title: Corticospinal excitability changes following blood flow restriction training of the tibialis anterior: a preliminary study.
abstract: OBJECTIVE
  To examine the neural excitability of projections to the tibialis anterior (TA) following blood flow restriction training (BFRT). This is the first study to examine the TA following BFRT.
  
  
  METHODS
  Ten subjects performed each experiment. Experiment one consisted of BFRT at 130 mmHg (BFRT-low). Experiment two consisted of BFRT at 200 mmHg (BFRT-high), training (TR-only) and blood flow restriction at 200 mmHg (BFR-only) performed on separate days. Blood flow restriction was applied to the thigh and training consisted of rapid dorsiflexion contractions against gravity every 10 s for 15-min. The motor evoked potential (MEP) peak-to-peak amplitudes were recorded pre-intervention and 1-, 10-, 20- and 30-min post-intervention and expressed relative to the maximal peak-to-peak M-wave at each time-point.
  
  
  RESULTS
  Experiment one revealed no difference in MEP amplitudes for BFRT-low over time (P = 0.09). Experiment two revealed a significant effect of time (P < 0.001), with 1-min post-intervention MEP amplitudes significantly facilitated compared to pre-intervention, but no effect of intervention (P = 0.79) or intervention*time interaction (P = 0.25). Post-hoc power calculations were performed for the intervention*time interaction.
  
  
  CONCLUSIONS
  Corticospinal excitability of projections to the TA did not change following BFRT-low and corticospinal excitability changes between BFRT-high, BFR-only and TR-only interventions were not different over time. In experiment two, there was a significant main effect of time 1-min post-intervention which was mainly due to the BFRT-high intervention. Post-hoc power calculations revealed that 15 subjects were required for a significant interaction effect 80% of the time however, as the changes in corticospinal excitability were not prolonged, a new dataset of ≥ 15 subjects was not acquired.
authors.affiliation: Hammel Neurorehabilitation and Research Center, Aarhus University, 15 Voldbyvej, 8450 Hammel, Denmark.
authors.forename: Erhard Trillingsgaard
authors.initials: ET
authors.lastname: Næss-Schmidt
authors.affiliation: Hammel Neurorehabilitation and Research Center, Aarhus University, 15 Voldbyvej, 8450 Hammel, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Morthorst
authors.affiliation: Hammel Neurorehabilitation and Research Center, Aarhus University, 15 Voldbyvej, 8450 Hammel, Denmark.
authors.forename: Asger Roer
authors.initials: AR
authors.lastname: Pedersen
authors.affiliation: Hammel Neurorehabilitation and Research Center, Aarhus University, 15 Voldbyvej, 8450 Hammel, Denmark.
authors.forename: Jørgen Feldbæk
authors.initials: JF
authors.lastname: Nielsen
authors.affiliation: Hammel Neurorehabilitation and Research Center, Aarhus University, 15 Voldbyvej, 8450 Hammel, Denmark.
authors.forename: Peter William
authors.initials: PW
authors.lastname: Stubbs
keywords: Neuroscience; Physiology