A heel lift is a wedge-shaped insert placed inside a shoe, directly beneath the heel. This device elevates the heel bone, changing the angle of the foot and the alignment of the leg and body. By altering biomechanics, the lift helps redistribute pressure, modify gait patterns, and address musculoskeletal issues. The therapeutic purpose is to restore balance or reduce strain on soft tissues by influencing the kinetic chain from the foot up to the spine.
Primary Functions
One main reason for using a heel lift is to compensate for a Leg Length Discrepancy (LLD), where one leg is measurably shorter than the other. This difference can be structural (bone length) or functional (muscle imbalances or joint issues). When placed in the shoe of the shorter leg, the lift helps level the pelvis and spine, mitigating compensatory adjustments in gait and posture. This can alleviate pain in the lower back, hips, or knees caused by uneven weight distribution.
The second primary function involves reducing tension on the posterior soft tissues of the lower leg. Raising the heel effectively shortens the functional length of the calf muscle group, immediately decreasing mechanical stress on the Achilles tendon and the plantar fascia. This reduction in tensile load provides relief for conditions such as Achilles tendinitis and plantar fasciitis. For Achilles issues, the lift limits dorsiflexion, protecting the tendon from excessive stretching during walking or running.
Material and Design Variations
Heel lifts come in various materials suited to specific applications. Solid plastic or firm cork are preferred for LLD correction because they are durable and resist compression, ensuring the added height remains constant. Maintaining a fixed height is important when correcting a structural imbalance, as compression would negate the intended correction.
Materials like viscoelastic gel, foam rubber, or silicone are used when the primary goal is shock absorption, cushioning, and mild tension relief. Adjustable lifts feature a stacked, layered design, often made of firm foam or plastic, allowing the user to fine-tune the height in small increments. This adjustability is useful during the initial phase of treatment when the body is adapting to the new alignment.
Lifts are categorized as internal (placed inside the shoe) or external (built onto the outer sole). Internal lifts are suitable for smaller height differences, typically up to 10–12 millimeters. When a correction greater than 10 millimeters is required, an external modification to the shoe’s sole is often necessary to maintain foot stability and fit, as greater internal heights can cause the foot to slip out.
Determining the Correct Height
Determining the correct heel lift height is a clinical process, ideally performed under the guidance of a healthcare professional. For LLD, the discrepancy is measured using methods like clinical block tests or radiographic imaging. A common starting principle is to use a lift that is only a portion of the measured difference, sometimes half, to account for the body’s long-term adaptations.
An incremental approach is recommended, where the lift height is increased gradually over several weeks to allow the spine and pelvis time to accommodate the change. Adding too much height too quickly can be counterproductive, potentially causing new discomfort or strain. Adjustable lifts facilitate slow, controlled increases, such as adding 2-3 millimeters at a time.
For conditions like Achilles tendinitis, the required height is generally smaller, focusing on the minimum elevation needed to immediately reduce tension and alleviate pain. The goal is immediate relief, not full correction, so the lift is often used temporarily until the soft tissues heal. Patient feedback and comfort are important factors, as the body’s response measures the lift’s effectiveness.
Practical Application and Placement
Once the appropriate height is established, proper placement within the shoe is necessary. The lift should sit securely in the very back of the shoe, directly under the heel bone (the heel counter area). If the shoe has a removable insole, placing the lift underneath the insole helps keep it firmly in position and provides a more gradual feel under the foot.
Footwear compatibility is important; closed-back shoes, such as athletic shoes or lace-up boots, are best suited for accommodating lifts. Open-backed shoes like sandals generally do not provide the necessary structure to secure the lift or contain the heel, making them unsuitable for therapeutic use.
For LLD, the lift is typically placed only in the shoe of the shorter leg to restore symmetry. However, for bilateral conditions like Achilles tendinitis, a small lift may be placed in both shoes to reduce tension equally. For long-term LLD correction, using the same elevation in all regularly worn footwear maintains consistent body alignment.