Spastic paresis comprises both muscular and neurological disorders affecting movement through mostly the antagonist muscles compared to the agonist : muscular : spastic myopathy, shortening, stretch-sensitive paresis and neurogenic : spastic dystonia and cocontraction.~About gait, most of the litterature focuses on distal muscles targets. There are no studies about proxmial muscles role (gluteus maximus). Anesthesic perineural block have the disavantage to induce sensitive block as intramuscular block do not.
To assess feasability, tolerance of anesthesic intramuscular motor block. To study immediate effects on differents muscles : gluteus maximus, rectus femoris in a hemiparetic population (over 15 days) To precise the role of the muscles which could be rehabilitatoin targets.