The main aim of this study was to evaluate the medium-term efficacy of an intervention involving personalized, automated text messaging (SMS), following face-to-face rehabilitation sessions, on activity limitation in people with chronic low back pain. We hypothesize that personalized SMS follow-up, following face-to-face rehabilitation sessions, could reduce activity limitation in people with chronic low back pain. Prospective multicenter randomized controlled trial.

Participants in both groups, experimental and comparator will have 4 face-to-face multidisciplinary rehabilitation sessions.

Participants in the 2 groups will have a face-to-face medical-kinesthetic clinical consultation at M3.

Participants in the experimental group will be monitored by personalized SMS messages over 6 months.

Non-specific low-back pain is one of the leading causes of activity limitation worldwide. Physical exercise is the treatment that has the best proven its efficacy on pain and activity limitation. Adherence to treatment is an essential factor in its effectiveness. Adherence decreases over time and is low in the medium and long term. Lack of patient follow-up is incriminated in poor adherence. Improving the follow-up of chronic low back pain patients appears to be an important lever for improving their function in the medium and long term.

The Memoquest digital solution (Calmedica) solution is based on a conversational robot that generates SMS messages. It integrates an alert and relay system by the therapist.

Participants will be recruited from patients seen in consultation in the physical medicine and rehabilitation (PMR) departments and in the networks of physicians and town-based MKs at the three centers. Randomization will be centralized.

Patients in the 2 groups will have 4 face-to-face multidisciplinary rehabilitation sessions, lasting 1h30 each, over approximately 15 days (2/week over 2 weeks). During these sessions, participants will learn a personalized exercise self-program (APE).

Participants in the 2 groups will have a face-to-face medico-kinesitherapy clinical consultation at M3: the doctor will question the patient about the evolution of his pain, check for the absence of warning signs and assess the tolerance and efficacy of pharmacological treatments, where appropriate. The physiotherapist will question the patient on the completion of the exercises in the self-program, and will provide additional information if necessary. The physiotherapist may also suggest modifications to the exercises to support the participant's progress.

Participants in the experimental group will be monitored by personalized SMS messages, over 6 months: from the end of the face-to-face rehabilitation sessions, they will receive 2 types of messages on their cell phones:

• Messages type A (received weekly for the first two weeks, then every 15 days): exercise reminders and encouragement
• Messages type B (received monthly): assessment of APE practice over the past week: "how many times did you do your exercise program last week?". Depending on the response: <3 or ≥ 3 times: participants will receive messages of encouragement or will be asked about the main obstacle encountered (keyword); levers adapted to the obstacle will be delivered to them. If participants wish to receive further information, they will be directed by a link to the Cochin PRM department website.

If the patient raises the same obstacle during 2 successive exchanges, or if the patient does not respond to the reminder message (48 hours after the initial message), or if the response is not appropriate, the participant will be called on the telephone by an MK taking part in the study.

The participant may withdraw from the study at any time by mentioning

Inclusion Criteria:

• People with chronic low back pain (common low back pain, duration of low back pain > 3 months)
• People who own a cell phone and have mastered the basics of using it (consulting and sending sms).
• Person with a moderate to high self-efficacy for exercise score (SEE score ≥ 31/90).
• Patient having signed the study participation consent form. Patient affiliated to a social security scheme or entitled beneficiary

Exclusion Criteria:

• Any other pathology affecting postural stability or voluntary active mobility
• Contraindication to exercise
• Lumbar spine surgery in the 12 months prior to inclusion in the study
• Inability to write, speak or read French
• Psychiatric and/or behavioral disorders
• Current pregnancy (declarative) No inclusion of persons covered by articles L. 1121-5 to L. 1121-8 and L. 1122-1-2 of the French Public Health Code (e.g. minors, protected adults, etc.).

statisticians will be masked