M. Roser, M. Becker, N. Rokhmanova
Motive Labs,
United States
Keywords: passive exoskeleton, metabolic cost, military footwear, biomechanics, elastic energy storage, wearable biomaterial, human performance augmentation
Summary:
Modern dismounted military operations require personnel to carry equipment loads of 80–120+ pounds over extended durations and challenging terrain, creating cumulative fatigue that degrades speed, endurance, and cognitive performance. Existing models consistently underestimate real-world metabolic cost of military load carriage, and current solutions force operators to choose between mission-essential equipment and mobility. There is an acute need for a lightweight, passive technology that reduces metabolic burden without adding electronic signatures, batteries, or maintenance complexity. We present the FlyBand Propulsion Performance ExoBoot, a human-powered exoskeleton platform that integrates advanced biomaterial elements within a combat boot to amplify locomotion efficiency with zero external energy input. The system employs a patented exotendon mechanism — biomimetic structures that mimic and extend native Achilles and anterior tibialis tendon function — to store elastic energy during the gait cycle and return it as kinetic energy during propulsion. A carbon fiber plate, building on principles from competitive "super shoe" designs that enabled sub-2-hour marathon records, is integrated with the exotendon system and optimized for anatomically correct energy transfer. The FlyBand architecture increases the fraction of elastic energy translated into forward motion. Metabolic cart testing on healthy young adults demonstrated that the FlyBand technology reduces the metabolic cost of walking by 9.06%, comparable to the 7.2% reduction reported for the landmark unpowered ankle exoskeleton by Collins, Wiggin, and Sawicki, but embedded discreetly in a standard military boot with no externally visible components. This metabolic benefit represents a "negative weight" effect equivalent to removing over 9 pounds of carried load, a meaningful operational advantage under heavy military load conditions. These laboratory findings represent conservative estimates; in environments imposing additional thermal stress, such as Arctic operations, benefits are projected to increase substantially as environmental stressors magnify the metabolic advantage. Biomechanical validation through Department of Defense-funded studies at a major research university demonstrated a 6.1% improvement in shuttle drill performance and up to 7.3 degrees of increased range of motion compared to conventional military boots with traditional ankle braces. Lateral ankle support testing validated that the integrated cartridge system provides 7–12 Nm of inversion torque resistance, matching or exceeding semi-rigid ankle braces while preserving full plantar/dorsiflexion motion. Clinical trials of the core technology platform demonstrated a 15% increase in gait speed and a 10% reduction in plantar pressure, metrics that translate directly to reduced fatigue and foot discomfort during extended operations. The platform is agnostic to boot configuration, enabling integration into low-visibility hiker-style boots, riverine canvas designs, and desert configurations across multiple operational domains. Extended field evaluation with Special Operations personnel from multiple Special Forces Groups, Ranger Training Battalion cadre, and law enforcement tactical units has driven iterative design refinement including sole optimization for fast-roping. Built on over a decade of government-funded R&D validated through clinical trials with leading academic institutions, the FlyBand represents a mature technology at TRL 6 with a clear path to operational deployment, providing a passive, zero-signature, low-cost solution to the dismounted soldier's most fundamental performance constraint.