At the same speed of 5.4 mph(8.6 km/h), participants ran in standard sneakers but walked in Moonwalkers Dusk. Walking in Moonwalkers Dusk produced lower landing impact, less lower-limb mechanical work, and a lower heart rate and perceived exertion than running in sneakers at the same speed.

This was a short laboratory comparison involving five healthy participants aged 18–35. Each treadmill condition lasted four minutes. Motion and force analyses used minutes two through three, when participants had reached steady-state movement; mean heart rate was calculated across the full four-minute trial.

Four numbers that frame the result

Peak vertical force −43.4% Maximum vertical force during each step	Average loading rate −50.6% How quickly vertical force rose after contact
Stance-phase joint work −74.7% Hip, knee, and ankle mechanical work	4-minute mean heart rate −19.9 bpm Same speed, without the jump into running intensity

Values are descriptive five-participant means at 8.6 km/h( 2.4 m/s or 5.4mph). This study did not include inferential statistical testing.

The difference comes from gait, not from doing less

At 8.6 km/h, participants ran in standard sneakers but maintained a walking gait in Moonwalkers Dusk. Running includes an aerial phase in which both feet leave the ground, followed by a landing. Walking retains ground contact with at least one foot. A recent review describes the walk-to-run transition as a broader reorganization of the locomotor system as speed increases, rather than a single speed threshold.¹

This difference in gait is central to interpreting the results. Running generally produces a higher impact peak, requires the hip, knee, and ankle to absorb and generate more mechanical energy, and raises heart rate more steeply. This study did not compare running ability, and it did not test whether Dusk produces a smaller workout. It compared two ways of covering the same speed: one by running, one by walking with powered assistance.

Peak vertical force was nearly one bodyweight lower per step

Vertical ground reaction force is the upward force the ground applies to the body when the foot is in contact. Its peak indicates the largest instantaneous vertical load the body must manage during a step. A systematic review and meta-analysis found that, even within running, foot-strike pattern changes impact loading rate and redistributes mechanical demand between the knee and ankle.²

At 8.6 km/h, peak vertical force was 2.18 times bodyweight in sneakers and 1.24 times bodyweight in Moonwalkers Dusk—a difference of approximately 0.95 bodyweight, or 43.4%.

8.6 km/h condition	Peak vertical force	Average loading rate
Standard athletic shoes · running	2.18× bodyweight	Reference
Moonwalkers Dusk · walking	1.24× bodyweight	50.6% lower

Loading rate tells a related but different story: it measures how quickly force rises after the foot contacts the ground. Under the Dusk condition, the force was not only smaller; it also built more gradually.

In plain language: each step involved less of a running-style impact, and that impact arrived less abruptly.

These findings do not establish that injury risk is lower. A 2022 Sports Medicine systematic review found that biomechanical risk factors are injury-specific and that evidence remains limited for most factors.³ The present data show that repeated external mechanical loading of the lower limbs was substantially lower under the high-speed Dusk condition.

Powered propulsion took over much of the work normally performed by the legs

Each step can be divided into stance, when the foot is on the ground, and swing, when the leg moves forward to prepare for the next contact. Most lower-limb mechanical work occurs during stance.

At 8.6 km/h, total absolute work across the hip, knee, and ankle during stance was 1.544 J/kg in standard sneakers and 0.390 J/kg in Dusk—approximately one quarter as much. Stance-phase ankle work fell by 94.1%, consistent with the powered footwear taking over much of the support and propulsion normally supplied by the ankle and calf–Achilles complex.

Mechanical work at 8.6 km/h	Standard shoes	Dusk	Difference
Combined hip, knee, and ankle work during stance	1.544 J/kg	0.390 J/kg	−74.7%
Stance-phase ankle work	Reference	Lower	−94.1%
Combined hip, knee, and ankle work during swing	Reference	Lower	−55.3%

Lower total work does not mean that every joint demand was lower at every instant. The footwear adds mass at the end of the leg, which can increase local control demands during swing. At 8.6 km/h, all five participants also showed higher positive hip work during stance, and several joint-level swing peaks increased. Even so, cumulative three-joint work across swing was 55.3% lower, while the reduction during stance was substantially larger than those local increases.

Research on a different class of wearable assistance has shown that personalized ankle-exoskeleton support can increase natural walking speed and reduce energy used per distance.⁴ This independently supports the broader principle that external assistance can alter locomotor cost, but the device and outcome measures differ and do not validate the Dusk results. Mechanical joint work is not the same as calorie expenditure, and this study did not directly measure metabolic energy use.

How movement was measured

Reflective markers were used to track lower-limb and footwear motion. A Qualisys motion-capture system recorded marker trajectories, while a Bertec instrumented treadmill measured forces underfoot. The synchronized data were then reviewed as three-dimensional motion and joint-mechanics models.

Reflective markers track the position and movement of the lower limb and Dusk in three-dimensional space.

