plantar pressure relief

8/7/2019 Plantar Pressure Relief

1/20


2/20

INTRODUCTION

Foot ulcers in patient with DM precede 85%

of all non-traumatic lower limb amputations

Most plantar foot ulcers are caused by acombination of loss of protective sensation

due to peripheral neuropathy, a complication

of the disease, and elevated levels of

mechanical stress as a result of change infoot structure

Forefoot and toe region plantar ulcers>>


3/20


4/20

INTRODUCTION

Mechanism ofFOS redistribution of load

from forefoot to proximal regions by a rocker

bottom outsole and a negative heel

configuration

The aim of this study was to assess the

offloading efficacy of four different FOS

models in comparison with cast shoe andcontrol shoe in a group of diabetic patients

with peripheral neuropathy


5/20

Methods, subject

24 neuropathic diabetic patients (20 men, 4

women) at high risk for plantar foot

ulceration

The mean (SD) age, height, weight andbody-mass index of the subjects was 60.0

(7.0) years, 1.72 (0.07) m, 92.0 (15.2) kg,

and 30.9 (4.3) kg/m2

5 patients had diabetes type 1, 19 patientstype 2


6/20

Methods, subject

Loss of protective sensation due toneuropathy was confirmed by the inabilityto sense a 10-g SemmesWeinsteinmonofilament at one of the four plantar footsites tested (hallux, first and fifthmetatarsal head, and heel) or the inabilityto sense a vibration of 25 V at the great toeas measured with a Neurothesiometer

(Horwell ScienticLaboratory Supplies,Wilford, Nottingham, UK).

Each patient had at least one footdeformity


7/20

Methods, subject

Excluded were patients with a current footulcer, inability to walk a distance of 20 mrepeatedly without walking aid, lower-extremityamputation, active neuro-osteoarthopathy or

Charcot deformity, equinus foot deformity, andtreatment for serious medical conditions orinjuries other than diabetes mellitus that mayinterfere with lower limb function (walking).

The study protocol was approved by the

LocalResearch Ethics Committee and each subject

gave written informed consent before the startof the study.


8/20

Methods, Footwear


9/20


10/20

Methods, data analysis Each foot was divided into six anatomical regions: heel,

midfoot, first metatarsal heads, second-to-fifth metatarsalheads, hallux, and lesser toes. For each region, peak pressure,

pressuretime integral (PTI), and forcetime integral (FTI) were

calculated

Load transfer was calculated between the offloading footwear

and the control shoe.

Statistical analysis was using SPSS (Version 14.0)

For all normally distributed data ANOVA

Bonferroni post hoc testing was used for multiple pairwise

comparisons between footwear conditions. For data that was not normally distributed Wilcoxon signed-

rank test

A significance level of P < 0.05 was adopted for all analyses.


11/20

Result


12/20

Result

Fig. 2. Load transfer diagrams showing the mean regional differences and inter-

regional load transfer in normalized FTI between each of the five offloading

footwear conditions and the control shoe. Diagram A, Thanner Cabrio FOS; B,

RattenhuberTalus FOS; C, Fior&Gentz HannoverFOS; D, Fior&Gentz Luneburg

FOS; and E, Mabal cast shoe. The breadth of the arrows is proportional to the

absolute amount of load transfer. MTH; metatarsal heads.


13/20

Result

Perceived walking comfort varied

substantially between footwear

conditions with the control shoe

perceived as most comfortable (VAS

score 8.2) and the Fior&Gentz Luneburg

shoe as least comfortable shoe (VAS

score 2.7)


14/20

Discussion

The results of this study show that the fourFOS modelstested were effective in offloading the forefoot in at-riskneuropathic diabetic patients.

Substantial reductions in peak pressure compared to acontrol shoe were achieved in the regions where mostfrequently ulcers develop: 5158% at the metatarsal headsand 3849% at the hallux. Significant reductions in theseregions were also found for the PTIs.

All fourFOS models tested were equally effective inoffloading the forefoot, with small differences present

between the different models in most foot regions. Thepeak pressure reductions found in this study are of thesame magnitude as those reported in an earlier study of agroup of ulcer patients tested in several offloading devices,including a similar type FOS


15/20

Discussion

Significant differences in metatarsal head peak pressuresfound between the FOS and Mabal cast shoe were notmimicked by differences in metatarsal head PTIs. PTI isdefined by the area under the peak pressure time curve.Apparently, longer contact times or more flattened and

broader peak pressure curves at these regions in the FOSexplained this difference in pattern between peak pressureand PTI results

The mechanism of action of the FOS, as assessed usingthe load transfer diagrams shown in Fig. 2, was clearly alarge transfer of load from the forefoot to the midfootregion. On average 40% of the total force impulse presentin the forefoot and toe regions was transferred to proximalfoot regions


16/20

Discussion

The load transfer diagrams also show

that only small portions of load were

transferred from the midfoot to the heel

in the offloading footwear.


17/20

Discussion

All FOS models were perceived as

significantly less comfortable to walk in

when compared with the control shoe and

the Mabal cast shoe. Most likely, the designfeatures of the FOS that caused substantial

pressure relief in the forefoot were also

responsible for more walking discomfort in

this group of patients who already havesensory loss in their feet and therefore

more difficulty with walking


18/20

Discussion


19/20

Conclusions

The data showed that all FOS models were

effective in their primary goal, relieving

forefoot pressure in at-risk neuropathic

diabetic patients.

Therefore, these shoes may be effective in

offloading and healing plantar forefoot ulcers,

although the low comfort scores should beconsidered as this may potentially affect

adherence to treatment


20/20

plantar pressure relief

Documents