PDA

View Full Version : FHL Surface EMG: Summary



Gaspar Morey
09-20-1998, 08:54 PM
Sorry for the delay, but I wanted to wait until I got through this.

I got the protocol cited in the last reply, but there is no electrode
placement for the FHL or FDC cited. So I´m still looking for any
references. If you´ve got them they´re greatly welcome.

Here´s the summary.

MY ORIGINAL POSTING:

A time ago I received the references of an Article from the list.

Joji Kayano, "Dynamic fuinction of medial foot arch", J. Jpn.Orthop.
Ass.; 60: 1147-1156; 1986

In this article the author says he got surface EMG from the FHL (flexor
hallucis longus), but he doesn´t describe the location of the
electrodes.

Does anybody know if it can be done? And if so, how?
Does anybody know how to reach Joji Kayano?
-----------------------------------------------------------

REPLIES:

1. Jeremy Linskell wrote:

There is a protocol developed by Yves Blanc, which is documented in
the CAMARCII deliverable on clinical evaluation protocols. The
electrodes are placed directly posterior to the tendon of tibialis
posterior and obviously you willl need to perform careful
cross-talk tests. However the most important element in achieving
useful signal from such muscles is probably the correct electrode/gel
combination (assuming the performance of the pre-amps etc is
sufficiently good); you really need to be using EEG-type electrodes.
Yves is the man you need to talk to really.


Jeremy Linskell
Manager, Gait Analysis Laboratory
Co-Ordinator, Electronic Assistive Tehcnology Service
Dundee Limb Fitting Centre
Dundee, DD5 1AG, Scotland
tel +1382-730104, fax +1382-480194
email: j.r.linskell@dth.scot.nhs.uk
web: http://www.dundee.ac.uk/orthopaedics/dlfc/gait.htm

----------------------------

2. John Brault wrote:

The text "Anatomic Guide for the Electromyographer" by Delagi, et al.
(ISBN 0-398-03951-8) instructs in the the proper insertion of fine wires

into the FHL. It recommends inserting the electrode "obliquely five
fingerbreadths above the insertion of the Achilles tendon and anterior
to the medial border of this tendon towards the tibia.

Having performed both fine wire insertions and surface EMG to the lower
leg, I do not think one could sample the FHL with surface electrodesJohn
Brault
without considerable cross talk from adjacent muscles (tibialis
posterior, soleus, flexor digitorum longus). Look at the cross
sectional anatomy of the distal leg and you will get a good idea of this

problem.

John Brault

--------------------
In answer to John Brault, Jeremy Linskell wrote:

You can reasonably determine the level of cross talk by performing
cross talk tests. Given the differing roles of the muscles you
mention I would suggest that only FDL might be a problem.

Jeremy Linskell
Manager, Gait Analysis Laboratory
Co-Ordinator, Electronic Assistive Tehcnology Service
Dundee Limb Fitting Centre
Dundee, DD5 1AG, Scotland
tel +1382-730104, fax +1382-480194
email: j.r.linskell@dth.scot.nhs.uk
web: http://www.dundee.ac.uk/orthopaedics/dlfc/gait.htm


--------------
I contacted Yves Blanc, this was his answer:

Hello Gaspar,

>From previous trials comparing fine wires in the FHL and FDC and surface
electrodes it was impossible to discriminate among these 2 muscles with
surface electrodes. This make sense when we look at the anatomy of the
area. In most of the leg I have dissected, the muscle belly of the FHL
reaches the point of tangency of the posterior bulky part of the medial
malleolus. The FDC is a bit shorter but however the two fleshy parts are
too
close to record different EMG signals.
For my evaluation I have used SensorMedics ref. 650 414 miniature skin
electrodes with a pick up diameter of 2.5 mm,15mm apart centre to
centre.
They were located behind the medial malleolus, the lower one at the
point of
tangency of the posterior bulky part of the medial malleolus. As the two
muscles are synergistic (as shown by fine wires) in toe movements and
during
gait, running, jumping (but are silent in standing), it was impossible
to
recognise to which percentage each one contributed in the combined
recorded
signal.
I still use the same location when a broad estimate of their timing is
needed.

For the CAMRC II protocol for Cerebral Palsy you must contact Professor
Tommaso LEO at:
leo@bioma.ee.unian.it (Tommaso Leo)
It is possible that in one of the deliverables issued during the project
you
may find a drawing with recommended electrode placements. Beware that
they
are valid only if someone uses the electrodes I have referred.

Good luck,



--

////
( @@ )
*********************oOO*(__)*OOo***************** **
* Gaspar Morey Klapsing *
* INSTITUTE FOR ATHLETICS AND GYMNASTICS *
* SPORTS UNIVERSITY COLOGNE *
* http://www.dshs-koeln.de/turnen/instgerp.htm *
* mailto:GM@cartero.com *
* mailto:MOREY@hrz.dshs-koeln.de *
* Phone: + (0)221 4982-413 *
* Fax: + (0)221 4973454 *
* Private: + (0)221 4992842 *
* *
* Snailmail: Carl-Diem-Weg, 1 - 8/14 *
* D-50933 COLOGNE *
************************************************** *********

-------------------------------------------------------------------
To unsubscribe send UNSUBSCRIBE BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://www.bme.ccf.org/isb/biomch-l
-------------------------------------------------------------------

-------------------------------------------------------------------
To unsubscribe send UNSUBSCRIBE BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://www.bme.ccf.org/isb/biomch-l
-------------------------------------------------------------------