The analysis view combines the three-dimensional model, synchronized laboratory image, and marker trajectories.

The same speed, without the jump into running intensity

At 5.4 km/h, heart rate was similar between conditions. At 8.6 km/h, the difference widened: mean heart rate across the full four-minute trial was 139.3 bpm while running in sneakers and 119.3 bpm while walking in Moonwalkers Dusk. That is still a working heart rate at a running-range speed. The difference is that Dusk did not require the extra intensity spike that came with switching from walking to running.

Heart rate was recorded with the Polar Verity Sense. A 2024 study comparing optical sensors with medical-grade ECG found high overall validity, including for the Verity Sense, while also identifying activity- and intensity-specific differences.⁵

8.6 km/h measurement	Standard shoes · running	Dusk · walking	Difference
Four-minute mean heart rate	139.3 bpm	119.3 bpm	−19.9 bpm
Peak heart rate	167.8 bpm	137.4 bpm	−30.4 bpm
Minutes 2–3 mean heart rate	150.6 bpm	132.8 bpm	−17.8 bpm
Mean Borg RPE	6.0	3.8	−2.2

Raising speed from 5.4 to 8.6 km/h added 34.6 bpm in standard sneakers but only 12.2 bpm in Dusk. At the lower speed the two conditions were similar. The gap opened once the standard-shoe condition became a run.

Perceived exertion was recorded with the Borg RPE scale, which is sensitive to how the scale is anchored and is best read alongside physiological measures.⁶ At 8.6 km/h, all five participants reported a lower RPE in Dusk, alongside a lower mean heart rate.

This is lower intensity at the same speed, not less exercise. Speed and duration were fixed, so the test measured the cost of covering that pace—not how much a person would do in a day. Heart rate still climbed with speed, and anyone wanting more stimulus can go longer or farther.

The differences were larger in the higher-speed condition

5.4 km/h · both walking Peak vertical force was 16.6% lower in Dusk. Mean heart rate and perceived exertion were broadly similar.

8.6 km/h · run vs walk Peak vertical force was 43.4% lower. Mean heart rate was 14.3% lower. Mean RPE was 3.8 instead of 6.0.

The clearest conclusion from this test is that when the standard-shoe condition changed from walking to running, Dusk still held the same speed with a walking gait. Impact, joint work, and heart rate were lower because the task stayed a walk, not because participants stopped working.

 

Fast walking, without the extra cost of running

At the higher test speed, three separate result sets pointed in the same direction. Lower peak force and loading rate indicated less running-style impact. Lower cumulative joint work indicated that the footwear took over much of the push that the legs otherwise supply in running. Heart rate and RPE were lower at the same speed, but they were not flat: Dusk still produced a working cardiovascular response while remaining a walk.

Together, these findings suggest that Moonwalkers Dusk does more than increase walking speed. It lets people cover a running-range pace without taking on the extra impact, joint work, and intensity spike that came with running in this test. That is a different exercise profile, not the absence of one.

Discover Moonwalkers Dusk

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References

These papers support the technical context for gait transition, impact and joint loading, wearable assistance, heart-rate device validity, and RPE. The Moonwalkers Dusk values reported in this article come from the internal study and are not validated by these external publications.

1. Voigt M, Hansen EA. The puzzle of the walk-to-run transition in humans. Gait & Posture. 2021;86:319–326.

2. Xu Y, Yuan P, Wang R, et al. Effects of foot strike techniques on running biomechanics: a systematic review and meta-analysis. Sports Health. 2021;13(1):71–77.

3. Willwacher S, Kurz M, Robbin J, et al. Running-related biomechanical risk factors for overuse injuries in distance runners: a systematic review considering injury specificity and the potentials for future research. Sports Medicine. 2022;52(8):1863–1877.

4. Slade P, Kochenderfer MJ, Delp SL, Collins SH. Personalizing exoskeleton assistance while walking in the real world. Nature. 2022;610:277–282.

5. Neudorfer M, Kumar D, Smeddinck JD, et al. Validity of four consumer-grade optical heart rate sensors for assessing volume and intensity distribution of physical activity. Scandinavian Journal of Medicine & Science in Sports. 2024;34(11):e14756.

6. Malleron T, Har-Nir I, Vigotsky AD, Halperin I. Rating of perceived effort but relative to what? A comparison between imposed and self-selected anchors. Psychology of Sport and Exercise. 2023;66:102396.

How to interpret these findings: This was a short laboratory comparison involving five healthy participants aged 18–35 on a level treadmill, not a clinical trial. The article reports descriptive group means; the source report did not provide inferential statistical testing. The findings should not be generalized to broader populations or interpreted as proof of injury prevention, disease treatment, or a clinical outcome.

Study design: within-participant comparison of standard sneakers and Moonwalkers Dusk at matched treadmill speeds. Measurement systems: Qualisys motion capture, Bertec instrumented treadmill, and Polar Verity Sense heart-rate monitor.

Ethics committee approval documentation can be provided upon request.