Plantar force distribution in Parkinsonian gait: a comparison between patients and age-matched control subjects

This study aimed to ascertain whether roll-off of the feet during gait was essentially different in patients with Parkinson's disease from that of elderly control subjects. Twenty-two patients, belonging mainly to Hoehn & Yahr grades III and IV, and 30 elderly people participated in the study. Plantar force distribution data were collected of two consecutive strides using pressure-sensitive insoles as part of the pododynograph system. Results showed that when correcting for gait speed and sex differences, patients with Parkinson's disease walked with significantly lower relative peak forces at the forefoot and heel and increased load at the midfoot. The onset of peak forces indicated slower load acceptance on the heel and early forefoot loading which was confirmed by a reduced amplitude of the centre of force along the length of the foot compared with healthy controls. Roll-off was significantly reduced in patients with Parkinson, a feature which was specific for the disease rather than a result of reduced gait speed alone.