PLANTAR FOOT PRESSURE OF LOWER LEG AMPUTEES ...

RESULTS AND DISCUSSION
As expected the pressure patterns of the prosthetic leg differed significantly from the
remaining leg for most variables and measuring sites, during gait as during running (table 1). It
is, however, remarkable that peak heel pressures show no differences during gait. This
confirms the results from Veves et al (1992) concerning the peak pressures of non-diabetic
amputees for gait. But with increasing speed, as during jogging, the normal foot seems to
accept higher peak loads than the prosthetic foot. Also the build up of pressure (load rate) is
always much higher for the normal heel. This may be due to the dominant presence of the
compliant Flex-Foot, which is known for its highly efficient return of stored energy during
heel impact (Czernieckl, Gitter and Munro, 1991).
As for the forefoot and in contrast with the stabilizing thrust being on the first metatarsal
head in the normal foot, the prosthetic forefoot bears weight centrally. The maximal pressure
under the forefoot is about the same for both feet, but the prosthetic forefoot shows a higher
loading rate, probably due to its rigid metal structure.
WALKING
RUNNING
%
contact
time
Pmax
(N/cm 2 )
%
load
time
load rate
(N/cm 2 /ms)
%
contact
time
Pmax
(N/cm 2 )
%
load
time
load rate
(N/cm 2 /ms)
HM n 45 ± 8 69 ± 20 12 ± 7 2.89 ± 1.33 49 ± 5 93 ± 33 12 ± 4 7.64 ± 5.10
p 42 ± 13 64 ± 29 27 ± 9 0.99 ± 0.47 39 ± 18 66 ± 39 35 ± 9 1.95 ± 0.98
HL n 45 ± 8 60 ± 22 13 ± 7 2.62 ± 1.87 48 ± 5 88 ± 34 10 ± 4 8.78 ± 6.14
p 43 ± 13 61 ± 30 30 ± 8 0.77 ± 0.38 40 ± 17 66 ± 43 36 ± 8 1.89 ± 1.09
M1 n 76 ± 7 40 ± 24 82 ± 6 0.09 ± 0.05 75 ± 6 55 ± 28 63 ± 10 0.44 ± 0.25
p 61 ± 11 27 ± 9 68 ± 11 0.10 ± 0.04 63 ± 12 37 ± 17 59 ± 10 0.39 ± 0.23
M3 n 79 ± 5 30 ± 13 81 ± 5 0.06 ± 0.02 75 ± 8 35 ± 9 64 ± 4 0.25 ± 0.09
p 66 ± 9 43 ± 14 70 ± 12 0.15 ± 0.05 68 ± 12 62 ± 24 64 ± 9 0.54 ± 0.27
M5 n 66 ± 9 13 ± 8 66 ± 13 0.04 ± 0.02 60± 9 22 ± 12 64 ± 11 0.21 ± 0.11
p 63 ± 11 27 ± 8 68 ± 12 0.09 ± 0.04 59± 18 33 ± 14 62 ± 13 0.41 ± 0.42
T1 n 56 ± 17 40 ± 21 74 ± 7 0.15 ± 0.06 74 ± 11 45 ± 26 62 ± 10 0.36 ± 0.20
p 29 ± 18 47 ± 34 75 ± 9 0.32 ± 0.15 37 ± 19 33 ± 30 64 ± 10 0.46 ± 0.33
Table 1: Mean and standard deviations of the plantar pressure variables of the prosthetic (=p)
and the normal (n) foot for walking and running (bold figures indicate a significant difference
between both means with p