Exoskeletons in the Mountains: Extra Support or Extra Burden?
In December 2024 NATO MW COE staff with the cooperation of Slovenian 132nd Mountain Regiment and Science and Research Center Koper executed field test of a passive exoskeleton.
The use of exoskeletons in military applications has become a focal point of research, driven by the need to enhance their operational capabilities. Wearable passive or active robotic systems are engineered to augment human biomechanics by providing mechanical assistance for load carriage, reducing physiological fatigue, and mitigating the risk of musculoskeletal injuries associated with carrying heavy loads or performing strenuous tasks in complex environments. As many publications pertaining to current military specific exoskeletons have focused on a single activity or task, researchers from military-oriented research institutes from USA, CAN and AUS have proposed a Consensus paper on testing and evaluation of military exoskeletons for the dismounted combatant. Therefore, the aim of this study was to follow the consensus and perform laboratory and field tests with a specific passive exoskeleton (MECH SUIT).
METHODS: 10 healthy male military soldiers (average age: 31.6 ± 9.3 years; body height: 182.1 ± cm; body mass: 83.5 ± 13.9 kg), members of the 132nd Mountain Rgt. volunteered for the study were used as testers. Tests were scheduled for two consecutive days, field testing day and laboratory testing day. Each day, participants performed the same task twice, in a random order. The first time (morning hours) with an exoskeleton and the second time (afternoon hours) without the exoskeleton. In field test participants performed a 1 km move with 16×6 m bounds and 18 m leopard crawl with 35 kg backpack (without exoskeleton) or 50 kg backpack (without exoskeleton). An overall, walking, bound and crawl times were recorded, with heart rate at finish, and a Borg perception (1-20) of effort in legs, arms/shoulders, lower back and overall were assessed at the finish of bounds, crawl and overall move.
RESULTS: Performance in the time trial, bounds, and leopard crawl was worse by 71.4%, 63.5%, and 137.8%, respectively, when using the exoskeleton. Participants also felt more exhausted with the exoskeleton, except for arm effort in bounds and crawling.
CONCLUSION: Soldiers performed worse in field tests, when they were performed with evaluated exoskeleton. Furthermore, perceived rate of effort was also higher when exoskeleton was mounted, especially for legs and lower back. Similar findings were observed also in other passive exoskeletons in movement test. It seems that passive military exoskeleton are effective in off-loading some load from the human body during static standing but not in dynamic walking on flat and sloped surfaces. We could conclude that exoskeleton was ineffective during dynamic hiking, bounding and leopard crawling tasks with 35 kg backpack.
DISCUSSION:
Military exoskeletons are designed to reduce strain on soldiers by offloading some of the weight they carry. But do they really work in real-world conditions? Our latest research suggests otherwise.
When soldiers tested a passive exoskeleton in the field, their performance actually declined. Tasks took significantly longer—63.8% longer for bounding, 71.4% longer for hiking, and a staggering 137.8% longer for leopard crawling. On top of that, wearing the exoskeleton made them feel more exhausted, especially in their legs and lower back.
Similar results have been found in other similar studies on passive exoskeletons. While some designs may help redistribute weight when standing still, they don’t provide much benefit during movement on uneven terrain. Poor fit and design issues often make them ineffective for dynamic activities. Even when adjusted properly, they may not align well with the body, limiting their usefulness.
This isn’t the first time exoskeletons have faced usability challenges. Previous research has shown that many participants struggled to complete walking tests simply because they felt uncomfortable wearing one.
While the idea of an exoskeleton reducing soldier fatigue and injury risk sounds promising, current passive designs don’t seem to be the solution—at least not yet. To truly support military personnel, exoskeletons need better customization and improved functionality for tasks like marching, bounding, and crawling.
Until then, soldiers may be better off relying on their own strength and endurance rather than bulky, restrictive gear.
