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

The goal of this prospective observational study is to evaluate changes in cognitive and behavioural markers associated with central sensitisation between the start and end of an exercise retraining programme on an exercise bike, in adult patients suffering from chronic lower back pain associated with an untreated degenerative spine, worth or without referred pain. The main changes it will evaluate are: \- Changes in cognitive and behavioural markers associated with central sensitisation between Day 0 and Day 40 during exercise retraining on an exercise bike as part of a rehabilitation programme for chronic low back pain Participants will undergo the followings: * A calibration test used to define moderate exertion on an ergocycle, corresponding to a perceived exertion of 4-5/10 on the modified Borg scale * Exercise-induced pain intensity assessment tests to detect changes in the intensity of pain during physical activity and the activity's potential to cause pain, realised on ergocyle * Exercise rehabilitation on an ergocycle * Final tests to assess cognitive and behavioural markers related to central sensitisation and pain intensity, as at baseline.

Inclusion Criteria: * Adult patients, ages 18 through 75 inclusive, admitted to the Musculoskeletal Rehabilitation Unit at the Concarneau Regional Hospital * Chronic low back pain due to degenerative spine disease that has not been treated surgically, with or without referred pain * Low back pain intensity of 4/10 or less on the EVA scale * Pain lasting more than 12 months (= critical period for cerebral impairment) * Oswestry score between 21% and 40% * CSI score of 33/100 or higher for women and 25/100 or higher for men * Patients enrolled in or covered by a social security program * Patients who have signed a consent form Exclusion Criteria: * Patients with acute low back pain of traumatic or neoplastic origin * Patients with a contraindication to moderate-intensity physical activity (Borg 4-5/10 on the modified Borg scale) * Inability to participate in sessions due to pain unrelated to low back pain or a disability * Pregnant or breastfeeding patients * Patients under legal guardianship or conservatorship