View Full Version : Normalizing EMG-data in CND

Ilse Jonkers
07-28-1996, 05:39 PM
Dear subscribers,

Following the issue of normalization of EMG as posted by Roger James, I would like to bring this
question to the use of normalization techniques in central neurological pathology esp. in CP-children.

For several applications of clinical gait analysis, the analysis of the raw EMG signal and its relation to
gait cycle seems to work. However, for my recent work I would like to come to a summary of muscle
force/behaviour around the ankle joint before and after treatment in a population of hemiplegic and
diplegic CP-children. While investigating the possibility of using a combined EMG-torque measurement
around the ankle joint, several of my colleagues have stressed the fact that this is a measure of the
patients' ability to produce analytical movement more than a strength measure. Especially the wide
variety of motor control that is seen in these patients in analytical, dynamic and synergic contractions
made me worry about the validity of using a static analytical contraction as a reference value to muscle
force during a more complex motor pattern as gait.
I would be interested in the approach that is used by other centres in this respect, more specifically
whether quantified EMG is used in CP-children or central neural pathologies and if yes, for what reason.
Which normalisation techniques are used and for what purpose. Is the use of electrical stimulation
possible and if yes, does it reflect the voluntary force production
of the muscle in these patients?
Any recommendation on procedures that allow me to summarize the muscle behaviour as measured
with surface EMG before and after treatment would be appreciated.

When a sufficient number of answers is received, I will post a summary of the responses.

Thanks in advance.

Ilse Jonkers