Context: People with chronic low back pain (CLBP) suffer from weaknesses in their core muscle activity and dysfunctional breathing. Inspiratory muscle training (IMT) was recently developed to treat this condition. Objectives: The present study was conducted to investigate the effect of IMT on core muscle activity, pulmonary parameters, and pain intensity in athletes with CLBP. Design: This study was designed as a single-blind, randomized, controlled trial. Setting: Clinical rehabilitation laboratory. Participants: A total of 23 male and 24 female athletes with CLBP were randomly divided into the experimental and control groups. Main Outcome Measures: The experimental group performed IMT for 8 weeks, 7 days per week and twice daily, using POWERbreathe KH1, beginning at 50% of maximum inspiratory pressure with a progressively increasing training load. The surface electromyography muscle activity of the erector spinae, multifidus, transverse abdominis and rectus abdominis, respiratory function and Visual Analogue Scale score were also measured before and after the intervention in both groups. The repeated-measures analysis of variance and 1-way analysis of covariance were further used to compare the intragroup and intergroup results following the intervention. Results: The findings of the study revealed that multifidus and transverse abdominis activity, as well as respiratory function, increased significantly in the IMT group (P < .05). Moreover, a descending trend was observed in the Visual Analogue Scale score in the experimental group (P < .05). Conclusion: The results showed that IMT can improve respiratory function, increase core muscle activity, and, consequently, reduce pain intensity in athletes with CLBP.
Leila Ahmadnezhad, Ali Yalfani and Behnam Gholami Borujeni
Behnam Gholami-Borujeni, Ali Yalfani and Leila Ahmadnezhad
This study was conducted to evaluate the effects of 8-week inspiratory muscle training on activity in the ankle muscles of athletes with chronic low-back pain. A randomized controlled trial involving 45 men and women with chronic low-back pain was carried out. Electromyography activity in the tibialis anterior, peroneus longus, gastrocnemius medialis, and gastrocnemius lateralis muscles of the dominant leg was recorded. Secondary outcomes included biopsychosocial indices, such as pain, disability, anxiety and depression, fear-avoidance beliefs, and fear of (re)injury. Static and dynamic overhead squat tests showed that inspiratory muscle training decreased activity in the tibialis anterior, peroneus longus, and gastrocnemius medialis muscles. In the static single-leg squat test and the descending phase of the dynamic equivalent, such a decrease was observed in all the 4 muscles. Inspiratory muscle training significantly reduced pain severity and activity in the tibialis anterior, peroneus longus, and gastrocnemius medialis muscles during the ascending phase of the dynamic single-leg squat test. On the basis of the findings, 8 weeks of inspiratory muscle training may constitute useful rehabilitation for reducing excessive activity in ankle joint muscles and aiding chronic low-back pain recovery.