The aim of the study was to investigate if progressive resistance strength training (PRST) can have a beneficial effect on muscle weakness, activity limitations and participation restrictions in adults with traumatic brain injury (TBI). Seven people, six men and one woman, participated in this AB single-system trial. The mean age was 35.6 years (range 21.0–63.0, SD = 14.0), the mean time after head injury was 14.5 years (range 4.5–26.0, SD = 8.7) and the mean for length of coma was 11.3 weeks (range 0.3 to 16.0, SD = 6.1). After an 8-week baseline phase, community-based PRST was conducted twice a week for 8 weeks. Changes in maximal isotonic strength (1RM for arm and leg press), activity limitation (maximal gait speed and three items on the Motor Assessment Scale, MAS) and participation restriction (BICRO-39 Scale) were evaluated across the baseline and intervention phases. Leg press strength significantly increased in four participants and arm press strength significantly increased in two participants. T...