Objectives: The respiratory function is often overlooked in people with Low Back Pain (LBP), while it is one of the factors for the continuation and recurrence of lumbar spine injury. Aim of this study was survay the immediate effect of Respiratory Muscle Sprint-Interval Training (RMSIT) on the plantar pressure variables of athletes with LBP. Methods: This randomized controlled trial was conducted on two groups with LBP, one experimental group (24 patients) and one control group (23 patients). The plantar pressure variables were recorded using a plantar pressure measurement device. The experimental group performed the RMSIT protocol. The RMSIT was fulfilled as six sets of 30-second deep breathing exercises (with two minutes of rest between sets) with constant tidal volume, maximum breathing rate, and added resistance. The paired t-test and one-way covariance tests were used to analyze the data. Results: The results of (95%) confidence ellipse showed that RMSIT caused a significant decrease in the amount area of sway, but the exercise did not make a significant difference in the length of minor axis and length of the major axis. The results of the Center of Presure (COP) factors showed that the training program significantly reduced the amount of path length, the standard deviation in the Y axis, but the results did not show a significant difference in the velocity and standard deviation in the X axis in the experimental group. The results demonstrated no significant difference between the experimental and control group in the plantar pressure symmetry indices. Discussion: It can be concluded that, these exercises can be used to reduce some postural oscillation indices in athletes with LBP.
