Author(s): MATSUURA, T., Institution: KOKUSHIKAN UNIVERSITY, Country: JAPAN, Abstract-ID: 605

INTRODUCTION:
Individuals with spastic diplegic cerebral palsy (CP) often exhibit delayed motor skill development compared with individuals without disabilities. Such delays may occur even when upper-limb impairment is mild, potentially due to limited motor experience from early childhood. Recently, virtual reality (VR)–based training has attracted attention as an alternative means of providing motor experiences. The purpose of this study was to evaluate the effects of immersive VR training on motor skill performance in an individual with CP.
METHODS:
The participant was a 24-year-old adult with spastic diplegic CP. The participant performed 10 trials of a real-world ball-catching task using a ball-launching device, and the movements were recorded using a tablet computer. Subsequently, immersive VR training using a head-mounted display was conducted, consisting of 100 trials per day for four weeks. In the VR task, balls approached from the front along parabolic trajectories, and the participant attempted to catch them using both hands, which were tracked by a hand-tracking system. After training, the real-world ball-catching task was repeated. Videos were analyzed using an AI-based markerless motion capture system. Onset times of cervical spine, shoulder, and elbow movements, as well as ball-catching time, were compared before and after training using the Wilcoxon signed-rank test (p < 0.05).
RESULTS:
In the real-world task, the participant caught 8 of 10 balls before training and all 10 balls after training. Before training, the median (interquartile range) time from ball launch to movement onset was 0.23 s (0.18–0.26) at the cervical spine, 0.27 s (0.21–0.30) at the elbow, and 0.27 s (0.27–0.30) at the shoulder, indicating nearly simultaneous onset across joints. After training, onset times were 0.30 s (0.27–0.33) at the cervical spine, 0.35 s (0.30–0.37) at the elbow, and 0.37 s (0.30–0.42) at the shoulder. Movement onset at all joints was significantly delayed after training (cervical spine: p = 0.012; elbow: p = 0.018; shoulder: p = 0.025). Ball-catching time did not differ between conditions.
CONCLUSION:
This case study demonstrated that immersive VR training modified the temporal organization of upper-limb movements during a real-world ball-catching task in an adult with spastic diplegic CP. Before training, movement onset occurred almost simultaneously and earlier than the timing typically observed in healthy adults assessed at the same institution. After training, movement onset exhibited a delayed and sequential pattern that more closely resembled that observed in healthy adults. As ball-catching time did not change, these findings suggest improved motor planning and inter-joint coordination rather than slower performance. Furthermore, an increase in the number of successful ball catches was observed, suggesting a functional improvement in motor skill execution following VR training.