Predicting outcomes in the orthotic management of painful, idiopathic pes cavus

[Guest guest]

Clin J Sport Med. 2007 Sep;17(5):337-42.

Predicting outcomes in the orthotic management of painful,

idiopathic pes cavus.

Crosbie J, Burns J.

School of Physiotherapy, The University of Sydney, Sydney, New South

Wales, Australia.

OBJECTIVE: People who have extremely high arched feet are subject to

substantial foot pain, despite a lack of obvious pathology.

Customized foot orthoses improve pain and function and reduce foot

pressure, but their specificity is unclear. This study sought to

identify predictive variables for improvement and to determine

whether changes in foot pressure were correlated to changes in pain

and function.

DESIGN: Retrospective analysis of data from a randomized controlled

clinical trial.

SETTING: Clinical movement analysis laboratory, School of

Physiotherapy, University of Sydney.

PARTICIPANTS: Subjects with painful, idiopathic pes cavus.

INTERVENTIONS: Sixty-six subjects received customized foot orthoses;

sixty-seven subjects were allocated a sham intervention.

MAIN OUTCOME MEASURES: Foot pressure data, location and intensity of

pain, Foot Posture Index values, and anthropometric and quality of

life variables.

RESULTS: No relationship between change in foot pressure and change

in symptoms was found in either group. No individual characteristics

were linked to improvement. Subjects who improved most had

substantial pain, lowest function scores, and lowest scores for

quality of life variables at entry. There was a possible link, in

the orthosis group, between improvement and pain confined to the

rear-foot region.

CONCLUSIONS: The mechanisms by which orthotic intervention is

effective in improving pain and function in painful, idiopathic pes

cavus remain unclear and equivocal. A strong placebo effect may be

in place, or perhaps relatively small changes in foot pressure, even

those brought about by a flexible insole with limited shock-

absorbing properties, is enough to achieve a clinically meaningful

change in symptoms.