Aim: The current study was conducted to evaluate the effect of a respiratory muscle training session on ankle muscle activity in athletes with chronic low back pain performing overhead squats. Methods: The current double-blind, randomized, controlled trial was conducted on 24 patients randomly selected as the training group and 23 patients as the control group. The training group received the respiratory muscle training protocol. The electromyography activity of the tibialis anterior, peroneus longus, gastrocnemius medialis and gastrocnemius lateralis muscles of the dominant leg was recorded in the participants. Results: The findings showed that a session of respiratory muscle training reduced the activities of some ankle joint muscles when performing overhead squats, including tibialis anterior in the static and dynamic overhead squat tests and peroneus longus in the ascending phase. In the dynamic test, the angle to reach peak activity changed in tibialis anterior in the descending phase and also in tibialis anterior and peroneus longus in the ascending phase. Conclusion: Effects of respiratory muscle training prevented excessive ankle joint muscle activity through stimulating local muscles while performing overhead squats, which had indicated an improved postural control and multisectional proprioception to maintain postural stability and stimulated the local muscles of the core area.
