The OpenSocket: A New Kind of Prosthetic Arm

by Bump, a nonprofit design studio based in Champaign, IL

We’ve found a way to get prosthetic arms to the people that no one else is reaching, but we need your help to make it happen.

Our team spent the last 4 years creating the OpenSocket, a prosthetic arm for people in need. We’ve launched our device with almost 100 patients, but we need your help to get it to the next 1,000+.

Learn more




raised of $95,000 goal


days to go




Funding Period  

Oct 5 - Dec 1

Bump is a 501(C)(3) nonprofit organization based in Champaign, IL. Our vision is to provide a positive bump to organizations around the world through simple & innovative products. 

Our first product is the OpenSocket. We consider it to be the world's most accessible prosthetic arm. Contact us.

The Global Problem

The Global Problem

An amputee begging in Agra, Inda near the Taj Mahal

An amputee begging in Agra, Inda near the Taj Mahal

A pile of discarded molds in the corner of a prosthetic lab

A pile of discarded molds in the corner of a prosthetic lab

The Global Problem

Millions of people worldwide are missing a limb due to disease, violence, and countless other causes. An estimated 80% of these individuals are living in developing countries such as Guatemala, India, and Vietnam.

Unfortunately, it is almost impossible for people in developing countries to obtain prosthetic care--- the infrastructure is not there to provide it. While there are many organizations that would love to address this need, they face two key barriers:

Prosthetic Labs Are Expensive

A prosthetic lab requires expensive equipment in a dedicated facility. An organization would need to make a large capital investment before they even fit their first patient.

A Shortage of Trained People

For a clinic to provide prosthetic care, they must hire a full-time staff with highly specialized training. This staff must then fabricate a prosthetic device for each patient by hand. As a result, only 2% of people with amputations living in developing countries can access prosthetic care.

Our Innovative Solution

Our Innovative Solution


Our innovative solution is made up of two complimentary parts


In 2008, our team set out to tackle this global problem. We spent five years, researching, developing, and testing, and we’re excited to announce that we have uncovered a solution.

This solution is made up of two complementary parts, a technology and a distribution system:

Our Technology: The OpenSocket

The OpenSocket is a new type of prosthetic arm. It is just as functional as a conventional body-powered prosthetic arm but differs in the way it is made and fit to patients.

How it’s Made

A conventional prosthetic arm must be custom made for each patient. This is done by a highly-trained prosthetist using specialized tools.

The OpenSocket, alternatively, works like a modern shoe. We mass produce the OpenSocket ahead of time, so when a patient walks in the door, it’s ready to be fit.

Fitting the OpenSocket

Fitting the OpenSocket to a patient only takes about 30 minutes. With a highly-adjustable socket that bends to the contours of a patient's residual limb, this device achieves the same functionality as a custom-fit device without the need for custom fabrication. The person doing the fitting only needs to choose the right size, adjust some simple straps, and connect the harness and the prosthesis is ready to go.

Our System: A Network of Partnerships

Because conventional prosthetic care requires specialized tools and training, it is usually only available from a few centralized locations.

[map with just a few dots]

With the OpenSocket, we can create a much more de-centralized system and vastly increase the number of access points where people can receive prosthetic care.

[ map with a lot of dots]

Here’s how we create this decentralized network:


Form Partnerships

We partner with organizations already working in developing countries and give them some simple OpenSocket training.

Partners Find Patients

Our partners locate people who can benefit from the OpenSocket by advertising in local media and using their records of the region’s population.

Partners Buy OpenSockets

Bump sells the OpenSocket to our partners at $500 per unit, far less than they would typically pay for the equipment, extra staff, and materials needed to fabricate a custom prosthesis.

Partners Fit OpenSockets

Our partners fit patients with the OpenSocket and follow up with them over the long term.


A Proven System

A Proven System


This is not just an idea for a project, this is a proven system


A Proven System

This solution isn’t just a concept, it’s a proven system we have been testing and refining for the past two years. To date, we have partnered with 20 different organizations in 10 different countries, and 93 people have received prosthetic arms.


Evidence: What Our Patients Think

[Insert 3 Patient Stories (Carlos Video)]



Evidence: What Our Partners Think

Wuqu' Kawoq 

Peter Rohloff M.D., Ph.D. is the Medical Director for Wuqu’ Kawoq - Maya Health Alliance, and an instructor at Harvard Medical School. Peter frequently travels to Guatemala to work with people from impoverished Mayan communities. On one of his most recent trips he worked with a few other clinicians to fit 12 OpenSockets in 3 hours.

Orthopedic Institute of Honduras

Luis Boquin M.D. is a surgeon at the Orthopedic Institute of Honduras, and a member of his local Rotary Club. Luis and other Rotarians have orchestrated two successful camps in San Pedro Sula, Honduras to fit over 20 individuals with OpenSockets.

Where you come in

Where you come in


We have a responsibility to scale this solution to reach more than just 93 patients


The Bottom Line

The OpenSocket system is not just about a lower cost product, it’s about maximizing value for each user, and increasing the number of people who can receive prosthetic care. While there are many people working to give prosthetics to people in need, they cannot reach even a small percentage with conventional approaches.

With OpenSocket technology and an comprehensive plan for widespread distribution, we can dramatically increase access to prosthetic care.


This Is Where You Come In

We have a responsibility to scale this solution to reach more than just 93 patients. To do this we need to grow the capabilities of our organization in two essential ways:

1) Create Molds for Mass Production

Until now, we have made every OpenSocket in our workshop. This enabled us to be efficient in our development process and to quickly and iteratively improve our design. Now that the OpenSocket technology has been well tested and finalized, we need to create the molds to produce at a much larger scale. We have already secured  grant funding to help us start creating molds, but we can predict that we will need an additional $7,000 to complete the molds for three sizes.

2) Give Ourselves the Manpower to Build and Maintain the Network

Bump currently gets by on a tiny skeleton crew and a lot of volunteer power. With this limited bandwidth, we simply cannot execute this on a large scale.

To manage high-volume manufacturing, maintain international partnerships, and build new connections abroad, we need to invest in our team.



We’re asking for a minimum of $50,000 to begin the scale-up phase of the OpenSocket. Without scale-up, this program cannot reach full scale, and many people may be denied access to prosthetic care.

We need your help to make this happen. Donate today.


[Insert Champaign Section here?]



This budget outlines at a high level how we will spend the $95,000 to accomplish this mission.

Initial Scale Up Costs ($20K)

  • The costs to grow our manufacturing capabilities.
  • Tooling For Production (Molds) $10,000
  • Initial Production Run $10,000

6 Months of Guaranteed Operation ($75K)

  • 6 Months gives us enough time to grow network of partners to a sustainable level
  • General Operational $2,000/mo
  • Production Costs $3,000/mo
  • Staff - $2,500/mo x 3 People = $7,500/mo
  • Monthly Total of $12,500/mo x 6 months = $75,000
Total $95,000