Evaluation of Abductor Hallucis Neuromechanical Function and its Potential Role in Postural Control
Abductor Hallucis (AH), an intrinsic foot muscle, is thought to be involved in postural balance control. However, many AH functional properties and their relationship with standing postural control have not been quantified. This thesis aimed to quantify AH strength, voluntary activation (VA) and whole-muscle contractile properties and their relationship with standing postural control. Strength and VA were quantified from maximal great toe abduction contractions while contractile properties were quantified from electrically evoked twitch contractions. These properties were correlated to centre of pressure (COP) velocity and standard deviation during single-leg stance. AH contractile properties were like other slow contractile muscles, suggesting AH may be designed for slow, prolonged tasks such as postural balance control. Strength and contractile speed related negatively with COP velocity, suggesting that AH function may be important for successful postural control. Thus, improving AH function may serve to improve postural outcomes in clinical populations.