The high prevalence of stroke is a global problem causing well-known long-term disabilities. Post-stroke lower-extremity spasticity may cause severe functional limitations and pain. Spasticity is a phenomenon defined as disordered sensory-motor control, resulting from upper motor neuron (UMN) lesion, presenting as intermittent or sustained involuntary activation of muscles . Spasticity may interfere with motor function, and is a common reason for clinical interventions such as by physiotherapy, use of orthoses or other technical devices or drugs. Botulinum toxin A (BoNT-A) is a potent neurotoxin that is produced by the bacterium clostridium botulinum. BoNT-A, by blocking acetylcholine release at neuromuscular junctions, accounts for its therapeutic action to relieve dystonia, spasticity, and related disorders.