Quadriceps response to simulated knee injury
Quadriceps Motor Unit Adaptation to Simulated Knee Injury
This project will test whether filling the knee with fluid or temporarily numbing its nerves changes quadriceps muscle recruitment in healthy 18–30-year-olds.
Quick facts
| Phase | Early Phase 1 |
|---|---|
| Study type | Interventional |
| Enrollment | 45 (estimated) |
| Ages | 18 Years to 30 Years |
| Sex | All |
| Sponsor | University of Central Florida Academic / other |
| Locations | 1 site (Orlando, Florida) |
| Trial ID | NCT06999057 on ClinicalTrials.gov |
What this trial studies
Using a controlled laboratory model, investigators will simulate knee injury either by injecting sterile saline to create an effusion or by injecting lidocaine to produce temporary sensory deafferentation, with a sham injection as comparison. Healthy, physically active participants aged 18–30 will attend a single roughly two-hour session during which surface and decomposition EMG, isometric peak torque testing, and Hoffmann reflex measurements are collected before and after the intervention. The primary outcome is motor unit recruitment characteristics; secondary outcomes include measures of quadriceps inhibition (H-reflex) and isometric torque. The study aims to characterize acute neuromuscular changes that could inform future neuromodulatory or rehabilitation strategies after real knee trauma.
Who should consider this trial
Good fit: Ideal candidates are healthy, physically active adults aged 18–30 with no prior lower-limb surgery or recent major injury and no contraindications to needle procedures or lidocaine.
Not a fit: People with current knee injuries, older adults, pregnant individuals, those allergic to lidocaine, or individuals with significant cardiopulmonary, neurological, or psychiatric conditions are unlikely to receive direct benefit from participation.
Why it matters
Potential benefit: If successful, the findings could help design rehabilitation methods to reduce quadriceps weakness and improve recovery after knee injuries.
How similar studies have performed: Similar lab models using intra-articular saline and local anesthesia have produced measurable changes in quadriceps activation, though applying those results to clinical rehab remains limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: 1. Age 18-30 years 2. Physically active (Tegner ≥ 5) 3. No prior lower-limb surgery or major injury Exclusion Criteria: 1. Lower limb surgery or significant injury in past 2 years 2. Cardiopulmonary, neurological, or psychiatric disorders 3. Needle/electrical stimulation anxiety 4. Medications affecting neuromuscular or psychological function 5. Pregnancy 6. Allergic to lidocaine 7. Inability to elicit Hoffmann reflex
Where this trial is running
Orlando, Florida
- University of Central Florida — Orlando, Florida, United States (Recruiting)
Study contacts
- Study coordinator: Grant Norte, Ph.D.
- Email: Grant.Norte@ucf.edu
- Phone: 407-823-3188
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.