Ultra Slim
Classic dress device — a thin, lightweight semiflexible carbon frame for the narrowest, lowest-volume shoes, built congruent to the foot.
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The thinnest frame for the narrowest shoes.
The Ultra Slim is the classic dress device designed for very low-volume shoes. A semiflexible carbon frame keeps the orthotic thin and lightweight while still providing excellent support — letting it fit narrow fashion footwear where other devices can't.
Thin, light, and strong. The carbon Ultra Slim brings congruent, custom support to the lowest-volume shoes — built from the patient's own foot model, not an average, and modifiable at the clinician's discretion.
Dress flats & very low-volume shoes
A shallow heel cup and met-length shell make this the thinnest device in the Dress range — for the narrowest fashion shoes.
Thin, lightweight carbon frame
The semiflexible carbon shell delivers excellent support at minimal thickness and weight.
Rigidity to order
The frame can be built semi-flexible to very rigid on request to control biomechanical pathologies.
Functional correction, congruent to the foot.
Built from a positive model of the patient's foot and modifiable at the clinician's discretion — scanned and ordered through FootID Pro.
Shape is everything.
What separates Root from generic dress insoles is the precise morphological shape captured from the patient's foot — held in the exact clinical position the clinician chose. No averaging. No guesswork.
The Ultra Slim is built from a positive model of the patient's foot and can be modified at the practitioner's discretion. This means every device fits the patient it was made for — not an approximation.
Modern Root
Width adjusted considering both borders. Default for all Root models.
Traditional Root
Justified to the lateral border. Used for specific clinical indications at practitioner discretion.
Modern Root shape process
- Forefoot balanced to rearfoot — forefoot-to-rearfoot relationship is optimised as the first step in shape modification.
- Fat pad expanded ~3mm — ensures the device fills the calcaneal contour precisely for the patient's heel.
- Arch lowered ~3mm — creates optimal heel-to-arch-to-met-head geometry. Not applied to foam impressions.
- Width tuned to both borders — medial and lateral widths considered together, giving a foundation that matches the patient's actual foot width.
*Subtalar joint neutral is found by palpating the talus head against the navicular. The neutral position can present many joint-on-joint and bone-on-bone relationships and varies from person to person. An everted or inverted calcaneus may be a neutral position for an individual person. Biomechanical evaluation required.
How you hold the foot is what we build.
Root is not just the orthotic — it's the clinician's positioning, captured and preserved in the device. After scanning, FootID Pro asks the questions no other lab asks.
After every scan, we need to know:
- Was the subtalar joint held in neutral?
- Was the midtarsal joint maximally pronated — loading the 5th metatarsal head?
- Was the midtarsal joint maximally supinated — loading the 1st metatarsal head?
- Was the forefoot brought perpendicular to the rearfoot?
- Was a forefoot-to-rearfoot balance bisection achieved at 90° relative to the calcaneal bisection?
The positioning of those 19 joints in the foot is what gives us the shape.
CAD/CAM fabrication
- Scan or cast captured — clinician captures foot morphology via FootID Pro, holding the subtalar joint in the chosen clinical position.
- Shape modification applied — forefoot balanced to rearfoot, fat pad expanded, arch adjusted using Root's design process.
- Technical staff review — every device reviewed against Traditional Root, Modern Root, Blake Inverted, or Accommodative principles.
- Fabricated to the shape — the polypropylene frame and EVA post are fabricated to match the submitted shape precisely.
See how the scan becomes an order.
Watch Kevin capture a foot, confirm the clinical position, and send a Root order — start to finish.
Variation converted to anatomy-match accuracy by impression & fabrication method
How closely each method preserves the patient’s intended foot shape. Scale: 0–100%, where 100% = optimal congruence.
Plaster bandage is wrapped around the foot in the clinician’s prescribed corrected position, setting into a precise negative of the foot’s contour.
The foot is pressed into a crushable foam box, leaving a negative impression of the plantar surface.
An existing positive model from the patient’s previous orthotics is reused — KevinRoot accepts models from any lab, with frame-contour variance as low as 1%.
A digital scanner such as FootID Pro captures the foot surface as a 3D model.
A fiberglass casting sock is applied over the foot and cures to capture its contour.
Pedobarography captures the patient’s plantar pressure distribution (static or dynamic) at 1:1 scale — used with arch height and shoe size to select a redimold positive model, not to capture true 3D contour.
A direct-molding system using prefabricated, size- and arch-based positive models (33 in total) rather than an individual foot impression.
Heated material is vacuum-pressed over a plaster positive model, drawing it intimately into every contour.
The frame is 3D printed by selective laser sintering (SLS) directly from the CAD-designed digital frame.
