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Poster session 5: Offloading and biomechanics
P5.02
Biomechanical characteristics of patients with diabetic peripheral neuropathy during
active ulceration
Malindu Fernando, James Cook University, Townsville, Australia
Robert Crowther, James Cook University, Townsville, Australia
Peter Lazzarini, University of Technology, Brisbane, Queensland, Australia, Brisbane,
Australia
Margaret Cunningham, University of Stirling, Stirling, United Kingdom
Kunwarjit Sangla, The Townsville Hospital, Queensland, Australia, Townsville, Australia
Petra Buttner, The Townsville Hospital, Queensland, Australia, Townsville, Australia
Jonathan Golledge, James Cook University, Townsville, Queensland, Australia, The
Townsville Hospital, Quee, Townsville, Australia
Aim: Abnormal lower limb biomechanics due to diabetic peripheral neuropathy (DPN) are
known to be a significant contributor to initiating foot ulceration. This cross-sectional study
aimed to identify biomechanical characteristics of patients with DPN and chronic plantar foot
ulcers compared to type 2 diabetes controls and healthy controls.
Methods: 21 type two diabetes patients with active unilateral plantar foot ulcers (DFU
group), 69 type two diabetes control patients without ulcers (DMC group) and 56 healthy
controls without diabetes or ulcers (HC group) were recruited. Plantar pressure data were
collected utilising a three-step protocol and assessed in terms of pressure time integral
(PTI), mean pressure (MPP), maximum pressure (MSP), and contact area (CA). Three
dimensional movement analyses data relating to temporospatial-parameters (TSP),
kinematics, kinetics and muscle activation patterns were collected using a standard protocol.
Results: PTI was consistently higher in the DFU group at the midfoot and forefoot on both
the ulcerated (p<0.001) and non-ulcerated foot (p=0.001) compared to both controls. MPP
and MSP were inconsistently elevated in the DFU group. Midfoot CA were greater in the
affected (p<0.001) and non-affected (p<0.001) limbs of the DFU group compared to both
controls. Several TSP were significantly different in the DFU group including cadence
(p<0.001), walking speed (p<0.001), foot-off time (p<0.001) and double support times
(p<0.001) compared to controls. Kinematic analyses demonstrated significant differences in
push-off force. Several alterations in kinematic patterns were observed, including ankle
angle (p=0.044), knee angle (p<0.001) and hip angle (p=0.033) in the DFU group compared
to controls.
Conclusion: This study confirms that several biomechanical parameters are different in
patients with active plantar foot ulcers. Longitudinal studies assessing the potential impact of
these characteristics on ulcers may provide further information regarding factors which are
likely to influence ulcer healing.
Acknowledgements: Funding from the Queensland Department of Health, HP Research
Grant Scheme (2013-14), funding from the Graduate Research School, James Cook
University and funding from the NHMRC Australia supported this work.
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Page 1 of 9
P5.04
The effect of altered plantar soft tissue mechanical properties on the tissue's
cushioning characteristics
Panagiotis Chatzistergos, Staffordshire University, Stoke on Trent, United Kingdom
Roozbeh Naemi, Staffordshire University, Stoke on Trent, United Kingdom
Nachiappan Chockalingam, Staffordshire University, Stoke on Trent, United Kingdom
Aim: The mechanical behaviour of plantar soft tissues of people with type-2 diabetes
changes during the course of the disease[1] but the causes of this change and its effect on
tissue viability are not clear. A combined use of in-vivo measurements and modelling
enables the quantitative assessment of a tissue’s non-linear mechanical behaviour[2]. This
study aims to present a new method for the assessment of plantar soft tissue biomechanics
and to investigate the effect of altered tissue mechanical behaviour on its cushioning
properties.
Method: A new ultrasound indentation device was manufactured to study the macroscopic
mechanical behaviour of, plantar soft tissues[3]. An in-vivo measurement based
computational procedure was also developed for the subject-specific finite element
modelling of the heel-pad and the inverse-engineering of its material coefficients. The heelpad was simulated as a hyperelastic (1st order Ogden) material and its mechanical
behaviour was defined using two coefficients: μ and α.
This method was used to calculate the heel-pad material coefficients (μref, αref) for a nondiabetic subject and set the reference for the simulation of a broad range of tissue
mechanical behaviours. Peak barefoot pressure and the energy absorbed by the heel-pad
during heel-strike, were estimated for heel-pads with μ and α ranging between, 0.5μref ≤
μ ≤2μref and 0.5 αref ≤ α ≤1.5αref respectively. Increasing μ results in higher initial
stiffness while increasing α widens the difference between the tissue's initial and final
stiffness.
