Context:People with chronic low back pain (CLBP) suffer from weaknesses in their core muscle activity and dysfunctionalbreathing. Inspiratory muscle training (IMT)was recently developed to treat this condition.Objectives:The present study wasconducted to investigate the effect of IMT on core muscle activity, pulmonary parameters, and pain intensity in athletes withCLBP.Design:This study was designed as a single-blind, randomized, controlled trial.Setting:Clinical rehabilitationlaboratory.Participants:A total of 23 male and 24 female athletes with CLBP were randomly divided into the experimentaland control groups.Main Outcome Measures:The experimental group performed IMT for 8 weeks, 7 days per week andtwice daily, using POWERbreathe KH1, beginning at 50% of maximum inspiratory pressure with a progressively increasingtraining load. The surface electromyographymuscle activity of the erector spinae, multifidus, transverse abdominis and rectusabdominis, respiratory function and VisualAnalogue Scale score were also measured before and after the intervention in bothgroups. The repeated-measures analysis of variance and 1-wayanalysis of covariance were further used to compare theintragroup and intergroup results following the intervention.Results:Thefindings of the study revealed that multifidus andtransverse abdominis activity, as well as respiratory function, increased significantly in the IMT group (P<.05). Moreover, adescending trend was observed in the Visual Analogue Scale score in the experimental group (P<.05).Conclusion:Theresults showed that IMT can improve respiratory function, increase core muscle activity, and, consequently, reduce painintensity in athletes with CLBP.
