Low back pain intensity, microcirculation and muscle performance of the multifidus following back muscle strengthening in young elite oarsmen

Background: Low back pain is a problem that not only affects the general population but is also an underestimated problem in athletes involved in endurance sports. Rowing in particular has been associated with a high incidence of exercise-associated low back pain. Research question: The present study hypothesises that a device-assisted training programme leads to an improvement of the microcirculation and muscle performance of the multifidus muscle, which contributes to the reduction of exercise-associated low back pain. Type of study: Before-and-after trial Methods: Thirteen young elite oarsmen (five males, eight females; age range: 14.6-15.3 years) with exercise-associated low back pain performed a device-assisted training programme for isometric exercise of the low back 2-3 times per week for a duration of three months. To measure the training effect on the microcirculation and muscle performance of the multifidus muscle, simultaneous measurements of intramuscular pressure, tissue oxygen saturation, and median frequency shift in the surface electromyography were performed before and after the training period. The pain course was evaluated using a visual analogue scale. Results: The device-assisted training programme resulted in a median increase in maximum trunk torque (19N) and isometric exercise duration (44sec) coupled with a decrease in the frequency, duration and intensity of pain in 12 of 13 oarsmen. During the isometric endurance test, the increase in intramuscular pressure (17.0mmHg vs. 8.9mmHg) and the drop in tissue oxygen saturation (-6.6mmHg vs. 0.1mmHg) were significantly greater before training than after training. The median frequency shift in the surface electromyography remained unchanged. Conclusions: As the device-assisted training programme led to a reduction of exercise-associated low back pain and in addition resulted in an improvement of the microcirculation and muscle performance of the multifidus muscle, the hypothesis of this study seems to be confirmed. Therefore the findings of the present study strongly indicate that muscle training focusing on the multifidus muscle should be taken into consideration in the planning of back training programmes for oarsmen.