Effect of inversion and ankle bracing on peroneus longus Hoffmann reflex

Area of Science:

• Biomechanics
• Neuroscience
• Sports Medicine

Background:

• The peroneus longus (PL) muscle plays a crucial role in stabilizing the ankle.
• Understanding the neural control of the PL during inversion is vital for preventing ankle injuries.
• The Hoffmann reflex (H-reflex) is a valuable tool for assessing neural excitability.

Purpose of the Study:

• To investigate the effect of sudden ankle inversion on the PL H-reflex in healthy subjects.
• To determine if ankle bracing influences the PL H-reflex response during inversion.
• To explore the sensorimotor demands associated with ankle inversion.

Main Methods:

• Ten healthy subjects participated in the study.
• The PL H-reflex and maximum M-wave (Mmax) were measured under various conditions (flat, inversion, braced, unbraced).
• The PL H/Mmax ratio was analyzed using a 1x4 repeated measures ANOVA.

Main Results:

• A significant increase in the PL H/Mmax ratio was observed during sudden inversion without an ankle brace compared to a flat surface (P=0.04).
• Ankle bracing did not significantly affect the PL H/Mmax ratio during inversion (P=0.78).
• The findings suggest heightened sensorimotor demand during inversion perturbations.

Conclusions:

• Sudden ankle inversion elicits an increased PL H-reflex response in healthy individuals.
• Ankle braces do not appear to modulate the PL H-reflex during inversion.
• This suggests that the nervous system adapts to inversion perturbations, even when an ankle brace is applied.