Low back pain (LBP) is a common condition worldwide as the lifetime prevalence is up to 80%. It is defined as pain in the lumbosacral region in which the etiological causes are most often mechanical, and it is therefore defined as "non-specific LBP".

Lumbar belts are used in the treatment and secondary prevention of LBP. They are supposed to reduce the intensity of pain by improving the functional capacities of daily activities and thus preventing the risk of chronicity related to immobility (HAS).

Despite some proof of their efficiency in the literature, it is still not clear how the pressure applied by the belt and the immobilization constraints on the trunk improve the patient mobility.

Considering that LBP causes movement limitation, and that the lumbar belt contributes to initially decrease the pain intensity, as well as to improve the mobility and the functional capacities of the patient, we propose to evaluate the clinical and biomechanical effects of the lumbar belt during different trunk movements in subjects with and without LBP.

This is a clinical investigation on a CE marked medical device, used in accordance with its intended purpose, in the context of a post-marketing clinical follow-up with additional non-invasive procedures (IC SCAC: case 4.1 of the medical device regulation 2017/745).This is a prospective, monocentric, comparative and open clinical investigation.

The objective is to evaluate the clinical and functional effects related to spinal movements in 2 conditions, with and without the wearing of a lumbar belt. The study will be carried out with two groups of subjects: one group of subjects presenting an episode of LBP (NS>4) (subjects considered to have subacute or chronic nonspecific LBP according to the classification of LBP) and another group of control subjects with no spinal symptoms and no pain that could limit movement (healthy subjects).

Each group will undergo 2 visits on 2 separate days with a 30-day delay for the LBP subjects and a 7-day delay for the healthy subjects

• a first visit (V1) for inclusion, familiarization with a clinical and functional test, and an external measurement of spinal mobility during movements;
• a second visit (V2) for a clinical and functional evaluation, external measurements of spinal mobility and biomechanical measurements.

A third visit (V3) will be offered to healthy subjects for the measurement of spinal segment kinematics with the LombaSkin belt and Percko postural T-shirt.

Inclusion Criteria for subjects Low Back Pain:

• Male or female,
• Aged between 18 and 70 years,
• With a waist circumference between 75 cm and 110 cm,
• With a 18.5 < BMI < 30 kg/m2,
• Suffering from a current episode of non-specific low back pain (symptomatic subjects),
• At least one average low back pain at rest or during exercise in the last 72 hours collected at inclusion (≥ 4/10 on an EN scale),
• Followed by a primary care physician or specialist for this clinical condition,
• Having received or scheduled to receive an EOS type radiological workup in less than 6 months
• Affiliated or entitled to a social security system,
• Having signed the written consent.

Inclusion Criteria for healthy subjects:

• Male or female,
• Aged 18 to 70 years,
• With a waist circumference between 75 cm and 110 cm,
• With a 18.5 < BMI < 30 kg/m2,
• Never having suffered from LBP or any other type of lumbar disorder,
• Affiliated or entitled to a social security system,
• Having signed the written consent.

Exclusion Criteria:

• Subjects suffering from LBP of inflammatory, tumoral or infectious cause.
• Pregnant women.
• Subjects with cognitive or mental disorders or confirmed depression;
• Subjects who received an infiltration less than one month prior to the inclusion visit or planned during the study;
• Subjects with a known allergy to any of the materials;
• Subjects complaining of chronic, unstabilized or symptomatic cardiac or respiratory problems;
• Subjects with current participation in an interventional investigational drug or device therapy study that impacts the endpoints.
• Subjects under legal protection or unable to express their consent;
• Subject presenting a lumbar radicular syndrome (hiatal hernia, spinal stenosis...).