First principle

Gait function measurements were obtained through a level walking task. A 10 m long walkway and software for capturing human motion (First Principle, Northern Digital Inc., Canada) were used to capture the participants’ gait alongside position sensors (Optotrak Certus, Northern Digital Inc., Canada) and force platforms (Bertec Ltd, USA). Motion module marker guide (MusculoGraphics, Inc., USA), which is the standard method for motion analysis [30 (link)], was referenced when placing infrared LED markers (Smart marker, Northern Digital Inc., Canada) on the participants’ legs, as shown in Fig. 4. Participants were asked to walk at their most comfortable pace. Software for Interactive Musculoskeletal Modeling (SIMM, Motion Analysis Corp., USA) was used to extract the gait variables for which an ensemble average of three trials was used as the final value. The variables extracted were the spatio-temporal variables, stance, stride, and swing duration and the subdivisions of the gait cycle. All variables were calculated in reference to the left foot heel contact.Fig. 4

Motion capture and analysis system. A Position sensors and walkway, B lower limb marker placement: lateral and anterior view

Participants’ gait was recorded using software for capturing human motion (First Principle, Northern Digital Inc., Waterloo, ON, Canada) and motion sensors (Optotrak Certus, Northern Digital Inc., Waterloo, ON, Canada), which captured the position of 17 lower-limb markers. The gait parameters of the participants were obtained as an ensemble average of 3 trials of level walking across a walkway (10 m in length) and were processed using Software for Interactive Musculoskeletal Modeling (SIMM, Motion Analysis Corp., Rohnert Park, CA, USA). Spatiotemporal variables and subdivisions of the gait cycle were used to represent the gait function.