Flat footedness is divided into acquired flat foot which is a condition which develops after we have attained maturity and congenital flat foot which is a common condition and often not of pathological significance. Adult flat foot has many potential causes which include dislocation and fractures, foot abnormalities, arthritic changes and neurological conditions. The commonest cause however of this foot problem is a dysfunction of one of the foot tendons, the posterior tibial muscle tendon. The methods by which the tibialis posterior tendon malfunctions are varied and ascribed to degeneration, inflammation or trauma.
In scientific studies changes to the tibialis posterior tendon have been shown to be more frequent in people who are diabetic, overweight, have had operations or trauma to the midfoot and have a history of taking steroids. A higher incidence is also shown in patients who have an arthritic condition in the group of spondyloarthropathies, having a history in the family of psoriasis or joint related inflammatory conditions. A mechanical cause may also be common as older people without any explanatory pathology can also suffer from this tendon dysfunction. Rheumatoid arthritis sufferers may show this in 10% of cases.
Just underneath the inside bones of the ankle and for a short distance forward there is an area of reduced blood supply which affects the tendon which runs through this area, perhaps helping to explain why degenerative changes might be more important in this area. This tendon forms part of the support for the medial arch of the foot which has both active and passive components. The passive or static supports for the stability of the arch are the plantar fascia, the short and the long plantar ligaments and the spring ligament, also called to calcaneonavicular ligament. The spring ligament supports the ankle bone or talus and prevents it from sliding downwards or inwards.
The tendon of the posterior tibialis muscle is the most powerful support for the medial arch of the foot. Muscle contraction through the tendon raises the inside of the medial arch of the foot and turns the foot inwards if it is not planted. Loss of this muscle function from a rupture or damage to the tendon deprives the foot arch of its most powerful supporting influence which allows the muscles which turn out the foot to act without restraint. The foot can then undergo three main postural alterations: flattening of the medial foot arch; turning out of the forefoot and turning out of the hindfoot area.
All these changes lead to a loss of the ability of the rearfoot and the forefoot to be a rigid and stable platform which changes the patient's pattern of gait, making it less efficient. The tibialis posterior muscle has a powerful function and once this is reduced or lost the gastrocnemius and soleus, the main calf muscles, perform their action further back in the foot than normal. The talus or ankle bone is then moved inwards and down, stretching the spring ligament and gradually allowing the medial foot arch to lower as the joints move into different relationships with each other.
Initial patient report on presenting with problems secondary to acquired flat feet is that of a painful and swollen inner border of the ankle region and foot, particularly when on their feet. Patients may mention they have noticed a steady lowering of the foot arch and that they are taking weight on the inner part of the foot now. A reduction in strength and the pain may cause a patient to limp and reduce the effectiveness of push off in gait, with examination of the soles of the shoes indicating the abnormalities in patterns of walking. Foot assessment by a physiotherapist starts with the assessment of the feet and arches in standing.
If the foot is seen from behind the heel it is typical to be able to see the two outer toes, and seeing more means the forefoot is turned outwards. The physiotherapist will measure the angle made by the lower leg in relation to that of the heel, an angle which is increased as the heel bone turns outwards, a position known as valgus. On going up on tiptoe a normal foot performs a slight inward deviation of the heel as the large calf muscles power up.
In scientific studies changes to the tibialis posterior tendon have been shown to be more frequent in people who are diabetic, overweight, have had operations or trauma to the midfoot and have a history of taking steroids. A higher incidence is also shown in patients who have an arthritic condition in the group of spondyloarthropathies, having a history in the family of psoriasis or joint related inflammatory conditions. A mechanical cause may also be common as older people without any explanatory pathology can also suffer from this tendon dysfunction. Rheumatoid arthritis sufferers may show this in 10% of cases.
Just underneath the inside bones of the ankle and for a short distance forward there is an area of reduced blood supply which affects the tendon which runs through this area, perhaps helping to explain why degenerative changes might be more important in this area. This tendon forms part of the support for the medial arch of the foot which has both active and passive components. The passive or static supports for the stability of the arch are the plantar fascia, the short and the long plantar ligaments and the spring ligament, also called to calcaneonavicular ligament. The spring ligament supports the ankle bone or talus and prevents it from sliding downwards or inwards.
The tendon of the posterior tibialis muscle is the most powerful support for the medial arch of the foot. Muscle contraction through the tendon raises the inside of the medial arch of the foot and turns the foot inwards if it is not planted. Loss of this muscle function from a rupture or damage to the tendon deprives the foot arch of its most powerful supporting influence which allows the muscles which turn out the foot to act without restraint. The foot can then undergo three main postural alterations: flattening of the medial foot arch; turning out of the forefoot and turning out of the hindfoot area.
All these changes lead to a loss of the ability of the rearfoot and the forefoot to be a rigid and stable platform which changes the patient's pattern of gait, making it less efficient. The tibialis posterior muscle has a powerful function and once this is reduced or lost the gastrocnemius and soleus, the main calf muscles, perform their action further back in the foot than normal. The talus or ankle bone is then moved inwards and down, stretching the spring ligament and gradually allowing the medial foot arch to lower as the joints move into different relationships with each other.
Initial patient report on presenting with problems secondary to acquired flat feet is that of a painful and swollen inner border of the ankle region and foot, particularly when on their feet. Patients may mention they have noticed a steady lowering of the foot arch and that they are taking weight on the inner part of the foot now. A reduction in strength and the pain may cause a patient to limp and reduce the effectiveness of push off in gait, with examination of the soles of the shoes indicating the abnormalities in patterns of walking. Foot assessment by a physiotherapist starts with the assessment of the feet and arches in standing.
If the foot is seen from behind the heel it is typical to be able to see the two outer toes, and seeing more means the forefoot is turned outwards. The physiotherapist will measure the angle made by the lower leg in relation to that of the heel, an angle which is increased as the heel bone turns outwards, a position known as valgus. On going up on tiptoe a normal foot performs a slight inward deviation of the heel as the large calf muscles power up.
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