Patients with respiratory muscle weakness have reduced cough strength and this can cause difficulties with clearing respiratory secretions. This impaired secretion clearance can lead to respiratory infections and acutely can causing small airway occlusion with subsequent ventilation-perfusion mismatch adversely effecting pulmonary mechanics. The use of cough assist devices, such as mechanical insufflation-exsufflation (MIE) can improve secretion clearance. Although there is evidence that these devices can improve secretion clearance the optimal pressures or technique required to provide effective secretion clearance is not known. Furthermore the use of high pressure swings that are now frequently used in clinical practice could lead to lung derecruitment. The use of EIT would allow a novel and effective method of assessing the ability to clear secretions and optimise ventilated lung in neuromuscular patients with poor cough and assess post procedure derecruitment.