Results: A 50% decrease in μ increased peak pressure by up to 13% while 200% increase
in μ decreased pressure up to 7%. A 50% decrease in α increased the energy absorbed by
the tissue by 35% while a 50% increase in α decreased energy by 22%., , , ,
Conclusions: The heel-pad's cushioning properties appear to be negatively influenced by
tissue "softening" (i.e. decrease of µ) and the increase of the difference between the tissue's
initial and final stiffness (i.e. increase of a).
Acknowledgments: Funding from DiabSmart project is acknowledged (www.diabsmart.eu)
References:
[1]Chao et al.Ultrasound Med Biol 2011;37:1029–38
[2]Erdemir et al.J Biomech 2006;39:1279–86
[3]Chatzistergos et al.J Diabetes Complicat 2014;28:488-93
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Page 2 of 9
P5.05
Impact of big toe amputation on foot biomechanics
Mohamad Motawea, Mansoura specialized medical hospital, Alkhafji, Saudi Arabia
Fady kyrillos, Mansoura specialized medical hospital, Mansoura, Egypt
Ahmed Hanafy, Mansoura specialized medical hospital, Mansoura, Egypt
Ahmed Albehairy, Mansoura specialized medical hospital, Mansoura, Egypt
Omnia State, Mansoura specialized medical hospital, Mansoura, Egypt
Manal Tarshoby, Mansoura specialized medical hospital, Mansoura, Egypt
Hanan Gawish, Mansoura specialized medical hospital, Mansoura, Egypt
Mamdouh El-Nahas, Mansoura specialized medical hospital, Mansoura, Egypt
Background: The big toe plays an important role in foot biomechanics. During walking, it
poses twice the total pressure of the other four toes. It has a significant contribution in
windlass mechanism needed for push off; its amputation will change intensely in foot
biomechanics.
Aim: compare the peak pressures (PP) and pressure time integral (PTI) on the sole of the
foot in diabetic patients with unilateral amputations of the big toe (UABT) with preservation of
the 1st metatarsal, with the patients' contralateral intact foot (CIF).
Subjects and methods: Ten patients with UABT of at least 4 years duration were evaluated
with the in-shoe pressure measurement system¹ (ISP) in their diabetic footwear and plate
form² (PF) while they walk bare feet. We compared PP and PTI under all metatarsals, lesser
toes, midfoot and heel in UABT and CIF using Wilcoxon's matched pairs signed-rank test.
Results: Using ISP, PP and PTI were significantly higher under 1st metatarsal head (MTH),
lesser toes in the UABT compared with CIF, and non significant changes were found under
the lesser metatarsals and midfoot. Heel showed higher pressure on the CIF, but the results
were statistically insignificant., While using PF, PP and PTI were significantly higher under
1st MTH (p=0.01) and (p=0.02), 3rd toe (p=0.008) and (p=0.04), 4th and 5th toes together
(p=0.01) and (p=0.02), respectively in the UABT compared with CIF with non significant
changes over other regions.
Conclusion: Big toe amputation significantly altered pressure distribution of the foot with
increased foot pressure in forefoot area that contributes to an increased risk of re-ulceration
and re-amputation that necessitate in shoe intervention with custom made insoles.
References
1. Tekscan F-scan device 2. Tekscan Mat scan device
Comparing the results of peak pressure and pressure time integral on 1st metatarsal and
lesser toes between the foot with big toe amputation and the contralateral intact foot using
in-shoe pressure measurement system
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Page 3 of 9
P5.06
The possibility of a patient-specific foot orthosis based on three-dimensional
computer-aided-design (CAD) models
Tetsuji Uemura, Saga university hospital, Saga, Japan
Mamoru Kikuchi, Saga universityhospital, Saga, Japan
Takenoshita Hiromasa, Karatsu Red Cross hospital, Karatsu, Japan
Seiya Hagihara, Saga university hospital, Saga, Japan
Aim: Foot orthotic treatment is one of the major conservative methods used to handle foot
problems associated with diabetes. Total plantar contact foot orthoses are used to reduce
and redistribute peak pressures. For the fabrication of a total plantar contact foot orthosis,
the plantar surface in contact with the shoe is analyzed by the finite element method (FEM).
The computational FEM data was created by the three-dimensional computer-aided design
(3D-CAD) through adaptation of the model’s plantar MRI data. The pressure distribution over
the patient’s plantar surface will be obtained for the fabrication of a foot orthosis customized
for him/her.
