Someone posted an explanation on tone and contractures, but mixed them up a
little bit.
Tone relates to the TENSION of the muscle. Tone is assessed by how much
resistance is felt by a person who is moving a joint of a patient who
RELAXES as much as possible. A muscle can be hypertonic ( high tone) or
orthotonic (normal tone) or hypotonic (low tone). Muscle tone depends on
how many signals the muscle is receiving from the motor neurons in the
spinal cord. Muscle tone in SCI or TM is influenced by a lot of things,
temperature, pain, the bladder and bowels, stress, etc. A high tone muscle
burns more energy than a normal tone or low tone muscle.
Contraction is the active pulling (contracting) of a muscle. There are
concentric, excentric and isometric contractions. A concentric contraction
is where the muscle actively contracts and it becomes shorter. for example
when you stand up your quads (knee extensors) actively contract and become
shorter as your knees are extending. A excentric contraction is where the
muscle actively contracts but becomes longer. for example when you sit down
slowly in a controlled fashion, your quads actively contract but become
longer as your knees are bending. An isometric contraction is where the
muscle actively contracts but doesn't become longer or shorter (there is no
joint movement). for example when you're standing still with your knees
flexed, the quads actively contract but stay the same length as the knees
niether bend or extend. Other examples of concentric and excentric
exercises are walking upstairs (concentric) and walking downstairs
(excentric). Walking upstairs (concentric) takes more strentgh and burns
more energy then walking downstairs (excentric) because of gravity. But
walking downstairs might be more difficult for people with TM or SCI
because excentric contractions are more difficult to control.
Contracture is a (semi)permanent shortening of muscles, skin, tendons,
connective tissue, or scar tissue which reduces range of motion in joints.
Most cases of contractures in TM will be muscle contractures. a muscle
contracture is a muscle with a REDUCED MAXIMUM LENGTH. muscles prone to
contracture are calf muscles, hamstrings, and the fingerflexors.
Contractures are assessed by checking the maximum range of motion of
joints. Muscle contractures are caused by wrong positioning and imbalance
of tone between opposing muscles( for example flexors and extensors of the
ankle). Treatment and prevention consists of positioning ,stretching and
reducing the imbalance of tone between opposing muscles. Reducing muscle
tone imbalance can be achieved by reducing the tone in a high tone muscle
or increasing the tone in a low tone muscle. A contracture like pressure
sores is an unnecessary complication and the best treatment is prevention.
As a physiotherapist I hate have to treat/spend time on contractures and
pressure sores because it is time spent not treating TM or SCI.
I hope this helps to understand your therapist a bit better as he or she
goes on and on about muscles, when all you wanted was a short but clear
answer to your question.
Simon (PT)