Study of Cerebral Activation by fNIRS During Gait With Different Rhythmic Auditory Stimulations in Healthy Subjects
Condition: Healthy
Study type: Observational

Summary: 
      The purpose of this study is to investigate the cerebral activation in healthy subjects in 4
      conditions of gait :

        -  Gait at preferred cadence without auditory stimulation (Gait1)

        -  Gait with low tempo rhythmic auditory stimulation by music (RAS-Slow). The beat rate of
           the music was 68.5 per minute for all participants.

        -  Gait with fast tempo synchronous rhythmic auditory stimulation by music (RAS-Fast). The
           beat rate of the music was set to 10% above each patient's preferred gait cadence . The
           preferred cadence was considered as the mean of the 6 trials during Gait 1.

        -  Gait without auditory stimulation (Gait2) The investigators goal is to compare cerebral
           activation and gait parameters during the 4 different tasks using fNIRS.
    

Detailed description: 
      Gait and balance impairments caused by neurological disorders affect many people around the
      world and impact on independent living and quality of life. Gait rehabilitation is therefore
      highly important for individuals with neurological diseases. In recent years, rehabilitation
      strategies were carried out considering new technological devices and paradigms have been
      developed to increase the effectiveness of rehabilitation. Brain and clinical research have
      provided a new understanding of the capabilities of music to engage and shape motor functions
      to support brain recovery processes. Humans possess an ability to perceive and synchronize
      movements to the beating music. In context of motor rehabilitation, musical rhythm entrains
      movement in patients with neurological impairment, opening new frontiers for using rhythm and
      music to prime the motor system and favour improvement of deficiency consequences. Rhythmic
      auditory stimulation (RAS) is a gait rehabilitation method in which patients synchronize foot
      steps to a metronome or musical beats. Typically, rhythmic cues are matched to the
      individual's preferred cadence and, once the movement is entrained to the external cues, the
      rhythm is gradually increased by 5-10% over baseline. However, little is known about the
      neural correlates of gait during RAS.

      fNIRS (functional Near Infra Red Spectroscopy) is a functional method that allows to study
      the cerebral cortex changes during different tasks (like fMRI). This technique therefore
      makes it possible to study brain activation under more ecological conditions than fMRI and
      are therefore particularly suitable for exploring rehabilitation techniques.

      This research aims to study and compare in healthy subjects, using, the brain regions
      involved in 4 conditions of gait without and with rhythmic auditory stimulations.

      The protocol has 4 conditions :

        -  Gait at preferred cadence without auditory stimulation (Gait1)

        -  Gait with low tempo rhythmic auditory stimulation by music (RAS-Slow). The beat rate of
           the music was 68.5 per minute for all participants.

        -  Gait with fast tempo synchronous rhythmic auditory stimulation by music (RAS-Fast). The
           beat rate of the music was set to 10% above each patient's preferred gait cadence . The
           preferred cadence was considered as the mean of the 6 trials during Gait 1.

        -  Gait without auditory stimulation (Gait2) The investigators choosed a fixed order rather
           a randomized one, because the use of auditory stimulation may interferes with subsequent
           tasks. The comfortable gait was proposed as first and last conditions to check this
           aftereffect.

      The fNIRS will used the Brite MKII apparatus. Gait parameters were recorded by FeetMe(R)
      Monitor (insole version FTM-DK, Atmel firmware version 2.3.10, Nordic firmware version
      6.3.15).

      Four gait parameters, including speed, cadence, stride length and double support time were
      analyzed. Gait speed is defined as the walking distance in a second (in cm/s), cadence as the
      number of steps within a minute walk (in steps/min). Stride length indicates the distance (in
      cm) from initial contact of one foot to subsequent contact of same foot. Double support time
      occurs when both feet are in contact with the ground simultaneously, it is normalized to
      stride time and expressed in % Gait Cycle (%). These 4 parameters are the most commonly used
      when studying the effect of SAR on gait.
    

Intervention name(s): walking 25 m in 4 different conditions
Intervention type(s): Device
Intervention description(s): The protocol consisted of walking 25 m in 4 different conditions in the following order:
Gait1, RAS-Slow, RAS-fast, Gait2.
Gait 1 : preferred cadence without auditory stimulation
RAS-Slow : Gait with low tempo rhythmic auditory stimulation by music (68.5 per minute).
RAS-Fast : Gait with fast tempo (10% above each Gait1 cadence).
Gait2 : preferred cadence without auditory stimulation
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Healthy subjects aged between 18 and 40 years
      
Keywords: Rhythmic auditory stimulation; Gait; Near infrared spectroscopy