Preliminary Observations Examining the Acute Effect of Range of Motion Barbell-Bench Press Exercises on Markers of Electromyography, Muscle Oxygen Saturation, and Post-exercise Hyperemia of the Pectoralis Major
Full range of motion (fROM) exercises are the traditional method of improving muscular strength and hypertrophy during resistance training (RT), but partial range of motion (pROM) exercises have been used in rehabilitative and resistance training settings, and some recent studies have shown a positive benefit on how it may influence regional muscle growth. However, there is limited evidence examining potential mechanisms of how pROM may stimulate regional muscle growth. PURPOSE: The purpose of this study is to investigate regional or local differences in post-exercise hyperemia (US) of the pectoralis major (PM), PM oxygen saturation (SmO2), and synergist myoelectrical activity (sEMG) during flat (FB) and incline (IB) barbell bench press exercise bouts. METHODS: Two male and female subjects (Age: 22.2 ±0.9 y; Height: 170.0±3.4 cm; Weight: 71.3±7.1 kg; Body Fat: 17.60±4.2 %) were sequentially randomized to fROM and pROM during FB and IB (45° inclination) bench pressing exercises utilizing a Smith Machine (SM) barbell bench press (BP). The SM barbell was fitted with an EliteFTS™ shoulder saver pad during pROM bouts, and individuals were instructed to touch the pad to their chests and "not to lockout," their elbows. The ROM was measured using an elbow electric joint goniometer (DTS2D-Noraxon) and GymAware for distance (cm). 7-days prior to each ROM bout, strength testing (1RM) was completed to determine 75-80% intensity for ROM bouts. Pre-bout (Pre), immediate post-bout (IP), and 24 h post-ROM bout measures of reactive hyperemia in the regional areas of the right-side PM were collected at 10%, 25%, 40%, 50%, and 60 % distal the suprasternal notch in males and 10% and 25% were used for the females. Ultrasound (US; GE Logiq E9) measures cross-sectional area (CSA) using panoramic capability (LOGIQView®). Surface electromyography (sEMG) analysis was performed on each participant's right side for the following muscle groups: pectoralis major-clavicular head (PMC), pectoralis major-sternal head (PMS), anterior deltoid (AD), triceps-medial (TMB), and triceps-lateral brachii (TLB). To measure PM-O2 saturation, a Moxy Muscle Oxygen monitor was inserted on the subject's left side, 25% distal to the suprasternal notch. When necessary, MANOVAs were utilized to assess any preliminary differences. RESULTS: Our preliminary results show that ROM had no impact on IP-CSA measures in males and females at 10 (p=.17; n=4) and 25% (p= .18; n=4); variation was found in averaged peak amplitude for each participant’s primary muscle groups used during 1RM testing compared to the ROM bout (n=3); SmO2 was observed to be lowest during the pROM-IB condition (n=1). DISCUSSION/CONCLUSION: Currently, there is no effect of ROM nor BP on regional hyperemia (CSA) at 10 and 25%, there seems to be variation between average peak amplitude between 1RM and ROM bouts, and the pROM-IB condition measured the lowest PM-O2 saturation found during the bout.
Garcia, Katrina L. and Newmire, Daniel
"Preliminary Observations Examining the Acute Effect of Range of Motion Barbell-Bench Press Exercises on Markers of Electromyography, Muscle Oxygen Saturation, and Post-exercise Hyperemia of the Pectoralis Major,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
14, Article 98.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss14/98