Prosthetic Leg Suitable For Indian Conditions Developed By IIT Guwahati Researchers

IIT Guwahati researchers have developed a prosthetic leg which is specifically designed for Indian conditions, and is adjustable for people belonging to different age groups.

Researchers at the Indian Institute of Technology (IIT), Guwahati have developed a prosthetic leg specifically designed for Indian conditions, and which is suitable for uneven terrain. The prosthetic leg supports Indian needs such as cross-legged sitting, and deep squatting, and is also adjustable for different age groups and multiple stages of prosthesis use.

The research was funded by the Union Ministry of Education and the Department of Biotechnology, and was focused on eradicating the challenges associated with prosthesis development in India. The challenges include the high cost of devices with advanced features required by amputees to ensure highly functional mobility. Moreover, the affordable prosthetics available in the market have several functional limitations, and are not suited to Indian lifestyle. 

Therefore, a team led by Professor S Kanagaraj, Department of Mechanical Engineering, IIT Guwahati, set out to tackle the issues, and developed prototypes of prosthetics which are currently undergoing trials. 

In a statement released by IIT Guwahati, Kanagaraj said the knee joint developed by the research team has a spring assisted deep squat mechanism, which helps to use the Indian toilet more comfortably. Also, the knee rotating mechanism helps to reduce the fear of falling of patients while walking in an unknown terrain, and the adjustable link length in a knee helps to have either more stability or easy flexing, depending on age and requirement of the patients. 

Kanagaraj said that overall, the knee joint is designed to meet the Indian lifestyle which other products fail to fulfil.

What Needs Did IIT Guwahati Researchers Identify? What Solutions Did They Develop?

The IIT Guwahati researchers identified four needs of people who require prosthetics, and also developed novel solutions. 

First of all, market products developed using western technology ignore Indian locomotion needs such as cross-legged sitting, deep squatting for toilet use, and exercise postures in Yoga. The researchers identified a solution that advanced knee rotation mechanism can be developed in order to facilitate cross-legged sitting. The deep squat mechanism will help prevent the arrest of motion while standing up and reduce metabolic energy cost, the statement said.

The second need identified by the researchers is that additional stability is required for the patient at multiple stages of prosthesis use. Additional stability is very important during the initial training of the amputee for safety concerns and to address the fear of falling. The researchers developed a solution called knee-locking mechanism which can be activated and deactivated by the amputee when they encounter difficult conditions such as walking on uneven terrain, sloppy regions, and staircases.

The third need identified by the researchers is that more stability is required for patients who are at a higher risk of falling. Also, the residual length of the leg of the patient determines the prosthetic leg requirements. Therefore, link length adjustability and prosthesis alignment adjuster mechanism can be provided for customisation according to the patient's need. 

The fourth need identified is that dynamic balance is required during physical activity to prevent the risk of falling. The functioning of traditional ankle joints is hampered due to difficult terrain.

The researchers identified a solution through which the impact load on hard surfaces can be reduced, toe-off force can be maximised, and balance can be ensured while walking on difficult terrain.

The researchers used a design called 'Sankalp knee design' to reduce the abnormality noticed in their gait pattern of knee and foot. They optimised the prosthetic leg to meet all requirements, taking into consideration parameters such as comfort, weight, and functionality of lower limb prosthesis. An optimised prosthetic leg will ensure that a lower limb amputee can have improved quality of life, independence, and comfort level in doing daily activities.

What Are The Unique Aspects Of The Solution Developed By The Researchers?

The prosthetic leg designed for Indian conditions avoids arrest of motion while standing up from a deep squat position and provides extra energy during leg swing. Also, the customisable link length can be adjusted by the prosthetist to increase the stability and ease of flexion account to patient limb length, activity, or age. 

Using a knee rotor mechanism, cross-legged sitting is possible. In addition, the newly developed prosthetic leg provides extra stability during standing or rehabilitation activities. 

The prosthetic leg is tested as per International standard loading condition up to 100 kilogram per body weight, according to IIT Guwahati. Using suitable polymers, aluminium alloys and stainless steel, the researchers developed a prosthetic leg with reduced weight.

Also, a cost of around Rs 25,000 is ensured using the technology. 

A trained prosthetist performs the fixation of prosthetic leg components to various amputees. According to the statement, the amputees were able to use different functionalities of the prosthetic leg without any additional support. A 3D-printed test socket, verified using computer analysis, will be fitted into the prosthetic leg in the future.