Pain, AcuteNCT06411197
Exploration of Gait Biomechanics and Muscle Pain of the Lower Extremity
A study testing Hypertonic saline injection and Isotonic saline injection in people with Pain, Acute, run by Kristian Kjær Petersen at 1 site in Denmark.
Trial summary
This interventional study aims to test gait biomechanics in healthy individuals with and without experimental muscle pain in the lower extremities. The study aims to: A) Examine how experimental muscle pain in different types of muscles (ankle plantar-flexion, knee extension, and flexion muscles) affects kinematics… Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Pain, Acute
- What is being tested?
- Hypertonic saline injection and Isotonic saline injection
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 36 participants
- Where
- 1 siteDenmark
- Study dates
- 8 Nov 2023to 31 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy men and women aged 18-45 years
Who cannot join
- Pregnancy
- Drug addiction, defined as the use of cannabis, opioids, or other drugs
- Previous or current neurologic or musculoskeletal illnesses
- Current pain
- Lack of ability to cooperate
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Denmark1 site, 1 recruiting
- Recruiting
Aalborg University
Aalborg, North Denmark, 9000
Kristian KS Petersen, 31697510, kkp@hst.aau.dk
Emma Hertel, 60887473, eh@hst.aau.dk
About this study
This interventional study aims to test gait biomechanics in healthy individuals with and without experimental muscle pain in the lower extremities. The study aims to:
- Examine how experimental muscle pain in different types of muscles (ankle plantar-flexion, knee extension, and flexion muscles) affects kinematics, kinetics, and muscle activation
Participants will receive six muscle injections: a) Hypertonic saline (painful condition) and b) Isotonic saline (control condition) in 1) m. gastrocnemius, 2) m. semitendinosus, and 3) m. biceps femoris.
Read the detailed description
The proposed study will be a randomized, crossover design in which experimental pain will be induced in healthy subjects using hypertonic saline injections to three muscles of the lower extremities: The gastrocnemius muscle, the vastus medialis muscle, and the semitendinosus muscle. Participants will be block-randomized to receive an injection in each of the three muscles and will receive either the painful or control condition first for each muscle. The participant will always be blinded to the type of injection received.
Following the injection, there will typically be a 15-minute window of pain (45). Within this timeframe, motion capture will be carried out for both the control and painful conditions. During motion capture, the participants will perform multiple walking trials of approximately 10 meters. The participants will be equipped with electromyography (EMG) sensors on key muscles of the lower extremities. The participants will be asked for NRS ratings every 30 seconds throughout the 15 minutes with expected pain. There will be a 15-minute washout between the muscle injections.
- Conditions
- Pain, Acute
- Being tested
- Hypertonic saline injection, Isotonic saline injection
- Keywords
- Musculoskeletal pain, Healthy Participants, Biomechanics
- Medical subject headings
- Acute Pain, Musculoskeletal Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hypertonic saline injectionOther
Injection with hypertonic saline (7%)
Isotonic saline injectionOther
Injection with isotonic saline (0.9%)
| Study group | Role | What they receive |
|---|---|---|
| Gastrocnemius (painful condition) | Experimental | 1.5 mL injection of hypertonic saline (7%) to the gastrocnemius muscle. Receives: Other: Hypertonic saline injection |
| Gastrocnemius (control condition) | Sham comparator | 1.5 mL injection of isotonic saline (0.9%) to the gastrocnemius muscle. Receives: Other: Isotonic saline injection |
| Biceps femoris (painful condition) | Experimental | 1.2 mL injection of hypertonic saline (7%) to the biceps femoris muscle. Receives: Other: Hypertonic saline injection |
| Biceps femoris (control condition) | Sham comparator | 1.2 mL injection of isotonic saline (0.9%) to the biceps femoris muscle. Receives: Other: Isotonic saline injection |
| Semitendinosus (painful condition) | Experimental | 1.2 mL injection of hypertonic saline (7%) to the semitendinosus muscle. Receives: Other: Hypertonic saline injection |
| Semitendinosus (control condition) | Sham comparator | 1.2 mL injection of isotonic saline (7%) to the semitendinosus muscle. Receives: Other: Isotonic saline injection |
What is being measured
The primary outcome is the main question the study is designed to answer.
Infrared marker XYZ coordinates
Marker-based motion capture with infrared cameras will be used to estimate placement of reflective markers in the XYZ planes measured in millimeters. Reflective markers will be placed from head-to-toe on anatomical landmarks.
Measured: Baseline.
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'
Measured: Baseline.
Secondary outcomes (5)
Pain sensitivity.
Cuff-pressure algometry will be used to estimate pressure detection and tolerance thresholds, temporal summation of pain, and conditioned pain modulation.
Measured: Baseline.
Ground reaction forces
Ground reaction forces will be measured in Newtons with force plates embedded in the floor.
Measured: Baseline.
Ground reaction moments
Ground reaction moments will be measured in Newton-meters with force plates embedded in the floor.
Measured: Baseline.
Ground contact XZ location
Ground contact XZ coordinate location will be measured in millimeters with force plates embedded in the floor.
Measured: Baseline.
Muscle activation
Muscle activation will be measured in micro-volts using wireless EMG on the muscles of the lower extremities.
