Comparing Locomotion Techniques in Virtual Reality for People with Upper-Body Motor Impairments
Rachel L. Franz, Jinghan Yu, Jacob O. Wobbrock · 2023 · Proceedings of the 25th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS '23) · doi:10.1145/3597638.3608394
Summary
This paper presents the first empirical study comparing the accessibility of virtual reality locomotion techniques — methods for navigating virtual environments — for people with upper-body motor impairments. Despite over 100 distinct locomotion techniques existing in VR and the technology becoming increasingly mainstream, no prior data existed on which techniques work well for this population. The researchers tested six seated locomotion techniques with 19 participants who had conditions including spinal cord injury, muscular dystrophy, peripheral neuropathy, cerebral palsy, arthritis, essential tremor, and limb amputation. The techniques varied across control mechanism (controller buttons vs. body movement), body parts used (thumbs, fingers, head, arms, torso), and effort level. Teleport used aim-and-jump with a controller trigger; Astral Body controlled a third-person avatar via thumbstick; Sliding Looking moved forward with a button press while steering with head direction; Chicken Acceleration moved by leaning forward; Grab and Pull simulated pulling a rope; and Throw Teleport threw a virtual ball to teleport. Participants navigated to six targets arranged in a circle, maneuvering around obstacles, while the researchers collected trial times, hit rates, obstacle collisions, NASA-TLX workload ratings, presence and simulator sickness questionnaire data, and semi-structured interview responses.
Key findings
Three techniques emerged as clearly more accessible: Teleport, Astral Body, and Sliding Looking all required only single-controller input, minimal upper-body movement, and had low perceived workload. Teleport was the fastest (15.16s mean trial time), had the highest hit rate (0.86), hit the fewest obstacles (0.00 mean), and was consistently favored in interviews — it was the technique most participants said they would actually use in VR. The three poorer-performing techniques (Chicken Acceleration, Grab and Pull, Throw Teleport) required arm, head, or torso movement and had significantly higher workload scores. However, the most striking finding was that accessibility alone did not determine preference. Seven participants' preferred technique differed from their most comfortable one, and 10 participants' least preferred differed from their least comfortable. Despite poor performance metrics, Chicken was the second most popular technique because participants enjoyed the body-movement control, and Throw was many participants' third choice because it felt like a game. Factors like enjoyment, physical exercise value (one participant appreciated exercising an underused hand), entertainment, and sense of presence sometimes outweighed pure accessibility. Some participants even felt Teleport was "too easy" and "like cheating."
Relevance
This research has immediate implications for VR platform designers and game developers. The core design recommendation is that controller button inputs are more accessible than upper-limb or torso movement for locomotion, but designers should not simply default to the most accessible technique. Instead, VR applications should offer a range of accessible locomotion options and let users choose based on their own trade-offs between performance, comfort, enjoyment, and challenge. The finding that accessibility is not the only consideration — and that some users actively want techniques that push their physical abilities — challenges the assumption that the "easiest" option is always best. For the broader accessibility community, this underscores that people with disabilities are not solely seeking frictionless experiences; they want agency, variety, and the ability to make their own choices about effort and engagement. The study also identified practical hardware issues: controllers were too heavy for some participants, buttons were hard to find by touch, and the headset caused neck strain — all areas where VR manufacturers should improve physical accessibility.
Tags: virtual reality · locomotion · motor impairments · VR accessibility · interaction techniques · personalization · simulator sickness · user study