Clinical field testing of vulcanized Jaipur rubber feet for trans-tibial amputees in low-income countries

The development and testing of a modified natural rubber CR solid ankle-cushion heel prosthetic foot for developing countries

Background

Durable and locally fabricated prosthetic feet are important for developing countries. Modifications to the current CR solid ankle–cushion heel prosthetic foot could enhance current foot characteristics and reduce costs. The goal of this project was to modify the keel and rubber outer foot shell to enhance features and reduce costs of the current CR solid ankle–cushion heel offering.

Methods

The prosthetic foot was designed, fabricated and then tested mechanically for strain and displacement in a cyclic testing machine according to a component of the ISO-10328 testing protocol. Dynamic cyclic testing of both forefoot and heel portions of the foot was conducted.

Findings

Dynamic mechanical cyclic testing of the forefoot and heel at 1.28 kN for two million cycles at a rate of 1 Hz was successfully achieved. The final cost of producing the foot was roughly $16 USD. Limitations include the inability to perform the full battery of ISO-10328 foot testing, UV testing and a limitation to laboratory testing. Clinical studies examining practical application of the modified foot should be conducted.

Improved design and development of a functional moulded prosthetic foot

PURPOSE

In the Indian scenario, the Jaipur foot is a low-cost breakthrough that enabled the disabled person to adapt to the Indian environment. The aim of this study is to modify the present foot in terms of ankle support design and method of fabrication, foot moulds profile and the inner core material in order to improve the performance and durability.

METHOD

The optimized design of ankle support and flat foot profile moulds suitable for both left and right foot were developed through CAD/CAM and prosthetic feet were fabricated using ethylene vinyl acetate (EVA) foam as an appropriate alternative core material for microcellular rubber (MCR). The developed prosthetic feet were tested for rigidity by load-deflection analysis in universal testing machine.

RESULT

EVA foot had shown better rigidity than conventional MCR foot, which will help in weight transfer during walking and increase the durability. The CAD modeled ankle support and single block EVA had made the manufacturing process easy and reduced the weight of foot and improved Gait to the person fitted with it due to improved flat foot profile.

CONCLUSION

The new artificial foot had proven to be efficacious technically as well as functionally, which is clearly borne out from the extremely positive feedback given by the amputees. Implications of Rehabilitation Persons with below knee amputation are usually provided with transtibial prosthesis, which allows for easier ambulation and helps them to get back to their normal life. Transtibial prosthesis is an artificial limb that replaces a lower limb that is amputated below the knee. In our study, a new prosthetic foot with a modified ankle support and flat foot profile using better inner-core material than the conventional Jaipur foot was developed and the process was also optimized for mass production. The developed prosthetic foot can be fitted with both above and below knee exoskeleton type of prosthesis.

A scoping literature review of the provision of orthoses and prostheses in resource-limited environments 2000-2010. Part two: research and outcomes

BACKGROUND

Despite the activities of many orthotic and prosthetic provision organizations in resource-limited environments, there is still a great need and there are several areas for improvement, as identified in Part One of this series.

OBJECTIVES

Our goal was to examine outcomes and conclusions of research studies to produce an evidence base for determining factors that may lead to successful provision of orthoses and prostheses in resource-limited environments.

STUDY DESIGN

Literature review.

METHODS

We conducted a scoping literature review of all information related to orthotic and prosthetic provision in resource-limited environments published from 2000 to 2010. We extracted measured outcomes reported in all types of articles and analyzed conclusions from research studies.

RESULTS

Reported outcomes included durability, cost, satisfaction, use/nonuse of device, amount of utilization, walking speed, discomfort, pain, fit, misalignment, capacity for service provision, number of devices produced or delivered, and number of graduates from training programs.

CONCLUSIONS

There are many gaps in the evidence base, notably in measuring inclusion, participation, and quality of life for orthosis and prosthesis users in resource-limited environments. There is a paucity of reported outcomes for orthotics. Valid, reliable, and standard methods of data collection and reporting are needed to advance the field and enhance the evidence base.

Assistive technology in developing countries: a review from the perspective of the Convention on the Rights of Persons with Disabilities

BACKGROUND

The 'Convention on the Rights of Persons with Disabilities' (CRPD) requires governments to meet the assistive technology needs of citizens. However, the access to assistive technology in developing countries is severely limited, which is aggravated by a lack of related services.

OBJECTIVES

To summarize current knowledge on assistive technology for low- and lower-middle-income countries published in 1995 or later, and to provide recommendations that facilitate implementation of the CRPD.

STUDY DESIGN

Literature review.

METHODS

Literature was searched in web-based databases and reference lists. Studies carried out in low- and lower-middle-income countries, or addressing assistive technology for such countries, were included.

RESULTS

The 52 included articles are dominated by product oriented research on leg prostheses and manual wheelchairs. Less has been published on hearing aids and virtually nothing on the broad range of other types of assistive technology.

CONCLUSIONS

To support effective implementation of the CRPD in these countries, there is a need for actions and research related particularly to policies, service delivery, outcomes and international cooperation, but also to product development and production.

CLINICAL RELEVANCE

The article has a potential to contribute to CRPD compliant developments in the provision of assistive technology in developing countries by providing practitioners with an overview of published knowledge and researchers with identified research needs.

Lower-limb prosthetic technologies in the developing world: A review of literature from 1994-2010

In the mid-1990s, a number of key publications and meetings of experts identified major technical issues associated with prosthetic technologies intended for developing countries. These included inadequate durability of prosthetic feet, poor socket quality and prosthetic fit, improper alignment of prostheses, and inferior function of components. To examine the progress that has been made since then in addressing these issues, a comprehensive review of literature was performed. In total, 106 articles were selected and included in the review. The review examined prosthetic technologies categorized into feet and ankles, knees, sockets and suspension, and materials, structures, and alignment methods. Moreover, publications were categorized as technical development, clinical (lab-based) testing, or clinical field testing studies. The results reveal important work that has been carried out to develop and implement standardized outcome measures during field testing, allowing various existing prosthetic technologies to be evaluated in terms of their use, function, durability, and other factors. Progress has also been made toward addressing the aforementioned limitations of prosthetic technologies, however, more research and development is required. This includes improving the durability of the external cosmetic features of prosthetic feet, developing more functional prosthetic knee joints, and simplifying fabrication techniques to further improve outcomes associated with socket fit and prosthetic alignment. Research and development collaborations between developed and developing countries, and the dissemination of ongoing research, development, and evaluation activities are essential to the advancement of prosthetic technologies in these regions.

The Jaipur foot

The Jaipur foot was developed for barefoot amputees by Professor P. K. Sethi. He used local artisans and readily available materials. The prosthesis was cheap and could be made in one hour. It enabled amputees to work in rural conditions, muddy and wet fields and to climb trees. It has been widely used in India, South East Asia and Africa, where local variations to the design have now been made.