Discriminating spine coordination strategies during flexion-extension

The spine is an anatomically complex system with many degrees of freedom. Due to this complexity, multiple motor control strategies may exist to complete a given task. The aim of this work was to identify if distinct coordination strategies are used during spine flexion/extension (FE). Kinematic data were captured from male participants (n = 51) during a self-controlled spine FE task. Thoracic-lumbar continuous relative phase angles were extracted, and unsupervised machine learning (k-means clustering) was used to classify motor strategies within the participants sampled. The findings suggest that distinct strategies exist for the coordination of spine FE. These strategies differ in the temporal sequencing of intersegmental movement, and are not related to participant characteristics, total movement time, or range of motion.