Inclusion Criteria1. Were over the age of 18 and less than 80 years and had a stroke within 6 weeks.
2. Had slight spasticity of the triceps surae as defined by a score of 1-1+ on the Modified Ashworth Scale (MAS) or ankle clonus (+).
3. Had sufficient cognitive and communication ability as defined by MMSE (mini-mental state examination)>25.
4. Couldn't dorsiflex ankle and their LEMI (Lower Extremity Motor Index) < 10.
5. Were not receiving concurrent aminoglycoside antibiotics and oral anti-spasticity medication
Exclusion Criteria1. Known allergy or sensitivity to study medication or its components.
2. Infection or dermatological condition at the injection sites.
3. Any medical condition that may put the subject at increased risk with exposure , including diagnosed myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis, or any other disorder that might have interfered with neuromuscular function.
4. QTc criteria: QTc ≥ 450 millisecond (msec) or≥480msec for subjects with Bundle Branch Block-values based on either single electrocardiogram (ECG) values or triplicate ECG averaged QTc values obtained over a brief recording period
5. Liver function tests: aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≥2xULN; alkaline phosphatase and bilirubin ＞1.5xULN (isolated bilirubin >1.5ULN is acceptable if bilirubin is fractionated and direct bilirubin <35%).
6. Concurrent use of aminoglycoside antibiotics or other agents that might interfere with neuromuscular function.
7. Patients with severe cognitive impairment or neurological diseases affecting the implementation or evaluation of the test, and drug-dependent patients.
8. Presence of clinically unstable severe cardiovascular, renal or respiratory disease
9. Researchers believe there are other factors unfit to participate in this study of patients.