Premium
Bradykinesia, muscle weakness and reduced muscle power in Parkinson's disease
Author(s) -
Allen Natalie E.,
Canning Colleen G.,
Sherrington Catherine,
Fung Victor S.C.
Publication year - 2009
Publication title -
movement disorders
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.352
H-Index - 198
eISSN - 1531-8257
pISSN - 0885-3185
DOI - 10.1002/mds.22609
Subject(s) - weakness , physical medicine and rehabilitation , parkinson's disease , leg muscle , muscle weakness , muscle power , motor control , muscle strength , psychology , physical therapy , medicine , anatomy , neuroscience , disease
Muscle power (force × velocity) could clarify the relationship between weakness and bradykinesia in Parkinson's disease (PD). The aims of this study were to determine if patients with PD were weaker and/or less powerful in their leg extensor muscles than a neurologically normal control group and to determine the relative contributions of force and movement velocity/bradykinesia to muscle power in PD. Forty patients with PD and 40 controls were assessed. Strength in Newtons (N) was measured as the heaviest load the participant could lift. Power in Watts (W) was measured by having the participant perform lifts as fast as possible. The PD group were 172 N weaker (95% CI 28–315) and 124 W less powerful at peak power (95% CI 32–216) than controls. However, velocity at maximal power was only reduced compared with controls when lifting light to medium loads. When lifting heavy loads bradykinesia was no longer apparent in the PD group. These results suggest that reduced muscle power in PD at lighter loads arises from weakness and bradykinesia combined, but at heavier loads arises only from weakness. The absence of bradykinesia in the PD group when lifting heavy loads warrants further investigation. © 2009 Movement Disorder Society