Methods: The plantar foot-orthosis interface pressure distribution was calculated by
MSC.Marc, a commercially available FEM code. The computational FEM data of a foot
would be created from the patient’s plantar MRI data; the data for the orthosis would then be
adapted by 3D-CAD software. The ultimate foot data consists of soft tissue data and of bone
data, as shown and the orthosis data consists of two rubber layers, also shown in this
presentation. With the foot fixed at the ankle, the orthosis is pressed from below to the foot in
the upward direction as shown in this presentation.
Results:The stress distribution over the foot plantar, and that on the contact surface of the
orthosis are shown in Figure, respectively. The stress is seen to peak near the heel and the
toes. The stress distribution was first obtained on the flat-surfaced model orthosis. The FEM
then analyzed the stress distribution over the slanted orthosis to obtain the uniform stress.
The appropriate shape of the orthosis was ultimately created on the basis of the FEM
analysis results.
Conclusions: The present study has shown that the custom-made orthosis for a given
patient can be designed by FEM analysis based on the numerical data created from his/her
plantar MRI data followed by the 3D-CAD adaptation.
Boundary condition using foot and orthosis model(upper),Mises stress distribution of foot
plantar(middle) and orthosis for contact surface(below)
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Page 4 of 9
P5.07
The orthotic management after chopart amputation in diabetic patients
Roberto De Giglio, Azienda Ospedaliera Legnano, Abbiategrasso, Italy
Gianmario Balduzzi, Azienda Ospedaliera Legnano, Abbiategrasso, Italy
Teresa Mondello, Azienda Ospedaliera Legnano, Abbiategrasso, Italy
Viviana Zoppini, Azienda Ospedaliera Legnano, Abbiategrasso, Italy
Barbara Musto, Azienda Ospedaliera Legnano, Abbiategrasso, Italy
Ilaria Formenti, Azienda Ospedaliera Legnano, Abbiategrasso, Italy
Sara Lodigiani, Azienda Ospedaliera Legnano, Abbiategrasso, Italy
Giacoma Di Vieste, Azienda Ospedaliera Legnano, Abbiategrasso, Italy
One of the greatest difficulties in diabetic patients undergoing amputation Chopart in the
after surgery appears to recover the walk, waiting for a shoe or a customized brace, the
realization of which for various reasons can take from one to three months. It is difficult even
find devices that protect the patient not only outside the home, but also while walking in own
home. The application of a total contact cast is not always usable for problems related to the
wound and or to the patient.
Method: In this work enrolled 12 diabetic patients (8 males and 4 females) who underwent a
unilateral Chopart amputation for various reasons (Chopart bilateral amputations was not
considered). In the postoperative phase, exactly within the first two months after surgery, we
evaluated the possibility of the devices used by patients to walk by dividing them into two
groups: in GROUP A (6 patients) was given the use of a brace leg-foot pneumatic pre-format
dedicated to Lisfranc, and, Chopart amputations (called BODY ARMOR PRO TERM), while
in group B (6 patients) was prohibited the load until the construction of a cast customized.,
The duration of observation was 60 days.
Results: In GROUP A we have observed, in the study period, no harmful event with the tutor
BODY ARMOR PRO-TERM. Patients included in this group reported a greater comfort,
without any difficulty in walking on level straight, but also up and down the stairs.
In GROUP B we observed a case of re-opening of the surgical wound, the occurrence of 3
ulcerative lesions in two patients, respectively one in an Achilles region area, one in a
plantar area of the heel and one re-ulceration in the lateral portion of the fifth finger.,
Conclusions: In our experiences the BODY ARMOR PRO-TERM is the indispensable
device for shooting the load early in patients with amputation Chopart, both at home and
outside of it. The BODY ARMOR PRO-TERM is joined the protocols of our department for
the management of Chopart amputations. It would undoubtedly be an extension of trials and
biomechanical investigations that include the study of the kinetics and kinematics in order to
collect more precise parameters on different devices off-loading in order to assist the
clinician in selecting the most appropriate orthosis.
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Page 5 of 9
P5.08
Pro and con in using felted foam on diabetic foot ulcer
Nanne Bonnichsen, Steno Diabetes Center A/S, Gentofte, Denmark
Annemarie Pedersen, Steno Diabetes Center A/S, Gentofte, Denmark
Klaus Kirketerp-Møller, Steno Diabetes Center A/S, Gentofte, Denmark
Anne Rasmussen, Steno Diabetes Center A/S, Gentofte, Denmark
Aim: To identify the pro and cons in using felted foam as an “new” additional offloading in
our centre, in combination with sandals or cast, in diabetic, ”hard to heal”, foot ulcer.
