If you're one of the many currently in training for the gruelling 100-kilometre Oxfam Trailwalker event taking place between November 19 and 21, you'll want to finish well and, equally importantly, finish in good condition. Dr David Cosman, a sports-injury specialist, has teamed up with Escapade Sports and is offering free assessments of the way you run and walk - and discounted corrective insoles if you do not do so properly. An experienced practitioner in foot orthotics and sports-injury therapy, Cosman has worked with professional and amateur athletes and specialises in detecting and reducing problem foot and ankle mechanics. His goal is not only to help prevent injuries but also to increase sporting capability. Cosman and his team of experts will observe and record movement on the in-store treadmill at Escapade Sports. A technician will then take a mould of your feet, if needed, and an assessment will be made. Cosman says the most common problem is overpronation, which is when the feet roll inward too much. It's estimated that about 80 per cent of the population suffers to some degree from overpronation, which can cause stress and injuries to the knees and back. Cosman says: 'There are 52 bones in the feet. The unique structure of the foot allows it to support the full weight of the human body. It does not function alone but works in conjunction with the ankle, knee, hip and lower back. If one part of the foot fails in its positioning, then biomechanical chain reactions will occur with resulting injuries.' The problem can be rectified, according to Cosman, by corrective insoles, which can be inserted into most shoes. Cosman says his insoles differ from off-the-shelf arch supports in that they are of a higher standard and are custom made. They slide easily into running shoes and provide immediate benefits. The insoles are available at a special introductory price at Escapade Sports this month. The first pair will cost HK$2,000 and subsequent pairs HK$1,600. From next month, they will cost HK$2,500 per pair. The free gait analysis is available at Escapade Sports by appointment. Escapade Sports is at 1/F, Yee Hing Building, 19 Leighton Road, Causeway Bay, tel: 2891 1855; www.escapade.com.hk .