Adaptations of Lumbar Biomechanics after Four Weeks of Running Training with Minimalist Footwear and Technique guidance: Implications for Running-Related Lower Back Pain

Objectives To investigate the changes in lumbar kinematic and paraspinal muscle activation before, during, and after a 4-week minimalist running training. Design Prospective cohort study. Setting University research laboratory. Participants Seventeen habitually shod recreational runners who run 10–50 km per week. Main outcome measures During stance phases of running, sagittal lumbar kinematics was recorded using an electrogoniometer, and activities of the lumbar paraspinal muscles were assessed by electromyography. Runners were asked to run at a prescribed speed (3.1 m/s) and a self-selected speed. Results For the 3.1 m/s running speed, significant differences were found in the calculated mean lumbar posture (p = 0.001) during the stance phase, including a more extended lumbar posture after minimalist running training. A significant reduction in the contralateral lumbar paraspinal muscle activation was also observed (p = 0.039). For the preferred running speed, similar findings of a more extended lumbar posture (p = 0.002) and a reduction in contralateral lumbar paraspinal muscle activation (p = 0.047) were observed. Conclusion A 4-week minimalist running training program produced significant changes in lumbar biomechanics during running. Specifically, runners adopted a more extended lumbar posture and reduced lumbar paraspinal muscle activation. These findings may have clinical implications for treating individuals with running-related lower back pain