## Stance Phase Duration: normative values

Dear all,

Probably like many of you out there, I usually start off my teaching about gait with the normal
cycle. I have always asserted that normal stance duration is about 62%, yet it just occurred to
me that this is probably wrong.

In our own paper, back in 1985*, Mike Whittle and I reported the following regression equations:

Stance Duration = -3.5*speed + 64.2% (corr. 0.71)
Stance Duration = -6.7*stride length + 69.4% (corr. 0.74)

For normal speed and stride lengths of 1.5 m/s and 1.5 m both these equations predict a stance
duration of 59%, which is, I think roughly correct. If any of you have any data I'd be very
interested to know if you agree with me.

My question, then, is where did this figure of 62% come from? Isn't it time we rounded it off to 60%?

Chris

Dr. Chris Kirtley MD PhD
Associate Professor
Dept. of Biomedical Engineering
Catholic University of America
620 Michigan Ave NE, Washington, DC 20064

*Kirtley C, Whittle MW & Jefferson RJ (1985), Influence of Walking Speed on Gait Parameters.,
Journal of Biomedical Engineering  7(4): 282-8.

normal subjects aged 13 to 75 years (91 Caucasians and 128 Chinese) for gait
analysis.  I am attaching a table with respect to stance duration for your
interest.  Stance duration for subjects younger than 45 years is about 62%
(Chinese 61.9 Â± 1.9%, Caucasians 61.8 Â± 2.5%), and that for subjects older
than 45 years is a bit longer (Chinese 62.3 Â±1.9%, Caucasians 63.6 Â±3.9%).

Wen-ling Chen, D.Phil. P.T.
Department of Physical Therapy
National Cheng Kung University
Taiwan

I have studied the normal gait of healthy young students, the results are as follows(mean(sd)):

male(n=21):
height:172.8(4.5)cm
stance duration: 61.5(1.9) %
stride length:1.36(0.11) m
speed:1.26(0.12)  m/s

female(n=7):
height:160.5(2.4)cm
stance duration: 60.9(2.5)  %
stride length:1.23(0.11)  m
speed:1.16(0.12)  m/s

As a part of a new study, recently we've done a validation study with our own gait analysis system, Physilog, and Elite+ForcePlate on 27 subjects with total number of 229 gait cycles recorded by all three devices.
The Stance duration, according to the reference system, Elite+Forceplate, was: 59.9% (STD=3D2.5%). Our own system (which is an ambulatory device = based on gyroscopes) had this results for the stance phase: 59.3%  (STD=3D2.9%). For the time being we're writing an article on our study...

Best Regards
Arash

Arash Salarian
Swiss Federal Institute of Technology-Lausanne (EPFL)
Laboratory of Movement Analysis and Measurement
STI - Institute for Biomedical Engineering
Bat - ELG
CH-1015 Lausanne
Tel: +41-21-693-5627   Fax: +41-21-693-2614

Chris,
Good data on temporal factors in walking and running can be found  in:
J.Nilsson and A.Thorstensson Adaptability in frequency and amplitude of leg movements during
human locomotion at different speeds. Acta Physiol Scand 129: 107-114 (1987)

In normal walking the product of speed and double support time is
about constant at 20 cm (their Fig 4c). As a % of stride time it
decreases from 12% to 5% at 3(!) m/s (their Fig 3c) . So 12% is not
far off for normal speeds, but there is certainly a dependence of
speed.

Interestingly, Nilsson and Thorstensson made their subjects not
only walk/run at their self-chosen pace, but also at the  fastest/

At Hof
Institute of Human Movement Sciences &
Laboratory of Human Movement Analysis AZG
University of Groningen
A. Deusinglaan 1, room 321