J Mickelborough

02-22-1999, 01:30 AM

At 05:20 PM 2/16/99 , I wrote:

>We are collecting temporal and spatial measures of gait from elderly

>people, some of whom are hemiparetic.

>I am searching for an index of symmetry to apply to these parameters.

>

>I recall seeing an argument recently that such an index should be based

>upon differences between right and left side values, rather than upon a

>ratio of the two. This made sense, but unfortunately I cannot now find the

>paper in which I read this.

>

>There are a few references in the archives, which I am following up, but I

>would appreciate any further thoughts on this matter.

I received a variety of replies, some giving a formula for side-to-side

symmetry, while others suggested references, a summary of which I have put

below.

Many thanks to all who replied - I'm still trying to get hold of some of

these papers - special thanks to those who emailed copies

Jane

First: A summary of the references given:

Allard, P, Capopozzo A, Lundberg, A, & Vaughan C. (eds) Three-dimensional

Analysis of Human Locomotion" 1997, John Wiley & Sons pp. 307-334

Dingwell, J.B., Davis, B.L., and Frazier, D.M., (1996) "Use Of An

Instrumented Treadmill For Real-Time Gait Symmetry Evaluation And Feedback

In Normal And Below-Knee Amputee Subjects," Prosthetics And Orthotics

International, 20: 101-110.

Giakas G and V Baltzopoulos, (1997). Variability and inter-trial symmetry

of ground reaction forces during walking using time and frequency domain

parameters. Gait & Posture 5, 189-197.

Giakas G, V Baltzopoulos, PH Dangerfield, JC Dorgan and S Dalmira. (1996).

Comparison of gait patterns between healthy and scoliotic patients using

time and frequency domain analysis of ground reaction forces. Spine 21(19),

2235-2242.

Herzog, W., Nigg, B.M., Read, L.J., and Olsson, E. (1989). Asymmetries in

Ground Reaction Force Patterns in Normal Human Gait. Medicine and Science

in Sports and Exercise, 21 (1): 110 - 114.

Jeng, Holt, Fetters and Certo, (1996). Self-optimization of walking in

nondisabled children and children with spastic hemiplegic cerebral palsy.

Journal of Motor Behavior, 28(1), 15-27.

Kaufman & al. (1996). Gait asymmetry in patients with limb length

inequality. Journal of Pediatric Orthopaedics 16: 144-150.

Kulkarni J., Curran B., Ebdon-Parry M., Harrison D., (1995) 'Total contact

silicone partial foot prostheses for partial foot amputations'. The Foot

vol.5, pp.32-35.

Liu & al. (1998). Kinematic and kinetic asymmetry in patients with

leg-length discrepancy. Journal of Pediatric Orthopaedics 18: 187-189.

Peham C, Scheidl M, Licka T. A method of signal processing in motion

analysis of the trotting horse

J. Biomechanics, Vol. 29, No. 8, pp. 1111-1114, 1996

Peham C, Licka T, Scheidl M, Girtler D. Supporting forelimb lameness:

clinical judgement versus computerised symmetry measurement. Equine

Veterinary Journal, in print

Here are the replies I received:

I did some work on gait symmetry in BK amputee patients for my maters

thesis a few years ago. After looking at the various ways several other

people had used to quantify asymmetries, we decided on the following

formula:

Symmetry Index ("SI") = (Xl - Xr) / (Xl + Xr) * 100%

where "Xl" and "Xr" are the values of any variable X for the left and right

sides. This equation resulted in SI values with a continuous linear range

from -100% to +100%, where 0% denoted perfect symmetry between left and

right. We modified this from a paper by Herzog et al. (1989) where they

had used the difference divided by the average, which resulted in a similar

distribution, with a range of -200% to +200%.

I have a *.pdf file of the manuscript we published in Prosth. & Orth Intl.

which I can send you if you would like.

References:

Dingwell, J.B., Davis, B.L., and Frazier, D.M., (1996) "Use Of An

Instrumented Treadmill For Real-Time Gait Symmetry Evaluation And Feedback

In Normal And Below-Knee Amputee Subjects," Prosthetics And Orthotics

International, 20:

101-110.

Herzog, W., Nigg, B.M., Read, L.J., and Olsson, E. (1989). Asymmetries in

Ground Reaction Force Patterns in Normal Human Gait. Medicine and Science

in Sports and Exercise, 21 (1): 110 - 114.

>--------------------------------------------------------

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

Jonathan Dingwell, Ph.D.

Postdoctoral Research Associate

Rehabilitation Institute of Chicago

345 East Superior, room 1406

Chicago, Illinois, 60611

Phone: (312) 908-8738

FAX: (312) 908-2208

E-Mail: j-dingwell@nwu.edu

Web: http://www.smpp.nwu.edu/

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

You might consider calculating the residual difference between the right

and left data sets as an index of asymmetry. This is the Root Mean Squared

RMS difference and the RMS value will be directly proportional to the

degree of asymmetry between right and left sides. I have attached an excel

file to illustrate the process. I used this method for determining a

Right-Left asymmetry in the following paper on partial foot prostheses:

Kulkarni J., Curran B., Ebdon-Parry M., Harrison D., (1995) 'Total contact

silicone partial foot prostheses for partial foot amputations'. The Foot

vol.5, pp.32-35.

