Tibialis anterior analysis from functional and architectural perspective during isometric foot dorsiflexion: a cross‐sectional study of repeated measures

• Published in: Journal of foot and ankle research Vol. 8; no. 1; pp. 74 - n/a
• Main Authors: Ruiz Muñoz, Maria, González‐Sánchez, Manuel, Cuesta‐Vargas, Antonio I.
• Format: Journal Article
• Language: English
• Published: London BioMed Central 18-12-2015; BioMed Central Ltd; Wiley
• Subjects: Ankle; Anterior Tibial Muscle; Electromyography; Foot; Gait; Multiple Regression Analysis; Physiological aspects; Tibia; Ultrasonography; Ankle; Anterior Tibial Muscle; Electromyography; Multiple Regression Analysis; Ultrasonography
• ISSN: 1757-1146; 1757-1146
• DOI: 10.1186/s13047-015-0132-3

Background
The purpose of the present study is to establish the relationship and degree of contribution between torque and sonomiography variables (pennation angle – muscle thickness), and electromyography variables (EMGAreaUnderCurve – EMGMaximalPeak) of the tibialis anterior muscle during (TA) maximal and relative isometric foot dorsiflexion (IFD). Secondary aim: To determine the measurement's reliability.
Methods
Cross‐sectional study. 31 participants (15 men; 16 women) performed IFD at different intensities (100, 75, 50, and 25 %) of the maximal voluntary contraction (MVC) (three times for each intensity). Outcome variables: To determine the torque, pennation angle, muscle thickness, EMGMaximalPeak, and EMGAreaUnderCurve. Statistical analysis: In order to test the measurement's reliability, Cronbach's alpha and standard error of the measurement were determined. An inferential analysis was carried out using Pearson correlations(r). For each contraction intensity, a multiple regression analysis was performed, where the dependent variable was torque and the independent variables were EMGAreaUnderCurve, EMGMaximalPeak, muscle thickness and pennation angle.
Results
All outcome variables show excellent reliability. The highest correlation value was 0.955 (thickness 100 % – thickness 25 %). R2 values ranged from 0.713 (100 % MVC) to 0.588 (25 % MVC).
Conclusion
The outcome variables demonstrated excellent reliability in terms of measuring IFD at different intensities. The correlations between all outcome variables were moderate‐to‐strong. TA functional and architectural variables have a significant impact on the torque variance during IFD at different intensities.