Shop Knee Pain Achilles Tendonitis Arch Pain Arthritis Athlete’s Foot Blisters Callus Cavus Foot HomeConditionsKnee Pain X-Line TPD Insoles The TPD insole is an orthotic device designed for Tibialis Posterior Dysfunction, a condition that can cause rapidly developing flat feet and pain on the inside of ankle, arch and/or shin. £28.95 + More Stay one steap ahead in the treatment of foot and lower limb conditions. Call the HealthyStep team on 01457 839549