Participants' characteristics separated by impairment in the four subsystems (i.e., muscle strength, distance vision, lower-limb proprioception and cognition) involved in gait control (n = 1792).

SD: Standard deviationBMI: Body mass indexTUG: Timed Up & GopTUG: Performed Timed Up & GoiTUG: Imagined Timed Up & Go*: Group composed of the 723 participants with impairment in one subsystem and of the 685 participants with impairments in more than one subsystem†: Comparison with healthy participants based on unpaired t-test or Chi square test, as appropriate‡: Impairment in muscle strength, distance vision, lower-limb proprioception was defined as being in the lowest tertile of performance. The other two tertiles combined were used to define normal performance.§: Combination of episodic memory impairment (i.e., short mini-mental status examination score ≤5/6) and executive impairment (i.e., one or more errors made in the execution of drawing the face of the clock and/or the hands of the clock).#: Mean value of 3 trials measuring the maximal isometric voluntary contraction strength measured with computerized dynamometers expressed in Newton per square meter¶: Binocular vision acuity at distance of 5 m with a Snellen letter test chart||: Mean value of left and right side and based on graduated tuning fork placed on the tibial tuberosity measuring vibration threshold**: Considered if one or more errors were made in the execution of drawing the face of the clock and/or the hands of the clock††: Calculated from the following formula: [(Timed “Up & Go—Timed “Up & Go” imagined) / (Timed “Up & Go” + Timed “Up & Go” imagined) / 2] x 100P-value significant with Bonferroni’s correction (i.e., PParticipants' characteristics separated by impairment in the four subsystems (i.e., muscle strength, distance vision, lower-limb proprioception and cognition) involved in gait control (n = 1792).