Influence of Movement Speed on Gait Mechanics in Patients with Early Parkinsonʼs Disease

Abstract

Introduction: Activities of daily living require frequent modulations of movement speed (e.g. while crossing a street). Reports suggest that healthy older adults increase their walking speed by preferentially increasing their hip and knee joint kinetics (Kerrigan et al. 1998). PURPOSE: To examine the mechanisms by which individuals with early Parkinson's disease (PD) alter their movement speed during self-selected and “fast as possible” walking conditions. METHODS: Ten patients with early PD, diagnosed within 3 yrs and not receiving dopaminergic therapy, performed three 6-meter walking trials at two movement speeds: 1) self selected, and 2) “as fast as possible”. Ground reaction forces (GRFs) were measured at 1560Hz and an 8-camera motion analysis system (60 Hz) was used to quantify segment kinematics and joint range of motion (ROM). Net joint moments (NJM) and extensor support moments (SM) were calculated using standard inverse dynamics procedures. Paired t-tests were used to assess the differences between walking conditions (P <0.05).FigureRESULTS: The ROM was greater at the hip (46±3° vs. 41 ±4°) during fast walking whereas differences were not evident at the knee or ankle. The NJM at the hip (2.05 ±0.4 vs. 1.40±0.4Nm/kg) and knee (0.77±0.2 vs. 0.57±0.2 Nm/kg) were also greater with fast walking. Peak SM increased by 24% between self-selected and fast conditions. CONCLUSION: In agreement with reports regarding healthy older adults, this cohort with early PD increased their walking speed by preferentially increasing hip ROM, and both hip and knee NJMs, without altering ankle mechanics. The findings differ, however, from a previous report in persons with PD, where increases in walking speed were associated with changes in range of motion across all lower extremity joints (Morris et al. 2005). Future studies will be required to delineate the influence of disease severity upon speed modulation across other task conditions (e.g. stair climbing and sitting/standing). Supported by the Kinetics Foundation