A program of 8 VR exercises will be applied, of a therapeutic nature, based on the applied exercises of the "Back School", aimed at gaining strength, stability, mobility and flexibility of the abdomino-lumbo-pelvic region and the lower extremities. For each exercise, the VR goggles will manipulate the visual proprioceptive information by modifying the perceived degree of lumbar flexion and extension, i.e., in the VR goggles they will perceive that your movements are different from what you are actually doing.

The same therapeutic exercise program will be applied as the experimental group, but without VR. The training methodology and progression of loads, evaluations and supervision by the physiotherapist will also be the same.

The VR therapeutic exercise program will be implemented for 6 weeks at a frequency of 2 sessions per week with the aim of improving pain and disability, kinesiophobia, range of motion (ROM), catastrophizing, quality of life, and physical fitness. This group will perform the 8 VR exercises of "Back School" by manipulating visual proprioceptive information during all lumbar movements. They will be performed in 2 sets whose intensity and repetitions will be configured and individualized by a self-reported rating of perceived exertion (RPE) through the Borg 6-20 scale. The appropriate training intensity is established with an RPE score between 13 and 17; for this reason, the first 2 weeks will work at an RPE of 14, the 3rd and 4th weeks at an RPE of 15; and finally, the last 2 weeks will work at an RPE of 16. The first 3 weeks will work without additional load, and the last 3 weeks will work with weights, increasing their weekly load individually.

Measured with a Visual Analogue Scale (0-10 points). Higher scores mean a worse pain.

Measured with an electrogoniometer

Measured with the Roland Morris Questionnaire (0-24 points). Higher scores mean a worse disability.

Measured with the International Physical Activity Questionnaire (short-form). This is a 7-item scale used to assess physical activity. Results are divided into different activity levels (low or inactive, moderate, and high activity), and scores are obtained by multiplying the duration of physical activity by the intensity of a task that is metabolically equivalent for each activity level in the last 7 days.