title: Compensatory muscle activation during forced respiratory tasks in individuals with chronic spinal cord injury.
abstract: When lesions in the spinal cord occur, the neural activation of respiratory muscles is compromised (De Troyer and Heilporn, 1980; De Troyer et al., 1986, 1990; Estenne et al., 2000a) resulting in significant respiratory dysfunction (De Troyer and Heilporn, 1980; Linn et al., 2000, 2001; Yokoba et al., 2003). However the underlying mechanisms that contribute to this dysfunction remain unclear. The aims of this study were: (1) to investigate whether a correlation exists between pulmonary function and the International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI) examination scores for sensory and motor function; (2) to evaluate whether compensatory muscle activation plays a role in pulmonary function after spinal cord injury (SCI). We recorded Forced Vital Capacity (FVC); Forced Expiratory Volume in 1s (FEV1); and electromyography (EMG) of respiratory muscles during maximum respiratory tasks in 36 with SCI and 15 neurologically intact participants. Results indicate that pulmonary function (FVC, FEV1) was strongly correlated with motor and sensory scores from the ISNCSCI exam and maximal expiratory pressure (MEP) was also significantly related to ISNCSCI sensory scores (ρ=0.73, p<.001) and moderately, but significantly correlated to motor scores (ρ=0.41, p=.04). After SCI, there is a compensatory recruitment of accessory muscles upper trapezius during maximal inspiratory pressure (MIP) and pectoralis and latissimus dorsi during MEP that is significantly higher than in non-injured (p<.001).
authors.affiliation: University of Louisville, Health and Sport Sciences, United States; University of Louisville, Neurosciences Collaborative Center, Frazier Rehab Institute, Louisville, KY, United States. Electronic address: Daniela.tersondepaleville@louisville.edu.
authors.forename: Daniela
authors.initials: D
authors.lastname: Terson de Paleville
authors.affiliation: University of Louisville, Department of Bioinformatics and Biostatistics, United States.
authors.forename: Douglas
authors.initials: D
authors.lastname: Lorenz
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae; D002908:Chronic Disease; D004576:Electromyography; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D010369:Pectoralis Muscles / Q000503:physiopathology*; D017568:Rectus Abdominis / Q000503:physiopathology*; D012119:Respiration; D012132:Respiratory Muscles / Q000503:physiopathology*; D012677:Sensation; D012720:Severity of Illness Index; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D064171:Superficial Back Muscles / Q000503:physiopathology*; D013904:Thoracic Vertebrae; D014797:Vital Capacity
keywords: Electromyography; Respiratory function; Spinal cord injury