The Effects of Muscle Vibration on the Development of Spasticity and Neuroplasticity in a Post-stroke Population

Several studies have recently tested the use of muscle vibration for the rehabilitation of patients after a stroke. When applied in a repeated and focused manner, this vibration appears to promote the recovery of functional capacities through the mechanisms of neuromuscular plasticity. These results are encouraging, showing in particular a significant decrease in spasticity in post-stroke patients in the chronic phase (\> 6 months after stroke), on the upper and/or lower limbs. However, very few studies have been done on this type of early intervention. Muscle vibration may therefore be an innovative therapy to complement the care that is currently offered in the acute and subacute phase of post-stroke rehabilitation. Moreover, brain plasticity after a stroke is particularly high in the 3 months after the accident, but the vast majority of studies having evaluated the impact of vibration in a chronic phase (\> 12 months post-stroke). It is likely, however, that the influence of vibration, particularly on brain plasticity, is increased in the acute or subacute phase (first 6 months). To date, the effect of vibration on spinal cord or cortical plasticity has not been quantified in the acute or subacute phase. This is why the second part of this project (phase 2) aims to systematically evaluate and quantify the neuroplastic and functional effects of post-stroke vibration in the early phase. Phase 1 - Validation of a method for measuring spasticity (upper limb) with an isokinetic dynamometer 32 patients with ischemic and/or hemorrhagic stroke (\> 3 months after stroke) Phase 2 - Use of this objective technique to measure the effect of a muscle vibration protocol to limit the onset of spasticity in a population of 100 patients following a stroke, in the acute or subacute phase (\< 6 weeks post-stroke) in a randomized trial: * intervention group: usual rehabilitation + muscle vibrations * control group: usual rehabilitation + placebo vibrations