Assessment of Pain Perception and the Impact of Central Sensitization on Biopsychosocial Manifestations During Physical Activity in Patients With Chronic Low Back Pain

Patients with chronic low back pain who are scheduled to receive care at the Musculoskeletal Rehabilitation Unit of the Cornouaille Rehabilitation Center in Concarneau for low back pain rehabilitation-either through a group program on a part-time inpatient basis or an individual program on a full-time inpatient basis-will be considered for inclusion in the study.

Eligible patients will be enrolled after the investigator has provided them with comprehensive verbal and written information, conducted initial assessments, verified the inclusion and exclusion criteria, and obtained signed informed consent from the patients. For inpatients, verification of inclusion and exclusion criteria will take place on the day of admission to the Concarneau PRC during the initial evaluation.

Upon admission, the patient is assessed according to standard criteria for the management of patients with low back pain (measurements of spinal mobility: Fingers-to-Floor Distance (FFD), spinal inclinometry in flexion and extension, lateral bending, Schober's test, muscle strength assessment: Shirado and Sorensen tests, measurement of hamstring and quadriceps hyperextensibility), to which are added the Oswestry Questionnaire to assess disability related to low back pain, the CSI questionnaire, which assesses symptoms of central sensitization, and an evaluation of various cognitive-behavioral markers related to central sensitization, including sensitization due to motor disorders (Luomajoki tests), sensitization due to kinesiophobia (Tempa Scale of Kinesiophobia and KINAP), and sensitization due to catastrophizing (Pain Catastrophizing Scale).

After enrollment, patients will undergo a calibration test on an exercise bike on Day 1 to determine the power required to maintain a constant moderate effort corresponding to an intensity of 4-5/10 on the modified Borg scale. Then, to assess the pain-inducing potential of exercise on an ergocycle, they will perform two tests (on Day 3 and Day 5) to evaluate changes in pain during moderate, sustained exercise.

During their rehabilitation for low back pain, patients undergo exercise retraining on an ergocycle. From Day 8 through Day 40 (3 times per week, on Mondays, Wednesdays, and Fridays), the patients' perceived exertion will be assessed at the end of each ergometer session to verify that they are indeed maintaining a constant moderate level of exertion.