*2.1. Participants*

In order to participate, the volunteers had to be free of pain, and due to data capture requirements, their body mass index (BMI) had to be <sup>≤</sup>30.0 kg/m<sup>2</sup> . All the participants had to demonstrate adequate gait stability (timed up-and-go test [25]), an age- and sex-accorded walking speed (two-minute walk test [26]) and spinal function (back performance scale [27]), as well as an appropriate joint mobility in order, theoretically, to be able to perform a physiological gait pattern [28]. Interested volunteers were excluded from participation in cases where they reported a history of surgery or fracture between the spinal segments of C7 and the pelvis. Further exclusion criteria were medical or therapeutic treatments due to spinal or pelvic girdle complaints (C7-pelvis) within the last 12 months or medical or therapeutic treatments due to musculoskeletal problems (musculoskeletal system except for C7-pelvis) within the last six months prior to the investigation.
