Influence of Pain on Exercise-induced Hypoalgesia

NCT ID: NCT05299268

Last Updated: 2022-04-20

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 34 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-03-08
• Study Completion Date: 2022-04-12

Brief Summary

The purpose of this study is to investigate how acute pain induced by hypertonic saline prior to exercise influence the magnitude of exercise-induced hypoalgesia after 1x3 min seated isometric knee extension exercise in healthy women. The study is a blinded randomized cross-over trial The results from the study may be of great importance to the understanding of exercise-induced hypoalgesia, and whether the presence of pain affects the effects of exercise.

Detailed Description

Exercise is recommended to promote and maintain health and as treatment for more than 25 chronic diseases and pain conditions.

The mechanisms underlying pain relief of exercise are largely unknown but may be related to the modulation of central descending pain inhibitory pathways after acute exercise bouts. Exercise-induced hypoalgesia (EIH) is typically assessed as the temporary change in pressure pain thresholds (PPT) after a short acute exercise bout and EIH is seen as a proxy of descending pain inhibitory control. In general, EIH seems hypoalgesic (functional) in asymptomatic subjects. A hyperalgesic (impaired) EIH response has been reported in different chronic pain populations, although a functional EIH response also has been reported in subgroups of knee osteoarthritis patients. This implies differences in the acute response to exercise between healthy (pain-free) subjects and chronic pain patients, but it is still unknown whether the presence of pain itself affects the pain alleviating response (i.e. the EIH response) to acute exercise.

It is hypothesized that acute pain will decrease the EIH response magnitude following hypertonic saline injection compared with the control injection. This study will increase the insight into the EIH mechanisms in healthy subjects in general, and how the presence of pain affects the body's own ability to modulate pain during exercise.

Conditions

Pain; Healthy

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: DOUBLE

Study Groups

Pain (hypertonic saline)

Injection (1 ml) of painful hypertonic saline (5.8%) prior to performance of the 1x3 min Seated Isometric Knee Extension

Group Type: EXPERIMENTAL

Pain (hypertonic saline)

Intervention Type: BEHAVIORAL

A bolus injection (1 ml) of hypertonic saline (5.8%) is injected into the dominant vastus medialis muscle 20 cm proximal from the basis of patella before performance of the 1x3 min Seated Isometric Knee Extension.

No pain (isotonic saline)

Injection (1 ml) of non-painful isotonic saline (0.9%) prior to performance of the 1x3 min Seated Isometric Knee Extension

Group Type: PLACEBO_COMPARATOR

No pain (Isotonic saline)

Intervention Type: BEHAVIORAL

A bolus injection (1 ml) of isotonic saline (0.9%) is injected into the dominant vastus medialis muscle 20 cm proximal from the basis of patella before performance of the 1x3 min Seated Isometric Knee Extension

Interventions

Pain (hypertonic saline)

A bolus injection (1 ml) of hypertonic saline (5.8%) is injected into the dominant vastus medialis muscle 20 cm proximal from the basis of patella before performance of the 1x3 min Seated Isometric Knee Extension.

Intervention Type: BEHAVIORAL

No pain (Isotonic saline)

A bolus injection (1 ml) of isotonic saline (0.9%) is injected into the dominant vastus medialis muscle 20 cm proximal from the basis of patella before performance of the 1x3 min Seated Isometric Knee Extension

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Pain-free
• Understands and writes Danish

Exclusion Criteria

• Pregnancy
• Previous addictive behaviour defined as abuse of hash, opioids or other euphoric substances.
• Previous painful or mental illnesses, neurological or circulatory diseases in the form of heart or lung disease.
• Surgery in the lower extremities within the last 12 months
• Chronic or actual pain on the days of testing
• Under the influence on the days of testing
• Inability to cooperate

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: Yes

Sponsors

University of Southern Denmark

OTHER

Sponsor Role: collaborator

Aalborg University

OTHER

Sponsor Role: lead

Responsible Party

Steffan Wittrup Christensen

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Steffan WM Christensen, PhD

Role: PRINCIPAL_INVESTIGATOR

Aalborg University

Locations

Dept. Of Health Science and Technology, Aalborg University

Aalborg, , Denmark

Countries

Denmark

References

Mohrsen A, Lund H, Rasmussen SZ, Vaegter HB, Vela J, Hansen S, Christensen SWM. Acute exercise of painful muscles does not reduce the hypoalgesic response in young healthy women - a randomized crossover study. Scand J Pain. 2023 May 4;23(3):599-607. doi: 10.1515/sjpain-2022-0127. Print 2023 Jul 26.

Reference Type: DERIVED

PMID: 37137551 (View on PubMed)

Other Identifiers

S-20210184

Identifier Type: -

Identifier Source: org_study_id