TY - JOUR
T1 - LOG-TRANSFORMED ELECTROMYOGRAPHY AMPLITUDE-POWER OUTPUT RELATIONSHIP
T2 - SINGLE-LEG KNEE-EXTENSOR VERSUS SINGLE-LEG CYCLE ERGOMETRY
AU - Noble, Eric B.
AU - Pilarski, Joshua M.
AU - Vora, Harshal K.
AU - Zuniga, Jorge M.
AU - Malek, Moh H.
N1 - Publisher Copyright:
© 2019 NSCA National Strength and Conditioning Association. All rights reserved.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - Comparing and contrasting motor unit recruitment and activation for the same muscles for multiple versus single-joint exercise may provide a better understanding of neuromuscular fatigue. The purpose of this study, therefore, is to compare the slope and y-intercept terms for the 3 superficial quadriceps femoris (QF) (vastus lateralis, rectus femoris, and vastus medialis) muscles derived from the log-transformed electromyography (EMG) amplitude-power output relationship between the single-leg knee-extensor ergometry (KE) and the single-leg cycle ergometry (CE). Ten healthy college-aged men who engaged in regular physical activity visited the laboratory on 2 occasions separated by 7 days to perform either single-leg CE or single-leg KE in a randomized order. For each visit, subjects performed incremental exercise until voluntary fatigue. Electromyography electrodes were placed on the superficial QF muscles. The slope and y-intercept terms, for each muscle, for the EMG amplitude versus power output relationship was examined using the log-transformed model for each subject's data. The results indicated no significant (p . 0.05) mean differences for either slope or y-intercept terms between exercise modes and across muscles. In addition, separate repeated-measures analyses of variance (ANOVAs) were used to determine mean differences for the slope and y-intercept values between the 3 muscles. In addition, separate 2 (mode: CE or KE) 3 intensity (intensity: 30, 60, and 90% of maximal workload) repeated-measures ANOVAs were conducted for each muscle. There was a significant (p , 0.05) mode 3 exercise intensity interaction for each muscle. Follow-up testing indicated that in most cases, the normalized EMG amplitude was significantly higher for single-leg KE than single-leg CE. These results indicated that incremental single-leg KE activates the superficial QF muscles significantly greater than single-leg CE.
AB - Comparing and contrasting motor unit recruitment and activation for the same muscles for multiple versus single-joint exercise may provide a better understanding of neuromuscular fatigue. The purpose of this study, therefore, is to compare the slope and y-intercept terms for the 3 superficial quadriceps femoris (QF) (vastus lateralis, rectus femoris, and vastus medialis) muscles derived from the log-transformed electromyography (EMG) amplitude-power output relationship between the single-leg knee-extensor ergometry (KE) and the single-leg cycle ergometry (CE). Ten healthy college-aged men who engaged in regular physical activity visited the laboratory on 2 occasions separated by 7 days to perform either single-leg CE or single-leg KE in a randomized order. For each visit, subjects performed incremental exercise until voluntary fatigue. Electromyography electrodes were placed on the superficial QF muscles. The slope and y-intercept terms, for each muscle, for the EMG amplitude versus power output relationship was examined using the log-transformed model for each subject's data. The results indicated no significant (p . 0.05) mean differences for either slope or y-intercept terms between exercise modes and across muscles. In addition, separate repeated-measures analyses of variance (ANOVAs) were used to determine mean differences for the slope and y-intercept values between the 3 muscles. In addition, separate 2 (mode: CE or KE) 3 intensity (intensity: 30, 60, and 90% of maximal workload) repeated-measures ANOVAs were conducted for each muscle. There was a significant (p , 0.05) mode 3 exercise intensity interaction for each muscle. Follow-up testing indicated that in most cases, the normalized EMG amplitude was significantly higher for single-leg KE than single-leg CE. These results indicated that incremental single-leg KE activates the superficial QF muscles significantly greater than single-leg CE.
KW - Exercise physiology
KW - Fatigue
KW - Incremental test
KW - Neuromuscular response
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U2 - 10.1519/JSC.0000000000001950
DO - 10.1519/JSC.0000000000001950
M3 - Article
C2 - 31033774
AN - SCOPUS:85042711222
SN - 1064-8011
VL - 33
SP - 1311
EP - 1319
JO - Journal of strength and conditioning research
JF - Journal of strength and conditioning research
IS - 5
ER -