Measured: Baseline.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 May 2024
- Study start8 Nov 2023
- Primary completion1 Jun 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pain, AcuteStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 36 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Kristian Kjær Petersen
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Kristian Kjær Petersen, Aalborg University
- Investigators
- Kristian KS Petersen, Principal investigator, Aalborg University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06411197
- Sponsor's protocol ID
- N-20220063-2
- Status last verified
- Sep 2025
- First submitted
- 8 May 2024
- Last updated
- 2 Oct 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Exploration of Gait Biomechanics and Muscle Pain of the Lower Extremity
- ClinicalTrials.gov ID
- NCT06411197
- Acronym / sponsor ID
- N-20220063-2
- Conditions
- Pain, Acute
- Keywords
- Musculoskeletal pain, Healthy Participants, Biomechanics
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 36 participants (estimated)
- Lead sponsor
- Kristian Kjær PetersenUniversity, hospital or other
- Study start
- 8 Nov 2023 (actual)
- Primary completion
- 1 Jun 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 13 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This interventional study aims to test gait biomechanics in healthy individuals with and without experimental muscle pain in the lower extremities. The study aims to:
- Examine how experimental muscle pain in different types of muscles (ankle plantar-flexion, knee extension, and flexion muscles) affects kinematics, kinetics, and muscle activation
Participants will receive six muscle injections: a) Hypertonic saline (painful condition) and b) Isotonic saline (control condition) in 1) m. gastrocnemius, 2) m. semitendinosus, and 3) m. biceps femoris.
Detailed description
The proposed study will be a randomized, crossover design in which experimental pain will be induced in healthy subjects using hypertonic saline injections to three muscles of the lower extremities: The gastrocnemius muscle, the vastus medialis muscle, and the semitendinosus muscle. Participants will be block-randomized to receive an injection in each of the three muscles and will receive either the painful or control condition first for each muscle. The participant will always be blinded to the type of injection received.
Following the injection, there will typically be a 15-minute window of pain (45). Within this timeframe, motion capture will be carried out for both the control and painful conditions. During motion capture, the participants will perform multiple walking trials of approximately 10 meters. The participants will be equipped with electromyography (EMG) sensors on key muscles of the lower extremities. The participants will be asked for NRS ratings every 30 seconds throughout the 15 minutes with expected pain. There will be a 15-minute washout between the muscle injections.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 6
| Arm | Type | Receives |
|---|---|---|
| Gastrocnemius (painful condition) | Experimental | Other: Hypertonic saline injection1.5 mL injection of hypertonic saline (7%) to the gastrocnemius muscle. |
| Gastrocnemius (control condition) | Sham comparator | Other: Isotonic saline injection1.5 mL injection of isotonic saline (0.9%) to the gastrocnemius muscle. |
| Biceps femoris (painful condition) | Experimental | Other: Hypertonic saline injection1.2 mL injection of hypertonic saline (7%) to the biceps femoris muscle. |
| Biceps femoris (control condition) | Sham comparator | Other: Isotonic saline injection1.2 mL injection of isotonic saline (0.9%) to the biceps femoris muscle. |
| Semitendinosus (painful condition) | Experimental | Other: Hypertonic saline injection1.2 mL injection of hypertonic saline (7%) to the semitendinosus muscle. |
| Semitendinosus (control condition) | Sham comparator | Other: Isotonic saline injection1.2 mL injection of isotonic saline (7%) to the semitendinosus muscle. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Healthy men and women aged 18-45 years
Key exclusion criteria (5 listed)
- Pregnancy
- Drug addiction, defined as the use of cannabis, opioids, or other drugs
- Previous or current neurologic or musculoskeletal illnesses
- Current pain
- Lack of ability to cooperate
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hypertonic saline injectionInjection with hypertonic saline (7%) | Other | Biceps femoris (painful condition), Gastrocnemius (painful condition), Semitendinosus (painful condition) |
| Isotonic saline injectionInjection with isotonic saline (0.9%) | Other | Biceps femoris (control condition), Gastrocnemius (control condition), Semitendinosus (control condition) |
Primary outcome
Infrared marker XYZ coordinates
Time frame: Baseline.
Marker-based motion capture with infrared cameras will be used to estimate placement of reflective markers in the XYZ planes measured in millimeters. Reflective markers will be placed from head-to-toe on anatomical landmarks.
Pain intensity (NRS 0-10)
Time frame: Baseline.
Pain during intervention is measured continuously every 30 seconds on a numeric rating scale from 0 'no pain' to 10 'the worst pain imaginable'
5 secondary outcomes
Pain sensitivity.
Time frame: Baseline.
Ground reaction forces
Time frame: Baseline.
Ground reaction moments
Time frame: Baseline.
Ground contact XZ location
Time frame: Baseline.
Muscle activation
Time frame: Baseline.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Oct 2025.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Kristian KS Petersen principal investigator
Aalborg University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hypertonic saline injection and Isotonic saline injection in people with Pain, Acute, run by Kristian Kjær Petersen at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Kristian KS Petersen (31697510, kkp@hst.aau.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Infrared marker XYZ coordinates (time frame: Baseline.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Oct 2025.