Learning Patterns of Pivoting Neuromuscular Control Training–Toward a Learning Model for Therapy Scheduling

Objective: The goal of this study was to investigate the learning patterns in leg pivoting neuromuscular control performance over six-week pivoting neuromuscular control training (POINT) and to estimate how many sessions at beginning are needed to estimate the overall pivoting neuromuscular control learning curve. Methods: Twenty subjects (ten females, ten males) participated in 18 sessions of POINT (three sessions per week for six weeks) program using an off-axis elliptical trainer. Performance measures including pivoting instability and stepping speed were quantified for each study session during a stepping task while subjects were asked to control pivoting movements under a slippery condition. Learning curve relating the pivoting instability to training sessions was quantified by the power law and by the exponential curve as a function of sessions or days with three parameters: The limit of learning, rate of learning, and learning capacity. Results: The power and exponential learning models characterized the learning curves similarly with no differences in ${\text{R}}^{2}$. No significant sex differences were found in the limit of learning, rate of learning, and learning capacity. Based on ${\text{R}}^{2}$ and RMSE, data from the first three study sessions might be enough to estimate the pivoting neuromuscular performance over the whole training period. Conclusion: The findings showed that subjects’ motor skills to improve pivoting instability followed the learning curve models. Significance: The findings and models can potentially be used to develop more effective subject-specific therapy scheduling.