Evaluation of plantar pressures in people with hallux valgus using principal component analysis.

BACKGROUND

Foot deformities are serious problems in the elderly as they increase the risk of falling.

OBJECTIVE

This study aimed to examine the relationship between foot plantar pressure during gait and hallux valgus (HV).

METHODS

Foot-pressure data were recorded using an F-scan II system. We analyzed the entire waveform of plantar pressure during gait from 37 healthy adults using principle component analysis (PCA), conducted using a 370 × 357 matrix of time-normalized plantar data of 7 areas during gait (5 gait trials × 2 (both feet) of 37 participants × 51 data points × 7 plantar areas). Two-way (plantar pressure × presence or absence of HV) analyses of variance were conducted on the principal component scores (PCSs) of principal component vectors (PCVs) 1 through 5, each of which exhibited more than 5% variance.

RESULTS

The PCA clarified that the 2nd, 3rd, and 5th PCVs (PCV 2, 3, and 5) were related to HV (p< 0.01). These PCVs exhibit a significant interaction between plantar pressure area and HV presence.

CONCLUSIONS

The larger plantar pressure of the HV group around the hallux area during walking compared with the non-HV group is a dominant difference in plantar pressure features due to HV.