text: …measured immediately after each walking task.
  fNIRS measurement
  The details of the fNIRS system (OMM-2001; Shimadzu, Kyoto, Japan), which used continuous-wave laser diodes with three wavelengths of near-infrared light (780, 805, and 830 nm), are described elsewhere (Miyai et al. 2001, 2002, 2003).