Drew Harrison

Have a hunt for work by Pat Goldie (probably in Archives), she has done

some work on gait symmetry after stroke but I can't recall if this has been

published.

I would suggest that you contact her directly but at present she is away

from La Trobe University (Australia) on sick leave. She will be back in

April sometime [P.Goldie@latrobe.edu.au]

Good luck

Julie

Julie Bernhardt, PhD

Physiotherapy Research Coordinator

North West Sector

North Western Health Care

Melbourne, VIC, Australia

Malcolm Granat - working at theUniv of Strathclyde carried out work on

assessing gait in a hemiparertic stroke population. Their work has been

published and a search should provide you with a possible reference. David

Dr. Anand.D.Pandyan

Centre for Rehab. Eng. Studies

M25-Stephenson Bldg

University of Newcastle

Newcastle Upon Tyne

UK - NE1 7RU

Tel ++ 44 (0)191 - 222 5434

Fax ++ 44 (0)191 - 222 8600

e-mail A.D.Pandyan@ncl.ac.uk

http://www.ncl.ac.uk/crest/

We use a symmetry index to evaluate the lameness of horses. I think this

method is also useful in human motion analysis. We place a marker in the

symmetry-axis (e. g. head) and than we calculate the Fourier-coefficients

of the vertical motion. The Fourier-coefficients separate the motion in

symmetrical and asymmetrical parts. We described this method in:

"A method of signal processing in motion analysis of the trotting horse"

C. Peham, M. Scheidl and Theresia Licka J. Biomechanics, Vol. 29, No. 8,

pp. 1111-1114, 1996

"Supporting forelimb lameness: clinical judgement versus computerised

symmetry measurement"

C. Peham, Theresia Licka, M. Scheidl and D. Girtler Equine Veterinary

Journal, in print

This method can be extended to use all three motion direction, but you have

to take care, because in vertical and horizontal (running direction) the

fundamental wave and the odd harmonical parts are the asymmetrical part and

the even harmonical waves are the symmetrical parts of the motion. In the

transversal motion the fundamental wave represents a symmetrical motion.

Christian Peham [christian.peham@vu-wien.ac.at]

I'm using a transformation of right and left kinetic parameters (obtained

from force plates) into a common differential mode, in clear analogy with

electronics.

If p1 were a parameter obtained with the left plate and p2 were the same

parameter measured with the right plate, the derived parameters would be

defined as follows:

p(COM)=(p1+p2)/2

p(DIF)

>We are collecting temporal and spatial measures of gait from elderly

>people, some of whom are hemiparetic.

>I am searching for an index of symmetry to apply to these parameters.

>

>I recall seeing an argument recently that such an index should be based

>upon differences between right and left side values, rather than upon a

>ratio of the two. This made sense, but unfortunately I cannot now find the

>paper in which I read this.

>

>There are a few references in the archives, which I am following up, but I

>would appreciate any further thoughts on this matter.

I received a variety of replies, some giving a formula for side-to-side

symmetry, while others suggested references, a summary of which I have put

below.

Many thanks to all who replied - I'm still trying to get hold of some of

these papers - special thanks to those who emailed copies

Jane

First: A summary of the references given:

Allard, P, Capopozzo A, Lundberg, A, & Vaughan C. (eds) Three-dimensional

Analysis of Human Locomotion" 1997, John Wiley & Sons pp. 307-334

Dingwell, J.B., Davis, B.L., and Frazier, D.M., (1996) "Use Of An

Instrumented Treadmill For Real-Time Gait Symmetry Evaluation And Feedback

In Normal And Below-Knee Amputee Subjects," Prosthetics And Orthotics

International, 20: 101-110.

Giakas G and V Baltzopoulos, (1997). Variability and inter-trial symmetry

of ground reaction forces during walking using time and frequency domain

parameters. Gait & Posture 5, 189-197.

Giakas G, V Baltzopoulos, PH Dangerfield, JC Dorgan and S Dalmira. (1996).

Comparison of gait patterns between healthy and scoliotic patients using

time and frequency domain analysis of ground reaction forces. Spine 21(19),

2235-2242.

Herzog, W., Nigg, B.M., Read, L.J., and Olsson, E. (1989). Asymmetries in

Ground Reaction Force Patterns in Normal Human Gait. Medicine and Science

in Sports and Exercise, 21 (1): 110 - 114.

Jeng, Holt, Fetters and Certo, (1996). Self-optimization of walking in

nondisabled children and children with spastic hemiplegic cerebral palsy.

Journal of Motor Behavior, 28(1), 15-27.

Kaufman & al. (1996). Gait asymmetry in patients with limb length

inequality. Journal of Pediatric Orthopaedics 16: 144-150.

Kulkarni J., Curran B., Ebdon-Parry M., Harrison D., (1995) 'Total contact

silicone partial foot prostheses for partial foot amputations'. The Foot

vol.5, pp.32-35.

