Distribution of muscle strength impairments following stroke

Abstract

Objective: The purpose of this study was to quantify the distribution of strength impairments soon after stroke. We were specifically interested in differences in impairments between proximal and distal actions, flexion and extension actions, and upper and lower limb actions. Design: We conducted a retrospective chart review of strength scores of patients with acute stroke. Setting: Inpatient rehabilitation unit. Subjects: Forty-eight patients with a primary diagnosis of stroke underwent initial testing on admission; 31 of the same patients underwent final testing prior to discharge. Main outcome measures: The strength of eight muscle actions was assessed bilaterally using hand-held dynamometry. Force measurements obtained were expressed in newtons and as a percentage of normal. Results: Strength was impaired bilaterally but more so on the side contralateral to the brain lesion. Distal muscle actions were less impaired than proximal muscle actions on the stronger side. Extension actions were less impaired than flexion actions bilaterally but primarily in the upper limbs. Upper limb actions were less impaired than lower limb actions only on the stronger side. Conclusions: With a few exceptions, our results do not support common clinical assumptions regarding the distribution of strength impairments following stroke.