This interventional study aims to test the effects of sleep disruption on pain sensitivity and biomechanics in healthy individuals during experimental knee and shoulder pain. The main question the study aims to answer is: 1\) Does sleep fragmentation increase experimental knee and shoulder pain and what are the underlying mechanisms? Participants will receive two injections a) Hypertonic saline (painful) in the knee and b) hypertonic saline (painful) in the upper arm.
This study will include healthy participants for one baseline session and one follow-up session separated by three nights of experimental sleep disruption. The sleep fragmentation will involve three forced awakenings per night for three consecutive nights between sessions. These awakenings will be planned at 00:00, 02:30, and 05:00. In each session, the participant will answer questionnaires and have their pain sensitivity assessed using cuff-pressure algometry. Following this, they will first receive a painful saline injection into the infrapatellar fat pad of the knee. After a washout period, they will receive another painful saline injection into the deltoid muscle of the shoulder. For both injections, the pain will be rated on an NRS scale (0 representing 'no pain' and 10 representing 'worst pain imaginable') every 30 seconds, and the distribution will be marked on a body chart.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
30
0.25 mL injection with hypertonic saline (7%) in the infrapatellar fat pad. 1.2 mL injection with hypertonic saline (7%) in the deltoid muscle.
Aalborg University
Aalborg, North Denmark, Denmark
Knee Pain intensity (NRS 0-10)
Pain during intervention is measured continuously every 30 seconds on a numeric rating scale from 0 'no pain' to 10 'the worst pain imaginable'
Time frame: Baseline (day 1) and follow-up (day 4)
Shoulder Pain intensity (NRS 0-10)
Pain during intervention is measured continuously every 30 seconds on a numeric rating scale from 0 'no pain' to 10 'the worst pain imaginable'
Time frame: Baseline (day 1) and follow-up (day 4)
Pain sensitivity
Cuff-pressure algometry will be used to estimate pressure detection and tolerance thresholds, temporal summation of pain, and conditioned pain modulation.
Time frame: Baseline (day 1) and follow-up (day 4)
The Pittsburgh Sleep Quality Index score
19 items summarized to a single score ranging from zero to 21 with higher scores reflecting worse quality of sleep.
Time frame: Baseline (day 1) and follow-up (day 4)
The Pain catastrophizing Scale score
13 items summarized to a single score ranging from zero to 52 with higher scores reflecting more catastrophizing.
Time frame: Baseline (day 1) and follow-up (day 4)
The Hospital Anxiety and Depression Scale score
14 items summarized into two 7-item subscales measuring symptoms of anxiety and depression. Each subscale score ranges from zero to 21 with higher scores reflecting more severe symptoms.
Time frame: Baseline (day 1) and follow-up (day 4)
The Knee injury and Osteoarthritis Outcome Score
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42 items divided into five subscales: pain (9 items), activities of daily living (17 items), sport and recreation function (5 items), knee-related quality of life (4 items), and other symptoms (7 items). Each subscale is scored from zero to 100 with higher scores reflecting increased severity of knee problems.
Time frame: Baseline (day 1) and follow-up (day 4)
Rapid Assessment of Physical Activity score
9 items scored into summarized categories of either: Sedentary; under-active; under-active regular - light activities; under-active regular; or active.
Time frame: Baseline (day 1) and follow-up (day 4)
Pain distribution by number of pixels marked on a body chart
Area marked with pen will be computed into a score of the ratio of pixels marked compared to the total pixels on the body chart.
Time frame: Baseline (day 1) and follow-up (day 4)
Video-based motion capture
Video recordings of the participant will be obtained, and will later be processed using machine learning to evaluate the gait pattern.
Time frame: Baseline (day 1) and follow-up (day 4)