Liu & al. (1998). Kinematic and kinetic asymmetry in patients with

leg-length discrepancy. Journal of Pediatric Orthopaedics 18: 187-189.

Peham C, Scheidl M, Licka T. A method of signal processing in motion

analysis of the trotting horse

J. Biomechanics, Vol. 29, No. 8, pp. 1111-1114, 1996

Peham C, Licka T, Scheidl M, Girtler D. Supporting forelimb lameness:

clinical judgement versus computerised symmetry measurement. Equine

Veterinary Journal, in print

Here are the replies I received:

I did some work on gait symmetry in BK amputee patients for my maters

thesis a few years ago. After looking at the various ways several other

people had used to quantify asymmetries, we decided on the following

formula:

Symmetry Index ("SI") = (Xl - Xr) / (Xl + Xr) * 100%

where "Xl" and "Xr" are the values of any variable X for the left and right

sides. This equation resulted in SI values with a continuous linear range

from -100% to +100%, where 0% denoted perfect symmetry between left and

right. We modified this from a paper by Herzog et al. (1989) where they

had used the difference divided by the average, which resulted in a similar

distribution, with a range of -200% to +200%.

I have a *.pdf file of the manuscript we published in Prosth. & Orth Intl.

which I can send you if you would like.

References:

Dingwell, J.B., Davis, B.L., and Frazier, D.M., (1996) "Use Of An

Instrumented Treadmill For Real-Time Gait Symmetry Evaluation And Feedback

In Normal And Below-Knee Amputee Subjects," Prosthetics And Orthotics

International, 20:

101-110.

Herzog, W., Nigg, B.M., Read, L.J., and Olsson, E. (1989). Asymmetries in

Ground Reaction Force Patterns in Normal Human Gait. Medicine and Science

in Sports and Exercise, 21 (1): 110 - 114.

>--------------------------------------------------------

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

Jonathan Dingwell, Ph.D.

Postdoctoral Research Associate

Rehabilitation Institute of Chicago

345 East Superior, room 1406

Chicago, Illinois, 60611

Phone: (312) 908-8738

FAX: (312) 908-2208

E-Mail: j-dingwell@nwu.edu

Web: http://www.smpp.nwu.edu/

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

You might consider calculating the residual difference between the right

and left data sets as an index of asymmetry. This is the Root Mean Squared

RMS difference and the RMS value will be directly proportional to the

degree of asymmetry between right and left sides. I have attached an excel

file to illustrate the process. I used this method for determining a

Right-Left asymmetry in the following paper on partial foot prostheses:

Kulkarni J., Curran B., Ebdon-Parry M., Harrison D., (1995) 'Total contact

silicone partial foot prostheses for partial foot amputations'. The Foot

vol.5, pp.32-35.

Drew Harrison

Have a hunt for work by Pat Goldie (probably in Archives), she has done

some work on gait symmetry after stroke but I can't recall if this has been

published.

I would suggest that you contact her directly but at present she is away

from La Trobe University (Australia) on sick leave. She will be back in

April sometime [P.Goldie@latrobe.edu.au]

Good luck

Julie

Julie Bernhardt, PhD

Physiotherapy Research Coordinator

North West Sector

North Western Health Care

Melbourne, VIC, Australia

Malcolm Granat - working at theUniv of Strathclyde carried out work on

assessing gait in a hemiparertic stroke population. Their work has been

published and a search should provide you with a possible reference. David

Dr. Anand.D.Pandyan

Centre for Rehab. Eng. Studies

M25-Stephenson Bldg

University of Newcastle

Newcastle Upon Tyne

UK - NE1 7RU

Tel ++ 44 (0)191 - 222 5434

Fax ++ 44 (0)191 - 222 8600

e-mail A.D.Pandyan@ncl.ac.uk

http://www.ncl.ac.uk/crest/

We use a symmetry index to evaluate the lameness of horses. I think this

method is also useful in human motion analysis. We place a marker in the

symmetry-axis (e. g. head) and than we calculate the Fourier-coefficients

of the vertical motion. The Fourier-coefficients separate the motion in

symmetrical and asymmetrical parts. We described this method in:

"A method of signal processing in motion analysis of the trotting horse"

C. Peham, M. Scheidl and Theresia Licka J. Biomechanics, Vol. 29, No. 8,

pp. 1111-1114, 1996

"Supporting forelimb lameness: clinical judgement versus computerised

symmetry measurement"

C. Peham, Theresia Licka, M. Scheidl and D. Girtler Equine Veterinary

Journal, in print

This method can be extended to use all three motion direction, but you have

to take care, because in vertical and horizontal (running direction) the

fundamental wave and the odd harmonical parts are the asymmetrical part and

the even harmonical waves are the symmetrical parts of the motion. In the

transversal motion the fundamental wave represents a symmetrical motion.

Christian Peham [christian.peham@vu-wien.ac.at]

I'm using a transformation of right and left kinetic parameters (obtained

from force plates) into a common differential mode, in clear analogy with

electronics.

If p1 were a parameter obtained with the left plate and p2 were the same

parameter measured with the right plate, the derived parameters would be

defined as follows:

p(COM)=(p1+p2)/2

p(DIF)