The painful rubbing sensation on the back of your foot caused by certain footwear is a common mechanical injury. This irritation results from continuous friction between your skin and the shoe material, typically the stiff part at the back. The resulting damage can range from simple redness to a significant injury that compromises the skin’s protective barrier.
What Is the Resulting Injury Called?
The primary injury that occurs when a shoe rubs your heel is called a friction blister. This is an injury that happens beneath the skin’s surface layers. The continuous, repetitive motion creates shear forces that cause a mechanical separation between the skin layers, allowing plasma-like fluid to fill the resulting void, which forms the recognizable bubble. If the friction immediately strips away the top layer, the result is a friction abrasion—an open, raw scrape or sore. Both blisters and abrasions represent a failure of the skin tissue due to excessive shear stress, requiring careful attention to prevent infection.
Mechanical Reasons for Heel Friction
The mechanism that causes this injury is a combination of bone movement and high friction forces within the shoe. As you walk, friction between the skin and the shoe lining prevents the skin surface from moving synchronously with the bone, causing the soft tissue to stretch and deform with each step. This lack of synchronous movement leads to mechanical fatigue within the skin layers.
Improper shoe sizing is a frequent cause, as shoes that are too loose allow the heel to slide up and down excessively, increasing shear cycles. Conversely, shoes that are too tight create concentrated pressure points, which also increases the friction force at a specific spot. Stiff materials, particularly the rigid heel counter found in many new shoes, also contribute by resisting the foot’s natural movement.
Immediate Treatment for Heel Blisters and Abrasions
The goal of immediate care is to protect the injured area from further damage and infection. If a friction blister is intact and not causing significant pain, leave the blister roof in place, as this provides a natural, sterile barrier against bacteria. The area should be covered loosely with a soft bandage or a donut-shaped piece of moleskin to cushion it and redirect pressure around the blister.
Draining and Open Blisters
If the blister is large, extremely painful, or has already torn open, drainage may be necessary to relieve pressure. To drain an intact blister, sterilize a fine needle with rubbing alcohol and gently prick the edge of the blister in a few spots, allowing the fluid to drain while leaving the skin flap intact. For both drained and spontaneously burst blisters, wash the area gently with soap and water, and apply an antibiotic ointment or petroleum jelly to keep the site moist. Cover the area with a nonstick bandage or sterile gauze, changing the dressing daily and watching for signs of infection.
Strategies for Preventing Shoe Rub
Proactive measures focus on reducing the shear forces and friction between the heel and the footwear. Selecting the correct shoe size is important; try on shoes later in the afternoon when feet are slightly swollen to ensure a proper fit. The heel should feel secure within the shoe with minimal vertical movement.
Specialized socks, such as synthetic blends, reduce friction by wicking away moisture, unlike cotton which retains it. Using anti-blister balms or applying adhesive products like moleskin directly to vulnerable heel areas creates an artificial friction barrier. New shoes should also be broken in gradually by wearing them for short periods to soften stiff materials and allow the shoe to conform to the foot’s shape.