Individuals with delayed trunk muscle reflexes have different muscle activation patterns to a complex lifting task

In accordance to Panjabi’s spinal stability model, if a deficit existed in one spinal stability system another system is thought to compensate to maintain spinal stability. This study examined whether those with delayed trunk reflexes did modify muscle activation patterns to complete a dynamic lifting task lifting tasks while minimizing spinal motion. Results show individuals with delayed trunk reflexes had higher antagonist co-activation in both the sagittal and frontal plane for this lifting task. These patterns provide evidence to support that active stiffness of the spine compensates for a delay in reflexive adjustments.