We love when students send us the stuff they are thinking about.

Sometimes it is a paper they found, sometimes it’s something they have been noticing, and sometimes it is a full-on ChatGPT rabbit hole that lands in our inbox and makes us stop and think.

This week, one of our students sent us a long exchange he had been having about ligaments and joint restriction.

His thought was that if the muscles relax but you still hit a firm end range, maybe the restriction is more capsuloligamentous than muscular.

Yep. Could be. 🤷‍♀️

But this is where ligaments get way more interesting than simply calling them “short.”

Ligaments and joint capsules are highly innervated sensory tissues. They contain mechanoreceptors and nociceptive nerve endings, and their input can influence muscle activity, joint control and even muscle spindle behaviour.

We actually teach some of this research in our RAPID classes.

So maybe the story is not always just a tight muscle restricting a joint. And maybe it is not simply a short ligament restricting it either.

The sensory information coming from the joint tissues can influence the nervous system, which can then change muscle activity and how that joint is being controlled.

And before anyone gets too excited, no, a firm end-feel does not give us X-ray vision into which exact tissue is stopping the movement.

It could be capsule, ligament, disc, muscular guarding, or degenerative change…or a glorious little cocktail of all of them.

This is why we get twitchy when we turn a clinical finding into a neat structural story.

RAPID has always been interested in ligaments, capsules, and periosteum, not because we think our thumbs are magically lengthening a short ligament, but because these tissues are highly innervated and send a hell of a lot of information into the nervous system.

Change the input and sometimes pain, guarding and movement change very quickly.

That is a lot more interesting than blaming another “tight muscle.”

Til next week…treat those ligaments!

Sherry and Rob