1. Prescription footwear for obese
Submitted by
R.H.Ramanan
Reg:no.200541707
Footwear Science And Engineering
Guided by
Mr.S.Mathivanan Dr.B.N.Das
Scientist,SDDC Scientist
CLRI Head of the Department
SDDC,CLRI

2. OBESITY
 People possess excess of body weight
compared to standards and have high
proportions of body fat are classified as obese

3. Obesity population
 According to American Orthopedic Foot and Ankle Society(AOFAS), one
quarter of population in US are observed as obese
 In UK , half of women and two thirds of men of the total population are
obese
 According to the survey conducted by All India Institute of Medical
Science, in India it was found that 34% of men & 40.3% of women were
overweight & obese
 It is estimated that there are more than 300 million obese people world
wide

4. Examples of the prevalence of obesity in adults
throughout the world

5. Projected prevalence of obesity in adults
by 2025

6. Causes of obesity
 The following factors play major role in the
development of obesity
1. Genetic
2. Environmental
3. Psychological
4. Other factors

7. Measurement of obesity
 Obesity can be quantified by BMI
 BMI can be calculated by
BMI= Weight (in kgs) /{ Height (in m) x Height (in m) }
 if BMI is (< 18.5) -underweight
 If BMI is (18.5-24.9)-normalweight
 If BMI is (25-29.9)-overweight
 If BMI is (30-39.9)-obese

8. Characteristics of obese gait
When compared to normal weight individuals, the obese
people have reported
 Slower walking speed
 Reduction in step length
 Reduction in step frequency
 Longer stance phase duration(3%)
 Shorter swing phase(5%)
 Greater period of double support
 Large step width
to maintain dynamic balance
Source: obesity review /The international association for the study of obesity

9. Ground reaction force and plantar pressure
generated in obese gait
 It is observed that peak pressure were 40-45% higher in obese
subjects during stance for BMI-36.0(men)&BMI-38.0(WOMEN)

10. Gait Analysis: Techniques and
Recognition of Abnormal Gait
April 30, 2007
Force Platform
The reaction force
produced by the ground is
called the Ground
Reaction Force (GRF),
which is basically the
reaction to the force the
body exerts on the
ground.
Kinetics

11. Gait Analysis: Techniques and
Recognition of Abnormal Gait
April 30, 2007
Use Inverse Dynamics
to compute Joint Forces,
Joint Torques
(Moments) and Joint
Power.
Kinetics

12. Gait Analysis: Techniques and
Recognition of Abnormal Gait
April 30, 2007
• Vertical GRF
• Muscular Forces
• Reaction force from
external moment
Knee Loading

13. -time interval or sequence of motions
occurring between two consecutive initial
contacts of the same foot;

15. Number of steps per minute.
WALKING SPEED is the distance covered over a period of
time.
slow70m./min
Medium 95/min
Fast 120m/min

16. objective
 The main objective of the project is to develop
prescription footwear for obese foot
complications in order to provide better
comfort, fit and support for the users.

17. Plan of work
 Identify the obese people for study
 Measurements of foot of obese (proportional
measurement, plantar surface of foot)

18. Experimental work on construction of footwear for
obese
 The materials of varying densities would be identified
for midsole (pressure distribution)
 The chosen material would undergo compressibility
and resilience test and its relationship with
bodyweight of obese for its suitability in developing
comfortable footwear would be critically examined

19.  Identification of material for reinforcement of
counters
 Design and development of side and heel counters
 Design of bottom sole (for stability)
 Fabrication of prescription footwear

20. BMI AND FOOT MEASUREMENT OF OBESE
AND NON OBESE

21. TABLE 2

22. PRESSURE STUDY OF PATIENT 1 WITH BMI 24.48(madhani)
Left heel and Left metatarsals

23. Right heel and right metatarsals

24. PRESSURE STUDY OF PATIENT 2 WITH BMI 38.42(Thiruganam)
Left heel and left metatarsals

25. Right heel and right metatarsals

26. Pressure study of patient 3 with BMI 36.93(lingam)
Left heel and left metatarsals

27. Right heel and right metatarsals

28. Pressure study of patient 4 with BMI 41.03(krishnan)
Left heel and left metatarsals

29. Right heel right metatarsals

30. TABLE 3

32. Formula to calculate Density:
Mass
Density= ----------------
Volume

33. . Formula to calculate cushioning factor:
Graph area x planimeter area
 Walking energy= ---------------------------------------
Measurable area
Thickness x force applied
 Cushioning factor = --------------------------------------
Walking energy

34. Formula to calculate the compression set (%):
Initial thickness-final thickness
Compression set = -------------------------------------------- x 100
Initial thickness

35. TESTING RESULT OF MATERIALS

36. GRAPHICAL REPRESENTATION OF CUSHIONING
FACTOR OF IDENTIFIED SAMPLES:
CUSHIONING FACTOR

37. GRAPHICAL REPRESENTATION OF COMPRESSION
SET PERCENTAGE OF IDENTIFIED SAMPLES:
COMPRESSION SET PERCENTAGE

38. SELECTION OF MATERIALS FOR THE FABRICATION
OF FOOTWEAR
 Upper: Upper material-soft cow upper black colour
Lining material-soft cow lining
 Mid sole: EVA
Thickness:
Density: 0.141 g/cc
Hardness: 32-40 shore A
 Out sole: TPR
Thickness:
Density:
Hardness: 60 shore A
 Insole: Fiber board

39. DESIGN OF FOOTWEAR TO IMPROVE POSTURAL
STABILITY FOR OBESE
 Heel height
 Midsole cushioning.
 Slip resistance of footwear outsole
 Heel-collar height.
 Midsole flaring.
 Extended counter stiffeners

40. Heel height:

41. Midsole cushioning:

42. Slip resistance if footwear outer soles:

43. Heel-collar height:

44. Midsole flaring:

45. Extended counters

46. FLOW CHART FOR CONSTRUCTION OF FOOTWEAR:

47. THANK YOU