AR Precision Mastery: Enhanced Feedback For Overhead Work

Overhead workers such as those in manufacturing experience increased postural sway when working for extended periods, putting them at greater risk of falls. This can be partially attributed to leg muscle fatigue and mechanoreceptive fatigue of the cervical spinal extensors. Thus, it is of interest to leverage tools such as augmented reality (AR) to introduce additional visual information during performance of such tasks, allowing workers to consciously correct their balance. PURPOSE: To investigate whether visual cues delivered through AR affect balance control in participants performing an overhead task. METHODS: Nine novice overhead workers were recruited to complete two randomized, counterbalanced study sessions where they performed an overhead paint-by-numbers task with and without AR. A custom AR application using the headset’s accelerometers and rate gyroscopes displayed information regarding anterior/posterior (A/P) and medial/lateral (M/L) head motion. Participants completed 15 work-rest cycles of 3 minutes of work to 1 minute of rest (for a total of one hour). Two force plates measured center of pressure (COP) excursion, velocity, and total path, as well as ground reaction force (GRF) asymmetry between the two legs. Additionally, electromyography (EMG) data were recorded to assess muscle activity of the lateral gastrocnemius (LG) and gluteus medius (GM). RESULTS: Preliminary results (n = 5) indicate when using AR, participants’ COP velocity increased in both the M/L (0.005 m/s) and A/P directions (0.02 m/s) compared to no AR (M/L = 0.003 m/s, A/P = 0.01 m/s). Furthermore, when using AR participants’ COP traveled for a longer total path (0.57 m) compared to no AR (0.45 m). In addition, GRF asymmetry was reduced when using AR (16% difference between legs) compared to no AR (31% difference between legs). No differences in EMG activity between the two conditions were found. CONCLUSION: AR was effective in altering balance control, as evidenced by more rapid COP corrections and a greater COP path. Moreover, AR use led to a more balanced weight distribution between the legs. However, these changes were not accompanied by alterations to muscular balance control strategies. These results highlight the utility of AR to improve workplace health and safety.