The Effect of Percussion Massage Therapy on the Recovery of DOMS in Physically Active Young Men Delayed Onset Muscle Soreness = DOMS

Primary outcomes

1. Muscle pain

   Time frame: From enrollment to the end of treatment for 3 days

   The intensity of muscle pain was quantified using the visual analogue scale (VAS), which comprises a 10-cm straight line with one end labelled (score of 0) and the other end labelled intolerable pain (score of 10). Subjects were required to provide a rating of their perceived lower-limb muscle soreness for each leg on a scale of one (no soreness) to ten (maximal soreness). Two measurements were recorded on the VAS scale, and the average was calculated.

2. Knee joint ROM

   Time frame: From enrollment to the end of treatment for 3 days

   A modified kneeling lunge was employed to assess knee joint ROM. The procedure was as follows: the subjects left leg was bent at the knee, the thigh was parallel to the ground, and the left lower leg was perpendicular to the ground; the right leg was bent at the knee, and the upper body was maintained in an upright position. The subject was required to adjust the position in order to stretch the right hip to the point of discomfort. The angle to which the right hip was stretched was measured and used as a criterion for subsequent measurement of the ROM. The investigator then bent the subjects right knee until the level of discomfort was reached. At this point, the angle between the thigh and calf was recorded using a goniometer, with the following landmarks: the lateral malleolus, the lateral epicondyle, and the center of the vastus lateralis. A larger angle indicated a smaller ROM of the knee joint.

3. CMJ

   Time frame: From enrollment to the end of treatment for 3 days

   The CMJ was performed in accordance with the established methodology described in the existing literature, and the variables with the CMJ were evaluated using a BTS P-6000 three-dimensional force platform (BTS Bioengineering, Milan, Italy), with a sampling frequency of 1000 Hz. Three trials were conducted for each subject, and the highest vertical jump height was selected for analysis. The variables obtained included the jump height, the peak ground reaction force during the propulsion phase, and the propulsion impulse. The jump height was calculated from the time spent in the air. The peak ground reaction force was obtained from the force-time curve, and the calculation of the propulsion impulse was based on the previous literature.

4. Surface EMG

   Time frame: From enrollment to the end of treatment for 3 days

   In this study, wireless sEMG (Noraxon USA Inc., Scottsdale, AZ, USA) was employed to collect the integrated EMG (iEMG) from the vastus medialis, rectus femoris, and vastus lateralis during the completion of the CMJ on the dominant leg, with a sampling frequency of 1000 Hz. The skin surface was prepared by abrasion and alcohol swabs. Disposable Ag-AgCl circular surface electrodes (4 mm diameter) were filled with electrode jelly and attached 2.5 cm apart to each muscle. Once the EMG test was complete, the raw data were processed using Noraxon TeleMyo (Noraxon USA Inc., Scottsdale,AZ, USA) software for rectification, smoothing, and filtering. In order to eliminate the effect of time phase, the signal was partitioned in 10-ms windows to find for each muscle and each subject its maximal activation over CMJ (iEMGmax). iEMGmax was considered to be 100%. Then, the iEMG of CMJ duration was divided by the time (iEMG/T) and expressed in percentage iEMGmax.