There is a current, albeit unproven, thought about the dangers of repetitive spinal flexion. Those who repeat this unfounded belief feel repetitive forward bending places the spine in a less than optimal position leading to back pain or injury. These thoughts have been disproven by the research and forward bending of the spine does not place undo harm on the spinal tissues. In addition, these statements do not account for the majority of Americans and athletes who repeatedly enter into this range of motion without injury or pain.
A study by Foss and colleagues examined the prevalence of low back pain symptoms among former endurance athletes (Am J Sp Med. 2012). Athletes were grouped by the direction of loading required by their sport including flexion (cross country skiing), extension (rowing), and compared them to their age matched peers. The authors found no difference between the athletes and the control group in regard to LBP recurrence over the previous 12 months. Although the authors reported a training volume of >550 hours per year was determined as a risk factor for the onset of low back pain during the prior 12 months. This article highlights the safety of repetitive movements in the spine.