The investigators want to demonstrate that there is an optimal expiratory pressure when using mecanical in-exsufflation for each patient in neuromuscular disease. This compromise is between the need to generate a high pressure difference between alveoli and the mouth and the need to avoide and superior airways collapsus.

he investigators want to demonstrate that there is an optimal expiratory pressure when using mecanical in-exsufflation for each patient in neuromuscular disease. This compromise is between the need to generate a high pressure difference between alveoli and the mouth and the need to avoide and superior airways collapsus.

Inclusion Criteria:

• man or female age18 years
• neuromuscular disease
• coughassist adaptation treatment
• peak cough flow<270liter/minute

Exclusion Criteria:

• acute organ failure
• insufflation contrindication
• pregnant women/no affiliation to a social security scheme
• plan of legal protection