Degree of Safety Against Falls Provided by 4 Different Prosthetic Knee Types in People With Transfemoral Amputation: A Retrospective Observational Study

Using mobile eye tracking to measure cognitive load through gaze behavior during walking in lower limb prosthesis users: A preliminary assessment

BACKGROUND

Lower limb amputation does not affect only physical and psychological functioning but the use of a prosthetic device can also lead to increased cognitive demands. Measuring cognitive load objectively is challenging, and therefore, most studies use questionnaires that are easy to apply but can suffer from subjective bias. Motivated by this, the present study investigated whether a mobile eye tracker can be used to objectively measure cognitive load by monitoring gaze behavior during a set of motor tasks.

METHODS

Five prosthetic users and eight able-bodied controls participated in this study. Eye tracking data and kinematics were recorded during a set of motor tasks (level ground walking, walking on uneven terrain, obstacle avoidance, stairs up and ramp down, as well as ramp up and stairs down) while the participants were asked to focus their gaze on a visual target for as long as possible. Target fixation times and increase in pupil diameters were determined and correlated to subjective ratings of cognitive load.

FINDINGS

Overall, target fixation time and pupil diameter showed strong negative and positive correlations, respectively, to the subjective rating of cognitive load in the able-bodied controls (-0.75 and 0.80, respectively). However, the individual correlation strength, and in some cases, even the sign, was different across participants. A similar trend could be observed in prosthetic users.

INTERPRETATION

The results of this study showed that a mobile eye tracker may be used to estimate cognitive load in prosthesis users during locomotor tasks. This paves the way to establish a new approach to assessing cognitive load, which is objective and yet practical and simple to administer. Nevertheless, future studies should corroborate these results by comparing them to other objective measures as well as focus on translating the proposed approach outside of a laboratory.

Prosthetic Rehabilitation After Transfemoral Amputation in a Patient With an Ipsilateral Girdlestone Hip: A Case Report

To date, there have been no reported cases of patients walking with a prosthesis after receiving an ipsilateral transfemoral amputation following the Girdlestone procedure. We administered a four-month prosthetic rehabilitation program to a 66-year-old man after his transfemoral amputation following the Girdlestone procedure. As a result, he was able to walk using the prosthesis for his daily activities. The prosthesis socket featured a quadrilateral configuration. The patient's ability to ambulate after the Girdlestone procedure was attributed to his ischial tuberosity serving as the primary load-bearing site in the transfemoral prosthesis. With appropriate prosthetic design, fabrication, and rehabilitation, patients can walk using a transfemoral prosthesis even in cases of transfemoral amputation following the Girdlestone procedure.