The main objective is to evaluate the feasibility of two different rehabilitation protocols that differed from the number of treatment sessions (1 session of ESWT versus 3 weekly sessions of ESWT), in patients with triceps surae spasticity after stroke. In both arms the other ESWT parameters (types of ESWT, intensity, frequency, location) and stretching sessions are the same.

Secondary objectives: to compare functional performances in these two groups of patients receiving the different rehabilitation protocol with ESWT, using the following parameters:

- Six Minutes walking test (6MWT) ; - Time Up & Go (TUG); - Modified Ashworth scale (MAS); - Lower Extremity Functional Scale (LEFS); - passive ankle range of motion (p-ROM), pain (NRS); and presence of ankle clonus. These parameters are assessed during baseline (T0), after 4 weeks (T1) and after 12 weeks (T2).

Inclusion Criteria:

• Adult patients of legal age
• Time elapsed since the stroke between 6 and 60 months
• Autonomous or supervised walking with or without aids
• Spasticity of the sural triceps> 1 on the MAS scale

Exclusion Criteria:

• Joint stiffness of the lower limbs due to other pathologies (ex orthopedic or rheumatological);
• Conditions that interfere with evaluation or collaboration in rehabilitation treatment (major psychiatric illnesses, clearly detectable cognitive deficits, severe pre-existing disabilities, sensory disturbances, etc.)
• Focal antispasmodic toxin treatments in the previous 3 months or phenolic blocks in the previous 9 months in the treatment region
• Treatments with central antispasmodic drugs with dosage modifications in the last week of starting treatment
• Individual neurorehabilitation treatments in progress