Effects of Roller Massage on Short-Term Passive Muscle Stiffness

Following screening for eligibility and consent, subjects will be assigned randomly to one of three groups: a placebo control group and two roller massage groups (treatment groups). The treatment groups will each receive a single bout of roller massage. One treatment group will receive a massage at medium intensity (25 newtons of force directed perpendicular to surface of thigh), the other treatment group at high intensity (45 newtons of force directed perpendicular to surface of thigh). The placebo group will receive a single bout of sham ultrasound. Both placebo and treatments will be delivered to the anterior thigh with the participant in a supine position. Each procedure will last for 10 minutes. In all groups, muscle stiffness, natural oscillation frequency, elasticity, relaxation time, and creep at the vastus lateralis will be measured using a myotonometer. PROM for knee flexion will also be measured in both groups using goniometry. All measurements will be taken at 3 different times: immediately before treatment or placebo, immediately after treatment or placebo, and 30 minutes after treatment or placebo. Myotonometric measurements of the vastus lateralis will be taken 2/3 of the way down between the anterior superior iliac spine and lateral aspect of the patella, in accordance with guidelines for the Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles. For goniometric measurement, participants will be in supine position on an examination table. The investigator will flex the participant's hip to 90 degrees and then, using a dynamometer (to ensure consistent applied force for all participants), flex the participant's knee. To measure knee flexion PROM, the goniometer will be positioned with the axis at the lateral epicondyle of the femur, the stationary arm in line with the lateral midline of the femur toward the greater trochanter, and the moving arm in line with the fibular head and lateral malleolus. During the time between the second and third measurements, subjects will be asked to sit quietly.