A novel sensor-based real-time tracking game for assessing ankle proprioceptive effects on sensorimotor performance.

Proprioceptive deficits have been linked to balance and risk of falling in older adults. In this study, we assessed the effects of proprioceptive deficits on sensorimotor performance using a sensor-based real-time tracking game (SRT) that utilizes a moving target on a screen. The current methods to measure proprioceptive deficits can be difficult to use and may not be sensitive to minor deficits. We recruited 19 young participants (mean age = 21.8 ± 1.32, 55% female) and 10 older adults (age = 73.6 ± 7.73, 60% female). We placed a gyroscope on the top of the intermediate cuneiform bone to track movements. Both legs were tested with three separate SRT tracks with different difficulties. To disturb visuo-proprioceptive performance, we applied vibration to the tibialis anterior, peroneus longus, soleus, and gastrocnemius. We hypothesized that younger participants would score better than older participants, the dominant ankle would perform better than the non-dominant ankle, and participants would perform better without vibratory stimulation. We measured the amplitude and directional accuracy of the performance. Amplitude accuracy was measured by calculating the straight-line distance from the tracker to predetermined track. Directional accuracy was defined as the percentage of time the participant remained in the free zone (defined by average performance among the young sample) at every instant of time. Results showed significant effects for amplitude and directional accuracy by age (p < 0.001), vibration condition (p < 0.012), and testing side (p < 0.026). Our results showed that SRT is sensitive enough to measure effects of visuo-proprioception changes caused by aging, dominant vs. non-dominant sides, and outside disturbance. Through accurate detection of visuo-proprioceptive deficits, we may potentially identify risk of falling associated with such deficits.