Flat Feet Explained- Part Two

As the calf muscles contract and a person rises up on tiptoes to bring the bodyweight over the heads of the metatarsals there is normally an inward deviation of the heel region. This inward deviation will not be present if there is a significant dysfunction of the tendon of the posterior tibial muscle and the patient may not be able to attain the position or can do so in part and with pain. The physio will move on to palpating the tendon insertion with the leg up on a plinth, searching for swelling, pain or tenderness. To test muscle power the physio will resist the inward and downward action of the foot.

Palpation of the length of the tendon during the muscle power testing is performed to check its integrity, followed by measuring the dorsiflexion of the ankle with a straight knee which is usually at least twenty degrees. Longer term flat foot can mean this is limited as the foot has been in a slight downward and outward position for long enough to develop a contracture, a tightening up of the soft tissues. The forefoot may also be subject to the development of an abnormal posture over time and should be reviewed. If the patient has pain, some deformity, problems with gait and managing footwear then treatment may be appropriate.

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.

Settling down of the inflammatory and acute phase permits the use of in shoe orthotics to maintain foot posture and a referral to physiotherapy to increase joint ranges of movement and develop increased strength. The rear foot posture can be controlled more precisely if a flexible and painful dysfunction develops by using an ankle foot orthosis or AFO. The next stage of dysfunction, an increasingly rigid deformity, can be managed by more extensive and customised bracing which can extend to above the knee. Such conservative forms of management are the choice for individuals who demand less physically from their feet.

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.

Rupture of the tendon can be managed by trimming up the tendon stumps and performing a repair with the tendons end to end. Avulsion of the tendon from its attachment on the navicular can be managed by re-attaching the tendon to its bony insertion. Other tendons in the anatomical area can also be used to reinforce the tendon which is lacking, thereby increasing the tendon function. Osteotomy of various bones can be performed with the aim of restoring the normality of the interrelationships between the bones, allowing normal alignment, reduced stresses across the ligamentous structures and more chance for surgical changes to the soft tissues to cope.

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 Physiotherapists 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 Sheffield visit his website.