man with prosthetic leg walking his dog
A new study at VCU focuses on ways to improve the understanding of a prosthesis user’s mobility. (Getty Images)

Study to develop new measure of prosthesis awareness in individuals with lower limb loss

Benjamin Darter’s project — funded by a $1.97 million grant from the U.S. Department of Defense — focuses on ways to improve the understanding of a prosthesis user’s mobility.

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A new study at Virginia Commonwealth University is focusing on ways to improve the understanding of a prosthesis user’s mobility.

Benjamin Darter, Ph.D., an associate professor in the VCU College of Health Professions’ Department of Physical Therapy, received a $1.97 million grant in 2021 from the U.S. Department of Defense for his four-year project titled “Exploring the Impact of Microprocessor-Controlled Knees on Prosthesis Awareness and Overall Health.” The project will ultimately implement a newly developed measure of prosthesis awareness to further explain the clinical benefits of microprocessor-controlled knees.

Darter is collaborating with the University of Washington and the Hanger Institute for Clinical Research and Education to develop a measure assessing how much individuals with lower limb amputation need to “pay attention” to their prosthetic limb during activity. The project will also study how the need to pay attention changes when a person uses a prosthesis with a microprocessor-controlled knee.

“The more a person has to concentrate and attend to the use of their prosthetic device, the less a person is able to pay attention to other things in their surroundings,” Darter said. “Being out in public and having to navigate uneven terrain, a busy environment or carrying objects while walking are examples of situations that can overload someone’s ability to process their movements and the environment around them. The result is a person might be at higher risk for tripping and falling.”

There has been a lot of attention over the past two decades on amputation, especially within the military population, and a focus on developing the best care for these individuals, Darter said.

“Advancements in prosthetic design, such as microprocessor-controlled motion, allow in theory for the device to do more of the work for the person. For instance, users of microprocessor-controlled knees say they benefit from the device making it so they do not have to think about every step they take,” Darter said. “For years, people have studied these new devices; however, the measures of how we look at performance haven’t always shown that these new devices are better than older designs. This disconnect is particularly apparent in terms of existing measures not reflecting what users say regarding their experience with these more technologically advanced devices.”

Darter said that clinicians have many options for assessing what patients are physically capable of doing while using their prosthetic limbs, but measures to assess other elements of function are needed. Measurement of these other elements could help demonstrate how technological advances really benefit a user, he said.

The research team hopes the measure developed during this project will assist clinicians in their ability to more completely understand the walking ability of individuals with lower extremity amputation.

Darter and his team are actively seeking participants for this study. Those who have an amputation on one or more limbs, have used a prosthetic limb for at least six months and are over age 18 may qualify to be part of the study. Individuals seeking more information about this study can contact the research team at or call (804) 628-3594.

Established in 1969 as the School of Allied Health Professions, the VCU College of Health Professions offers programs at the baccalaureate, post-baccalaureate certificate, master’s, post-master’s certificate and doctoral levels in nine disciplines, including medical laboratory sciences, gerontology, health administration, nurse anesthesia, occupational therapy, patient counseling, physical therapy, radiation sciences and rehabilitation counseling. For more, visit