Fig. 3From: Natural history of respiratory muscle strength in spinal muscular atrophy: a prospective national cohort studyLongitudinal patterns of peak cough flow (PCF) in L/min in different SMA types. n = number of patients; obs = number of observations. The horizontal lines represent two important thresholds. In adults and children over 12 years of age a PCF of 160 L/min is necessary for effective secretion clearance and a PCF of 270 L/min or more is associated with resilience to respiratory infectionBack to article page