The study is the first to examine how people incorporate a lower-limb robotic prosthetic into their body image and how that changes with practice. Researchers recruited nine able-bodied participants for a four-day experiment. Each participant walked on a treadmill with the prosthetic attached and the knee bent at a right angle. They were asked to walk as quickly as possible without using the handrails. After practice, participants watched computer animations showing a range of walking gaits and picked the gait that best matched their performance.
Performance improved significantly over the four days, but participants’ self-assessments changed unexpectedly. At first they judged their gait as more off-balance and stilted than it actually was. By the end they judged their gait as more fluid and natural than it actually was. Participants focused on torso position when judging and paid little attention to the prosthetic device. The researchers suggest adding visual or other feedback during training to help users calibrate their body image and to address overconfidence, which can reduce effort to improve.
The paper appears in the open access journal PNAS Nexus and the work was supported by the National Institutes of Health and the National Science Foundation.
Difficult words
- incorporate — add something into a single whole
- prosthetic — artificial body part used to replace a limb
- gait — a person's usual way of walkingwalking gaits
- stilted — unnatural or awkward in movement or style
- torso — the main part of the body without limbs
- calibrate — adjust something carefully to make it accurate
- overconfidence — too much belief in one's own ability
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think visual or other feedback during training would help people judge their movements better? Why or why not?
- How could being overconfident reduce a person's effort to improve when learning to use a prosthetic?
- If you tried a new device while walking, what body parts or movements would you pay most attention to and why?
Related articles
Lower chemotherapy dose helps people 80+ with lymphoma
A study found that people aged 80 and older with a common lymphoma often do better with a lower chemotherapy dose. Researchers used data from community cancer clinics and say the smaller dose kept effectiveness while reducing side effects.
