Muscle strength and spatiotemporal gait parameters in people with Parkinson's disease. A pilot study

Introduction. Muscle weakness in persons with Parkinson disease (PD) has been frequently recognized as a nonspecific symptom. In other neurological conditions, lower limb weakness, specifically quadriceps weakness, is the factor that causes greater gait disability. Little research has evaluated the relationship between lower limb muscle strength, using objective tools, in PD persons and gait performance. The aim of this study was to analyze the correlation between lower limb muscle strength, using an isokinetic dynamometer, and the spatiotemporal gait parameters in PD, compared with age- and sex- matched healthy controls. Subjects and methods. The study was conducted with 7 persons with PD -Hoehn and Yahr (HY) between II-III- and 7 healthy controls. Isokinetic knee and ankle tests at 60 and 120 degrees/s and the 10-meter walking test at comfortable and fast walking speed, were performed on all recruited subjects. Results. Significant differences in lower limb strength-related measures and gait parameters were observed between persons with PD and controls. Gait parameters showed excellent correlations (rho = 0.7) for both lower limb: ankle plantar flexion work/body wearing at 180 degrees/s with number of steps (indirect) and stride (direct) at both speeds, and between the ankle plantar flexion peak torque/ body wearing at 180 degrees/s with number of steps (indirect) and stride (direct) at maximum speed; and between knee extension work/body wearing at 60 degrees/s) with stride (direct) at self-selected speed. Conclusions. Persons with PD (HY II-III stages) lower limb muscle strength correlates excellently with gait pattern, showing lower isokinetic strength than healthy subjects of the same age and sex. This protocol showed safety to be performed in a larger sample.