Exercise and Pain Sensitivity

Exercise and Alterations in 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.

Study Overview

• Status: Terminated
• Conditions: Knee Pain
• Intervention / Treatment: Other: Knee muscle strengthening exercises; Other: Upper extremity strengthening exercises; Other: Cardiovascular fitness exercises

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Copenhagen, Denmark
    • The Parker Institute, Frederiksberg University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age between 18 and 35 years
• Untrained (i.e. less than 2 hours of organised exercise per week in the last 6 months - physical activity related to transportation (e.g. bicycling) is not included)
• Generally healthy according a medical exam at screening, history
• Willing and able to participate in all measurements
• Willing and able to attend all training sessions
• Willing to keep the habitual activity and amount of training constant (ie screening activity and training volume).
• 20 ≤ body mass index (BMI) ≤ 28 kg/m2
• Speak, read and write Danish

Exclusion Criteria:

• Pregnant or breastfeeding
• Current or previous symptoms of autoimmune disease (eg, inflammatory bowel disease, multiple sclerosis, lupus, rheumatoid arthritis)
• Planned surgery during the study period
• Current or former musculoskeletal injuries or illnesses, including but not confined to:
• Ligament Injuries
• Meniscus Injuries
• Osteoarthritis
• Patellofemoral Pain Syndrome
• Backache
• Neck pain
• tendinopathy
• Current or past diagnosis, signs or symptoms of significant cardiovascular disease, including but not limited to:
• Ischemic heart disease
• Arteriosclerosis
• Medical conditions that contraindicate exercise, including but not limited to:
• Chronic or congenital heart disease
• Asthma
• Chronic Obstructive Pulmonary Disease
• Past or current diagnosis, signs or symptoms of significant neurological disease, in-incl. but not limited to:
• Blood clot in brain
• Stroke
• Clinically significant head trauma within the last year
• Peripheral neuropathy
• Epilepsy or seizures
• Impaired balance
• Alcohol or drug abuse within the past 5 years
• Past or current diagnosis, signs or symptoms of major psychiatric disorder
• Regional pain syndromes like fibromyalgia
• Regional pain caused by lumbar nerve root or cervical radiculopathy with or at risk for developing it

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in pressure pain sensitivity	Baseline, and after 12 weeks of exercise

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in muscle strength	Muscle strength is measured in knee extension and flexion and in arm extension and flexion (bench press and pull)	baseline and after 12 weeks
Change in cardiovascular fitness	Watt max test is performed on a bicycle ergometer to estimate the maximal oxygen uptake velocity	baseline after 4 weeks and after 12 weeks
Change in baroreflex sensitivity	Heart rate and blood pressure variability is measured during rest and during quiet standing.	baseline after 4 weeks and after 12 weeks

Collaborators and Investigators

• Sponsor: Henning Bliddal
• Investigators: Principal Investigator: Marius Henriksen, PT,PhD, Senior Researcher

Publications and helpful links

General Publications

• Henriksen M, Klokker L, Bartholdy C, Graven-Nielsen T, Bliddal H. The Associations between Pain Sensitivity and Knee Muscle Strength in Healthy Volunteers: A Cross-Sectional Study. Pain Res Treat. 2013;2013:787054. doi: 10.1155/2013/787054. Epub 2013 Sep 17.

Study record dates

Study Major Dates

• Study Start: May 1, 2011
• Primary Completion (Actual): March 1, 2012
• Study Completion (Actual): March 1, 2012

Study Registration Dates

• First Submitted: May 9, 2011
• First Submitted That Met QC Criteria: May 9, 2011
• First Posted (Estimate): May 11, 2011

Study Record Updates

• Last Update Posted (Estimate): October 5, 2012
• Last Update Submitted That Met QC Criteria: October 4, 2012
• Last Verified: October 1, 2012

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Immune System Diseases; Hypersensitivity
• Other Study ID Numbers: 101.01; 10-093704 (Other Grant/Funding Number: Danish Research Council)