The carbon-shaft of HEPHAISTOS was individually tailored for each subject, taking a plaster cast of the lower leg as anatomical template. Two weeks before study start, subjects were familiarized with HEPHAISTOS and final adjustments were made to facilitate a natural gait pattern. The following link leads to the webpage of the DLR with a video clip showing a subject walking with HEPHAISTOS (http://www.dlr.de/me/en/desktopdefault.aspx/tabid-7389/). The 11 subjects began the intervention in a staggered order, with three subjects per day over 4 days. Throughout the intervention subjects had to wear HEPHAISTOS during all locomotive activities that required loading of the legs. During this time subjects had to visit the DLR at least once a week for routine examinations, for measurements or for a weekly report. Table 2 depicts the time course of the entire study for one subject including all measurements and events.