.
Causes of subacromial impingement:
Subacromial Impingement comes on when the subacromial space is made smaller. This can happen acutely or suddenly with an injury or trauma. For example, with a fall when the arm bone is shunted up in to the subacromial space and pinching the structures within. This can also happen over a longer period of time with aging and symptoms progressively increasing. Osteoarthritis or wear and tear of the shoulder joint can result in the laying down of extra bone or spurs which can shrink the size of the subacromial space. Functional issues can also result in a reduced subacromial space size. For example rounded shoulders as a result of poor desk posture can lead to weakness in the shoulder and a forward tilting of the scapular.
The smaller the subacromial space the increased chance of the boney surfaces coming in contact with the tendons and bursa travelling through the space. Inflammation and microtears can occur as a result of this.
Risk factors for subacomrial impingment include repetitive arm motions (especially overhead – e.g. throwing, swimming, cleaning, painting), poor desk posture, poor sleep posture, smoking, weak shoulder muscles and/or misshaped bones which make up the subacromial space.
Symptoms of subacromial impingement:
Some of the symptoms of subacromial impingment include:
- Pain around the shoulder joint (sometimes referring to the elbow)
- Loss of shoulder range of motion
- Aggravated by overhead movements
- Aggravated at night
- Aggravate by laying on symptomatic shoulder in bed
Symptoms may come on suddenly after an acute injury or more commonly progress slowly as repetitive pinching of tendons/bursa between the boney surfaces results in increasing inflammation.
What you can do right now for subacromial impingement?
Reduce inflammation, increase blood flow, traction, activating shoulder external rotator muscles and improving desk posture are some immediate therapies that can be helpful in subacromial impingement. The video at the top of the page demonstrates some of these techniques.
Decrease inflammation. Inflammation of structures within the subacromial space, like a vicious cycle further reduce the space beneath the acromion. Temporarily bringing down inflammation can reduce symptoms and begin the recovery process. Ice application, anti-inflammatory gel application or anti-inflammatory medication (where appropriate) can be indicated.
Increase blood flow. Once the inflammation has been bought on you may consider applying a heat pack the region. Muscle tendons traditionally have a poorer blood supply and heat attracts nutritious blood flow locally and promotes repair.
Traction exercises. Using a weight (3-5kg) to the draw the tendons through the subacromial space and gently/rhythmically swing the arm. This will aim to add space back to the subacromial space and encourage the movement of the rotator cuff tendons through the space. Try doing this for 2-3 minutes per day within pain limits.
Activate shoulder external rotator muscles. Using a resistance band activating through the shoulder external rotators aims to open up the space underneath the acromion. Initially aim for 3 sets of 15 reps with 60 second rest periods between each set. Watch the video for a clearer explanation and demonstration.
Improving posture. Sitting at a desk all day with poor posture can reduce the size of the subacromial space. Trial taking microbreaks every 30-60 minutes, practicing desk stretches or even a stand up desk.
Physio and osteo treatment for subacromial impingement:
Assess, diagnose, hands on treatment and formutlate management plans.Your physiotherapist or osteopath will perform a number of tests and assess the painful shoulder for range of motion, strength and structural integrity. Assessment will also be performed at other body regions including the upper back, neck, chest, elbow and wrist. This will create a picture of whether you are truly suffering from a subacromial impingement, whether further imaging is required and what caused your shoulder irritation in the first place. It will also play an important role in the customization of your treatment and management plan.
Your osteopath or physiotherapist will spend time explaining to you about your shoulder condition, what caused it, what other parts of the body contributed to your current condition, how together you are going to work on getting it better and answering any questions you may have.
Hands on therapy will focus on increasing the subacromial space, decreasing inflammation, maintaining shoulder range of motion, improving shoulder mechanics, improving posture, correcting biomechanics of the arm and decreasing muscular tension and imbalances.
Do you need and MRI to diagnose sub acromial impingement?
No. If performing a series of specific motions and tests brings back a positive result matches with your symptoms and case history your physiotherapist or osteopath can diagnose you with a subacromial impingement. In some cases, your physio or osteo may refer you to get some imaging to confirm their diagnosis. X-Ray, MRI and ultrasound are the images that may be considered.
How long until subacromial impingement gets better?
Subacromial impingment symptoms can resolve within 1-3 weeks. Other cases can take 3-12 months depending on severity. It is recommended that an individual trial conservative management (e.g. physiotherapy or osteopathy) before considering more invasive treatment options. These include surgery or corticosteroid injections.
In some cases, or after a 12-month period of having no response to physiotherapy or osteopathy surgery may be considered. Depending on the specific case; torn ligaments may be repaired, bursa removed or parts of bone cleaned up to increase the subacromial space.
Time until full recovery will be dependent on the cause, severity and how long the condition has been present.
By Sydney CBD Osteopath Dr Abbey Davidson