Muscle InhibitionEarly Phase 1NCT06999057
Quadriceps Motor Unit Adaptation to Simulated Knee Injury
A Early Phase 1 study testing Joint Effusion via 60 mL Sterile Saline and Intra-articular Lidocaine in people with Muscle Inhibition and Knee Injury Simulation, run by University of Central Florida at 1 site in United States.
Trial summary
This study investigates how simulated knee injury-via artificial joint effusion or deafferentation-affects quadriceps motor unit behavior in healthy young adults. Participants will complete neuromuscular testing during a single 2-hour lab session. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Muscle Inhibition, Knee Injury Simulation
- What is being tested?
- Joint Effusion via 60 mL Sterile Saline and Intra-articular Lidocaine
- Type of treatment
- Injection or infusion, Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 45 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Aug 2026to 1 Aug 2027
- Phase
- Early Phase 1
- 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 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age 18-30 years
- Physically active (Tegner ≥ 5)
- No prior lower-limb surgery or major injury
Who cannot join
- Lower limb surgery or significant injury in past 2 years
- Cardiopulmonary, neurological, or psychiatric disorders
- Needle/electrical stimulation anxiety
- Medications affecting neuromuscular or psychological function
- Pregnancy
- Allergic to lidocaine
- Inability to elicit Hoffmann reflex
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Meredith Chaput, Ph.D. contact
United States1 site, 1 recruiting
- Recruiting
University of Central Florida
Orlando, Florida, 32816
Grant E. Norte, 407-823-3188, Grant.Norte@ucf.edu
About this study
This study investigates how simulated knee injury-via artificial joint effusion or deafferentation-affects quadriceps motor unit behavior in healthy young adults. Participants will complete neuromuscular testing during a single 2-hour lab session. This research seeks to improve understanding of muscle inhibition and inform interventions after real-world knee trauma.
Read the detailed description
Using a controlled laboratory model, the investigators will simulate knee injury through two methods: (1) intra-articular saline injection to induce effusion, and (2) intra-articular lidocaine injection to induce sensory deafferentation. Healthy participants aged 18-30 will undergo surface and decomposition EMG, isometric strength testing, and reflex measurements before and after the intervention. The primary outcome is motor unit recruitment characteristics, with secondary outcomes including quadriceps inhibition (Hoffmann reflex) and isometric peak torque. The findings will inform future neuromodulatory approaches in rehabilitation.
- Conditions
- Muscle Inhibition, Knee Injury Simulation
- Being tested
- Joint Effusion via 60 mL Sterile Saline, Intra-articular Lidocaine, Sham injection
- Keywords
- Quadriceps, Electromyography, Motor Unit, Knee Effusion, Lidocaine, Deafferentation, Neuromuscular Adaptation, Muscle Strength
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Joint Effusion via 60 mL Sterile SalineDevice
Injection of sterile saline into the knee joint to simulate joint swelling and induce quadriceps inhibition.
Intra-articular LidocaineDrug
Injection of 7 mL lidocaine into the knee joint to simulate deafferentation by temporarily blocking sensory input.
Sham injectionOther
Simulated knee injection using a stage needle without skin penetration, used to blind participants and serve as control.
| Study group | Role | What they receive |
|---|---|---|
| Effusion Group | Experimental | 60 mL sterile saline injected into knee Receives: Device: Joint Effusion via 60 mL Sterile Saline |
| Deafferentation Group | Active comparator | Lidocaine (single intra-articular dose) Receives: Drug: Intra-articular Lidocaine |
| Control Group | Sham comparator | Sham procedure with fake needle Receives: Other: Sham injection |
What is being measured
The primary outcome is the main question the study is designed to answer.
Motor Unit Recruitment (amplitude relative to recruitment threshold)
Measured via surface EMG decomposition
Measured: Baseline, 0, 30, and 60 minutes post-intervention
Motor Unit Recruitment (firing rate relative to recruitment threshold)
Measured via surface EMG decomposition
Measured: Baseline, 0, 30, and 60 minutes post-intervention
Secondary outcomes (2)
Quadriceps Inhibition (Hoffmann Reflex)
Measured with femoral nerve stimulation
Measured: Baseline, 0 and 60 minutes post-intervention
Isometric Peak Torque (Quadriceps Strength)
Measured with isokinetic dynamometer (Biodex)
Measured: Baseline and 60 minutes post-intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 May 2025
- Study start1 Aug 2026 (estimated)
- Primary completion1 Aug 2027 (estimated)
- Study completion1 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Muscle InhibitionStudies 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
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parallel Assignment
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Central Florida
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Grant Norte, University of Central Florida
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06999057
- Sponsor's protocol ID
- Knee_Injection_Study:6295
- Status last verified
- May 2025
- First submitted
- 20 May 2025
- Last updated
- 1 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data (IPD) related to primary and secondary outcomes, including motor unit recruitment characteristics, quadriceps strength, and Hoffmann reflex measurements, will be shared with qualified researchers upon reasonable request.
