If you have tendon pain, the chances are you don’t really understand the concepts of load and capacity. Nature offers a smorgasboard of stresses and pressures to help you screw up your tendons. I think someone once said suffering is good for the soul, and tendons believed them . Tensile, compressive, and shearing loads can get a tendon pain party well and truly on the way!
You need to begin by understanding what your tendon capacity is. Being scientific “A tissue is at full capacity when the individual can perform functional movements at the volume and frequency required without exacerbating symptoms or causing tissue injury”. All you have to do to injure your tendon is to exceed its capacity. Fun tendon facts 1) . Each tendon is unique and needs to be respected . The tendon of an athlete will take a lot more abuse than a sedentary person
In every little tendon, there are tenocytes. They sit there monitoring mechanical loads . They love it when appropriate loads are placed on them, they get very annoyed when too much is dumped on them. Optimal, progressive loads result in an increase in tendon happiness. This process happens slowly, and if too much load is placed on a tendon too quickly, you can really mess them up.
Tendons are just as slow to heal after an injury, which can make them challenging to treat. Tendons can be subjected to tensile, compressive, or shearing loads, and each of the loads affects the tendon differently. It can be helpful to identify the type of load that has resulted in a particular tendon in jury.
Tensile stress is when two forces pull in opposite directions. All tendons are designed to withstand a bit of pulling. Tendons store and release energy, similar to a spring. Activities involving speed, jumping changing direction and other stupid stuff, places a really high tensile loads on tendons and can make them ache
Compressive forces occur where the tendons pass “boney sticky out bits”. The Achilles tendon is squished at the superior calcaneus during ankle dorsiflexion and the gluteus medius and minimus tendons “get theirs” from the greater trochanter during hip adduction.
Another fun fact: Tendons are not only compressed by bony structures. The mid-portion of the Achilles tendon is subjected to compressive and shearing loads from the surrounding musculature, tendons, and the posterior retinaculum. Everything is welcome to get in on the game!
It never rains it pours. Bad stuff rarely happens in isolation. To be truly awful, you want several factors combining to create a real pain mix up! It is usually a combination of tensile forces with compression that places the tendon in a vulnerable state. This is when the tendon is required to store and release energy at the same time as compressing over a boney fulcrum.
If you want to brew up shearing force fun, try, repetitive activities such as kicking in swimming or pedaling in cycling or rowing for your elbows. Anything when there is repeated dorsiflexion/plantar flexion. If you thought you could lean back and laugh at the runners, think again!
These forces can irritate the sheath of the tendon as well as the structures surrounding the tendon. With shearing forces, the tendon rubs excessively on the boney bone bit compromising the structures around the tendons (the paratenon) and creates an inflammatory response. This “paratenonitis” is different to tendinopathy and recognising the difference is important to fix it.
If you want to know more about the food you need to eat to help your tendons, or the therapy you need or anything to do with being marvellous, do join the mailing list of email for a PT or therapy session on Andrew@andrewstemler.com