Discussion
The present study proposes for the first time a causal relationship between the involvement of M1 and the early learning and consolidation of a balance task. This can be concluded as the rTMS group demonstrated a significantly worse consolidation (i.e. numerical loss of performance from the end of the acquisition phase to the start of the retention test) of the balance task in contrast to the sham-rTMS group (which showed a significant increase in performance). Previous studies had demonstrated that higher cortical centers (especially M1) adapt in response to balance learningWhen balance skills are learned over a longer-time period, the involvement of cortical centers seems to decreaseDespite the meaningful results, potential limitations of the study must be addressed. Since suprathreshold rTMS was applied, the intensity of the stimulation was sufficient to contract the target muscle and therefore, also led to re-afferent activity. For this reason, it cannot be excluded that not only the disruption of M1 was responsible for the impaired consolidation but also the afferent input from the target muscle