Tendons of the Thumb
March 1, 2018
Tendons of the Thumb
March 1, 2018
Muscular injuries to the thumb heal quickly with a week or two of rest. When thumb injuries are acute and/or chronic this usually means that the tendon structure in injured. Tendons are fairly avascular and have very minimal blood circulation.
Tendons heal approximately six times slower than muscles. It's also difficult not to use your thumb in daily life so the injured tendons get strained over and over again. That's why treatment is so important. The sooner the treatment begins after the injury the more likely the recovery will be swift. You will want to wait at least 3-4 days to let the good scar tissue form before applying friction therapy. Gentle massage is fine and helpful in the first few days.
Applying Friction Therapy
All of the tendon injuries in the thumb respond well in my experience to friction therapy. You can use either your thumb or middle and index fingers to perform the therapy, and it's best to switch back and forth between them so you don't get tired and injure yourself. Remember to apply pressure in one direction only. After you've applied friction therapy to the tendon in one direction for a while, switch to moving in the opposite direction.
This helps to minimize your fatigue, catch the fibers in both directions and make the treatment more tolerable for the client. Continue for 4-5 minutes, take a rest, and then do it again, for a total of 8-10 minutes. As the client improves, you can gradually reduce the treatment time. After the friction therapy, apply massage to the thumb, hand and forearm.
Locating & Treating the Extensor Pollicis Longus & Brevis Tendons
Locating the extensor pollicis longus or brevis tendon strain is usually quite straightforward. Ask the person to extend their thumb so the structure is under tension, and then apply mild to moderate friction strokes across the longus or brevis tendon you have identified as injured. Do this at various points along the tendon to figure out exactly where on the tendon the injured fibers are.
Because these injuries don't cause any referred pain, the location of pain tells you the location of the injury. Once you've pinpointed the injured portions of the tendon, have the person relax their thumb as you perform friction therapy. Each stroke should cross completely over the tendon. This applies to each of the tendon injuries; as soon as you locate the areas you'll be working on, the client can relax their thumb.
Locating & Treating the Flexor Pollicis Longus & Brevis Tendons
The flexor pollicis longus and brevis tendons are a little more difficult to locate. We will concentrate on the longus since that is the one most often injured. With one hand, hold the person's thumb pad at the distal thumb and have them exert some flexion force.
As they do that, use your other hand to palpate the injured tendon located in the medial portion of the thenar eminence (closer to the index finger) along its length until you find the tender areas. Be sure the person keeps up the tension so you can find it easily. Once you know where the injured portions of the tendon are the person can relax. Friction the tendon at a 90-degree angle to the fibers for 4-5 minutes, take a break and then do it again. Total time should be 8-10 minutes with a break or two.
Locating & Treating the Abductor Pollicis Longus & Brevis Tendons
Abductor pollicis injuries usually involve the longus tendon, which is located right next to the extensor pollicis brevis. We will focus on the longus since that is the one that gets injured more often. Have the person move their thumb into abduction to make it easier to find the tendon. It is slightly anterior and behind the extensor pollicis brevis tendon.
Ask the person to wiggle their thumb side to side so that you can more easily differentiate the abductor longus tendon from the from the extensor pollicis brevis tendon. They are very close together so it takes a bit of work to find the abductor tendon. Once you have located it palpate the structure to locate the precise area or areas of pain. Once you have found the right place, have the client relax the thumb and begin the treatment.
Locating & Treating the Adductor Pollicis Longus & Brevis Tendons
Place one of your thumbs on the medial aspect of the client's IP joint, and ask them to push the thumb medially toward their fingers so the tendon becomes taut and hold it there. Use your thumb or finger of the other hand to palpate either distally or proximally to the MP joint of the thumb. Palpate along the tendon to find the area of injury which will be tender to the touch, then ask the client to relax and begin to work.
As the client starts to improve from the treatment begin adding strength exercises for the client to do daily at home. If the exercises are painful or even uncomfortable it means it is too early to begin. Wait until they can do the exercises with no pain or discomfort. Begin with simple isometric exercises that I will describe next.
Exercises to Prescribe
I will describe these exercises using only your hand. Have the client place the middle of their index finger on top of the nail of their thumb and try to push up with the thumb into extension for a couple of seconds. Then place the index finger below the distal pad of the thumb and press down into flexion for several seconds. Next, place the tip of the index finger on the medial side of the thumb between the tip of the thumb and the first joint and draw the thumb toward the fingers in adduction for a moment.
Then place the tip of the index finger on the lateral side of the thumb and press out into abduction. This allows the client to move in four directions without any equipment. Repeat these four isometric exercises five times.
I suggest the client do this series 4-5 times per day. This is the least expensive and most efficient way to strengthen the fingers.
There are mechanical devices available on the internet if the client prefers those. The Xtensor Hand Exerciser, the Thumb Helper, the Cando Digi-Flex Hand & Finger Exerciser, Finger Master Hand Strengthener, among others. There are also many strengthening exercises using soft spongy balls, see "Therapy ball hand and wrist exercises" on YouTube.