Abstract
Lissajous plots are 2D visualizations that depict the interaction between two oscillating signals, illustrating their phase and frequency relationship through distinctive patterns. In the context of bimanual coordination, Lissajous plots serve as augmented visual feedback by mapping the force or motion of one limb to the x-axis and the other limb to the y-axis, providing real-time feedback on the synchronization and rhythm between the two limbs. This visual guidance helps individuals adjust their movements to achieve the desired coordination pattern, making it particularly useful in motor rehabilitation and training scenarios. PURPOSE: Determine the level of accuracy of bimanual force production with isometric force coordination tasks and investigate if increasing strength of force produced impacts accuracy. METHODS: Twenty young healthy participants were tested, first providing a maximum voluntary contraction (MVC) through isometric abduction contractions performed with the first dorsal interossei (FDI) muscles against fixed force transducers. This calculation was then used to set a target force of 10% and 30% of each subject’s MVC. Each participant also completed two different coordination patterns, one at 0° and one at 180°, at both target force goals, using four different Lissajous feedbacks, classic Lissajous (CL), overshoot feedback (OF), target feedback (TF), and color feedback (CF). Subjects each completed 112 trials. RESULTS: For absolute error (AE) of relative phase, a main effect of task was observed (p < 0.001), indicating greater errors for the 180° task (44.88 ± 11.93) compared to the 0° task (10.18 ± 2.54). For variability of relative phase (VE), a main effect of feedback was identified (p = 0.041), suggesting that additional feedback increased variability in bimanual force coordination (CL: 21.48 ± 2.07 compared to TF: 24.90 ± 4.63, OF: 23.87 ± 2.56, CF: 23.91 ± 2.72). For force accuracy during the 0° task, a main effect of feedback was found (p < 0.001), with the CF condition producing higher percent accuracy (CF: 21.94 ± 14.34) compared to other feedback conditions (CL: 5.49 ± 4.78, TF: 17.04 ± 11.13, OF: 18.82 ± 11.16). For the 180° task, a significant main effect of feedback was observed, showing that the OF
condition resulted in the highest force accuracy (OF: 44.83 ± 22.98) compared to the other conditions (CL: 29.74 ± 28.11, TF: 43.41 ± 19.04, CF: 39.57 ± 24.83). CONCLUSION: Additional information regarding task performance in the Lissajous plot was not found to impact spatiotemporal performance with in-phase coordination but does impact the performance for the anti-phase tasks. This finding suggests that tasks and feedback may impact performance through different mechanisms. It is suggested to conduct further research to gain a better understanding of the impact of force feedback when utilizing Lissajous plots.
Recommended Citation
Luthria, Ananya; Weinrich, Madison M.; Balthazor, Brock; Wagner, Jackson; and Kennedy, Deanna M.
(2025)
"Force Meets Feedback: Investigating the Impact of Lissajous Visual Augmentation on Bimanual Coordination and Force Accuracy,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
17, Article 44.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss17/44
