“…Regarding the classification of longer motional activities, various speeds and types of forward movements were also tested, such as slow, normal and rush walking [25], jogging [22,33,[42][43], and running [23-25, 33, 40]. Some works tried to differentiate different directions of an activity type, like level walking, walking downstairs and upstairs [23, 33-34, 38-39, 42] or walking backwards [43]. Yang et al [42] recorded even continuous rotational movements, such as walking left-circle or right-circle, and turning left or right.…”