Walking speed is commonly used to predict stroke severity and assess functional walking status (i.e., household, limited community and community walking status) post-stroke. The underlying mechanisms that limit walking speed (and functional walking status by extension) need to be understood to improve post-stroke rehabilitation. Previous experimental studies have shown correlations between paretic plantarflexor output during the pre-swing phase and walking speed and suggest that the paretic hip flexors can compensate in some hemiparetic subjects. Modeling and simulation studies of healthy walking have shown that the ankle plantarflexors, soleus (SOL) and gastrocnemius (GAS), and uniarticular hip flexors (IL) are essential contributors to the walking subtasks of forward propulsion, swing initiation and/or power generation during pre-swing. However, the relationships between functional walking status and individual muscle contributions to these walking subtasks in hemiparetic walking are unknown. The goal of this study was to use 3D forward dynamics simulations to investigate the relationships between functional walking status in post-stroke hemiparetic walking and muscle contributions to forward propulsion, swing initiation and power generation.