Seems the more we practice skilled movement the less we need to consciously think about what we are doing. Scientist keen to put this to the test took high-heel experts and novices and put them on a tread mill before assessing their cognitive and motor performancse. The subjects were required to complete a memory task whilst wearing either gym shoes or high heels. When compared neither group showed lower working memory performance when walking than when sitting, irrespective of shoe type. It appears those expert in high-heel walking were able to adapt their walking style to shoe type even when cognitive tasts were changed. The researchers have concluded high-heel expertise is more than likely associated with flexible adjustments of movement patterns than conscious control by the brain . Another study was carried out to investigate the effect of differing heel height on the electromyographic (EMG) activity in the muscles vastus medialis (VM) and vastus lateralis (VL) during a sit to stand activity. Using repeated measures twenty five (25) healthy females carried out a standardised sit to stand activity under 4 conditions: i.e. barefoot, and with heel wedges of 1, 3, and 5 cm in height. EMG activity was recorded from VM and VL during the activity. Data were analysed using 1x4 repeated measures Analysis of variance (ANOVA). The results showed the average rectified EMG activity differed with heel height in both VM (F2.2, 51.7 = 5.24, p < 0.01), and VL (F3, 72 = 5.32, p < 0.01). However the VM: VL EMG ratio was not significantly different between conditions (F3,72 = 0.61, p = 0.609). Researchers concluded as heel height increased, there was an increase in EMG activity in both VM and VL, but no change in the relative EMG intensity of VM and VL as measured by the VM: VL ratio. This showed that no VM: VL imbalance was elicited.
Edwards L, Dixon J, Kent JR, Hodgson D, Whittaker VJ. 2013 Effect of shoe heel height on vastus medialis and vastus lateralis electromyographic activity during sit to stand. J Orthop Surg. 2008 Jan 10;3(1):2
Schaefer S, Lindenberger U 2013 Thinking while walking: experienced high-heel walkers flexibly adjust their gait. Front Psychol. 2013 Jun 3;4:316.