Neuropathy & Landing Gear — the mechanical foundation first
Neuropathy changes
what you feel.
Not what the ground does.
The ground is still flat. Every step still misloads the same subtalar joint axis (the pivot between your heel bone and the bone above it — angled at 42° of inclination and 16° of deviation). Two million people — different conditions, different starting points — walked on the same floor. They got the same answer.
Shop T-100 Landing GearPut them in your shoes. Take a step. Your body will tell you.
95 out of 100 say yes. The other 5 get every cent back.
Or keep reading — the ground problem comes before everything else.
Flat ground is an unnatural surface. For everyone. Every step.
The human foot evolved on varied terrain. The subtalar joint — the hinge below your ankle that governs how your entire body moves above it — requires an asymmetric surface to sequence correctly. Flat ground removes that surface. Every step, thousands of times a day.
The subtalar joint axis runs at 42° from horizontal and 16° toward the body's midline. It is not a symmetric structure — and it has never been designed for a symmetric floor. When that axis is never correctly loaded, the kinematic chain above it — the ankle, knee, hip, and lower back — compensates with every step it takes.
This is the mechanical context for every person who walks on flat ground. Neuropathy, arch pain, knee pain, fatigue — these are different experiences of the same upstream problem. Landing Gear addresses the upstream problem. The geometry. The axis. The foundation that comes before everything else.
It knows what the ground feels like.
Documented by Manter in The Anatomical Record, 1941. The axis that governs how the entire foot, ankle, and leg sequences through each step.
The axis deviates toward the body's midline. Every arch support on the market is symmetric. The geometry mismatch is structural.
No other OTC insole has demonstrated statistically significant STJ correction through controlled 3D gait analysis. Landing Gear is the only one measured.
If your feet feel worse after long hours on hard floors — retail shifts, warehouse work, hospital rounds — that's the flat-ground problem compounding on an already-challenged kinematic chain. The floor is the constant. Landing Gear changes what your foot meets when it lands.
The longest nerves in the human body run through your feet.
Every misloaded step reaches them.
Peripheral neuropathy affects the distal nerves first — the longest pathways, the most mechanically exposed. The foot and lower leg are already the most structurally vulnerable. Flat ground loads them incorrectly 8,000 times a day. The mechanical problem doesn't pause for the nerve problem.
The foot's spring mechanism depends on the subtalar joint rotating through its 42°/16° axis correctly. When that happens, pronation at heel strike stores kinetic energy in the Achilles and plantar fascia — and the supination that follows releases it as forward propulsion. Impact is absorbed, converted, and returned as motion. The peripheral nerves that run through the plantar fascia, along the tibial pathway, and around the ankle are moving through tissue that is working as it was designed to work.
When flat ground forces the STJ outside its optimal axis, the spring mechanism doesn't fully engage. Impact doesn't convert — it transmits upward as compressive force through soft tissue. The same pathways that peripheral nerves run through absorb that load on each stride, at the exact location where neuropathy already makes the tissue more vulnerable to it.
Motor nerve damage from neuropathy weakens the intrinsic foot muscles, altering how the foot plants and how load distributes across the sole. Sensory nerve damage removes the proprioceptive feedback that normally guides micro-adjustments in gait. Both effects make the foot more dependent on correct geometric input from the ground up — and more vulnerable when that input is absent. Landing Gear provides the geometric input. The 42°/16° axis, set at the heel, before the rest of the foot loads.
Heel strikes flat ground. STJ pronates past its optimal axis. The spring mechanism doesn't engage. Compressive force distributes through the soft tissue pathways where peripheral nerves run — 8,000 times a day, at the location neuropathy makes most vulnerable.
Landing Gear sets the 42°/16° geometry at heel contact. The STJ sequences through its correct axis. Pronation stores kinetic energy; supination returns it as forward propulsion. Soft tissue load distributes as it was designed to — through motion, not compression.
Landing Gear does not treat peripheral neuropathy. It changes the mechanical environment the affected nerves operate in — reducing the repetitive compressive tissue stress that flat ground generates at the precise location where neuropathy makes the foot most vulnerable to it.
The entire insole category was built on a model that has since been overturned.
This matters for neuropathy patients specifically — because they are often handed arch supports by well-meaning clinicians following a paradigm that peer-reviewed science formally abandoned in 2023.
