Force instrumented treadmill

In this study we re-analyzed an existing dataset from our prior publication (Matijevich et al., 2019 (link)), in which ten recreational runners performed 30 running conditions where for each condition the running speed and slope was varied. These data are publicly archived (Matijevich et al., 2019 (link)). The dataset includes 5 males and 5 females (age: 24±2.5 years; height: 1.7±0.1 m; mass: 67±6 kg) all of whom reported running a minimum of 10 miles per week. All participants gave written informed consent to the original protocol, which was approved by the Institutional Review Board at Vanderbilt University. To briefly summarize methods, 30-second trials were collected across a range of speeds (2.6–4.0 m/s) and slopes (−9 to +9 degrees), while runners wore their own personal running shoes. Ground reaction forces were collected at 1000 Hz on a force-instrumented treadmill (Bertec), synchronously with unilateral lower-limb kinematics at 100 Hz (Vicon). For further details on the experimental protocol or rationale underlying the running conditions see Matijevich et al., 2019 (link).

Subjects completed testing in randomized walking speed conditions (0.5, 1.0, 1.5, 2.0 m/s) on a Bertec force-instrumented treadmill used to detect heel strike and toe off events for each limb. During testing, additional experimental conditions were completed, but we focus this analysis on continuous walking conditions at different speeds. Each speed conditions were completed, but we focus this analysis on continuous walking conditions at different speeds. Each speed condition lasted 3-minutes with rest periods between. Subjects were instructed to walk normally while restricting unnecessary eye blinks, head motions, or jaw clenching. Because our fastest locomotion condition was near the preferred human walk to run transition speed [45 (link)], we asked subjects to remain walking in each condition. Prior to gait speed conditions, a standing baseline trial was also recorded.