Abstract
Background
A pedobarograph is a device that records pressures exerted by the foot on contact with the ground. Clinically most publications using pedobarography investigated diabetic foot pressures for prevention of ulcers, and assessing gait and sway. Only limited work was done on the effects of foot surgery on foot pressures. Any comparison between papers is hampered by the absence of available defined normal ranges of foot pressures.
Aims of Study
The objective of the research project is to describe the foot pressures for 250 volunteers and to identify any trends and relationships of age, sex, body mass index (BMI), shoe & foot size and ethnic origin to foot pressures. The study is to provide a baseline upon which further comparative clinical research can be built.
Materials and Methods
a sample size of 250 volunteers was determined after statistical advice. Ethics approval was sought. Recruitment was done after consent from Leicester Royal Infirmary and Leicester University. Volunteers with lower limb injury, diabetes, peripheral vascular disease or spinal cord injuries were excluded.
Participants walked barefooted onto a (Takscan) matrix pressure mat. They walked at a speed they considered normal for themselves, as recommended by Taylor et al. We used the two step initiation protocol, invented by Myers-Rice et al to control the stride length, volunteers stood two steps away from the mat and hit the mat in their second step. Five steps per foot were collected for each patient and the average per foot area was calculated. The five steps method provided a coefficient of reliability of 0.94. Each foot was divided into 13 areas using the Tekscan software package.
Data analysis was done using SPSS. Study participants’ characteristics (age, sex, foot size, height, weight and BMI) were summarised as a whole and by ethnic group, in tabular and graphical form. Histograms of foot pressure parameters (mean peak pressure at the medial and lateral heel, the mid foot, the head of each metatarsal and at each toe) were generated. The confidence interval was set to 95% and the level of significance to 0.05. Regression analysis testing was carried out to determine any significant relations between the variables. Coefficient of determination was reported for models including age, sex and ethnic origin, with and without adjustment for other body size measures.
Results
Study population demographics, as well as BMI, height, weight and the average foot size were described. The average peak foot pressure for each foot area for each ethnic group was described and compared. Regression analysis of the variables has shown statistically significant associations between >70 years age group and low midfoot pressure, high BMI/weight and high midfoot pressure, big foot size and high midfoot pressure. The white western European group had the highest overall foot pressures.
