Effects of Muscle Cooling on Motor Unit Firing of the Quadriceps: A Pilot Feasibility Study
Wake Forest University
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.
Description
This randomized, cross-over pilot study will recruit 24 healthy young adults (12 men and 12 women) between the ages of 18 and 35 years. Participants will attend two in-person laboratory visits separated by a minimum of 48 hours. Visit 1 will include informed consent, eligibility confirmation, baseline assessments, and familiarization procedures. Visit 2 will include experimental testing under thermoneutral and cooled conditions.
Eligibility
- Age range
- 18–35 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * 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. Exclusion Criteria: * 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 lat…
Interventions
- ProcedureCryotherapy
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.
Location
- Department of Health and Exercise Science at Wake Forest UniversityWinston-Salem, North Carolina