Effects of Muscle Cooling on Motor Unit Firing of the Quadriceps
ConditionHealthy
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-35
SponsorWake Forest University
About this trial
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.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
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.
Disqualifiers
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),
Trial design
Design model
Crossover
Treatments tested in this trial
Cryotherapy
Procedure/SurgeryFor 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.
Treatment groups
24 Participants
are divided into 2 treatment groupsGroup A: Sequence AExperimental treatment 1 intervention
Group B: Sequence BExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
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.
Time frame
Immediately after the intervention2
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.
Time frame
Immediately after the intervention3
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).
Time frame
Immediately after the interventionSecondary outcomes
1
Slope of MUAP-FR relationship
Slope of the linear regression relating MU firing rate to MU action potential amplitude during MVCs under thermoneutral and cooled conditions.
Time frame
Immediately after the intervention2
Y-intercept of MUAP-FR relationship
Y-intercept of the linear regression relating MU firing rate to MU action potential amplitude during MVCs under thermoneutral and cooled conditions.
Time frame
Immediately after the interventionOther outcomes
1
Maximal Voluntary Contraction (MVC) Force
Peak knee extensor force (N) achieved during MVC testing under thermoneutral and cooled conditions.
Time frame
Immediately after the interventionSponsors and contacts
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Source ClinicalTrials.gov