Flat Feet – Part Two

In the raising up on tiptoe manoeuvre we should observe that as the calf muscle exerts its power to raise the body weight over the metatarsal heads, the heel should adopt a slight inward slant. If the tibialis posterior tendon is not functioning well this inward movement of the heel does not happen and patients may find the action difficult, painful or not possible. The physiotherapist will next check the foot up on the bed and palpate around the insertion of the tendon for pain, tenderness and swelling. Then the foot will be held in an inwards and foot down position and the patient asked to hold it there as the physio applies resistance to test the muscle power.

During the strength test the tendon can be felt to check that it is present all along its route, then the ability of the patient to pull their foot up with the knee straight is measured, typically at least 20 degrees. In flat foot which has been present for some time this movement may be limited with the inward movement, the foot having been in an outward and downward position for long enough to develop tightness, known as a contracture. The forefoot will also be checked for the maintenance of an abnormal position. Treatment will be pursued if the patient has pain and deformity which is disabling, problems with walking or problems managing shoes.

If the patient has painless flat feet and can walk relatively normally then continuing with normal footwear and perhaps insoles will be appropriate. In more acute cases of inflammation of the posterior tibial tendon immobilisation in a plaster of Paris cast, physiotherapy, anti-inflammatory drugs, braces and orthotics are mainstays of treatment. If large stresses are not applied through this area, such as with older people, then conservative treatment in this way can be useful and avoid operation. Pain is the major presenting factor in the early acute stage of this condition and if there is little then weight bearing through the cast may be permitted.

After the acute inflammatory stage has settled down then orthotics can be employed to support the foot posture and physiotherapy started to increase the ranges of motion of tight joints and increase muscle strength. An AFO or ankle foot orthosis can be used to control the hindfoot posture more strongly as the condition worsens towards a painful but flexible foot deformity. As the deformity increases in rigidity then braces which reach to the knee or above and are individually casted may be necessary. These methods are useful for less active or older individuals who do not demand so much of their feet, leaving surgical management in case of failure.

The initial surgical management of the more acute phase of this condition is done by a release of pressure from opening up the tendon sheath and cleaning up any irregularities in the tendon (debridement) and repairing tears. Immobilisation in a below knee cast for three weeks is a typical post-operative management, with the operation aimed at preventing further deterioration of the condition. Once the dysfunction proceeds to a more severe phase there are a very large number of surgical options, little agreed surgical process and a difficult job to ensure a good outcome.

A ruptured tendon can be trimmed and an end-to-end repair performed, or if avulsed from its bony attachment this can be re-attached to the navicular bone. In more complex surgical procedures the tendons of other local muscles can be used as reinforcements to the posterior tibial muscle tendon, so restoring some of its function. The bony anatomy can also be reshaped by performing an osteotomy and realigning the joint relationships, such an operation on the calcaneum or heel bone aimed at restoring alignment, reducing forces through the plantar and spring ligaments and permitting the soft tissues to endure less stress.

The main aim of surgery is to produce a foot which can adapt flat to the ground, take normal footwear and be without pain. It is possible for surgery to cause an over correction or an under correction in foot posture and surgeons must take great care in aligning the various aspects of a more normal foot posture. The aim of surgery in the beginning is to halt progress towards potential tendon rupture.

Jonathan Blood Smyth is the Superintendent of Physiotherapy at an NHS hospital in the South-West of the UK. He writes articles about back pain, neck pain, and injury management. If you are looking for Physiotherapists in Bournemouth visit his website.