Reliability and validity of the Stryd Power Meter during different walking conditions

The Styrd Power Meter is gaining special interest for on-field gait analyses due to its low-cost and general availability. However, the reliability and validity of the Stryd during walking on positive slopes using different backpack loads have never been investigated. Is the Stryd Power Meter reliable and valid for quantifying gait mechanics during walking on positive inclines and during level walking incorporating load carriage? Seventeen participants from a police force rescue team performed 8 submaximal walking trials for 5-min at 3.6 km·h−1 during different positive slope (1%, 10% and 20%) and backpack load (0%, 10%, 20%, 30% and 40% of body mass) conditions. Two Stryd devices were utilized for reliability analyses. Validity of cadence and ground contact time (GCT) were analyzed against a gold standard device (Optojump). The Stryd demonstrated acceptable reliability [mean bias: