Abstract
Question In the present study we aimed to investigate the effects of continuous theta burst stimulation (cTBS) over the posterior parietal cortex (PPC) and how it effects body sway and the integration of light touch. Methods In right-handed young adults, cTBS with an intensity of 80% of the passive motor threshold was applied for 60 s over the left and right Posterior Partial Cortex. Additionally, a sham condition was applied. Target locations were identified using real-time neuronavigation. Participants were tested blindfolded in quiet upright Tandem-Romberg stance before and after each stimulation interval. During these tests they were instructed to actively initiate and cease finger contact with an earth-fixed referent in response to an acoustic signal. Testing was carried out on two non-consecutive sessions. Body sway was recorded in terms of Centre of Pressure (CoP) and trunk kinematics in addition to forces and torques at the contact point. Results The results of 13 healthy right handed participants reveal that cTBS over the right PPC affected postural control. The overall level of body sway was decreased after inhibition, while the effect of Light Touch was still present. Inhibition of the left PPC or sham stimulation did not decrease the overall level of body sway. Conclusion The cause of this effect might be strategies of the motor control system that lead to a co-contraction and thus reducing body sway. However, this does not mean that participants were more stable. Another possible explanation might be that inhibition of the right PPC disrupts processes for state estimation of body sway in spatial reference frames or mechanisms of stability self-exploration (i.e. Zatsiorsky and Duarte, Motor Control, 1999; Ehrenfried et al., Brain Res Cogn Brain Res, 2003; Kiemel et al., J Neurophysiol, 2006).
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call