Foam Resilience (Shock Absorption)
The lower the percentage of resilience, the more the impact and shock are absorbed into the foam, lessening the shock radiating up the leg to the knees, hips and back. ProTech's ShockAbsorb™ foam has superior foam resilience for sustained cushioning at the heel and foot.
Foam Compression Set (Foam Bounce-back)
Describes how well the foam returns to its original shape and thickness following compression. The higher the number, the thinner the foam becomes after compression, resulting in less cushioning and shock absorption.
ProTech's ShockAbsorb™ retains 95% compression set, absorbing the pressure and impact but not transferring back to the muscle, joints and tendons. ProTech's ShockAbsorb™ and Pinnacle's premium foam are superior in returning to original shape and thickness for prolonged, continued comfort and durable wear.
Foam Compression Fatigue (Foam weardown over time)
Foam is compressed to 50% of its original thickness, released, and then compressed again repeatedly. The higher the resulting number, the more it does not recover and becomes thinner, resulting in continued degradation over time.
ShockAbsorb and Pinnacle premium foams retain steady compression return over time for a more lasting, durable product.
Polypropylene Arch Shell
PowerStep's polypropylene arch shell supports and stabilizes both the medial and lateral sides of the foot, and the deep heel cup reduces calcaneal shifting, supporting knees and back. The shell places the foot in proper alignment, reducing stress on ligaments and tendons by creating a more supportive environment around the knee, reducing hyperextension and miniscus grinding.
• Compression Set: ASTM D1056
• Compression Fatigue: Compression Fatigue Apparatus and Instrom 5565
• Resilience: ASTM D2632
• Arch Shell: Clinical Study “Clinical Efficacy and Cost-Effectiveness of Bespoke and Prefabricated Foot Orthoses for Plantar Heel Pain: A Prospective Cohort Study” Kate Ring & Simon Otter