Hi Reader,

Shear plays a critical role in blister formation and managing it properly is key to prevention. This month's newsletter explores how to reduce shear where it counts, without compromising foot function.

From ENGO’s pinpoint friction relief to Spenco’s pressure-reducing and shear-absorbing insoles, to Injinji’s unique toesocks, we highlight the tools and insights that help you make evidence-informed recommendations for your patients. Plus, don’t miss the latest findings from our friction coefficient testing, now available for replay.

I hope you enjoy this one!

Rebecca

SMART FRICTION CONTROL

Targeted Friction Management

Friction is essential for traction inside the shoe, but when it’s too high in the wrong spots, it leads to blisters.

That’s why friction management should be targeted, not global.

🧴 Global reduction (like applying lubricant across the whole foot) can interfere with propulsion, reducing efficiency and increase the risk of injury.

🎯 Targeted reduction: Products like ENGO Blister Patches let you focus on the specific high-friction areas causing blisters while preserving natural foot function everywhere else.

ENGO’s ultra-low-friction surface:

• Applies directly to your shoe or insole (not your skin)
• Provides long-lasting relief (300+ miles of use)
• Helps reduce the coefficient of friction where it matters most
• Keeps the rest of the foot stable for normal propulsion, braking, and direction changes

For runners, hikers, tennis players, netballers, and anyone experiencing friction-related foot issues, ENGO is a practical and performance-friendly solution.

FRICTION-REDUCING INSOLES

Spenco Insoles

Blister prevention isn’t just about friction reduction. Some materials absorb shear, so there's less shear left to occur within the foot.

Spenco’s closed-cell neoprene insoles and orthosis covers are a textbook example of how to absorb shear on the plantar surface.

✅ Reduce pressure

By spreading load over a larger surface area, Spenco lowers compressive force—one half of the friction equation (F = μN)

✅ Absorb shear

Spenco’s soft, springy material deforms slightly with movement. This helps the skin surface move in-sync with the overlying bone at an earlier moment, reducing the magnitude of shear experienced in the soft tissues of the foot.

🧪 Clinical research confirms it:

• Just 0.5% of athletes developed blisters with Spenco vs 25% without
• In Coast Guard training, Spenco reduced blister/callous rates to 5% (vs 17% with Poron and 33% with no insole)

As shown in the blister prevention strategies framework, Spenco provides two blister-causing mechanisms:

✔️ Lower pressure (and therefore firction force)

✔️ Absorb shear

💡 Bonus: Flat Spenco insoles are also a smart fix for heel edge blisters caused by contoured heel cups, and so common in endurance walking activities.

🧦 CHOOSING SOCKS

Toesocks for Blister Prevention

Toesocks are a smart choice for preventing blisters between the toes, and Injinji stands out for its anatomical fit, high-quality materials, and activity-specific designs.

Here’s how to guide your patients in choosing the perfect toesock for their specific needs:

✅ Fibre Type

• Coolmax® (synthetic): Excellent moisture-wicking performance. Found in the Run, Trail, Liner+Runner, and Compression series.
• NuWool® (natural): Merino blend that insulates and regulates moisture. Used in the Outdoor and Liner+Hiker series.

✅ Sock Weight (Thickness)

• Lightweight: Thin and breathable – ideal for warm weather or layering
• Original Weight: Light padding throughout for everyday use
• Midweight: Extra cushioning under the heel and forefoot
• Ultra Run: Full terry construction – maximum comfort for long distances

✅ Activity-Specific Features

• Trail Series: Midweight with a double cuff to keep debris out
• Outdoor Series: Warm, NuWool-based protection for hiking
• Liner+Runner & Liner+Hiker: Built-in double-sock systems for more comprehensive friction control

With precise toe contouring, two interdigital sock layers, and no irritating seams, Injinji toesocks help reduce shear and friction where it matters most.

OFFICE HOURS

COF Shockers

In this session, Rebecca revealed the results of recent coefficient of friction (COF) testing across six sock types and a range of blister-care materials used by podiatrists and their patients. From tapes and insole covers to double-socks and silicone gel, we explored which combinations offer the best blister protection via the COF-reduction mechanism, and why material choice matters more than you might think.
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​🎥 Watch the replay here: COF shockers - The socks and tapes you thought were low friction… aren’t.​

PARTNER WITH US FOR FREE!

Socks

Certain have the potential to manage moisture, reduce pressure and absorb shear.

The good news? We stock some fine options and you can access them at exclusive wholesale prices.

✅ Injinji Toesocks – Separate the toes to reduce interdigital friction; moisture-wicking and ideal for toe blisters

✅ Balega Socks – Soft, synthetic blend with low COF and high breathability; great all-rounder for active patients

✅ Smartwool Socks – Natural thermoregulation with a mid-range COF; helps manage moisture and friction on long walks

✅ ArmaSkin Socks – A COF-reducing system that lowers shear between sock layers (not skin); ideal for multi-area blister relief

Becoming a Blister Prevention Wholesale Partner is completely free! Join the growing network of practitioners who are enhancing their blister care offerings while maintaining healthy margins.

Sign up to Blister Prevention Wholesale here.

BLISTER PREVENTION

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