Effects Of Heel Heights On Dynamic Stability During Stair Descent In Young Female

PURPOSE: To investigate the effects of heel heights on dynamic stability during stair descent in young female. METHODS: Forty healthy young females were recruited to participate in this study. The participants were instructed to descend a 6-step staircase at a self-selected comfortable speed, wearing heeled shoes of four same heel types but different heel heights (flat:1 cm, low:3 cm, medium:5 cm, and high:7 cm). A motion capture system and two force pates were used to determine locomotion synchronously. Dynamic stability with dominant lower limb was evaluated using the displacement between the center of mass (CoM) and center of pressure (CoP) (CoM-CoP Max), CoM–CoP inclination angles (IA) and margin of stability (MoS) in mediolateral (ML) and anterior-posterior (AP) direction during stance phase. A one-way ANOVA was performed to compare the differences of dynamic stability among heel heights. RESULTS: Forty participants (age: 22.30 ± 1.03 years, height: 1.66 ± 0.05 m, weight: 52.10 ± 3.47 kg, and BMI 19.54 ± 0.31 kg/m2) completed this study. One-way ANOVA showed no significant difference in CoM-CoP Max(p > 0.05), IA(p > 0.05) and MoS(p > 0.05) in the AP direction of the four heel heights. However, significant differences were found of CoM-CoP Max(p = 0.019), IA(p < 0.001), and MoS(p = 0.006) in the ML direction. Post-hoc indicated that compared with 1 cm heel height, ML CoM-CoP Max significantly reduced (from 0.89 ± 0.06 to 0.07 ± 0.02, p = 0.016) in 7 cm heel height. Compared with 1 cm and 3 cm heels height, ML IA significantly reduced (from 5.28 ± 1.07 to 4.27 ± 1.06, p < 0.001; from 5.11 ± 1.03 to 4.27 ± 1.06, p = 0.003), and ML MoS significantly reduced (from 0.12 ± 0.02 to 0.10 ± 0.27, p = 0.023; from 0.12 ± 0.02 to 0.10 ± 0.27; p = 0.029) in 7 cm heel height. CONCLUSIONS: The dynamic stability would be significantly reduced when wearing high heels of more than 5 cm during walking down the stairs in young female. The negative influence of heel height on dynamic stability is mainly manifested in the stable control of ML direction. So risk of falls in the ML direction might be greater during stair descent in young female with high heel shoes.