Gery

Optimization of the Step Roll-Over

with a Population of

Low Activity Level Amputees

Bonnet X., De La Torre M., Bouchard C., Deboissy F., Mille J

PROTEOR, Dijon, France

Gery

Context : Factors influencing the mobility of lower limb amputees

Davies et Datta, Prosthet Orthot Int 2003

Correlation between mobility level and various factors (Harold Wood

Stanmore mobility grade)

For 357 lower limb amputees (average age : 68 years) [16-95]

Population with prosthetic follow-up

Mobility factors

Age

Amputation level

Amputation cause

Gery

Walking Speed Evolution

Bohannon, Age and Ageing 1997

Toburn 1995, Barth 1992, Casillas 1995, Jones 1994, Lemaire 1993,

Hermodsson 1994, Hsu 2006, Postema 1997, Pwers 1996,

Schmatlz 2002, Snyder 1995, Underwood 2004

Valid people

Traumatic

origin

Vascular

origin

Age (years)

Walk

ing s

peed (

m/s

)

Gery

Step Roll-Over

Adapted from C.W. Radcliffe 1962

Gery

Optimization of the Step Roll-Over

with a Low Activity Level Patient

To improve the leg segment position compared to the plumb-line

To decrease pressures during forefoot weight bearing

S A C H

Gery

Material and methods

Measurement study

4 patients : 3 TT, 1 TF

Pressure in the socket (4 areas)

Step roll-over :

• Length of the first and terminal parts of the step

• Evolution of the angle between the leg segment and the plumb-line

Repeated AB-BA measurements

Satisfaction survey

15 patients, average age 72.5 years [54-90],

10 TT, 5 TF (lock knee)

ESAT (QUEST 2)

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Patient Selection

L1 Activity Level

TT TF

Other knee

Locking knee

Age > 65 years

Age < 65 years

First prosthesis

< 6 months

First prosthesis

> 6 months

Other foot

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Results : Pressure in the Socket

C2

C3 C1 C4

Max

pre

ssu

re (

Kp

a/K

g)

Max

pre

ssu

re (

Kp

a/K

g)

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Results : Kinematics

S A C H Terminal part of the step

Leg segment angle

OHS = opposite heel strike

Gery

QUEST Results

Technical items :

Dimension

Weight

Adjustment

Safety

Sturdiness

Ease of use

Comfort

Efficiency

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QUEST Results

Items considered as the most important by the patients of this survey :

Safety

Comfort

Weight

Safety Comfort Weight

Not satisfied

Little satisfied

More or less satisfied

Rather satisfied

Very satisfied

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Discussion

Pressure in the socket

Values of the same order than those of the litterature

Decrease at the level of the patellar tendon

Length of the terminal part of the step

Varies too much to demonstrate an influence of the step length

(under these conditions)

Better evolution of the leg segment angle during the unilateral body

weight support

Satisfaction

Safety

Comfort

Weight

Gery

Conclusion

GERY foot advantages

Step roll-over (leg segment motion)

Comfort (pressure in the socket)

Lightweight

Population of patients with L1 activily level, especially

Trans-femoral patients with locking knee

Patients with a walking frame

Prospects

To continue the study with a larger population

Gery

Many thanks for your attention