Muscle strength testing in Parkinson's disease

Isotonic muscle strength measured by a quantitative technique was decreased in early Parkinson's disease compared to age-matched controls. Weakness was present both on the affected and unaffected side in hemiparkinsonism. Similar degrees of weakness occurred in limbs with tremor or rigidity. Muscle weakness appears to be a primary symptom of Parkinson's disease which may relate to disturbed motor programming due to basal ganglia dysfunction.