View Full Version : Responses to inquiry regarding construction of goniometers

Danny Too
05-17-1994, 04:27 AM
Thank you to all those who had responded to my inquiry for assistance
regarding goniometers. I have summarized the responses.

The original request was:

> Does anyone out there have information on how to construct an
> electrogoniometer (ie, what specifications are required in a
> potentiometer,etc), or whether one can be purchased commercially
> (and if so, any addresses would be helpful).
> I am trying to construct (or procure) an electrogoniometer to
> obtain hip, knee and ankle angles in conjunction with EMG data while
> cycling on an ergometer. We have a Noraxon tethered EMG system. I
> assume I would needa power supply, some connector to get the EMG
> signal from the control unit and from the elgon to the A/D board.
> Unfortunately, more often than not, we have to be our own>technicians as
> well. I have not had a whole lot of experience doing this and any
> information or help will be greatly appreciated.
> If there is a large enough response or interest to my inquiry, I will
> post it on the network.
> >************************************************** ********************
> * >*
> * Danny Too Phone: (702)-895-4875 >*
> * University of Nevada Las Vegas Fax: (702)-895-4231 >*
> * 4505 Maryland Parkway E-mail: tood@nevada.edu >*
> * Las Vegas, NV 89154-3034 >*
> * >*
> >************************************************** ********************

There is one company that had contacted me after my original request and
That company

Therapeutics Unlimited
2835 Friendship Street
Iowa City, Iowa 52240
Phone (319)-351-2435

is not listed in the summary below, sells individual electrogoniometers
for $285.00 each. But you would need their mainframe and power supply
for $1100 and probably their electrogoniometer module ($500). With their
system, EMG modules ($900) can be added on as well as force/pressure modules
($950) and an event marker module ($500). For someone starting a lab with
only $2000-$3000 of start-up funds, this may not be a bad way to start (and
add onto the system as the need arises or as funds become available)

The responses, summarized, are as follows.

From: mnechani@gac.edu (Mark A Nechanicky)

>From a previous post:

From: Christophe CHARTIER

P&G Biometrics Limited
Newbridge Road Industrial Estate
Blackwood Gwent NP2 2YD
United Kingdom
Tel: +44 495 228 000
Fax: +44 495 229 389

The tel and fax are the same, but the address may have changed, see

From: Mark A Nechanicky
Dieter Rosenbaum
Antonio A. F. Quevedo

The Marketing Director
Penny & Giles Biometrics Limited
Blackwood Gwent NP2 2YD
United Kingdom
Tel: +44 495 228 000
Fax: +44 495 229 389

From: Owen Evans

Ola Ro
PO Box 275 Okern
N-0511 Oslo
Tel: +47 22 63 75 84

From: Marina Torre

Via Padova 55
I-20127 MILANO

Tel: +39 2 2847289
fax: +39 2 2847311

In North America

From: Mark A Nechanicky
Duane Knudson
Antonio A. F. Quevedo

Neal Handler
Penny and Giles Inc.
2716 Ocean Park Blvd. Suite 1005
Santa Monica, CA 90405-5209
Tel: +1 310 452 4995
393 0014
Fax: +1 310 450 9860

From: Dan Gottesman

Penny & Giles Controls Inc.
163 Pleasent St.
Attleboro, MA 02703
Tel: +1 508 226 3008
Fax: +1 508 226 5208


From: Nancy.Hamilton@uni.edu

Hi Danny -
Marlene had an article in Kinesiology Review way back in 1968 that
explained how to build an electrogoniometer. I have had pretty good luck with
those directions. I feed directly into a Lafayette EMG recorder (paper) with
not too much trouble. This is also how Helga built the ones she used at U of I.
Here is the complete citation for that article:

Adrian, M.J. 1968 An Introduction to Electrogoniometry. Kinesiology
Review. pp.12-17, Washington D.C., AAHPERD.

I get my parts at Radio Shack for very little money.

Good luck :-)

Nancy Hamilton

From: "Dr. Thomas Bochdansky"

We are a gaitlab group situated at Univ. Vienna Austria, Dept. PMR
We use straingage goniometers because of their flexibility. They are easy to
fit. The datacollection is done by original software or in parallel with
our EMG Noraxon System and Noraxon Software.

Penny and Giles Blackwood limited
Blackwood Gwent
NP2 2YD United Kingdom

* Josef Kollmitzer Dipl.Ing. *
* Dept. PM&R *
* Univ. Vienna *
* Waehringer Guertel 18-20 *
* A-1090 Vienna AUSRIA *
* Tel: +43-1-40400-2308 *

From: INVX000

Dear Dany,
I have used two types of pots. with defferent characteristics.
1) by Waters International
WPM 18-09-101
RES. 5K LIN:0.1%
it is a servo potentiometer you cak use it as the pivot point itself.
2) by Spectrol
MOD 132-0-0103
RES. 10K LIN : .5%

I was happy with both the first is about 100.00$ each, the second
is about 50.00$.
To set a pot. you need a power supply and some connectors.
Good luck, if I can be for any more help let me know.

