Study: NCT04193969

Intervention type: DIAGNOSTIC_TEST
Group type: EXPERIMENTAL
Intervention: Pressure pain assessment using computer controlled cuff algometry
Description: Pressure pain sensitivity is assessed. The pressure is gradually increased and pain is rated by the participant on an electronic visual analogue pain rating scale (VAS) which is connected to the equipment. The assessment is performed on the lower leg and the upper arm. The pain free leg and the left upper arm is used in the patient group. The leg used in the control group will be chosen in a balanced manner meaning that half will receive pressure on the left leg and the other half on the right leg. The pain detection threshold (PDT), pain pressure tolerance threshold (PPT) and pressure pain intensity perceived as 6 on the VAS (VAS6) at the leg site is registered. The PDT and PPT on the arm site is registered.

Intervention type: DIAGNOSTIC_TEST
Group type: EXPERIMENTAL
Intervention: Pressure pain assessment using computer controlled cuff algometry
Description: Pressure pain sensitivity is assessed. The pressure is gradually increased and pain is rated by the participant on an electronic visual analogue pain rating scale (VAS) which is connected to the equipment. The assessment is performed on the lower leg and the upper arm. The pain free leg and the left upper arm is used in the patient group. The leg used in the control group will be chosen in a balanced manner meaning that half will receive pressure on the left leg and the other half on the right leg. The pain detection threshold (PDT), pain pressure tolerance threshold (PPT) and pressure pain intensity perceived as 6 on the VAS (VAS6) at the leg site is registered. The PDT and PPT on the arm site is registered.

Intervention type: DIAGNOSTIC_TEST
Group type: EXPERIMENTAL
Intervention: Temporal summation (TS)
Description: 10 repeated inflations on the lower leg with a 1 sec interval. The pressure used at each pressure is equivalent the PPT measured at baseline. Each inflation is rated on the VAS. TS is registered as the increase pain intensity.

Intervention type: DIAGNOSTIC_TEST
Group type: EXPERIMENTAL
Intervention: Temporal summation (TS)
Description: 10 repeated inflations on the lower leg with a 1 sec interval. The pressure used at each pressure is equivalent the PPT measured at baseline. Each inflation is rated on the VAS. TS is registered as the increase pain intensity.

Intervention type: DIAGNOSTIC_TEST
Group type: EXPERIMENTAL
Intervention: Conditioned pain modulation (CPM)
Description: The cuff on the upper arm is inflated until 70% of the PPT is reached. While the pressure on the arm is kept constant the cuff on the leg is inflated. PDT, PPT and VAS6 pressure at the leg site is registered during the tonic stimulation (pressure on the left arm). The procedure on the leg is repeated within 30 seconds after the pressure is released on the arm site.

Intervention type: DIAGNOSTIC_TEST
Group type: EXPERIMENTAL
Intervention: Conditioned pain modulation (CPM)
Description: The cuff on the upper arm is inflated until 70% of the PPT is reached. While the pressure on the arm is kept constant the cuff on the leg is inflated. PDT, PPT and VAS6 pressure at the leg site is registered during the tonic stimulation (pressure on the left arm). The procedure on the leg is repeated within 30 seconds after the pressure is released on the arm site.

Intervention type: DIAGNOSTIC_TEST
Group type: EXPERIMENTAL
Intervention: Low back pain rating scale (LBPRS-pain)
Description: A questionnaire measuring the intensities of low back pain and leg pain currently, on average the last two weeks and the worst pain within the same period.

Intervention type: DIAGNOSTIC_TEST
Group type: EXPERIMENTAL
Intervention: Oswestry Disability Index
Description: A questionnaire measuring the disability in relation to low back pain and leg pain.