Perceptual, Mechanical, and Electromyographic Responses to Different Relative Loads in the Parallel Squat.
Chapman, M, Larumbe-Zabala, E, Gosss-Sampson, M, Colpus, M, Triplett, NT, and Naclerio, F. Perceptual, mechanical, and electromyographic responses to different relative loads in the parallel squat. J Strength Cond Res 33(1): 8-16, 2019-The effectiveness of the OMNI-RES (0-10) Scale and the electromyographic signal for monitoring changes in the movement velocity were examined during a set to muscular failure using different percentages of 1 repetition maximum (1RM) in the parallel squat exercise (PSQ). Twelve men (26.3 ± 5.8 years) were evaluated on 8 separate days with 48 hours of rest between sessions. After determining the 1RM value, participants underwent 7 tests until achieving muscular failure with the following percentage ranges: 30 to <40%, 40 to <50%, 50 to <60%, 60 to <70%, 70 to <80%, 80 to <90%, and >90%. An optical rotary encoder measured mean accelerative velocity (MAV), and the OMNI-RES (0-10) Scale was used to express the rating of perceived exertion (RPE) after every repetition of each set. In addition, the normalized root mean square signal of the surface electromyography (N-EMG) was calculated for the vastus medialis muscle. The RPE expressed after the first repetition and when the maximum value of MAV was achieved along the sets was lower (p < 0.001, d > 0.8) than the RPE that corresponded to a 10% drop in MAV and at failure. In addition, the initial RPE was useful to distinguish different loading zones by anchoring the OMNI-RES value to the magnitude of the relative load (<60%, 60 to <70% or ≤70% 1RM). Similar patterns were observed using the N-EMG. In conclusion, apart from differentiating between relative loads during a set to failure in the PSQ, the RPE and the N-EMG can both reflect changes associated with the initial, maximal, 10% drop in movement velocity and the muscular failure.
Department of Life and Sports Science, Medway Kent, University of Greenwich, Chatham, United Kingdom.
Mark
M
Chapman
Clinical Research Institute, Health Sciences Center, Texas Tech University, Lubbock, Texas.
Eneko
E
Larumbe-Zabala
Department of Life and Sports Science, Medway Kent, University of Greenwich, Chatham, United Kingdom.
Mark
M
Gosss-Sampson
Department of Life and Sports Science, Medway Kent, University of Greenwich, Chatham, United Kingdom.
Mark
M
Colpus
Department of Health and Exercise Science, Appalachian State University, Boone, North Carolina.
N Travis
NT
Triplett
Department of Life and Sports Science, Medway Kent, University of Greenwich, Chatham, United Kingdom.
Fernando
F
Naclerio
D000054:Acceleration; D000328:Adult; D004576:Electromyography; D006801:Humans; D008297:Male; D009068:Movement; D053580:Muscle Strength; D005082:Physical Exertion; D011187:Posture; D052097:Quadriceps Muscle / Q000502:physiology*; D014891:Weight Lifting; D055815:Young Adult