The use of red or near infrared light upon neurons of the lumbar plexus that are in distress due to retraction-induced ischemia. The surgeon may protect nerves made ischemic in the surgery by: a) making an incision in a patient, b) inserting an access device into the patient through the incision to at least partially create a path to a spine of the patient, and c) irradiating nervous tissue adjacent the path with an amount of NIR or red light effective to provide neuroprotection.