Rowing Simulator Modulates Water Density to Foster Motor Learning

Abstract

Although robot-assisted training is present in various fields such as sports engineering and rehabilitation, provision of training strategies that optimally support individual motor learning remains as a challenge. Literature has shown that guidance strategies are useful for beginners, while skilled trainees should benefit from challenging conditions. The Challenge Point Theory also supports this in a way that learning is dependent on the available information, which serves as a challenge to the learner. So, learning can be fostered when the optimal amount of information is given according to the trainee's skill. Even though the framework explains the importance of difficulty modulation, there are no practical guidelines for complex dynamic tasks on how to match the difficulty to the trainee's skill progress. Therefore, the goal of this study was to determine the impact on learning of a complex motor task by a modulated task difficulty scheme during the training sessions, without distorting the nature of task. In this 3-day protocol study, we compared two groups of naïve participants for learning a sweep rowing task in a highly sophisticated rowing simulator. During trainings, groups received concurrent visual feedback displaying the requested oar movement. Control group performed the task under constant difficulty in the training sessions. Experimental group's task difficulty was modulated by changing the virtual water density that generated different heaviness of the simulated water-oar interaction, which yielded practice variability. Learning was assessed in terms of spatial and velocity magnitude errors and the variability for these metrics. Results of final day tests revealed that both groups reduced their error and variability for the chosen metrics. Notably, in addition to the provision of a very well established visual feedback and knowledge of results, experimental group's variable training protocol with modulated difficulty showed a potential to be advantageous for the spatial consistency and velocity accuracy. The outcomes of training and test runs indicate that we could successfully alter the performance of the trainees by changing the density value of the virtual water. Therefore, a follow-up study is necessary to investigate how to match different density values to the skill and performance improvement of the participants.

Congruency of Information Rather Than Body Ownership Enhances Motor Performance in Highly Embodied Virtual Reality

“…Thus, our findings are in line with previous notions stating that visuo-tactile stimulation might not be necessary to induce and/or enhance body ownership in first-person perspective immersive virtual reality ( Maselli and Slater, 2013 ; Kokkinara and Slater, 2014 ; Rubo and Gamer, 2019 ). Nevertheless, haptic stimulation may have other favorable effects for motor learning and neurorehabilitation — e.g., for proprioception training ( Cuppone et al, 2016 ), to enhance somatosensory information during neurorehabilitation ( Gassert and Dietz, 2018 ; Özen et al, 2021 ), or to promote more variable tasks during training ( Basalp et al, 2019 ).…”

Effect of immersive visualization technologies on cognitive load, motivation, usability, and embodiment

“…During conventional VR-based neurorehabilitation, the VE is displayed on a 2D screen and patients interact via a symbolic virtual representation of their limb (e.g., a cursor). Although this provides useful visual guidance (Basalp et al 2019;Marchal-Crespo et al 2019, the lack of some depth cues (i.e., stereopsis and motion parallax) requires movements and object interactions that are far from those required in real conditions, limiting patients' opportunity to embody the virtual avatar and transfer of acquired skills to real practice (Bezerra et al 2018;de Mello Monteiro et al 2014). Our work is the first step to surpass these shortcomings as it provides a better understanding of the effects of different visualization technologies on subjective measures of cognitive load, motivation, technology usability, and embodiment that might have an important impact on neurorehabilitation.…”

Configurable 3D Rowing Model Renders Realistic Forces on a Simulator for Indoor Training

“…According to Equation (27), the natural frequency for transversal vibration of the rope is proportional to the square root of the rope tension and inversely dependent on the length of the rope. Confirming the relationship presented in Equation 27, three out of five ropes of the tendon based parallel robot are lengthened during catch-to-drive transition in the simulator, which reduces ω n and thus results in increased transversal vibrations on the ropes.…”

“…In the previous studies on the rowing simulator, the vibration problem could be suppressed by setting the minimum rope tension force (τ min rope ) to a fixed value of 50 N , since the rendered forces at the end-effector were low due to the fact that body-arm rowing was used as the rowing task [24][25][26][27]. However, this minimum rope tension of 50 N yielded neither realistic recovery forces nor eliminated the transversal vibration issue for the rapid, full-body rowing movement.…”

“…In our laboratory, we also developed a rowing simulator to support realistic training for sculling and sweep rowing indoors [23]. Thanks to the real-time control and dedicated hardware setup, our rowing simulator has been used for training of rowers [22] and motor learning related research such as augmented feedback designs [24,25] and robotic training strategies [26,27].…”