************************************************** ********
************************************************** ********
** **
** Vassilios Vardaxis **
** McGill University, Physical Education Department **
** 475 Pine Ave, West, P.Q. H2W-1S4, Montreal CANADA **
** **
** Email: invx@musicb.mcgill.ca **
** Fax: (514) 398-4186, Phone: (514) 398-4188 or 4184 **
** **
************************************************** ********
************************************************** ********

From: pklein@resu1.ulb.ac.be (Paul Klein)

>Hi Dan
Seven years ago we started building a electrogoniometer 3-D, 6 degrees of
freedom. A colleague of mine is now rather aware about requirements needed
of such a device: for instance influence of axial play of potentiometers on
final results. I guess he will contact you, but if not, you can reach him
with the adress:
> salviap@ulb.ac.be
Patrick Salvia
Lab for Functional Anatomy
Free University of Brussels

> ******************************************
> * Klein Paul Ph.D. *
> * Institut for Physical Therapy and *
> * Rehabilitation *
> * Free University of Brussels *
> * CP 168, Avenue P. Heger, 28 *
> * 1050 Brussels, Belgium *
> * *
> * Phone 32-2-6502470 Fax: 32-2-6502473 *
> * pklein@resulb.ulb.ac.be *
> ******************************************

From: "Steve Kirstukas"

danny, concerning your question below....

> Does anyone out there have information on how to construct an
> electrogoniometer (ie, what specifications are required in a
> potentiometer,etc), or whether one can be purchased commercially (and if
> so, any addresses would be helpful).

There's a commercially available electrogoniometer through a company called
Enduratec. It uses encoders rather than the less accurate potentiometers. It's
design is based on my master thesis (for more info. see Journal of Biomechanical
Engineering, Feb 1992)

You can reach Enduratec at Phone:612-828-9937 or FAX:612-828-9837

From: "Robert Newton"

> Does anyone out there have information on how to construct an
> electrogoniometer (ie, what specifications are required in a
> potentiometer,etc), or whether one can be purchased commercially (and if
> so, any addresses would be helpful).

I have looked at obtaining an electrogoniometer commercially and they are
all too expensive ($2000-$3000). I have also have no electronics ability but
have had some success using a 10k Ohm variable resister ($1.95). I use a 9
volt battery for a power supply and a 10k Ohm resister to produce a voltage
divider. The only problem is it is not linear and I have to calibrate it
throughout its range in about 5 degree increments and use a look-up table in
my software. The signal goes straight to an AD board along with EMG data.
For arms I glued two strips of perspex (from hobby shop) to either sider of
the pot.

The whole unit including cable cost less than $20.

I would be very interested in any replies you receive because I am not sure
if the electronic circuit I have used is optimal. If you need any more info
please contact me.

Are you attending the NSCA or ASB conferences this year?

================================================== ===================
Robert Newton Email: run1@psu.edu
Center for Sports Medicine Telephone: Int+ 1 814 865 7107
The Pennsylvania State University Facsimile: Int+ 1 814 865 7077
117 Ann Building, University Park, PA 16802
================================================== ===================

From: Dan Fuglewicz

Dear Danny:

Kistler manufactures a Belt Pack Accelerometer and EMG (BPAS) system which
have been sold to NASA. The power sypply and signal conditioning is housed
in two separate units which are worn by the subject. The system can handle
a combination of nine accelerometers and EMG's. An important feature is
the isolated EMG circuit.

The data is output via a 15-pin connector which is suited for a TEAC
recorder or our BioWare software. BioWare can accept up to eight user
defined inputs. Thus, when using BioWare, the BPAS system can utilize
eight of the nine channels.

The system is somewhat expensive (typical price range of $7K & $12K)
depending upon configuration, but is the only EMG isolated system utilizing
a single multiconductor teather. Typical operating life of the battery
system is 1.5 hrs. to 2hrs.

If you wish more information, let me know. Feel free to e-mail or call at


Bob Redd

From: Dan Gottesman

You might want to consider using either and inclinometer or accelerometers,
which will give you and orientation relative to gravity. You could
create a model to determine how much the acceleration of the limbs will
affect your results. The simplest solution might however be to just use
potentiometers mounted to a frame. The knee is not too hard, the main
problem being getting the center of rotation axis to be the save in the
body and the goniometer.

From: Moshe

Dear Danny:
I had a similar problem lately and was recommended to use the Penny & Giles
elgons. Unfortunatly I do not have their address here but I believe it was on t
he net last month.
I got their ads. It looks great and works good. However, their crosstalk and
repeatability is somewhat poor according to some users. Again, all details
are not with me but it was on the net during last month.
Good luck, Moshe

********************************************!***** **********************
* MOSHE NISSAN, PHD ! FAX: 972-3-6974546 *
* BIO-MEDICAL ENGINEER ! TEL: 972-3-6974720 (WORK)*
* Dept. Orthopaedics B' ! : 972-4-371788 (home) *
* 6 Weitzman st. Tel-Aviv 64239 ISRAEL ! Bitnet: RPRNISN@TECHNION *
************************************************** **********************

From: Quevedo@deb.fee.unicamp.br

Try to get the file "goniometers.txt", available through ftp at
the machine "cesar.unicamp.br", at the directory "pub/medicine/incoming".
This file contains the replies to a question I did about goniometers
last month.
Antonio Augusto Fasolo Quevedo
e-mail : Quevedo@deb.fee.unicamp.br