Changes in Motor Cortex Following Exercises for Chronic Low Back Pain

Driving Plasticity in the Motor Brain in Chronic Back Pain

The motor cortex of the brain changes following chronic pain and injury, and this is linked to pain-associated changes in motor behaviour. This study aimed to investigate whether therapeutic exercises in patients with chronic pain can induce reorganisation of the motor cortex and restore normal motor behaviour. The investigators hypothesised that motor training can induce reorganisation of the motor cortex and that these changes are related to improved motor behaviour.

The sensory and motor systems can reorganize following injury and learning of new motor skills. Recently we observed adaptive changes in motor cortical organization in patients with chronic back pain, which are closely linked to changes in motor behavior. Although pain-related alterations in behavior can be trained and are associated with improved symptoms, it remains unclear whether these meaningful functional outcomes are related to motor cortical reorganization. Here we investigate the effects of two interventions in people with chronic back pain: skilled motor training and a control intervention of self-paced walking exercise. We measured motor cortical excitability (motor threshold (MT)) and organization (center of gravity (CoG) and map volume) of the deep abdominal muscle, transversus abdominis (TrA), using transcranial magnetic stimulation (TMS). In addition, motor behavior of TrA was assessed during single rapid arm movements. The study helps to elucidate the mechanisms of specific motor exercises in chronic back pain management.

Inclusion Criteria:

• Sustained or episodic non-specific low back pain lasting longer than 3 months

Exclusion Criteria:

• Orthopaedic, neurological, circulatory or respiratory conditions
• History or family history of epilepsy
• Recent or current pregnancies
• Previous surgery to the abdomen or back
• Abdominal or back exercises in the preceding 12 months