Effects of Muscle Cooling on Motor Unit Firing of the Quadriceps

NCT07381920 | Recruiting

• 1 other identifier: IRB00026267
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

The overall objective of this pilot study is to establish the feasibility and methodological validity of using high-density surface electromyography to characterize motor unit behavior of the quadriceps under thermoneutral and locally cooled conditions, and to generate preliminary data to inform the design of a larger, hypothesis-driven study.

Conditions

Healthy

Keywords

muscle cooling; motor unit behavior; HDsEMG; Quadriceps

Outcome Measures

Primary Outcomes (3)

• Motor Unit (MU) Yield

  Number of unique motor units successfully identified (decomposed) from quadriceps HDsEMG recordings during maximal voluntary contractions (MVCs) under thermoneutral and cooled conditions.

  Immediately after the intervention

• HDsEMG Decomposition Accuracy

  Quality/accuracy of motor unit decomposition from quadriceps HDsEMG recorded during MVCs under thermoneutral and cooled conditions, based on decomposition quality metrics generated by the Delsys Neuromap Precision Decomposition III algorithm.

  Immediately after the intervention

• Proportion of Analyzable MVC Trials

  Percentage of MVC trials that yield HDsEMG data suitable for motor unit decomposition and analysis under thermoneutral and cooled conditions (successful decomposition and acceptable signal quality).

  Immediately after the intervention

Secondary Outcomes (2)

• Slope of MUAP-FR relationship

  Immediately after the intervention

• Y-intercept of MUAP-FR relationship

  Immediately after the intervention

Other Outcomes (1)

• Maximal Voluntary Contraction (MVC) Force

  Immediately after the intervention

Study Arms (2)

Sequence A

EXPERIMENTAL

Those randomized to Group A (n=12, 50% men) will perform the thermoneutral condition first, followed by the cooled condition.

Procedure: Cryotherapy

Sequence B

EXPERIMENTAL

Those randomized to Group B (n=12, 50% men) will perform the cooled condition first, followed by the thermoneutral condition.

Procedure: Cryotherapy

Interventions

Cryotherapy PROCEDURE

For the cold condition, an Aircast Thigh Pad (Aircast), connected to the Cryo Cuff IC cooler (DJO Global, Vista, California, USA) will be applied to the dominant thigh. The system circulates ice water maintained at approximately 10-15°C with intermittent compression. Cooling duration will be individualized based on mid-thigh skinfold thickness, consistent with published recommendations that account for the effect of subcutaneous tissue on intramuscular cooling9. Participants with a mid-thigh skinfold thickness of 0-10 mm will receive 10 minutes of cooling; those with a skinfold thickness of 11-20 mm will receive 25 minutes of cooling; those with a skinfold thickness of 21-30 mm will receive 40 minutes of cooling; and those with a skinfold thickness of 31-40 mm will receive 60 minutes of cooling. Participants will remain seated for the duration of the cooling treatment.

Sequence A; Sequence B

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Men and women between the ages of 18 and 35 years
• Healthy adults, defined as absence of significant acute/chronic medical condition, injury, and/or illness that may compromise subject safety, limit the ability of the participant to complete the study, and/or compromise the objectives of the study as determined by the Principal Investigator.

You may not qualify if:

• Current diagnosis or history of:
• major metabolic disease (e.g., type I and type II diabetes),
• neuromuscular disease (e.g., cervical spondylotic radiculomyelopathy, lumbar spondylosis, amyotrophic lateral sclerosis, Guillain-Barré syndrome, and acquired demyelinating polyneuropathies),
• cardiovascular disease (e.g., stage II hypertension, heart failure, myocardial infarction/ischemia, peripheral vascular disease, Raynaud's phenomenon, or other conditions associated with impaired peripheral circulation),
• significant myocardial or pericardial diseases (e.g. amyloidosis, constriction),
• moderate or severe valvular disease,
• pulmonary/respiratory disease (e.g., asthma, chronic bronchitis, emphysema, chronic obstructive pulmonary disease),
• cancer,
• renal disease,
• liver disease,
• or anemia.
• Current or recent musculoskeletal injury (e.g. fracture, sprain, dislocation) or any physical disability that precludes safe and adequate testing.
• Pregnancy or breastfeeding.
• Thigh circumference greater than 23 inches
• Mid-thigh skinfold thickness greater 40 mm

Sponsors & Collaborators

• Wake Forest University: lead

Study Sites (1)

Department of Health and Exercise Science at Wake Forest University

Winston-Salem, North Carolina, 27109, United States

RECRUITING

MeSH Terms

Interventions

Cryotherapy

Intervention Hierarchy (Ancestors)

Therapeutics

Central Study Contacts

Eliott Arroyo, PhD

CONTACT

336-758-5847; arroyoe@wfu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: January 19, 2026
• First Posted: February 2, 2026
• Study Start: January 20, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027
• Last Updated: February 27, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)