The effect of heel height of shoe on ankle muscle activation pattern in women with functional ankle instability during stair descending

Background. Wearing high-heeled shoes (HHS) increases the risk of musculoskeletal disorders, especially in unstable situations. This study was conducted to evaluate the electromyographic (EMG) activity of the ankle muscles during stair descent with HHS in women with and without functional ankle instability (FAI). Methods. In this experimental study, Thirty-six subjects were surveyed in 4 groups: The group 1: Ten non-habitual HHS wearer with FAI, group 2: Eight habitual HHS wearer with FAI, group 3: Ten non-habitual HHS wearer without FAI, and group 4: Eight habitual HHS wearer without FAI. The EMG activity was obtained from the tibialis anterior (TA), peroneus longus (PL), and gastrocnemius medialis (GM) muscles during stair descent with HHS and barefoot. Results. In non-habitual and habitual FAI group, onset latency of the TA and PL muscles was longer in the HH compared to barefoot. However, in healthy groups, onset latency of the selected muscles was longer only in the non-habitual healthy subjects. In the non-habitual FAI group there was a significant increase in TA and PL muscles onset latency compared to that in the non-habitual healthy group. EMG activity of the TA, PL and GM muscles were significantly greater in the HHS group compared to the barefoot in FAI and healthy groups during stair descending. Conclusions. The findings of this study suggest that wearing HHS may put people with FAI and without the experience of wearing HHS at greater risk for developing ankle sprains.