Abstract
1. This paper reports the investigation and the results of a line of treatment in thirty feet showing the peroneal spastic flat foot deformity. The questions that have aroused controversy are discussed, the evidence for previous opinions is examined, and some phenomena in relation to this condition are described.
2. It is suggested that previous opinions on this condition have been misleading, and have in many cases been made after incomplete investigation of too few cases.
3. Peroneal spastic flat foot can occur without a developmental tarsal anomaly.
4. The presence of a tarsal anomaly does not necessarily mean that the foot is incorrigibly stiff, and some of these feet show a full range of movement under anaesthesia.
5. There is no evidence from this series of cases to suggest that organic nervous disease or psychiatric disturbances played a significant part in the production of the deformity.
6. There is no evidence to suggest that the deformity is a manifestation of generalised rheumatoid arthritis.
7. This investigation does not reveal the cause of the deformity when the tarsal skeleton is normal, nor does it help to explain the reason for the onset of symptoms in a developmentally abnormal foot.
8. It is suggested that a tarsal anomaly makes the foot more likely, under average stress, to break down in this way, and that this deformity is also assumed by architecturally normal feet under heavy stress. In view of the frequency of minor tarsal anomalies among this series of thirty feet, it seems likely that all feet presenting the deformity of peroneal spastic flatness are to some degree structurally abnormal, although the exact site of the abnormality may escape us.