• Dr. Jason Rountree

Laser Therapy for Frozen Shoulder Pain

Hello! Today, I want to bring you some information about shoulder pain, sourced from a recent study that was published in Lasers in Medical Science in August of 2020. The title of the study we will be discussing is: Efficacy of High-Intensity Laser Therapy in Patients with Adhesive Capsulitis: A Sham-Controlled Randomized Controlled Trial.


Now, when you hear high-intensity laser therapy, we are not talking about surgical lasers or any super heating of the tissues or anything like that. We are merely describing a therapeutic laser that works the same as the cold lasers. It just works at a higher rate and is a higher dose of laser. For example, instead of half a watt of power, we are talking about lasers that are 10, 20 or 30 Watts of power or even more. They can typically accomplish the same results in a faster fashion. So, instead of a 45-minute treatment, you can expect around 10 minutes. In this study, the researchers went ahead and used this high intensity laser therapy on patients with adhesive capsulitis or, as it is more commonly known, frozen shoulder.


Adhesive Capsulitis (Frozen Shoulder)

Now, frozen shoulder is kind of an interesting disorder because it really does not happen anywhere else in the body. It is a product of the way the shoulder joint moves and responds to injury. What happens is the shoulder is either overused, or has too much repetitive motion done with it, or it may have a sprain or a strain injury. Then, this adhesive capsulitis (frozen shoulder), process sets in because you have development of fibrosis around the joint itself (meaning fibrous tissue starts to form there). Afterwards. you start to lose motion of that joint. It starts to become more painful, more stiff, and makes you have less range of motion. You stop being able to reach as high or behind yourself and certain motions become painful while other motions do not seem to be much of a problem. It tends to happen in 3 -5% of the general population.

However, it is much more common in people with diabetes - an estimated 20% of all diabetics will have frozen shoulder. This is believed to be due to the fact that diabetics do not have the ability to heal and recover as well as non-diabetics. They also tend to have more inflammation which is a real driver of adhesive capsulitis from what we know. It stimulates the formation of fibrous tissue much more quickly. If you have diabetes, you need to be aware that a minor injury could turn into something like frozen shoulder syndrome.


Pain Intervention with Frozen Shoulder

Now, what happens after you have frozen shoulder? Many cases seem to resolve in two to three years, but about 40% of patients tend to have persistent pain and stiffness for much longer than three years. So, it can be a long lasting and really significant life altering disorder. It does not mean that your shoulder is going to fall off, but it certainly is going to limit some of the things you can do with it such as golfing, tennis, or maybe even things like playing with the grandkids. These limitations are why most people pursue some form of treatment and, in many cases, conservative care can work pretty well. Most physical therapists have a decent protocol for working with frozen shoulder and it can work out quite well. If it does not help there are a few other options, such as injections or surgical alternatives. However, those are somewhat risky and usually not advised - at least until you have exhausted all of your conservative, non-invasive care options.


All of this is exactly what these researchers of the aforementioned paper wanted to see: is high-intensity laser therapy a good solution for the conservative care of frozen shoulder patients? Is this something that can really be helpful? Their idea going into it was that laser therapy would help reduce the pain, help improve the stiffness, and also increase the range of motion for patients that were suffering with adhesive capsulitis. At the same time, they took the participants and also put them through a standard physical therapy mobilization program. The program was designed to help move the shoulder more and help reduce pain.


Is Therapeutic Laser an Effective Treatment Option for Frozen Shoulder?

The study was conducted by having one group that would do the exercises as well as get laser therapy done, and another group that got the exercises but they then got sham laser therapy treatment, a fake laser treatment basically, so that they could control for the placebo effect. The researchers went through the effort of trying to eliminate that effect by having a real laser therapy treatment group and a fake laser therapy treatment group; however, everybody did the exercises to try and improve their mobilization and joint range of motion.

Now, every participant got treated five days a week for three weeks. At the end of it, all of the participants had improved ranges of motion and improved pain levels. Yet, the group that received real laser therapy had significantly less pain. What was somewhat surprising is the range of motion and the stiffness was actually about the same in both groups. So, even though the group that received laser therapy experienced less pain, it did not really have any improvements on how well they could move the shoulder.


When I first read this study, it was kind of surprising. I thought, "well, how, how did that work out? How do you have less pain yet you do not have functional improvement in how well that shoulder is working?" I started digging into the techniques that these researchers used.


**Before I go any further, I do not want this to be taken as criticism on the researcher's technique. It is absolutely critical in science that we do things that end up not working as well as we thought so that we can prove that there is a right way and a wrong way to do things.**


Obviously, these researchers found that there is a relief of pain by using laser therapy. What was going on that created good pain relief, but not necessarily an improvement of the range of motion over the group that was getting the sham treatment? Well, the first thing that I noticed when I was reading the article was that the patients were treated five times a week. Treatment on Monday, Tuesday, Wednesday, Thursday, and Friday all back-to-back. This seemed odd to me because, in practice, I have seen that we really do not need to treat every single day like that. Maybe treating every day did not allow the tissues to rest and recover and improve? Like going to the gym - if you go to the gym, you get better results by going three or four days a week rather than twice a day, every day.


The next part I looked at was how they did the treatment. These researchers used a fairly high-powered device and high-powered laser in the 8-12 watt range. They treated the one shoulder that was affected for 15 minutes. Now, that is a very long time for a large dose, high-power treatment and they did that every day. The next note is that they applied 100 joules per centimeter squared. The recommended dosages are between 5 and 10 joules per centimeter squared. So, this is a 10x higher dose than many other studies have done. Not only did they treat five days a week back to back, but they also treated for a long period of time at a high rate of power.


That is why I believe they saw a good reduction in pain, because you can overwhelm those pain sensors with a very high dose, but not able to see functional improvement in the shoulder. I believe they were treating too often, and I'm speculating they were treating it with too high of a dose. Did they do these patients any harm? No. That is one of the great things about laser therapy. Even if you do not quite have the protocols nailed down, you can still get some good results. Even if your power, dose, or treatment frequency is too high you will not negatively affect the patient. In conclusion, there was certainly something bit off here because, if you see a relief of pain, you should also see some better improvements in the ranges of movement.

Two Important Therapies for Frozen Shoulder

What I want to leave you with today is that when treating frozen shoulder laser therapy can be a great tool, but you are going to want to also implement interventions like exercise or PT. If you get the right type of equipment, the right dosage, the right treatment plan, the right treatment frequency - all of those little variables combined - that is when we see the very best results. That is what you will find at Montana Laser and Medical Center! We have well-designed, clinically proven treatment plans in place with equipment that can do the job.


If you are dealing with adhesive capsulitis (frozen shoulder) or if your current treatment plan is not really producing good results, definitely check us out. Do not let this go on for years! Try to regain that range of motion now so that you feel and function better. Additionally, if you correct this sooner rather than later, you are not going to lose strength. We know that when you lose strength in the shoulder, especially in the rotator cuff muscles, you become more and more likely to have a rotator cuff injury. That injury, on top of adhesive capsulitis, means you are more likely to end up in the surgeon's office. Call us today!