Kinematic and Performance Characterization of People with a Spinal Cord Injury Using Virtual Reality

Research Objectives: To investigate the kinematic and performance characteristics of people with a spinal cord injury (SCI) this study will compare movement tasks within a virtual reality (VR) environment across people with an SCI and control participants. It was hypothesized that arm kinematics for SCI participants would have decreased elbow extension, decreased shoulder angles, and increased wrist deviation compared to controls. It was hypothesized that movement performance of block cutting will be less centered and straight compared to controls.

Design: Study is a randomized, causation experiment with a cohort of people with SCI and a healthy control cohort. Participants played a customized VR game and focused on unilateral, mirrored, or opposing movement tasks. The movement task was to cut virtual blocks through the middle and in the direction indicated. Participants had to move both arms and leveraged a virtual saber, which extended 1 meter beyond the hand controller, to cut the blocks. Movement tasks were consistently paced ~2 seconds apart. Kinematics were collected at 240Hz using an 8-camera motion capture system (Vicon, Vero). Task performance was extracted using a publicly available modification package.

Setting: Data collections took place in the University of Dayton EMPOWER Lab or the Dayton Children’s Hospital Gait Lab.

Participants: Utilizing referred sampling, individuals with an SCI (n=7, 2 female, 30.37±15.86 years, 74.31±28.35 kg, 12.44±8.18 years since injury) participated in our study. Healthy age/gender matched participants (n=7, 2 female, 30.27±15.73 years, 64.64±22.01 kg) were recruited as a convenience sample.

Interventions: Not applicable.

Main Outcome Measures: Kinematic outcomes included peak elbow extension, shoulder and wrist deviation from neutral. Movement task performance outcomes included saber speed, distance to the center of the block (centeredness), and cut angle error (straightness), taken during each movement task.

Results: For all conditions, SCI participants had lower elbow extension and shoulder deviation but greater wrist deviation compared to control participants (all p< 0.0001). For SCI participants, unilateral tasks elicited greater kinematic excursions (excluding the wrist) compared to other conditions (all p< 0.0001). For all conditions, control participants had better performance with more straight, more centered, and higher velocity cutting capability compared to the SCI cohort (all p< 0.0001). For SCI participants, unilateral tasks had better performance compared to opposing tasks (all p< 0.0001).

Conclusions: Overall, the SCI participants were able to complete the tasks, but participants relied more on leveraging the length of the saber and were unable to perform as well as the control participants.

Author(s) Disclosures: Authors have no conflict of interest to disclose.