If you ever had shoulder pain, you know it isn’t pleasant. Pain when trying to lift your arm higher than your head, when you try to open a door, or even if you roll on the affected side at night when you are sleeping, it quickly becomes tiresome and can have a real impact on your quality of life.
What’s more, shoulder pain is common! Probably more common than you think. If we were to pick a selection of 1,000 random adults in Singapore and follow them for 1 year, 15 of them would go to see their primary health care physician because of a sore shoulder. If we were to follow that group of people over the course of their life, up to 70% of them would receive some kind of medical intervention to treat shoulder pain at some point. As a physiotherapist, there’s a good chance a few of these 15 people will end up in my office in any given year seeking to resolve this shoulder pain. When it comes to managing the pain of one of these individuals, the truth is, and it hurts me to admit this, medicine and those allied to medicine (physiotherapy, etc) are not doing a great job!
Now, I’m not trying to put myself or my medical colleagues down here. But the data speaks for its self. If we go back to our group of 15 sore shoulders, after 1 year of them presenting to their doctor or physiotherapist, previous longitudinal studies suggest that 40-50% will still have some degree of pain in their shoulder or they will have had another episode of shoulder pain. The numbers don’t look great. This isn’t necessarily anyone’s fault, it’s partly due to the nature of why shoulders hurt in the first place. The underlying issues often take time to resolve, even with treatment. However, if we compare the course of shoulder pain with other medical or musculoskeletal problems such as the flu, a twisted ankle, or a wry neck, we see a significant difference in the time to resolution of symptoms and also the reoccurrence rate.
Why am I telling you this? Because we want you to know that we are aware of the issue and are trying, as a community, to get better at serving your needs. There are dozens of research groups around the world dedicated solely to improving treatment for shoulder pain, there are new treatments constantly being dreamed up and tested to see if they can stand up to scientific rigor. One of these treatments is extra-corporal shockwave therapy (ESWT), and that is what I want to talk to you about today.
I am not going to go into detail about exactly what ESWT is and how it works, as I have done a previous write-up on it before and would encourage you to read it if you are interested in the mechanisms underpinning its use. But briefly, ESWT is a category of electrotherapy that uses high-energy sound waves that stimulates a healing response when applied to the body’s tissues. What I will do is give you an overview of the two most recent and high-quality clinical studies that have investigated the use of ESWT in 2 different subtypes of shoulder pain so that you are armed with the data to make an informed decision about a potential therapy should you be unlucky enough to have shoulder pain.
The most common type of shoulder pain is referred to as rotator cuff-related pain. This is an umbrella term that essentially means any issue with the muscles of the rotator cuff, a group of four muscles that help to hold the ball (head) of your shoulder in its socket. Rotator cuff-related pain can be caused by small tears in the muscles, tendinitis, overload, and stress to the muscle, and inflammation. This condition often presents as pain on moving the shoulder, especially lifting to the front, the side, and putting your hand up behind your back. Another common sign of this issue is pain at night when rolling onto the affected side. It’s important to note that rotator cuff-related pain, even with some restricted painful movement, is not the same as a frozen shoulder. Even if you can’t lift your arm without pain, it’s unlikely you have a frozen shoulder and you should always see a health care professional get a correct diagnosis.
The first study I want to tell you about was published this year by Li and colleagues in the international journal of biomedical research. Li et al investigated the effects of 4 sessions of ESWT spaced 1 week apart on 46 individuals with rotator cuff-related pain over the course of a year. Unlike real life, where we often utilise several treatment types at once such as exercise and hands-on therapy, Li and friends only used ESWT in isolation. Over the course of the study, they found a 50% drop in pain starting from 12-24 weeks following the treatment. There was also a significant reduction in pain and difficulty while doing functional tasks that happened around the same 12-24 week point post-treatment and continued to get better out to 12 months.
The second study I want to mention looks at a different and rarer subtype of shoulder pain called calcific tendinopathy. This condition is caused by a build-up of calcium deposits in the rotator cuff tendons. Symptomatic calcific tendinopathy is typically quite a painful condition where we see some significant restrictions in the range of motion of the shoulder and functional activity secondary to pain. ESWT is used in this condition to break down the calcium deposits and allow your body to absorb the broken down deposits, thus freeing the tendon to move again without pain. The use of ESWT has been widely investigated as a therapy for calcific tendinopathy and there is a consensus that it is highly effective.
The most recent data come from Louwerens and colleagues in 2020 who investigated the use of ESWT vs day surgery to remove calcific deposits from the shoulder tendons. As per the previous study, the calcific group was followed for 1 year following either surgical breakdown of the deposits or 4 sessions of ESWT targeted at the calcific tendons. At the one-year point, both groups showed approximately a 50% reduction in symptoms with the surgical group being marginally better, and despite being the less invasive option, ESWT actually led to a slightly quicker improvement in symptoms.
It is important to note that with both of these studies, no other intervention was offered. No exercises, no long-term pain killers, no hands-on therapy, no acupuncture. None of the other traditional interventions associated with shoulder pain, which, as we discussed earlier, are not perfect, but do improve outcomes. We can see from the above studies that ESWT as a stand-alone treatment has been demonstrated to lead to up to a 50% reduction in pain and functional limitations in the most common cause of shoulder pain. Any good physiotherapist or Dr would not recommend ESWT in isolation, as with any other treatment, ESWT should be part of a holistic treatment program that addresses all of the underlying factors that have contributed to the development of the condition. However, it is becoming clearer and clearer through reading the scientific research that the addition of ESWT to any plan that is managing shoulder pain is likely to have a significant positive impact on the outcome.
If we one last time return to our 15 folks with sore shoulders, it is with tools like ESWT where we hope to see meaningful change. The 50% reduction in pain and symptoms shown in recent studies may very well be lower than the 40-50% rate of persistent symptoms 1-year post-onset of pain I spoke about at the beginning of this blog. As much as I would love to say that is the case, as of yet, there is no direct data to support a lowering of persistent symptoms on a population level.
I will conclude by saying that as good as ESWT is, it isn’t a panacea and should be approached with as much skepticism as anything else. If you think that it is right for you, you should discuss the pros and cons thoroughly with your healthcare provider and make an informed decision. Here at Heartland Rehab, we are committed to providing you with the most up-to-date and impartial health advice to give the best possible outcome and health care experience. So please do reach out to us if you have any questions.