Quadriceps Motor Unit Adaptation to Simulated Knee Injury

NCT06999057 | Recruiting Early Phase 1 FDA Drug

• 1 other identifier: Knee_Injection_Study:6295
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 1

Brief 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. This research seeks to improve understanding of muscle inhibition and inform interventions after real-world knee trauma.

Conditions

Muscle Inhibition; Knee Injury Simulation

Keywords

Quadriceps; Electromyography; Motor Unit; Knee Effusion; Lidocaine; Deafferentation; Neuromuscular Adaptation; Muscle Strength

Outcome Measures

Primary Outcomes (2)

• Motor Unit Recruitment (amplitude relative to recruitment threshold)

  Measured via surface EMG decomposition

  Baseline, 0, 30, and 60 minutes post-intervention

• Motor Unit Recruitment (firing rate relative to recruitment threshold)

  Measured via surface EMG decomposition

  Baseline, 0, 30, and 60 minutes post-intervention

Secondary Outcomes (2)

• Quadriceps Inhibition (Hoffmann Reflex)

  Baseline, 0 and 60 minutes post-intervention

• Isometric Peak Torque (Quadriceps Strength)

  Baseline and 60 minutes post-intervention

Study Arms (3)

Effusion Group

EXPERIMENTAL

60 mL sterile saline injected into knee

Device: Joint Effusion via 60 mL Sterile Saline

Deafferentation Group

ACTIVE COMPARATOR

Lidocaine (single intra-articular dose)

Drug: Intra-articular Lidocaine

Control Group

SHAM COMPARATOR

Sham procedure with fake needle

Other: Sham injection

Interventions

Joint Effusion via 60 mL Sterile Saline DEVICE

Injection of sterile saline into the knee joint to simulate joint swelling and induce quadriceps inhibition.

Effusion Group

Intra-articular Lidocaine DRUG

Injection of 7 mL lidocaine into the knee joint to simulate deafferentation by temporarily blocking sensory input.

Deafferentation Group

Sham injection OTHER

Simulated knee injection using a stage needle without skin penetration, used to blind participants and serve as control.

Control Group

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age 18-30 years
• Physically active (Tegner ≥ 5)
• No prior lower-limb surgery or major injury

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Central Florida: lead

Study Sites (1)

University of Central Florida

Orlando, Florida, 32816, United States

RECRUITING

MeSH Terms

Interventions

Lidocaine; salicylhydroxamic acid

Intervention Hierarchy (Ancestors)

Acetanilides; Anilides; Amides; Organic Chemicals; Aniline Compounds; Amines

Central Study Contacts

Grant Norte, Ph.D.

CONTACT

407-823-3188; Grant.Norte@ucf.edu

Meredith Chaput, Ph.D.

CONTACT

Meredith.Chaput@ucf.edu

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: Parallel Assignment

Study Record Dates

• First Submitted: May 20, 2025
• First Posted: May 31, 2025
• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: May 1, 2026

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: The IPD and supporting documentation will be available beginning 6 months after publication of the primary manuscript. Data will remain available for 5 years following that date.
• Access Criteria: Qualified researchers with appropriate data use agreements in place may request access. Requests should be submitted to the Principal Investigator via email and will be reviewed by the study team. Data will be shared via secure file transfer protocols.

Locations

US (1)