Affordable, Adjustable Socket in the Works for Amputees in Need

A group of engineering students recently developed an inexpensive prosthetic socket designed for amputees in developing countries.

Jessica Menold, PhD, mechanical engineering student at Pennsylvania State University in State College, Penn., and Wesley Teerlink, a recent Penn State graduate, recently received an EXIST Business Start-Up Grant to build prototypes and test Amparo, their prosthetic socket. EXIST is a program within the German Federal Ministry for Economic Affairs and Energy.

“It has been an incredible opportunity Penn State has provided me with and I am excited that I have been able to launch [Amparo] and that my team is so supportive. We are committed to seeing Amparo become a reality for amputees in rural regions in developing countries,” Menold told O&P News.


Menold and fellow group members were part of the Global Engineering Teams (GET) Program, which partners students from different countries and cultures. Matthew Parkinson, PhD, associate professor of engineering design at the school and representative from Penn State to the GET consortium, served as a consultant on the project.

Jessica Menold, PhD
Jessica Menold
Matthew K. Dion
Matthew K. Dion

“I also supervise projects, providing outside expertise to several each year,” Parkinson said. “Recruiting and managing the students is easy. It is an attractive opportunity and we are able to select from the best Penn State has to offer.”

Menold has four teammates working on Amparo from Germany, including Teerlink, who moved there with his family after graduation to continue development.

“It is fulfilling to start prototyping and building things and working with amputees,” she said.

The only other U.S. team member is Matthew K. Dion, a biomedical engineer focusing on material mechanics and prototyping and a doctoral biomedical engineering student at Rensselaer Polytechnic Institute in Troy, N.Y. Dion provides the team with the background knowledge they need on lower limb biomechanics, prototyping, manufacturing practices, FDA regulations and intellectual property experience.

“One of the most exciting aspects of this project is seeing Penn State students taking what they have learned in the classroom and using it to help solve a real-world problem to benefit others,” Kathryn W. Jablokow, PhD, FASME, an advisor to Menold’s team, and an associate professor of mechanical engineering and engineering design at Penn State, said. “Engineers are known for their problem-solving ingenuity. In this case, there is a strong sense of humanitarian service as well.”


“We came up with the idea for the prosthetic socket following an extensive number of interviews with amputees in South Africa, Germany and the United States,” Dion said. “From these interviews, we identified a few key difficulties amputees face.”

Shown is a prototype of the Amparo adjustable prosthetic socket, created by a group of engineering students for amputees in developing countries.
Shown is a prototype of the Amparo adjustable prosthetic socket, created by a group of engineering students for amputees in developing countries.

Source: Menold J.

The key challenges pinpointed by the group included socket turnover rate, adjustability and customization. Dion said the group used these difficulties to design Amparo and addressed each issue while maintaining the simple and inexpensive design.

The group chose the name Amparo for the socket, which is Portuguese for “support.” Two of the team members are from Brazil and said this would be the perfect name for the product because it provides amputees with the support they need, Menold said.

“Throughout the entire process we have been connecting and talking with and getting ideas from amputees in Germany, the [United States] U.S. and Brazil to make sure we are constantly checking back in and staying grounded [in] the problem,” Menold said.

Amparo is made with a low-temperature thermoplastic that can be heated and molded into different shapes and has high strength capabilities. Once the mold hardens, users can make adjustments to the socket fit with the built-in adjustment features, according to Dion. He added the socket also was designed to interface easily with off-the-shelf components which comprise the remainder of the prosthesis including pylon, the foot and the standardized connector.

This summer, the group will be testing Amparo at numerous clinics in Brazil, Dion said.


“We have faced and still are facing a few challenges to create a socket that could potentially fit a wide range of amputees,” Menold said.

As every patient has a different sized residual limb, a one-size-fits-all socket is difficult to create, she said.

Though this limitation did place constraints on the research, Menold said the group is constantly building prototypes and testing them, which has catalyzed their learning. She said the failures led to success because Amparo improved with the development of each prototype.


“I love how Jessica has applied the design thinking and prototyping skills that she learned and honed at Penn State to gain unique insight into the challenges that amputees face,” Timothy W. Simpson, PhD, one of the group’s advisors and professor of mechanical and industrial engineering, engineering design and architecture at Penn State, said. “It seems obvious in retrospect, yet getting a socket to fit well for each person is still a serious issue that has not been addressed well. Hopefully, Jessica and her team will be the first to solve this problem in an elegant and cost-effective way.”

Future plans

Menold and Dion both said the group eventually plans to sell Amparo directly to O&P clinics for distribution initially in Brazil and would like to eventually sell in the United States.

Menold said traditional sockets can be expensive because of the amount of time it takes for the prosthetist to build and mold them in order to find the perfect fit for the amputees.

By using thermoplastic material that is easy to mold and customize, Menold and her team members have cut down the time it takes to fit amputees, leading to a reduced cost.

“None of us are looking to become millionaires by selling prosthetic sockets to the developing world, but rather we are looking to make a difference,” Dion said. “The World Health Organization estimates that 80% of the world’s amputees do not have access to modern-day prostheses, and if we at Amparo can make even the smallest dent in that number, then we will consider ourselves a success.”– by Monica Jaramillo

Disclosures: Dion, Jablokow, Menold, Parkinson and Simpson report no relevant financial disclosures.

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