Overview
Wheelchair users must be able to move around freely and access public buildings and transport, but current accessibility standards (e.g. maximum 8% ramp slope) are based on limited scientific evidence about the real biomechanical and perceived difficulties encountered by manual wheelchair users in daily life.
Manual wheelchair propulsion is not purely a motor activity: it also involves cognitive and emotional demands (attention, trajectory planning, stress and frustration management) that contribute to a mental workload. This cognitive dimension is still rarely integrated into biomechanical evaluation protocols.
This exploratory (pilot) study aims to test the feasibility of a protocol combining objective biomechanical data (shoulder joint loading estimated from motion capture and instrumented handrims) with the subjective experience of participants (perceived physical demand from the NASA-TLX questionnaire, perceived exertion from the Borg scale), during standardized and more realistic manual wheelchair propulsion tasks, including tasks performed under an added cognitive load (auditory-verbal 2-back dual task).
Description
Fifteen manual wheelchair users will be recruited and equipped with reflective motion-capture markers (Qualisys optoelectronic system, 10 cameras) and instrumented handrim wheels (6-axis force sensors) on their own wheelchair. During a single experimental session (maximum 2 hours), participants will perform several propulsion tasks: simple straight-line propulsion, propulsion with a concurrent cognitive task (auditory-verbal 2-back, dual task), propulsion on a ramp (slope below 8%, in line with French accessibility regulations), propulsion on varied floor surfaces, propulsion with turns, and propulsion along a path with an object to reach. Seated posture will be assessed before and after each task with the MCPAA 2.0 clinical scale, heart rate will be monitored with a connected watch, and pain will be checked regularly (participants stop if pain exceeds 7/10).
After each task, participants will rate their perceived physical, mental, temporal, performance, effort and frustration demand using the NASA-TLX questionnaire (French version) and their perceived exertion using the modified Borg (CR10) scale. A qualitative questionnaire will be administered at the end of the session.
Kinematic and kinetic parameters of the upper limb (including estimated shoulder joint loading) will be derived from the motion and force data using biomechanical models of the upper limb. Each participant acts as their own control, so the different experimental conditions are compared within participants. Correlations between the NASA-TLX physical demand subscore, the Borg score and the objective biomechanical shoulder load will be examined using Spearman correlation. As this is a pilot study, analyses will primarily aim to estimate effect sizes, assess protocol feasibility, and explore differences between experimental conditions.
The study is sponsored by the Centre Médico-Chirurgical de Réadaptation (CMCR) des Massues, Croix-Rouge française, and conducted in collaboration with the Laboratoire de Biomécanique et Mécanique des Chocs (LBMC, UMR\_T 9406, Université de Lyon), which receives only double-recoded, non-identifying data for biomechanical analysis. The study is funded by the Feed Feel Move project (I-SITE FUTURE).
Eligibility
Inclusion Criteria:
- Adult participant over 18 years of age
- Person having signed the informed consent form
- Duration of manual wheelchair use prior to the experiment greater than 2 weeks
- Ability to perform transfers autonomously, with or without a technical aid
- Functional criterion: patient who uses the wheelchair autonomously during the day
Non-inclusion Criteria:
- Refusal of the person to participate or to sign the consent form
- Diagnosed cognitive disorder
- Upper limb amputation
- Refusal of the person to propel the wheelchair bimanually
- Upper limb injury
- Average upper limb pain over the past two weeks, on a 0 (no pain) to 10 scale: \< 4
- Person aged over 70 years
