Trigger Finger

 Whenever I write a post, I do a bit of research just to make sure my facts are on point…and that I am spelling things correctly (thanks, auto-correct). I always have my own opinion on the correct treatment of certain syndromes; hence the reason for this blog. Usually, I disagree with the common treatments put out there since they are usually medication and exercise heavy. However, this time I felt a little more uncertain as to the viewpoint I wanted to take. Honestly speaking, I have not had many of these cases come through my door so when I was asked to write about it, I knew I needed to get more info under my belt in order to make sure my opinion was an educated one. As I started reading different articles and studies, I realized that once again the common treatments occurring were not even touching on the anatomical structures which are important. This being said, let us dive into what I think is a better way to treat this tough pathology.


Figure 1 – Flexor Tendons and Their Sheaths
Trigger finger (stenosing tenosynovitis) is a fairly common syndrome affecting those who work with their hands in strenuous jobs. This pathology is seen more in women than in men but it does occur in both sexes. The underlying reason why trigger finger occurs is due to the enlarging of the tendons in the hand and fingers due to inflammation. The tendons in the hand are held in place by sheaths which act as little tunnels for the tendon to glide through. Think of a broken cable on a bicycle. The tendon is the cable and the sheath is like the outer plastic which allows for the cable to glide in and out and do its job. This is a fantastic system until the tendon, due to improper stresses and inflammation, becomes enlarged and the sheath is now too tight around the tendon to allow it to glide freely.  This is where you will get the symptoms of trigger finger. The “sticking” sensation or even the complete inability to extend the finger depends on the amount of thickening occurring in the tendon. This becomes especially evident when thickening nodules in the tendon develop, basically creating a part of the tendon that is too big to fit through the sheath. This is what causes the most discomfort and the inability to extend the finger fully. 

In this circumstance, it is important to know the anatomy we are dealing with more in terms of composition than in mechanics. Thinking along this line, let’s talk about tendons.

Tendons are highly dense and fibrous connective tissue. They have little blood flow and are not elastic. In the hand, they are basically cables which are being pulled from higher up in the arm by acting muscles. In other words, when we are talking about this pathology, we need to realize that they are more a mechanical tool being used than the actual mechanic. This brings us to my main point. If trigger finger is caused by overuse of the tendons, is it not a logical conclusion to realize that since those tendons are driven by muscles, then those muscles will also be overused? With this theory in mind, I would suggest that our treatment should be focused more on specific forearm muscles than the actual tendons themselves. Yes, we will need to treat the tendons as well, but only treating in the hand itself, which is a common therapy, is only looking at part of the picture and missing important structures.

Now, in theory, trigger finger can happen to any finger. Depending on what finger is affected, the same treatment would be applied in the same manner but to different structures. There are two muscles for digits 2-5 that would be beneficial to treat. These include the flexor digitorum superficialis and flexor digitorum profundus because these are the muscles who’s tendons become inflamed.

 

Figure 2 – Flexor Digitorum Superficialis (sublimus)

Figure 3 – Flexor Digitorum Profundus
These muscles are very strong and are used a great deal in gripping maneuvers. So in any circumstance where this is happening a great deal, they are going to get overworked. This is where the thickening of their tendons due to inflammation will come in to play and potentially cause trigger finger. It is important to treat these muscles with the intent of breaking up adhesions and scar tissue. This not only applies to the muscle bellies themselves but also where the muscles start to divide into tendons more distally, just superior to the wrist. Many times this is where adhesions can actually glue the bifurcating tendons together forcing the muscle to overwork and create injury. Differentiating these tendons with manual therapy can make a big difference. 

Just distal to these tendons is the flexor retinaculum and the transverse carpal ligament. These structures are vastly important for the correct function of the flexor digitorum muscles. As the flexors of the wrist and fingers track into the wrist and hand they pass underneath both of these structures where they can become adhered to the actual tissue. Think of these structures as bridges that cross of over the tendons, running perpendicular to them. However, with increased tendon usage and potential tendon size, both have the ability to restrict the movement of these tendons and, thus, cause irritation as the tendons move, creating resistance and increased load on the musculature.

Figure 4 – Flexor Retinaculum and Trans. carpal ligament
The same treatment regimen can be applied to all the fingers except the thumb. Trigger thumb is the same as trigger finger except it affects the thumb and its tendon and tendon sheath. Once again, the transverse carpal ligament and the flexor retinaculum would be beneficial in treating this version of the pathology. However, the treatment of flexor pollicis longus would be the muscle involved. As I mentioned before, the focus should be put on the structures that have more effect on the tendons than the tendons themselves.
Flexor Pollicis Longus


By treating the actual musculature of the affected tendons, we have allowed the tendons and the muscles to function in an efficient manner. This should enable the tendons to heal and not continue to have chronic damage happen to them. However, the actual tendons do need to be addressed due to the fact that scar tissue and thickening of the actual tendons has occurred. Unfortunately, it can be difficult to affect tendons due to their make up as I mentioned earlier in the post. This is where patience is needed; both during treatment and for the patient. 

In order to treat the tendon involved, it is important to let time be your friend. Because of the high density of the tissue, any sort of a myofascial stretch, pin and stretch, or even deep stroke needs to be held much longer compared to treating muscle. These “holds” per say can be done for up to a minute to get an effective release. This allows for the tissue to have enough time to react and lengthen properly. If you are attempting to treat tendons using basic relaxing massage strokes, you will not get any effective change.

Cross-fiber friction can also be done. However, I find this to be irritating to a potentially already inflamed area and can cause more harm than good. If no inflammation is present I would not be opposed to this application, but discretion is suggested.

I will also mention Graston Technique as an effective tool for tendon treatment. It is a more aggressive but does release stubborn scar tissue quite well. If massage therapy is not working on a tough case I would certainly not hesitate to refer to a Graston Technique practitioner. 

I think the best tool we as therapists can use when it comes to the treatment of trigger finger, is being proactive. Treatment of trigger finger becomes increasingly harder the longer it is present. In other words, the more times there is injury followed by inflammation and increased thickening of tendons, the harder it is going to be to affect the damaged tissue. This being said, patients need to be educated that treatment will be much easier and results happen much quicker if it is treated early on and not after it has become a limiting problem. Get it early, get it good!


 

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