Pain Perception and Lumbar Biomechanics Are Modified After the Biering–Sorensen Maneuver in Patients With Low Back Pain

Purpose: Both isometric and aerobic physical exercise have shown to cause an increase in pain thresholds through the effect known as exercise‐induced hypoalgesia. A sustained isometric contraction of the lumbopelvic extensor muscles such as the one elicited by the Biering–Sorensen maneuver has been observed to increase pain thresholds in pain‐free subjects. Nevertheless, little is known about exercise‐induced hypoalgesia induced by isometric exercise in low back pain (LBP), and its possible effects in lumbopelvic biomechanics. The present study tries to show the effect of exercise‐induced hypoalgesia after an isometric Biering–Sorensen maneuver in nonspecific LBP patients and pain‐free subjects. Methods: This cross‐sectional observational study was conducted on 16 nonspecific LBP patients and 16 pain‐free control participants. Before and after the intervention, pain‐pressure thresholds (PPTs) were assessed with an electronic algometer in the lumbar region over the biceps femoris area and on the thenar eminence. Erector spinae (ES) activity and motion patterns of the lumbopelvic region were analyzed during a trunk flexion–extension exercise by surface electromyography (EMG) and electrogoniometry techniques, respectively. The intervention consisted of a 60‐s isometric Biering–Sorensen maneuver. Results: After the isometric contraction, PPTs were significantly higher on all areas, both in healthy participants and LBP patients ( p < 0.01), especially over the muscles most activated by the maneuver. LBP patients perceived a lower level of pain after the isometric maneuver ( p < 0.01). From all the EMG and electrogoniometry variables recorded during trunk flexion extension, participants in both groups only showed significant differences in the time spent in maximum lumbar flexion, which was longer after the isometric maneuver ( p < 0.05). Conclusions: The Biering–Sorensen maneuver induces a hypoalgesic effect locally over the areas of the extensor lumbopelvic muscles, and remotely, on the thenar eminence, both in nonspecific LBP patients and healthy people. The maneuver also causes alterations in trunk motion patterns. This study shows that the Biering–Sorensen maneuver could be useful to alleviate LBP and improve trunk motion patterns. The effects of isometric exercise should be investigated further to confirm its possible role as a supplementary analgesic measure in the treatment of LBP patients.