Muscle Activation during Hand Dexterity Tasks in Women with Hand Osteoarthritis and Control Subjects

Study DesignDescriptive cross-sectional study.IntroductionHand osteoarthritis (OA) is a condition that results in hand pain and disability. It is important to understand how muscle function impairments contribute to impaired dexterity.Purpose of the StudyTo compare muscle activation in women with and without hand OA and determine if the activation relates to measures of impairment and disability.MethodsElectromyography (EMG) was recorded from four muscles of the hand/forearm while subjects threaded (assembly) and unthreaded (disassembly) a small bolt. The groups were compared on the integrated EMG (IEMG) of four muscles using two-way repeated-measures analyses of covariance for the assembly and disassembly tasks.ResultsNo differences were found in muscle activation between groups when IEMG values were normalized by time (p > 0.05).ConclusionsPatients with OA have some indicators of altered muscle function. It is unclear whether these are adaptive or predisposing changes. When controlling for the time to perform a task, there were no significant IEMG differences between women with hand OA and control subjects.Level of Evidence2b.