Question: I was told I have extensor tone, but I'm confused as to what that is. Does it mean that when I extend my fingers there is tone or does it mean that at rest my fingers are extended. I've heard other therapist's talk about flexor tone. What's the difference?
: Excessive tone or hypertonia is when the muscles have too much muscle tone and may become stiff and difficult to move. Extensor tone refers to increased tone in the muscles that perform extension. Some examples of extensor muscles are your triceps that straighten the elbow or the quadriceps that straighten your knee. Flexor tone refers to increased tone in muscles that perform flexion. Examples of some flexor muscles are your biceps which bend your elbow, various forearm and hand muscles that bend your fingers or the hamstrings which bend the knee. One can have excessive tone at rest, and it may increase with movement. With extensor tone at rest, your fingers would tend to want to stay straight and trying to bend the fingers would be more difficult.
Sometimes, you will hear therapists talk about spasticity which is a particular type of hypertonia that is dependent on movement and velocity. With spasticity, muscle tone increases with passive movement (e.g. stretching) of a body part and is velocity dependent (faster passive movement results in higher muscle tone/resistance). With spasticity, patients usually have exaggerated reflex responses. With extensor spasticity, if someone tried to bend your fingers, the fingers would try to extend, and the faster someone tried to close them, the bigger the extensor response would be.