Motor point location index using regression equations for the tibialis anterior muscle

Abstract

The present study highlighted a novel motor point location index (MPLI) for the precise localization of the motor point (MP) of the tibialis anterior (TA) using a regression equation. Twenty healthy young adults (female=8; mean age ± SD=18.50 ± 0.32) were volunteered for this study. The regression analysis was performed by correlating the MP locations with anatomical landmarks. The TA muscle's MP location was bilaterally determined by needle electromyography (EMG) measurement. The anatomical landmarks included lower leg length (LLL), tibial tuberosity-intermalleolar line length (TT-ILL), the knee width (KW) and the leg width (LW). The excellent correlation between the TT-ILL and the vertical MP location was obtained, R(2) 0.815. Approximately 82% of the variance of the vertical MP location was accounted for by its linear relationship with the TT-ILL. The high correlation between the LW and the horizontal MP location was observed, R(2)=0.764. Approximately 77% of the variance of the horizontal MP location index was accounted for by its linear relationship with the LW. These findings indicate that the anatomical landmarks were useful to accurately predict MP locations for the TA muscle. Clinically, this MP location index using regression equations may be alternative for the current method that was not previously affordable.