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View Full Version : Calculation of EMG latency times



Gaspar Morey
09-24-2001, 08:53 PM
Dear community,

I've got to decide how to determine the onset of EMG activity from
several lower leg muscles during different tilt platform tests. For the
dynamic tests (jumping and landing) I used a threshold determined as
percentage from the maximal amplitude from the first recorded trial to
asses the onset. Since a few miliseconds in preactivation time are not
that relevant, this seemed to be an acceptable choice. Anyway the
preactivation times weren't very repeatable. This is different for the
latency times were differences are in the range of miliseconds.
In the literature latency times are often studied, but its determination
is seldom described and many times done by visual control. I would
greatly appreciate any ideas about the methodology to use. I think I'll
test some of the proposed (if any) methods and see what happens. Maybe
as suggested by D.Rosenbaum it is very difficult to rely on a pure
automatic determination without visual control and the "mixed" way is
the one to go.

As usual I'll post a summary of replies.

Thanks a lot in advance.


Gaspar.

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