For many individuals who have experienced a stroke, muscle weakness is the most prominent impairment. Both the theoretical and statistical relationships between muscle weakness and performance at functional activities suggest that weakness may be an appropriate target for therapeutic interventions. Researchers investigating the outcomes of strengthening regimens after stroke have routinely shown that resistance exercise leads to increased muscle strength, but that strength is typically measured using the same maneuvers that were used in training. Evidence supporting the use of strengthening regimens to reduce limitations in functional activity is equivocal.