Structural deviations in the foot and ankle predispose patients to changes in load-bearing, muscle imbalances and dynamic gait, resulting in compensatory strategies and overuse injuries. Orthotics are often fitted in such cases. During an orthotic dispense fitting, a podiatrist checks the static and dynamic response of the patient’s foot to the orthotic. The orthotic calcaneal stance position (OCSP) is a static objective measure, however it only shows the calcaneus positional changes, and does not reflect posture changes to the talus, mid foot and forefoot. Internationally, there is no common standard objective measures for static assessment during orthotic dispense fitting.
The foot posture index (FPI) is a validated clinical assessment tool that considers the foot positions in all planes (frontal, transverse, and saggital) and various anatomical segments (forefoot, mid foot and rearfoot). In the authors’ clinics, foot posture index (FPI) is used as a static assessment in orthotic dispense fitting in reducible, correctable conditions such as hypermobile pes planus.
FPI was taken (i) weightbearing barefooted (‘before’) and (ii) in orthotic stance (OS; ‘after’). We sampled a total of 20 hypermobile pes planus feet with orthotic intervention across the two clinics. Data was deidentified. Mean and standard deviation for each FPI component was computed and ‘before-after’ difference were tested using paired t-test.
Mean (SD) of barefoot FPI = 9.9 (1.5); orthotic stance FPIos = 3.9 (1.7). Mean difference in ‘before-after’ FPI = 6.0 (p <.001).
Discussion & Clinical Relevance
The orthotic stance FPI (FPIos) is able to assess and score foot posture corrections achieved through the orthotic prescription in hypermobile pes planus. Hypermobile flat feet (FPI≥6) were corrected to within normal range. The FPIos could be a way forward in improving documentation of clinical outcomes in podiatric setting. Future studies could assess treatment outcome in large populations to establish norms and expected outcomes. Established norms and expected outcomes could in turn increase patients’ confidence and manage clients’ expectations in podiatric orthotic intervention.