Flexion Relaxation Ratio Not Responsive to Acutely Induced Low Back Pain from a Delayed Onset Muscle Soreness Protocol

Figure 1

Sample of raw sEMG from the erector spinae on the left of the L5 lumbar level. A is active trunk flexion. B represents the point in the trunk range of motion where the lumbar paraspinals become myoelectrically silent and the passive structures such as the posterior spinal ligaments, discs, and fascia provide terminal flexion. Lastly, C represents the return from full trunk flexion.