Background/Objectives: Three-dimensional accelerometry data from the lower trunk during running is associated with intervertebral disc degeneration. The kinematic function known as the lumbo–pelvic–hip complex involves movements in the sagittal plane during running. If pelvic movement and acceleration in the anteroposterior direction are correlated, improving running mechanics may reduce the load on the intervertebral disc. This study investigated the relationship between the anteroposterior acceleration of the lower lumbar spine and pelvic tilt movements during running. Methods: Sixteen healthy male college students were enrolled and asked to run on a treadmill for 1 min at 16 km/h, and the acceleration data for their lower lumbar region and running motion in the sagittal plane were recorded. The pelvic tilt angle during running was calculated through two-dimensional motion analysis. Subsequently, a simple linear regression analysis was employed to clarify the relationship between the acceleration data of the lower lumbar region and the pelvic tilt angle during running. Results: The simple linear regression analysis indicated that the root mean squares of the anteroposterior acceleration of the lower lumbar spine were associated with the maximum pelvic tilt angle (r = 0.32, p = 0.003, adjusted R2 = 0.09) and its range (r = 0.42, p = 0.0001, adjusted R2 = 0.16). Conclusions: However, the adjusted R2 value was low, indicating that although the pelvic tilt angle during running may be related to acceleration in the anteroposterior direction, the effect is small.