###### Abstract  
Postural balance deteriorates as heel height increases, but the dual-task interference effect has not been investigated. This observational cross-sectional study investigated the influence of two concurrent cognitive tasks on balance performance while wearing shoes with different heel heights. We hypothesized that the concurrent cognitive demands' effect on balance deterioration would be more pronounced in shoes with increased heel height. Twenty-one women (21-54 years) were assessed for quiet stance balance performance while wearing shoes with low-, medium-and high-heel height. Cognitive interference on balance performance was investigated by a dual-task condition using a short memory (COGN_A) and verbal fluency (COGN_B) task. Balance performance was quantified by measuring center of pressure (CoP) path length and sway range, while errors made and scores in COGN_A and COGN_B assessed cognitive performance. Postural balance decreased as heel height increased with greater CoP path length and anteroposterior sway for the medium- and high-heeled shoes (\(p<0.001\)). Cognitive load did not affect balance performance (\(p=0.234\)-\(0.494\)), nor was there an interaction between cognitive load and balance with increasing heel height (\(p=0.281\)-\(0.375\)). The results suggest that cognitive load does not limit postural balance with increasing heel height, and that balance is more affected by the increased mechanical demands of heel height. heeled shoes; posture; cognitive load; task prioritization; balance performance; quiet stance +
Footnote †: journal: Applied sciences  
0000-0001-5000-0001-5000]M.A.E.A. On the other hand, postural control would provide a flexible and mechanically stable substrate to enable and facilitate the execution of concurrent cognitive tasks [15, 16, 17]. Within this context, the underlying theoretical assumption is that available resources are limited and they have to be shared between the motor and cognitive tasks or performance will be compromised [18, 19]. Balance control engages cognitive resources [20, 21] that are required for the continuous utilization and reweighing by the brain of the integrated sensorimotor information provided by the proprioceptive, vestibular and visual channels in order to determine the magnitude of postural sway to efficiently preserve balance and safety [22, 23, 24]. In healthy individuals, the cognitive resources devoted to postural balance control are largely automatic [25, 26] while requiring varying degrees of attention depending on the difficulty of the task [27, 28]. The continuous interaction between postural and perception-action tasks, defined as dual-tasking posture-cognition interference, is quite complex, with previous findings of dual-task postural studies being inconsistent [29, 30]. Specifically, there have been reported impairments in postural performance resulting from the diversion of the available attentional resources to the secondary cognitive task [31, 32, 33, 34], whereas decrements in cognitive task performance have been found due to the prioritization of balance safety, referred to as the \"posture-first strategy\" [35, 36, 37]. The adoption of the \"posture-first strategy\" depends on several factors such as the nature of the cognitive tasks, the instruction set, the choice of baseline conditions and, most importantly, the perceived level of postural threat [15, 38, 39]. For example, a \"posture-first strategy\" has been found during demanding locomotor activities at the expense of cognitive performance [35, 36, 37], but not during less demanding conditions such as standing [40, 41, 42]. Therefore, the issue of dual-task cognitive-postural interference still remains perplexing. To the best of our knowledge, there is no study where the effect of dual tasking has been considered in a challenging postural configuration like standing in high heels.