Central common drive to antagonistic ankle muscles in relation to short-term cocontraction training in nondancers and professional ballet dancers

Abstract

Optimization of cocontraction of antagonistic muscles around the ankle joint has been shown to involve plastic changes in spinal and cortical neural circuitries. Such changes may explain the ability of elite ballet dancers to maintain a steady balance during various ballet postures. Here we investigated whether short-term cocontraction training in ballet dancers and nondancers leads to changes in the coupling between antagonistic ankle motor units. Eleven ballet dancers and 10 nondancers were recruited for the study. Prior to training, ballet dancers and nondancers showed an equal amount of coherence in the 15- to 35-Hz frequency band and short-term synchronization between antagonistic tibialis anterior and soleus motor units. The ballet dancers tended to be better at maintaining a stable cocontraction of the antagonistic muscles, but this difference was not significant (P = 0.09). Following 27 min of cocontraction training, the nondancers improved their performance significantly, whereas no significant improvement was observed for the ballet dancers. The nondancers showed a significant increase in 15- to 35-Hz coherence following the training, whereas the ballet dancers did not show a significant change. A group of control subjects (n = 4), who performed cocontraction of the antagonistic muscles for an equal amount of time, but without any requirement to improve their performance, showed no change in coherence. We suggest that improved ability to maintain a stable cocontraction around the ankle joint is accompanied by short-term plastic changes in the neural drive to the involved muscles, but that such changes are not necessary for maintained high-level performance.

Effect of balance training on neuromuscular function at rest and during isometric maximum voluntary contraction

“…In general, the mechanisms of controlling antagonistic muscle activity during an action of an agonistic muscle include the inhibition of spinal α-motoneurons of the antagonist by reciprocal Ia inhibitory interneurons and the supraspinally mediated depression of afferent feedback by presynaptic inhibition during most movements. These mechanisms are controlled by supraspinal centers (Crone and Nielsen 1989;Nielsen 2004;Geertsen et al 2013). Although the exercises during balance training require simultaneous and alternating activity of antagonistic muscle groups (Nielsen and Kagamihara 1992;Nielsen et al 1994), our results indicate that the training regimen decreases co-activity of TA at the onset of contraction during an isometric MVC of the plantar flexors.…”

Changes in corticospinal drive to spinal motoneurones following tablet-based practice of manual dexterity

“…; Geertsen et al. ). Similar to this study, changes in coherence have been observed with improvements in motor performance (Perez et al.…”

“…; Geertsen et al. ), but disappear again within minutes following a single training bout, despite maintained motor performance abilities. In this study, we did not obtain a second delayed measure of coherence following motor practice, as the test was very time consuming and involved considerable mental and physical effort.…”

“…; Geertsen et al. ). Furthermore, it is beyond the scope of this article to compare tablet‐based practice with other potential interventions.…”

Calibration of the Leg Muscle Responses Elicited by Predictable Perturbations of Stance and the Effect of Vision

“…Co-contraction around the ankle joint occurs during tasks such as standing on one leg, balancing on an unstable platform or reacting to rotation of a support surface, or walking on a narrow beam (Diener et al, 1983; Keshner et al, 1987; Nielsen and Kagamihara, 1992; Geertsen et al, 2013) or after fatigue (Kennedy et al, 2012). However, co-contraction is not a rule under different critical postures (Sozzi et al, 2013).…”