Exercise and Pain Sensitivity
There is ample evidence that exercise therapy is beneficial with respect to pain in patients with osteoarthritis of the knee. However, the pain relieving mechanisms are unknown. To enhance the efficacy of exercise therapy a deeper understanding of the involved mechanisms is needed.
Different exercise types may affect the pain sensitivity differently. It is hypothesized that non-specific exercises (i.e. exercises that does not involve the knee) reduces the processing of pain in the central nervous system (central sensitivity) to knee joint pain in healthy subjects. It is also hypothesized that exercises that involve the knee (i.e. specific knee exercises) reduce the sensitivity of pain receptors in the knee (peripheral sensitivity) in healthy subjects.
Healthy volunteers are recruited and randomised to one of four interventions: 1: Muscle strengthening exercises involving the thigh muscles; 2: Muscle strengthening exercises involving the shoulder muscles; 3: Cardio-vascular fitness exercises; or 4: Control (no exercises). The active interventions include exercises three times per week for 12 weeks. Pain sensitivity and a range of explanatory variables is measured before the interventions, after 4 weeks and after 12 weeks.
|Knee Pain||Other: Knee muscle strengthening exercises Other: Upper extremity strengthening exercises Other: Cardiovascular fitness exercises|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
|Official Title:||Exercise and Alterations in Pain Sensitivity|
- Change in pressure pain sensitivity [ Time Frame: Baseline, and after 12 weeks of exercise ]
- Change in muscle strength [ Time Frame: baseline and after 12 weeks ]Muscle strength is measured in knee extension and flexion and in arm extension and flexion (bench press and pull)
- Change in cardiovascular fitness [ Time Frame: baseline after 4 weeks and after 12 weeks ]Watt max test is performed on a bicycle ergometer to estimate the maximal oxygen uptake velocity
- Change in baroreflex sensitivity [ Time Frame: baseline after 4 weeks and after 12 weeks ]Heart rate and blood pressure variability is measured during rest and during quiet standing.
|Study Start Date:||May 2011|
|Study Completion Date:||March 2012|
|Primary Completion Date:||March 2012 (Final data collection date for primary outcome measure)|
No Intervention: Control
No intervention for 12 weeks
|Active Comparator: Knee muscle strengthening exercises||
Other: Knee muscle strengthening exercises
Muscle strengthening exercises of the quadriceps and hamstring muscles will be performed based on a standard muscle strengthening exercise paradigm: 3 sets with 6-8 repetitions (corresponding to approximately 80% repetition maximum (RM)) will be performed. The training load will be progressed by means of weekly estimates of muscle strength to ensure a constant load of 80% RM. The exercises will be supervised
|Active Comparator: Upper extremity strengthening exercises||
Other: Upper extremity strengthening exercises
Muscle strengthening exercises of the upper amrs and shoulder girdle will be performed based on a standard muscle strengthening exercise paradigm: 3 sets with 6-8 repetitions (corresponding to approximately 80% repetition maximum (RM)) will be performed. The training load will be progressed by means of weekly estimates of muscle strength to ensure a constant load of 80% RM. The exercises will be supervised
|Active Comparator: Cardiovascular fitness exercises||
Other: Cardiovascular fitness exercises
Cardiovascular fitness exercises encompass circuit training including exercises on (but not limited to): ergometer cycles, treadmills (running), and cross-trainers. The exercise intensity is aiming at exercises within 60-85% of maximum heart rate (defined as 220 - age). The heart rate is monitored using a standard heart rate monitor. The exercises will be supervised
Please refer to this study by its ClinicalTrials.gov identifier: NCT01351558
|The Parker Institute, Frederiksberg University Hospital|
|Principal Investigator:||Marius Henriksen, PT,PhD||Senior Researcher|