Pain Assessment Through Integrated Neurophysiology and Multidimensional Profiling (PAIN-MAP)

Adults aged 18-45 with chronic low back pain (>3 months) and neural mechanosensitivity.

Healthy volunteers without pain.

Differences in oscillatory activity between groups and subgroups. Difference is defined as statistical significance in the t-test comparison of the spectral power.

Differences in cortical activity strength between groups and subgroups. Difference is defined as statistical significance in the t-test comparison of the current density strength as reconstructed via an inverse solution algorithm.

Differences in cortical connectivity between groups and subgroups. Difference is defined as statistical significance in the t-test comparison of a connectivity metric estimated from the cortical activity, as reconstructed via an inverse solution algorithm.

Differences in network topology between groups and subgroups. Difference is defined as statistical significance in the t-test comparison of a graph measure estimated from the connectivity matrices of Outcome 3.

Differences in pain intensity between groups and subgroups. This scale assesses subjective pain Intensity by selecting an integer from 0 to 10, where 0 represents complete absence of pain and 10 worst possible pain.

Differences in kinesiophobia between groups and subgroups. This questionnaire assesses kinesiophobia, i.e. the patient's fear of movement, physical activity, or re-inury due to pain. It includes 17 statements, where each statement is rated on a 4-point Likert scale, from 1 "Strongly disagree" to 4 "Strongly agree". Certain items, such as 4,8,12 and 16 are reversed scored. The total score is derived from the sum of all answers, with higher values indicating greater fear of movement.

Differences in catastrophizing between groups and subgroups. This questionnaire measures pain catastrophizing i.e. the negative thoughts and excessive emotions experienced by the patient when in pain. It includes 13 statements. The patient rates each statement from 0 "Not at all" to 4 "All the time". The total score ranges from 0 to 52, with higher scores indicating higher levels of catastrophizing.

Differences in sleep quality and the likelihood of insomnia between groups and subgroups. This scale assesses sleep quality and the likelihood of insomnia. It consists of 8 questions and each question has 4 response option from 0 "no problem/adequate" to 3 "severe problem/very inadequate". Total scores range from 0 to 24, with higher scores indicating more severe insomnia problems.

Differences in level of functional disability between groups and subgroups. This questionnaire measures the level of functional disability and how lower back pain affects daily activities. It consists of 10 questions. Each includes 6 possible answers scored from 0 (least impact) to 5 (maximum impact). The final score is calculated as a percentage ( total score of answers/ Maximum possible score x 100), where 0% means no disability and 100% maximum possible disability.

Differences in quality of life between groups and subgroups. This questionnaire assess quality of life across four domains (physical health, psychological well-being, social relationships and environment) via 26 questions on a 1-5 scale. Each domain yields a score transformed into a 0-100 scale, where higher values reflect better quality.

Differences in distance walked during the 6-Minutes Walking Test between groups and subgroups. During the 6-Minutes Walking Test the total distance a person can walk on a flat, hard surface will be measured in meters (m).

Differences in average walking speed between groups and subgroups. Average walking speed (kilometers per hour) will be measured during the 6-Minutes Walking Test.

Differences in cadence between groups and subgroups. Cadence will be calculated by the number of steps taken per minute (combined total of the two feet) and it will be measured during the 6-Minutes Walking Test.

Differences in stride length between groups and subgroups. Stride length will be calculated by the distance between two successive heel landings of the same foot and it will be measured during the 6-Minutes Walking Test.

Differences in stance time between groups and subgroups. Stance time will be calculated by the time during which the foot is in contact with the ground, standardized to be expressed as a percentage of the cycle time. It will be measured during the 6-Minutes Walking Test.

Differences in swing time between groups and subgroups. Swing time will be calculated by the time during which the foot is not in contact with the ground, standardized to be expressed as a percentage of the cycle time. It will be measured during the 6-Minutes Walking Test.

Differences in double support time between groups and subgroups. Double support time will be calculated by the percentage of the cycle during which both feet are in contact with the ground at the same time. It will be measured during the 6-Minutes Walking Test.

Differences in symmetry percentages between groups and subgroups. Symmetry expresses the congruence between the values obtained on the left and right foot for stance and swing time and determines whether one leg is used more than the other when walking. It will be measured during the 6-Minutes Walking Test.