A physical therapist, with more than 10 years of experience, performs a high-velocity low-amplitude spinal manipulation at the L5 level by means of the lumbar roll technique, performed with the subject in right lateral decubitus.

A physical therapist performance a simulated manipulation intervention, for which the same position as in the Intervention Group will be used, in right lateral decubitus with the left leg flexed and the left foot resting on the right popliteal fossa. Without stretching the paravertebral tissues, the participant will remain for approximately 20 seconds without receiving manual impulse.

A high-velocity low-amplitude spinal manipulation at the L5 level will be performance by means of the lumbar roll technique, with the subject in right lateral decubitus.

The measurements will be performed with the MyotonPro®. The subject will be positioned in prone position with both upper limbs around the body. They will be asked to breathe apnea for five seconds after exhaling to reduce the abdominal influence on the test. Measurements at the lumbar level will be performed by positioning the MyotonPro® probe perpendicular to the muscle belly of the erector spinae, 2.5 cm from the midline of the spinous process of L5. A measurement of the tibialis anterior will assess the effect of the remote manipulation. For this purpose, the subject will be positioned in supine decubitus with the lower limb in extension. A point will be located on the tibialis anterior muscle, three finger traverses from the crest of the tibia in a caudal direction.

An Algometer Commander™ JTECH will be used. Prior to the measurements, the subject will be familiarized with the evaluation by taking three measurements in the tenar region of the hand. During this phase, the subject will be asked to indicate, with eyes closed, the moment in which he perceives the painful sensation. The test will consist of a combination of three measurements administered to each muscle, with an interval between measurements of 3 to 5 seconds. The pressure stimulation will be applied with an algometer, gradually increasing the pressure by 0.5 kg per second until the subject manifests pain. The mean pressure at which the subject manifested pain will be calculated from these three measurements. The algometer will be placed perpendicular to the muscle bellies, and the subject will maintain the same position as in the measurement of the muscle mechanical propierties. The evaluation locations will be the L5 spinal Level and the tibialis anterior (bilaterally)