A positive model is CNC-milled (CAD/CAM) from an STS, 3D scan, plaster, or foam impression, then the frame is vacuum formed over it.
A CNC machine subtractively mills the frame from a block of polypropylene or EVA per the digital design.
*Redimold has no physical or digital foot impression — patient-foot-to-cast congruent accuracy is unavailable. Variation from positive model to frame is low.
How your patient's foot shape becomes a precision frame.
The journey from clinical capture to finished Ultra Slim frame is where Root's expertise lives. Every step preserves the shape and position the clinician chose for that patient.
- Foot impression captured — the clinician captures the foot using their preferred method. How the foot is held directly determines the congruency of the finished device.
- Positive model created — the impression becomes a physical plaster model or a digital CAD/CAM model. Digital models are stored indefinitely for future pairs.
- Root technicians modify the shape — every modification reviewed against the prescription. Rearfoot post, heel cup depth, and cover selection confirmed per patient.
- Ultra Slim frame fabricated — the semiflexible carbon shell is formed to the positive model. Protex top cover to met length and a suede bottom cover full wrap are applied, forefoot balanced to rearfoot.
FitFoot360 Foot Model
- Root digital model stored indefinitely → recalled for future pairs
- Root technicians modify the digital shape in real-time: arch, heel, width, postings
- Vacuum formed over CAD/CAM positive model, direct milled or 3D printed Root Frame — replicable, consistent, precise
Real-time control over shape, function, and fit.
FitFoot360 gives Root's technicians complete digital control over every dimension of the orthotic frame — in real time. What once required physical carving and guesswork is now precise, repeatable, and stored permanently for every patient.
Digital positive model
Stored indefinitely. Future pairs, replacements, or modifications can be fabricated from the exact same shape without a new impression.
Real-time shape modification
Root technicians control arch, heel, width, and postings directly in the software.
Every parameter visible
Heel cup depth, frame reinforcement, ray cut-outs, flanges, and more are set per patient, not per template.
Plaster and foam digitisation
Physical models can be digitised for permanent storage. Note: digitising may not perfectly replicate the intimate contours achieved when vacuum forming directly over plaster.
Built to their spec. Built for their foot.
Every parameter of the Ultra Slim is set to the individual patient — frame rigidity, rearfoot posting, heel cup depth, and covers are all chosen for that patient's anatomy and weight. Forefoot is balanced to rearfoot and the device is custom congruent to the foot model.
A thin, lightweight carbon shell delivers excellent support at minimal thickness — and can be built semi-flexible to very rigid on request.
Intrinsic rearfoot post built into the shell — rearfoot control with the lowest possible volume for narrow shoes.
A shallow 6mm heel cup pressed from the patient's calcaneus — contributing to the device's ultra-thin profile.
A clean functional shell with no filler — keeping the device as thin as possible for the narrowest fashion shoes.
A thin Protex top cover to met length — durable and low-bulk to keep the overall device profile minimal.
Suede bottom cover full wrap provides a soft interface in high-quality shoes and protects the carbon shell.
The full picture.
Everything you need to prescribe the Ultra Slim.
- Bone deformity
- Foot deformity
- Arthritis
- Musculoskeletal pathology
- Lower extremity pathology
- Poor posture
Recommended for
- Dress flats & very low-volume shoes
- Narrow fashion footwear
- Control of biomechanical pathologies
The Ultra Slim is the classic dress device designed for very low-volume shoes. Its semiflexible carbon frame keeps the orthotic thin and lightweight while still providing excellent support.
A shallow 6mm heel cup, Protex top cover, and met length contribute to its thin design — letting it fit narrow fashion shoes. The frame can be built semi-flexible to very rigid on request, and is finished with a suede bottom cover full wrap.
- L3000 (UCB)
- L3010 (longitudinal/metatarsal support)
- L3020 (arch support)
- L5000 (filler)
Based on configuration. For reference only. Final coding and billing are the provider's responsibility.
Delivery Time
- Standard: 2 weeks
- Expedited: Available on request
Excellent support at the lowest volume.
The Ultra Slim pairs a semiflexible carbon frame with an intrinsic rearfoot post — delivering excellent support and control of the subtalar and midtarsal joints while staying thin and lightweight. The shallow 6mm heel cup cradles the calcaneus and stabilizes the foot at the subtalar joint without adding volume that narrow footwear can't accommodate.
The carbon frame can be built semi-flexible to very rigid on request, and a Protex top cover to met length keeps the overall profile minimal — so the device performs and disappears into the narrowest dress shoes.
The thinnest frame
for the narrowest shoes.
Ultra Slim sits on the Dress frame profile — the lowest-volume Root frame,
built in semiflexible carbon for dress flats and very low-volume shoes.
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