The Relationship Between Volitional Activation and Muscle Properties in Incomplete Spinal Cord Injury

Purpose: Following a motor incomplete spinal cord injury (iSCI), there is decreased volitional activation and changes in composition, architecture, and stiffness of affected muscles. We investigated the relationship between muscle properties and volitional activation. Methods: The relationship between central activation ratio (CAR), maximum volitional torque (MVT), and muscle properties was assessed in the gastrocnemius of 6 participants with iSCI. Results: No significant relationship was found between CAR and muscle properties, while a significant relationship was found between CAR and MVT. Conclusion: Our findings suggest there may be no relationship between volitional activation and muscle; thus, certain patients with iSCI may benefit from therapies targeted at neural control.