Tendinopathy
A catch-all term for issues affecting tendons, the tissues that connect muscles to bones.
Muscles are the motors of the body, if we want to move pretty much anything we need to flex a muscle to do it. Flexing a muscle, means contracting it, the muscle itself gets shorter and creates a pulling force. Muscles are great at pulling things, but not so great at reaching what needs to be pulled on. They are bulky and require a lot of blood flow and resources, while the body parts that we want to move are often out at our limbs and extremities.
In order to produce movement a force must cross a joint. The bicep that moves the elbow has to have one end of the muscle on either side of the elbow joint for example. This is easily doable in the case of the bicep and elbow since it is a relatively large, central joint with lots of room for the bicep, but what about smaller areas like the wrist, ankles, fingers and toes?
This is where tendons come in. Tendons are fibrous, passive structures that connect muscles to bones. They don't create any force themselves; they merely transfer it from the muscles. Due to not needing to generate any power themselves, tendons can be much longer and compact than muscles and fit into smaller spaces. Some of the muscles that let us wiggle our toes originate all the way up in the calf and cross both the ankle and all the midfoot joints on the way to the toes.
Crossing this much distance puts many tendons at unique risk of damage. The paths that they follow are cordoned off with tissues called retinacula that make what are essentially tunnels for the tendons. Now since the tendons pretty much always have to cross joints and are passing through tight little retinaculum tunnels, sometimes they will rub up against the inner lining of the rentinaclum or the edges of the bones as the joint flexes.
Now, imagine a rope being pulled around the edge of a wooden crate on an old timey sailing ship. And let's say that the rope is being guided through a pulley too. The rope doesn't like being pulled at a weird angle, or rubbing up against the edge of the box, OR getting yanked through a pulley that is too narrow. If you keep that kind of treatment up long enough the rope will start to fray and deteriorate.
As you've probably guessed in this scenario the rope is a tendon, the wooden crate is the bones in a joint, and the pulley is a retinaculum. If tendons are being overused, either through overwork or being pulled at weird angles due to poor biomechanical alignment they can get irritated and inflamed. Infuriatingly inflammation is often coupled with swelling, which can make it even tougher for the tendons to move smoothly through the retinacula and create a feedback loop of irritation.
Anything that causes this kind of problem in the tendons is collectively called tendinopathy. Here tendin means tendon and the suffix -pathy is that super common way to end a word that just generally means 'suffering' or 'disorder'. Now tendinitis and tendinosis are two other words often associated with tendon troubles, they just have different suffixes. The -itis words mean inflammation and generally refer to acute or short term conditions, while -osis means 'disease state' and typically refers to more long term, degenerative conditions. Amusingly most of these words can be spelled either tendon- or tendin-, either works, they mean the same thing.
Ok neat. So, what can we do to help out with these various tendinopathies? Typically, a combination of custom orthotics, bracing, changing daily activities and physiotherapy can be effective. What exactly is most helpful depends on each individual pathology, which is something we will explore in the future.
