Healthy Subjects, Hyperalgesia
Conditions
Keywords
Muscle soreness, NGF-induced pain, Pain model, Long-lasting sensitization
Brief summary
The purpose of this study is to investigate and determine the time course and distribution on muscle hyperalgesia and muscle pain in a repeated, low dose NGF model. It is hypothesized that low dosages i.m injections of NGF are able to induce mechanical hyperalgesia and muscle soreness in a same manner (effect of duration) as for dosages previously used in NGF studies. Furthermore, it is also speculated if several injections of low dose NGF into the muscle combined are able to course immediate pain sensation and spreading of muscle hypersensitivity.
Detailed description
Effects of pain responses, symptom development and pattern (time course and distribution) following 5 i.m low dose injections of NGF injected into the tibialis anterior muscle will be compared to a high dose i.m injection of NGF injected into the contralateral side in healthy pain-free subjects.
Interventions
DRUGNGF
Intramuscular injection
Sponsors
Aalborg University
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Masking description
Double blind
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy and pain free volunteers
Exclusion criteria
* Pregnancy * Drug addiction defined as the use of cannabis, opioids or other drugs * Previous neurologic, mental illnesses, or psychiatric diseases. * Past history of chronic pain in the musculoskeletal system (muscle, joint, cartilage, connective tissue) * Participation in other pain trials throughout the study period * Lack of ability to cooperate * Taking any analgesic 24 hours before the injections * Performing any strenuous leg exercise through out the study period causing sore muscles
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Muscle sensitivity | Change from baseline at 3 weeks | Pressure pain thresholds (PPTs) are assessed over the tibialis anterior muscles using a handhold pressure algometer. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pressure-induced referred pain | Change from baseline at 3 weeks | At three predetermined sites within the tibialis anterior muscle, a constant pressure stimulation (120% of PPT) is evoked by use of the pressure algometer. Subjects color their perceived sensation of pain on an electronic schematic of the lower legs using Navigate Pain. |
| Activity-induced muscle soreness | Change from baseline at 3 weeks | Subjects perform 10 dorsiflexions with each leg. The perceived muscle soreness is reported using a numeric rating scale (NRS) and the area of soreness is colored on an electronic schematic of the lower legs (Navigate Pain). |
| Pain intensity | Assessed continuously at 0-5 min during the injections at each leg | Subjects rate their perceived pain intensity on a visual analogue scale (VAS) App (Aalborg University) as displayed on a tablet computer with a sample rate of 1 Hz. |
| Muscle soreness Diary | Change from baseline at 3 weeks | Two times a day subjects evaluate their muscle soreness using a Likert Scale of muscle soreness for lower limp |
| Activity-induced muscle soreness Diary | Change from baseline at 1 week | Subjects perform 10 dorsiflexions with each leg. The perceived muscle soreness is reported using a numeric rating scale (NRS) and the area of soreness is colored on an electronic schematic of the lower legs (Navigate Pain). The activity is performed at home on days in between the sessions |
Countries
Denmark
Outcome results
None listed