Kinematic Testing Methodology & Educational Scope

Last Reviewed: September 2026 • Publishing Organization: UEL HOLDING AS (Org.nr 937 818 750)

1. Force-Plate & Optical Capture Calibration

All stride metrics published on zenithmen.info are derived from instrumented dual-belt treadmill sessions (1000 Hz vertical and horizontal force sampling) synchronized with 8-camera 240 Hz infrared motion capture. Reflective markers are positioned at the calcaneus, fifth metatarsal, lateral malleolus, femoral epicondyle, and anterior superior iliac spine.

2. Mathematical Conventions

• Ground Contact Time (GCT): Defined as the exact interval (in milliseconds) where vertical ground reaction force exceeds 20 Newtons.
• Step Rate (Cadence): Total bilateral footstrikes recorded per 60-second steady-state window at constant belt velocity.
• Vertical Stiffness (k_vert): Calculated as peak vertical ground reaction force divided by the vertical displacement of the center of mass during stance.

3. Athletic & Educational Scope Notice

ZenithStride is an independent sports biomechanics and athletic training publication operated by UEL HOLDING AS in Norway. All calculators, cadence models, and kinematic studies provided on this portal are intended strictly for sports science education, running technique exploration, and athletic coaching discussion.

Runners experiencing acute musculoskeletal pain or joint trauma should consult a certified sports physiotherapist or orthopedic specialist before initiating high-intensity track intervals or altering footstrike geometry.