Methods: We selected patient with recalcitrant or recurrent ulcers or patients who did not
use the recommend offloading and were offered felted foam., A small case series with a total
of 20 diabetic patients between March and October 2014, was evaluated.
Results: Eleven (55%) patient with Type 2 diabetes, 16 (80%) male, mean age 59 years
(41-84 years), diabetes duration years 23 (5-45 years). The most common ulcer type was
neuropathic (70%), and placement was on the forefoot (45%), the mean duration of the foot
ulcer before using felted form was 20 weeks (1-94 weeks), all the patient have been
offloaded in cast, therapeutic sandals or prescribed footwear. Five ulcers were recurrent.
Eleven ulcers healed in the period, mean time was 18 weeks (3-94 weeks), eight ulcers did
not heal and one patient had a major amputation., Fourteen patients could change the felted
foam by themselves, once a week, half of them healed completed. In six cases the home
nurse changed the felted foam, this was a difficult task.
Visit in the foot clinic during treatment was 2 times (2-21 visits). In tree patients there was
infection witch led to termination of the felt treatment, two patients were lost to follow up.
Conclusion: In this small series we learned that felted foam could be a good solution if
patients can change the felt by themselves., Education and information to the patients home
care nurses is essential if felt is implemented and the patient is not able to change the felt
themselves. Patients with a vulnerable skin should not use the felt. We still need further
investigation and a controlled study.
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Page 6 of 9
P5.09
Effect of insole material on the plantar pressures of the at-risk diabetic foot
Aoife Healy, Staffordshire University, Stoke On Trent, United Kingdom
Roozbeh Naemi, Staffordshire University, Stoke On Trent, United Kingdom
T Revathi, India Diabetes Research Foundation, Chennai, India
Lakshmi Sundar, India Diabetes Research Foundation, Chennai, India
Nachiappan Chockalingam, Staffordshire University, Stoke On Trent, United Kingdom
Anju Pillai, India Diabetes Research Foundation, Chennai, India
Andrew Greenhalgh, London Sport Institute, Middlesex University, London, United Kingdom
Ambady Ramachandran, India Diabetes Research Foundation, Chennai, India
Aim: While a number of studies have assessed the effectiveness of therapeutic footwear in
preventing reulceration no research to date has examined their effectiveness in preventing
ulceration1. This study was aimed at examining the effect of two types of footbeds made of
two different materials commonly used as insoles on plantar pressures of the at-risk diabetic
foot during walking.
Methods: 68 patients with Type 2 diabetes and neuropathy (vibration perception threshold ≥
25V) were recruited from and tested at a specialist diabetes hospital. The patients were
randomised2 into two groups, one group were provided sandals with a micro-cellular
polymer insole and the other group were given sandals with a polyurethane insole. Barefoot
and in-shoe plantar pressures (MatScan and FScan, Tekscan, USA) were measured during
walking. 3 trials per foot using a two-step protocol3 for barefoot and 12 steps per foot for the
in-shoe measurement4 were analysed using the proprietary software. The foot was divided
into 12 regions and the peak pressure in each region was identified. Paired sample t-tests
were employed to test for differences between the barefoot and in shoe pressure
measurements for both footwear groups. Furthermore an independent t-test was used to test
for differences in peak pressure between the footwear groups.
Results and conclusion: Clear clinically relevant differences were observed between the
two footwear groups. The comparisons between barefoot and shod plantar pressures whilst
highlighting the usefulness of such measures, indicated how plantar pressures could be
redistributed using a foot bed even in the types of footwear that were used within this study.,
For the two footwear groups results for peak plantar pressures highlighted the ability of the
two materials to offload pressures. Results from this study form the basis for further
development of custom materials and foot bed design for different types of footwear.
References:
1.Healy et al. (2013) Journal of Diabetes and its Complications, 27(4): 391-400.
2.Naemi et al., (2013) Journal of Clinical Trials, 4:1.
3.Bus and Lange (2005) Clinical Biomechanics, 20(9), 892-9.
4.Arts and Bus (2011) Clinical Biomechanics, 26(8), 880-4.
Acknowledgements:EC Grant Agreement No 285985; under FP7-PEOPLE-2011-IAPP
www.diabeticfoot.nl
Page 7 of 9
P5.10
The effect of Gel filled therapeutic insoles on, plantar pressure and footTcpO2, in at
risk individuals with diabetes
William Munro, Anatomical Concepts UK Ltd, Glasgow, United Kingdom
Objectives: Co existing diabetes and peripheral vascular disease have increased
susceptibility to plantar ulceration. Therapeutic insoles reduce plantar pressure, but the
effect on transcutaneous tissue oxygenation (TcpO2) is unknown. This study examines the
effect of Gel filled therapeutic insoles on plantar pressure and foot TcpO2, in at risk
individuals with diabetes and peripheral vascular disease.
Research design and methods: ABPI in both lower limbs was measured in patients
attending the diabetes centre for complication screening. 21 individuals with ABPI<0.9 and
no active ulceration were invited to participate in the study. TcpO2 was, measured at the
apex of the great toes both before and after a 2 week period of therapeutic insole use
recordings of in-shoe pressure measurements without and with the therapeutic insoles were
made to ascertain any regional redistribution of plantar pressures (Forefoot, Midfoot and
Hindfoot)
Results: A mean reduction in peak forefoot pressure of 54.7Kpa(95%confidence interval
31.7-77.8Kpa, p<0.01) was observed. Mean Great toe TcpO2, increased by 2.29mmHg
(95% CI 0.87-4.97mmHg p<0.01)
Conclusion: The therapeutic insoles used may prevent new and recurrent pedal ulceration
in at risk patients with diabetes and peripheral vascular disease
Insoles used were Liqua Care
Colour pressure map showing regional foot pressures measured by the F-Scan without and
with the Liqua Care® insole in a representative individual (low foot pressure indicated by the
blue end of the colour spectrum)
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Page 8 of 9
P5.11
Are assessments of hallux valgus angles with computerised plantar pressure
measurements or clinical goniometry alternatives for radiography?
Antal Sanders, Leiden University Medical Center, Leiden, Netherlands
Daniël Janssen, University Hospital Maastricht, Maastricht, Netherlands
Nick Guldemond, University of Technology Delft, Delft, Netherlands
Joris Hermus, University Hospital Maastricht, Maastricht, Netherlands
Geert Walenkamp, University Hospital Maastricht, Maastricht, Netherlands
Lodewijk Van Rhijn, University Hospital Maastricht, Maastricht, Netherlands
Aim: Hallux valgus deformity has a prevalence of 3.5% in adolescents to 35.7% in adults
aged over 65 years. Radiographic measurements of hallux valgus angles (HVA), are
considered to be the most reproducible and accurate assessment of HVA. However, in
Europe, many podiatrists do not have direct access to radiography. Therefore, alternative
measurements are desired, such as computerised plantar pressure measurement and
clinical goniometry., The aim of this study was to establish the agreement of these
techniques and radiographic assessments.
Methods: HVA was determined in 186 participants with diabetes. Radiographic
measurements of HVA, were performed with standardised static weight bearing dorsoplantar
foot radiographs. The clinical goniometry for HVA was measured with a universal
goniometer. Computerised plantar pressure measurement for HVA was executed with an
EMED pressure platform and Novel-Ortho-Geometry, software. The intra-class correlation
coefficients (ICC) and levels of agreement were analysed using Bland & Altman plots.
Results: Comparison of radiographic measurements to clinical goniometry for HVA showed
an ICC of 0.81 (95% confidence interval (CI) 0.76-0.86; p<0.001). Radiographic
measurement versus computerised plantar pressure measurement showed an ICC of 0.59
(95% CI 0.49-0.68; p<0.001). Clinical goniometry versus computerised plantar pressure
measurement showed an ICC of 0.77 (95% CI 0.70-0.82; p<0.001). The systematic
difference of the computerised plantar pressure measurement compared with radiographic
measurement and clinical goniometry was 7.0 degrees (SD 6.8) and 5.2 degrees (SD 5.0),
respectively. The systemic difference of radiographic measurements compared with clinical
goniometry was 1.8 degrees (SD 5.0). The range of the mean difference, between the 3
measurement methods was 19.7 degrees or more.
Conclusions: The agreement of computerised plantar pressure measurement and clinical
goniometry for HVA compared to radiographic measurement of HVA is unsatisfactory.
Radiographic measurements and clinical goniometry yield better agreement compared to
radiographic measurements and computerised plantar pressure measurement. The
traditional radiographic measurement techniques, are strongly recommended for the
assessment of, HVA.
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