Study at a glance
From the registry record, last updated by the sponsor on 1 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Quadriceps Motor Unit Adaptation to Simulated Knee Injury
- ClinicalTrials.gov ID
- NCT06999057
- Acronym / sponsor ID
- Knee_Injection_Study:6295
- Conditions
- Muscle Inhibition, Knee Injury Simulation
- Keywords
- Quadriceps, Electromyography, Motor Unit, Knee Effusion, Lidocaine, Deafferentation, Neuromuscular Adaptation, Muscle Strength
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 45 participants (estimated)
- Lead sponsor
- University of Central FloridaUniversity, hospital or other
- Study start
- 1 Aug 2026 (estimated)
- Primary completion
- 1 Aug 2027 (estimated)
- Study completion
- 1 Aug 2027 (estimated)
- First posted
- 31 May 2025 (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 study investigates how simulated knee injury-via artificial joint effusion or deafferentation-affects quadriceps motor unit behavior in healthy young adults. Participants will complete neuromuscular testing during a single 2-hour lab session. This research seeks to improve understanding of muscle inhibition and inform interventions after real-world knee trauma.
Detailed description
Using a controlled laboratory model, the investigators will simulate knee injury through two methods: (1) intra-articular saline injection to induce effusion, and (2) intra-articular lidocaine injection to induce sensory deafferentation. Healthy participants aged 18-30 will undergo surface and decomposition EMG, isometric strength testing, and reflex measurements before and after the intervention. The primary outcome is motor unit recruitment characteristics, with secondary outcomes including quadriceps inhibition (Hoffmann reflex) and isometric peak torque. The findings will inform future neuromodulatory approaches in rehabilitation.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 3
- Model description
- Parallel Assignment
| Arm | Type | Receives |
|---|---|---|
| Effusion Group | Experimental | Device: Joint Effusion via 60 mL Sterile Saline60 mL sterile saline injected into knee |
| Deafferentation Group | Active comparator | Drug: Intra-articular LidocaineLidocaine (single intra-articular dose) |
| Control Group | Sham comparator | Other: Sham injectionSham procedure with fake needle |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Age 18-30 years
- Physically active (Tegner ≥ 5)
- No prior lower-limb surgery or major injury
Key exclusion criteria (7 listed)
- Lower limb surgery or significant injury in past 2 years
- Cardiopulmonary, neurological, or psychiatric disorders
- Needle/electrical stimulation anxiety
- Medications affecting neuromuscular or psychological function
- Pregnancy
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 |
|---|---|---|
| Joint Effusion via 60 mL Sterile SalineInjection of sterile saline into the knee joint to simulate joint swelling and induce quadriceps inhibition. | Device | Effusion Group |
| Intra-articular LidocaineInjection of 7 mL lidocaine into the knee joint to simulate deafferentation by temporarily blocking sensory input. | Drug | Deafferentation Group |
| Sham injectionSimulated knee injection using a stage needle without skin penetration, used to blind participants and serve as control. | Other | Control Group |
Primary outcome
Motor Unit Recruitment (amplitude relative to recruitment threshold)
Time frame: Baseline, 0, 30, and 60 minutes post-intervention
Measured via surface EMG decomposition
Motor Unit Recruitment (firing rate relative to recruitment threshold)
Time frame: Baseline, 0, 30, and 60 minutes post-intervention
Measured via surface EMG decomposition
2 secondary outcomes
Quadriceps Inhibition (Hoffmann Reflex)
Time frame: Baseline, 0 and 60 minutes post-intervention
Isometric Peak Torque (Quadriceps Strength)
Time frame: Baseline and 60 minutes post-intervention
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 1 May 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data (IPD) related to primary and secondary outcomes, including motor unit recruitment characteristics, quadriceps strength, and Hoffmann reflex measurements, will be shared with qualified researchers upon reasonable request.
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Regenerative Medicine for Joint Hypermobility and Instability
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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.
Meredith Chaput, Ph.D. contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Joint Effusion via 60 mL Sterile Saline and Intra-articular Lidocaine in people with Muscle Inhibition and Knee Injury Simulation, run by University of Central Florida at 1 site in United States.
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 3 inclusion and 7 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 1 May 2026. 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 United States. 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.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Grant Norte, Ph.D. (407-823-3188, Grant.Norte@ucf.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Motor Unit Recruitment (amplitude relative to recruitment threshold) (time frame: Baseline, 0, 30, and 60 minutes post-intervention). 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 1 May 2026.