Plantar pressure distributionPlantar pressure distributionin the normal and in the diabetic foot.in the normal and in the diabetic foot.

An introduction to the use of plantarpressure data in clinical and scientific research.

Kristiaan D’Août, PhD.

University of Antwerp, Belgium andCentre for Research and Conservation, Belgium.

in collaboration with

Jain Institute of Vascular Sciences, Bangalore, India. Dr. Suresh, Dr. Vivekanand, Dr. Vinaya

Diabetic Foot Society of IndiaMumbai, 13-15 October 2006

Biomechanics of the foot (healthy & diabetic)Biomechanics of the foot (healthy & diabetic)

1. Kinematics: movements, gait patterns

2. Kinetics: forces involved

3. Tissue properties

4. Plantar pressures

• important in the diabetic foot Ulcer formation through ischemia and/or tissue damage

• can be measured directly in a clinical setting

Pressure plate

• mobile plate (approx. 42 x 56 x 1 cm)• contains discrete pressure sensors (0.5 x 0.7 cm)• static and dynamic measurements (300 fps)

The « normal » human foot

Pressure insoles

• practical problems• mainly for footwear testing

How to measure plantar pressure?How to measure plantar pressure?

Overview sequence (each 33th frame)

Analysis: visual overview or focus on areas of interest

Time (s)

Pres

sure

(kPa

)

2. loading time

3.pressureimpulse

1. peak pressure

The three main pressure-related variables - clinical importanceThe three main pressure-related variables - clinical importance

1. Peak pressure

May be most responsible for tissue damage.

2. Loading time

May be most important in prolonged ischemia.Brief ischemia can not be avoided.

3. Pressure impulse

Combines both; is recently shown to play a role in stress injuries, along with loading rate.

Pressure results with healthy subjects and with patientsPressure results with healthy subjects and with patientsThree trials of the same subject

There is considerablevariation even within a standard protocol!

slowwalking

normalwalking

fastwalking

running turnleft

turn right standing sittingplantar

sittingball

Peak P

Time

Impulse

A case: First Metatarsal head during various tasksA case: First Metatarsal head during various tasks

There is huge variation between different daily activities

Peak pressure

Loading time

pressure impulse

Peak pressure seems high at the hallux only

The metatarsal region is loaded longer

Impulses at 3rd metatarsal are closeto those of the hallux!

#141 #156 #022

Indian, barefoot Indian, barefoot Indian, shod

Discussion and conclusionsDiscussion and conclusions

A pressure plate is a practical and highly useful tool in diabetic care:in prevention, treatment and follow-up. Yet, it is a recent techniqueand much research should be done.

It is also very valuable in orthotic and prosthetic tuning.

When time allows, normal daily behaviour of the patient should be mimicked.

When time allows, peak pressure, loading time and pressure impulseare all informative.

For a first screening, normal walking can be analysed in 5 minutes(one trial per foot, visual evaluation of the pressure profile).

Plantar pressures are but one tool for the physician. Measurementsshould be combined with other data (e.g. sensitometry), as thereare no unequivocal threshold « safe pressure » data to date.

kristiaan.daout@ua.ac.be

Acknowledgements

Dr. Suresh, Dr. Vivekanand, Dr. S. Praet, Dr. Rajendrakumar,Dr. Vinaya, Ms. Usha, Mr. Uday, Mr. Albert.The entire staff of the Jain Institute of Vascular Sciences, Bangalore.

Thank you!Thank you!