Inclusion Criteria:  Phase I  Male or female between the ages of 18-75 years old. Body Mass Index (BMI) ≥ 18.5 kg/m2 but <30 kg/m2 Be a licensed, practicing healthcare clinician (e.g. physical therapist, massage therapist, osteopathic physician, athletic trainer, chiropractor) Have at least 8 years of clinical experience in instrument-assisted soft tissue manual therapy  Phase II  Male and female subjects between 18-75 years old Body Mass Index (BMI) ≥ 18.5 kg/m2 but <30 kg/m2  Phase III  Male and female subjects, ages younger (≥18 but ≤30yo) and older (≥50 but ≤75yo) Body Mass Index (BMI) ≥ 18.5 kg/m2 but <30 kg/m2  Exclusion Criteria:  Phase I  <8 years of clinical experience in instrument-assisted soft tissue manual therapy practice Any known pain conditions, such as nerve impingement (radiculopathies), rheumatoid arthritis, osteoarthritis, or any other inflammatory conditions that could interfere with the participant's ability to perform basic IASTM stroke patterns. Any known cardiovascular, pulmonary, or metabolic disease that could interfere with the clinician's ability to perform basic IASTM stroke patterns.  Phase II  Known cardiovascular, pulmonary, or metabolic disease; Current smoking or those who quit smoking within the previous 6 months; Current use of anti-inflammatory or analgesics; Any history of back, neck, lower extremity, or abdominal surgery or injury; or back, neck, or leg pain within the previous 6 months that impaired function; Any co-morbidities that could contribute to back, neck, or leg pain (e.g., radiculopathies, rheumatoid arthritis, osteoarthritis, inflammatory conditions).  Phase III 1. The same exclusion criteria as for Phase II.  -