Multifractal analysis of proprioception and postural stability: a pilot study
Background. Postural analysis has traditionally been assessed using linear methods such as standard deviation to track movement variability, however, postural adjustment during dynamic movement is a function of nonlinear interactions of multiple systems including sensorimotor and vestibular systems that require nonlinear analysis. Kinesiology tape is promoted as a means of improving physical performance by enhancing proprioception rather than providing support to joints such as the ankle and knee. In order to investigate whether kinesiology tape effects postural control, participants were assessed performing a dynamic balance task under two taping conditions, whereby center of mass data were analysed using multifractal analysis methodology in a repeated measures design. To gauge the potential influence of different neurophysiological or mechanical adaptations to the adhesion of tape to skin, as opposed to the properties of a specific type of tape, the influence of rigid tape was also assessed.
Materials and methods. Four individuals, free of injury, performed the Y Balance Test under three conditions: without tape, with rigid tape (RT), and with kinesiology tape (KT) applied at the quadriceps, triceps surae and ankle. The two tapes were applied to the lower limb during separate testing sessions. All participants completed the Y Balance Test. Using the Y Balance test as a surrogate measure of whether proprioception influences postural control, multifractal dimension analysis was used to quantify the dynamic changes in the center of mass whilst undertaking the Y Balance Test. Statistical analysis included the Kruskal Wallis test to allow for non-normally distributed data and a Bonferroni corrected pairwise T test as a post hoc test to ascertain pairwise differences between the three conditions.
Results. The multifractal analysis of the dynamic changes in center of mass showed a typical multifractal spectrum with $D(q)$ values suggesting differences between the control and both taping conditions.
Conclusion. Postural sway during the YBT confirmed that complex sensorimotor feedback is required as characterized by the multifractal spectra with or without tape. Both kinesiology tape and rigid tape showed improvement in postural stability during the YBT, which may be associated with improved proprioception.