Journal article

Effect of surface stiffness on the neural control of stretch-shortening cycle movements

  • Márquez, G. Departamento de Ciencias de la Actividad Física y del Deporte, Facultad de Ciencias de la Actividad Física y del Deporte, UCAM, Universidad Católica San Antonio, Murcia, Spain
  • Morenilla, L. Learning and Human Movement Control Group, Facultad de Ciencias de la Actividad Física y del Deporte, University of A Coruña, Spain
  • Taube, Wolfgang Department of Medicine, Movement and Sports Science, University of Fribourg, Switzerland
  • Fernández-del-Olmo, M. Learning and Human Movement Control Group, Facultad de Ciencias de la Actividad Física y del Deporte, University of A Coruña, Spain
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    01.11.2014
Published in:
  • Acta Physiologica. - 2014, vol. 212, no. 3, p. 214–225
English Aim: It is accepted that leg stiffness (Kleg) increases when surface stiffness decreases, and vice versa. However, little is known how the central nervous system fulfils this task. To understand the effect of surface stiffness on the neural control of stretch-shortening cycle movements, this study aimed to compare modulation of spinal and corticospinal excitability at distinct phases after ground contact during two-legged hopping when changing from solid to elastic ground.Methods: Motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) and H-reflexes were elicited at the time of the short (SLR)-, medium (MLR)- and long (LLR)-latency responses of the soleus muscle (SOL) during two-legged hopping on different stiffness surfaces, elastic and stiff.Results: Soleus H-reflexes during two-legged hopping on the elastic surface were lower at SLR and larger at LLR than on the stiff surface (P < 0.05 for both comparisons). SOL MEP size was higher at the time of SLR during hopping on the elastic surface than on the stiff surface (P < 0.05) although the background EMG was similar.Conclusion: It is argued that this phase-specific adaptation in spinal reflex excitability is functionally relevant to adjust leg stiffness to optimally exploit the properties of the elastic surface. Thus, the increased corticospinal excitability on the elastic surface may reflect a more supraspinal control of the ankle muscles to compensate the decrease in reflexive stiffness at the beginning of touchdown and/or counteract the higher postural challenges associated with the elastic surface.
Faculty
Faculté des sciences et de médecine
Department
Département de Médecine
Language
  • English
Classification
Biology
License
License undefined
Identifiers
Persistent URL
https://folia.unifr.ch/unifr/documents/303972
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