Tone and Clonus ??

[chickiet]

All,

Can someone please help me understand what you mean when you refer to the term "tone" and also the term "clonus"?

Thanks,
Chris

[msweeney]

The term tone is often used on this forum for what medically is hypertonicity. We all have muscle tone, meaning the ability for our muscles to have rigidity. Proper rigidity is necessary in order to have normal muscle function. In fact too little tone is called hypotonicity and it also hampers proper movement. When our muscles become overly rigid in a manner that hampers normal movement then we have hypertonicity.

For me (and many of us) hypertonicity occurs as a response to inadequate sensory feedback or even hypersensitivity (too much feedback). When certain tasks challenge my left foots ability to balance and it fails a failure message is sent to my brain which kicks in the extensor reflex pattern. This pattern includes the increase of tone to such an extent that my leg becomes unable to move in the normal gait cycle.

Clonus is another reflex and occurs for many of us because of our spinal chord damage. It is an involuntary muscular contraction and relaxation in rapid succession. For me this occurs after twenty minutes of riding a recumbent cycle. The sudden dorsiflexion required by the upward pedal stroke sets this clonus response off. Surprisingly if I am riding an upright bike this clonus response is dampened due to the closed chain (the fact that my foot bears much more of the weight of my body in this activity). So then my problem becomes the discomfort of the seat due to my hypersensitivity in my groin and sit bones area. So if anyone has a solution to that (incredibly cushioning bike seat) please let me know.

I understand that clonus can occur in other parts of the body, but I am only familiar with the foot or ankle clonus.

Hope that is helpful...

Matt

[chickiet]

Hi Matt,

Yes, that is very helpful! Great explanation with just enough detail for me.

Thanks,
Chris