Outcome
Type |
Measure |
Description |
Time frame |
Safety issue |
Other |
Pupil Light Reflex |
Using a pupilometer, covering the other eye, the size of one pupil will be measured during the light reflex. This will be done for both eyes. |
This measurement will be taken pre-intervention, and directly post-intervention. It will also be taken in 15min intervals post-intervention until the PPT is back within 30% of the pre-intervention value. |
|
Other |
Resting State Electroencephalography |
Using electroencephalography (g.tec medical engineering, Austria), namely a cap of electrodes conducted to the head using gel, resting state brain activity will be recorded |
This measurement will be taken pre-intervention, and directly post-intervention. It will also be taken in 15min intervals post-intervention until the PPT is back within 30% of the pre-intervention value. |
|
Other |
Resting State Electrocardiography |
Using electrocardiography, namely electrodes placed on the torso of participants, resting state cardiac activity will be recorded. |
This measurement will be taken pre-intervention, and directly post-intervention. It will also be taken in 15min intervals post-intervention until the PPT is back within 30% of the pre-intervention value. |
|
Primary |
Pain Perception Threshold |
Pressure algometer cuffs, placed on the calf of participants, attached to an electronic visual analogue scale (VAS) measuring device will be employed. Per cuff, as it inflates, participants are asked to move the dial of the VAS when the pressure begins to be painful. The pressure at which this occurs is referred to as the pain perception threshold (PPT). |
This measurement will be taken pre-intervention, and directly post-intervention. It will also be taken in 15min intervals post-intervention until the PPT is back within 30% of the pre-intervention value. |
|
Primary |
Pain Tolerance Threshold |
Pressure algometer cuffs, placed on the calf of participants, attached to a visual analogue scale (VAS) will be employed. Per cuff, as it inflates, participants are asked to move the dial of the VAS when the pressure begins to be painful. They are then tasked to accordingly move the dial as the pain increases. Importantly, when the pain becomes intolerable, participants are tasked to press the red button which releases all pressure. The pressure at which this occurs is referred to as the pain tolerance threshold (PTT). |
This measurement will be taken pre-intervention, and directly post-intervention. It will also be taken in 15min intervals post-intervention until the PPT is back within 30% of the pre-intervention value. |
|
Primary |
Temporary Summation of Pain |
The pressure algometer cuff will inflate on the dominant leg for 1second, with a 1second break, to the given PTT 10 times consecutively. Participants are asked to move the VAS dial to the pain level at each inflation, without returning to 0 on the scale. Nothing will be done with the cuff on the opposite leg. |
This measurement will be taken pre-intervention, and directly post-intervention. It will also be taken in 15min intervals post-intervention until the PPT is back within 30% of the pre-intervention value. |
|
Primary |
Heartbeat Perception |
Randomly interleaved and without manual help, subjects will be tasked to count their own heartbeat across 3 time-intervals (25, 35 and 45 seconds). The difference between the perceived and actual heartbeat count is defined herein as the heartbeat perception. |
This measurement will be taken pre-intervention, and directly post-intervention. |
|
Primary |
Thermal Perception |
The QST.lab thermal stimulator contains 6 stimulation regions, which can individually be programmed. First, with all regions programmed identically, participants will be tasked to state when the stimulus is perceived as painfully cold and warm. These will respectively be the cold and warm thresholds. A thermal-grid illusion pattern will then be generated: this involves interleaving stimulation regions as cold (2deg above the cold threshold) and hot (2deg below the hot threshold). Participants will then be asked to rate the pain intensity of this stimulation (0=no pain, 10=worst pain imaginable). |
This measurement will be acquired pre-intervention, and directly post-intervention. |
|
Secondary |
Conditioned Pain Modulation |
The non-dominant leg will receive a continuous pressure of 70% of the PTT previously registered. The cuff on the dominant leg will gradually inflate. As this occurs, participants are once again asked to start moving the dial when the pressure begins to be painful, and to press the red button when this becomes intolerable. |
This measurement will be taken pre-intervention, and directly post-intervention. It will also be taken in 15min intervals post-intervention until the PPT is back within 30% of the pre-intervention value. |
|
Secondary |
Handheld Pain Perception Threshold |
For each side separately, a handheld pressure algometer will be applied at a constant rate of 30kPa/s, perpendicularly to the belly of the musculus trapezius. Participants will be instructed to press a button when they first perceive the pressure to be painful. This is referred to as the handheld pain perception threshold. |
This measurement will be taken pre-intervention, and directly post-intervention. It will also be taken in 15min intervals post-intervention until the PPT is back within 30% of the pre-intervention value. |
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