Saskia Baltrusch

90 Chapter 4 Figure 1: Laevo (Intespring, Delft, Netherlands). The user’s trochanter major is to be aligned with the hip centre of rotation of the device. For personal length adjustment and for keeping the device in place, straps are provided. The chest pad facilitates walking by rotating in the frontal plane. Allowance of hip flexion/extension is regulated by the smart joint. The counter measures the number of hip flexions while wearing the device. 2.2 Participants Thirteen men with no prior history of low back pain participated in this study. Their mean age, height and body mass, here presented in mean (sd), were: 28.9years (4.4), 1.80m (0.04)m and 76.9kg (12.0), respectively. Prior to the start of the measurement, participants received an information letter and signed informed consent. Approval for the experiment was given by the medical ethical committee of VU medical center (VUmc, Amsterdam, The Netherlands, NL57404.029.16). 2.3 Instrumentation and Data Collection Metabolic Costs The metabolic costs were determined through indirect calorimetry by using a breathing gas analysis system (Cosmed srl, Quark CPET, Rome, Italy), measuring the rate of oxygen consumption and carbon dioxide production.