A recent study indicates that individuals learning to use robotic prosthetic devices develop a different understanding of their body's movement compared to those acquiring natural physical skills.
Key Findings
Initially, users of prosthetic legs perceive their bodies as moving more awkwardly than they actually are. As practice leads to improved performance, users continue to misjudge their movements, but shift to an overconfident assessment of fluidity.
This research is the first to investigate this phenomenon in people using lower-limb robotic prosthetics, raising questions about enhancing the user experience with these devices.
Study Methodology
The study involved nine able-bodied participants who walked on a treadmill for four days. They used a robotic prosthetic attached to a knee bent at a right angle. Participants were instructed to walk as quickly as possible without using handrails.
After each practice session, participants selected a computer animation that they believed best represented their recent walking gait.
Observations and Implications
Participants' performance significantly improved over the four days. However, their self-assessment remained inaccurate throughout the study. They initially overestimated their gait's off-balance nature and later overestimated its fluidity, despite consistent objective improvement.
Researchers observed that participants primarily focused on their torso's position rather than the prosthetic device itself when assessing their gait.
These findings suggest that:
Providing users with visual or other forms of direct feedback could help them calibrate their body image and gait during training with a prosthetic device.
Additionally, addressing the observed overconfidence in movement skills is crucial to encourage continued effort and improvement among users.
Publication Details
The paper, titled "Projecting the New Body: How Body Image Evolves During Learning to Walk with a Wearable Robot," was published in the open-access journal PNAS Nexus. The study was supported by grants from the National Institutes of Health and the National Science Foundation.