Nasser Mohammad Rahimi - Department of Sports Injuries and Corrective Exercises, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran.
Reza Mahdavinejad - Department of Sports Injuries and Corrective Exercises, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran.
Seyyed Reza Attarzadeh Hosseini - Department of Exercise Physiology, Faculty of Sports Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.
Hossein Negahban - Department of Physical Therapy, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.

Objectives: Dynamic Neuromuscular Stabilization (DNS) approach evaluates and activates the spinal stabilizers to optimize the performance of posture and respiratory system. This study investigated the effects of DNS breathing exercises on upper and lower chest wall mobility (UCM and LCM), trunk extensor endurance, and thoracic kyphosis in a group of sedentary students with poor posture. Methods: In this randomized, controlled ۶-week trial, ۵۲ participants were randomly divided into two groups: a DNS breathing exercise group (n=۲۶) and a control group (n=۲۶). First, a pre-test of the UCM, LCM, trunk muscle endurance and thoracic kyphosis was done on each participant in random order. DNS breathing exercise protocol (six times a week for six weeks) was implemented and after its completion, all post-test parameters were taken. Descriptive statistical and the paired-sample t test were used to analyze the obtained data. Results: Significant improvements were observed in the post-test compared with pre-test in DNS breathing exercise group in UCM (۶.۲±۱.۶ vs ۴.۴±۰.۹ cm, P<۰.۰۰۱), LCM (۷.۷±۱.۷ vs ۵.۵±۱.۰ cm, P<۰.۰۰۱), trunk muscle endurance (۱۱۰.۱±۳۳.۵ vs ۸۸.۷±۳۴.۱ s, P<۰.۰۰۱), and thoracic kyphosis (۱۴۶.۹±۵.۵ vs ۱۴۲.۷±۴.۰ degree, P<۰.۰۰۱). In contrast, the change in these parameters in the control group was not statistically significant. Discussion: DNS breathing exercise with a focus on the integrated spinal stabilizing system and breathing techniques is an effective protocol to significantly improve UCM and LCM, trunk muscle endurance, and thoracic kyphosis. It is suggested that DNS breathing exercises be introduced to improve chest mobility and posture and provide physiological stabilization for the overall health and performance of student

Dynamic neuromuscular stabilization, Breathing exercise, Chest wall mobility, Thoracic kyphosis, Integrated spinal stabilizing system