The mobile adaptor–rigid lever model was the theoretical foundation for every arch support and orthotic design for decades. It described how the foot should transition from flexible shock absorption at heel strike to rigid lever at push-off — and it prescribed arch support as the mechanism to control that transition.
The model was never experimentally validated. It was a theoretical framework that became a design specification before anyone proved it was correct.
A comprehensive peer-reviewed analysis concluded that the mobile adaptor–rigid lever model is "not supported by available evidence" and called for the scientific community to formally abandon it as the basis for footwear and orthotic design.
This is not a fringe finding. Biological Reviews is published by the Cambridge Philosophical Society — one of the oldest and most respected scientific societies in the world. Every arch support insole — from pharmacy shelf to custom orthotic — was designed around a model this paper invalidated.
doi.org/10.1111/brv.12981 ↗What replaces it? The subtalar joint axis. The 42°/16° geometry documented in 1941 that the entire arch support category has always ignored. Landing Gear was designed around that axis — not the arch. That is not a preference or a marketing position. It is where the lever arm actually is.
"The floor hasn't changed. Your landing gear can."
Shop T-100 Landing Gear — $64.95 Read their stories →When the subtalar joint axis was used as the design specification, the correction was measurable.
BioMechanica LLC, an independent Portland biomechanics laboratory, conducted a controlled 3D motion capture study. n=31 subjects. All differences p << 0.005. No other OTC product has equivalent data.
The study measured tibia–heel deviation — how far each subject's gait deviated from the correct subtalar joint axis range during walking. Conditions included standard EVA foam, the market-leading OTC arch support (Superfeet), and both Protalus Landing Gear models. Twenty NaturalPoint Optitrack cameras at 100fps. 31 subjects measured under all four conditions.
Mean deviation from correct subtalar axis — n=31 subjects
Lower = closer to correct axis range. BioMechanica LLC, 2019. All differences p << 0.005.
| Product | Mean deviation | Visual | vs. standard |
|---|---|---|---|
| Standard EVA foam | 9.2° | Baseline | |
| Superfeet — arch support | 6.8° | −26% | |
| Protalus T-100 Landing Gear | 5.0° | −46% | |
| Protalus M-100 Landing Gear | 3.2° | −65% |
People walking within correct axis range — n=31
How many real people crossed into the mechanical range where the foot can sequence correctly.
"No other OTC insole has demonstrated statistically significant tibia–heel and tibia–arch pronation reduction through 3D motion capture. The geometry-based approach produced results the shape-based approach — including the best-selling arch support — could not."
— Dr. Martyn R. Shorten, Ph.D., Former Director, Nike Sport Research Laboratory · BioMechanica LLC, 2019Landing Gear gives the foot
the geometry it evolved for.
That's the claim. The foot gets the correct geometric environment at heel strike. What happens above that — in the ankle, knee, hip, and back — is what the body does with correct mechanics.
Arch contact happens at midstance — after the heel has already landed and set the starting position of the entire gait cycle. The arch support engages too late to change what the subtalar joint axis does at the decisive moment.
The two heel projections create an asymmetric surface the moment the foot lands — before the arch loads, before the kinematic chain sequences, before the step begins. The geometry is set from contact point one.
Molds, scans, and contours capture the foot standing still. But gait is not a static event — it's a sequence of rotations through a moving axis. Matching the static shape doesn't correct the dynamic motion.
The geometry was developed and validated through the full gait cycle — tested against the subtalar joint axis through every phase of each step. Not molded from a static position. Not a shape. A runway.
Every arch support is the same on both sides. The subtalar joint axis deviates 16° toward the body's midline. Symmetry cannot guide asymmetric rotation. The mismatch is structural and irreversible.
The medial heel projection is higher than the lateral — mirroring the 16° deviation of the subtalar joint axis. Not because it looks right. Because that's the geometry the axis needs to sequence through the correct range.
Flat ground has always made that decision for you.
The geometric foundation for every step
Start with the ground.
Start with T-100.
T-100 Landing Gear puts 61% of people within the correct subtalar joint axis range — compared to 19% with the leading arch support. Independent 3D motion capture. 31 subjects. If you need to step up to M-100's deeper geometry later, you will know.
Shop T-100 Landing Gear — $64.95 Step up to M-100 →Put them in your shoes. Take a step. Your body will tell you.
95 out of 100 say yes. The other 5 get every cent back.
Still not convinced?
Not sure if this is right for your situation?
Talk to someone who knows. Protalus Care is available Mon–Fri 6am–5pm PT.