scholarly journals Peer Review #2 of "A comparison of two gluteus maximus EMG maximum voluntary isometric contraction positions (v0.1)"

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1261 ◽  
Author(s):  
Bret Contreras ◽  
Andrew D. Vigotsky ◽  
Brad J. Schoenfeld ◽  
Chris Beardsley ◽  
John Cronin

Background.The purpose of this study was to compare the peak electromyography (EMG) of the most commonly-used position in the literature, the prone bent-leg (90°) hip extension against manual resistance applied to the distal thigh (PRONE), to a novel position, the standing glute squeeze (SQUEEZE).Methods.Surface EMG electrodes were placed on the upper and lower gluteus maximus of thirteen recreationally active females (age = 28.9 years; height = 164 cm; body mass = 58.2 kg), before three maximum voluntary isometric contraction (MVIC) trials for each position were obtained in a randomized, counterbalanced fashion.Results.No statistically significant (p< 0.05) differences were observed between PRONE (upper: 91.94%; lower: 94.52%) and SQUEEZE (upper: 92.04%; lower: 85.12%) for both the upper and lower gluteus maximus. Neither the PRONE nor SQUEEZE was more effective between all subjects.Conclusions.In agreement with other studies, no single testing position is ideal for every participant. Therefore, it is recommended that investigators employ multiple MVIC positions, when possible, to ensure accuracy. Future research should investigate a variety of gluteus maximus MVIC positions in heterogeneous samples.


Author(s):  
Wei-Han Chen ◽  
Wen-Wen Yang ◽  
Ya-Chen Liu ◽  
Wen-Hsuan Pan ◽  
Chiang Liu

Hula hoops are a popular piece of fitness equipment used to attempt to slim the waistline and improve core muscle endurance. Although there are obvious visible movements at the waist and hip, no study has quantified the intensity of muscle activity during hula hooping. Therefore, this study analyzed muscle activation in the torso and hip during hula hooping. Because injury to the waist often occurs after prolonged, repeated impact between the waist and a hula hoop, this study developed a novel waist fitness hoop that eliminates impact, called the “Mini Hoop,” and determined the effects of mini hooping on hip movement and muscle activation. A total of 16 healthy females performed hula hooping and mini hooping at a self-selected pace. Results showed that hula hooping caused larger muscle activation, with 46%–49% maximum voluntary isometric contraction for the external oblique, spinal erectors, and gluteus medius, whereas gluteus maximus and adductor longus muscle activation were with 22%–29% maximum voluntary isometric contraction. Mini hooping required a smaller range of hip motion in flexion, extension, abduction/adduction, higher pelvic oscillation frequency, and lower muscle activation for the external oblique, spinal erectors, gluteus medius, gluteus maximus, and adductor longus (13%–33% maximum voluntary isometric contraction) compared with hula hooping ( p < 0.05). In conclusion, hula hooping and mini hooping differ in their range of hip motion, pelvic oscillation frequency, and muscle activation requirements. Hula hooping is suitable for moderate-intensity core muscle activation, whereas the Mini Hoop is suitable for low-level core muscle activation.


Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2197
Author(s):  
Chia-Chi Yang ◽  
Po-Ching Yang ◽  
Jia-Jin J. Chen ◽  
Yi-Horng Lai ◽  
Chia-Han Hu ◽  
...  

Since there is merit in noninvasive monitoring of muscular oxidative metabolism for near-infrared spectroscopy in a wide range of clinical scenarios, the present study attempted to evaluate the clinical usability for featuring the modulatory strategies of sternocleidomastoid muscular oxygenation using near-infrared spectroscopy in mild nonspecific neck pain patients. The muscular oxygenation variables of the dominant or affected sternocleidomastoid muscles of interest were extracted at 25% of the maximum voluntary isometric contraction from ten patients (5 males and 5 females, 23.6 ± 4.2 years) and asymptomatic individuals (6 males and 4 females, 24.0 ± 5.1 years) using near-infrared spectroscopy. Only a shorter half-deoxygenation time of oxygen saturation during a sternocleidomastoid isometric contraction was noted in patients compared to asymptomatic individuals (10.43 ± 1.79 s vs. 13.82 ± 1.42 s, p < 0.001). Even though the lack of statically significant differences in most of the muscular oxygenation variables failed to refine the definite pathogenic mechanisms underlying nonspecific neck pain, the findings of modulatory strategies of faster deoxygenation implied that near-infrared spectroscopy appears to have practical potential to provide relevant physiological information regarding muscular oxidative metabolism and constituted convincing preliminary evidences of the adaptive manipulations rather than pathological responses of oxidative metabolism capacity of sternocleidomastoid muscles in nonspecific neck patients with mild disability.


2013 ◽  
Vol 115 (2) ◽  
pp. 167-175 ◽  
Author(s):  
H. S. Palmer ◽  
A. K. Håberg ◽  
M. S. Fimland ◽  
G. M. Solstad ◽  
V. Moe Iversen ◽  
...  

Strength training enhances muscular strength and neural drive, but the underlying neuronal mechanisms remain unclear. This study used magnetic resonance imaging (MRI) to identify possible changes in corticospinal tract (CST) microstructure, cortical activation, and subcortical structure volumes following unilateral strength training of the plantar flexors. Mechanisms underlying cross-education of strength in the untrained leg were also investigated. Young, healthy adult volunteers were assigned to training ( n = 12) or control ( n = 9) groups. The 4 wk of training consisted of 16 sessions of 36 unilateral isometric plantar flexions. Maximum voluntary isometric contraction torque was tested pre- and posttraining. MRI investigation included a T1-weighted scan, diffusion tensor imaging and functional MRI. Probabilistic fiber tracking of the CST was performed on the diffusion tensor imaging images using a two-regions-of-interest approach. Fractional anisotropy and mean diffusivity were calculated for the left and right CST in each individual before and after training. Standard functional MRI analyses and volumetric analyses of subcortical structures were also performed. Maximum voluntary isometric contraction significantly increased in both the trained and untrained legs of the training group, but not the control group. A significant decrease in mean diffusivity was found in the left CST following strength training of the right leg. No significant changes were detected in the right CST. No significant changes in cortical activation were observed following training. A significant reduction in left putamen volume was found after training. This study provides the first evidence for strength training-related changes in white matter and putamen in the healthy adult brain.


1999 ◽  
Vol 87 (5) ◽  
pp. 1758-1767 ◽  
Author(s):  
Samuel C. K. Lee ◽  
Cara N. Becker ◽  
Stuart A. Binder-Macleod

Stimulation trains that exploit the catchlike property [catchlike-inducing trains (CITs)] produce greater forces and rates of rise of force than do constant-frequency trains (CFTs) during isometric contractions and isovelocity movements. This study examined the effect of CITs during isotonic contractions in healthy subjects. Knee extension was electrically elicited against a load of 10% of maximum voluntary isometric contraction. The stimulation intensity was set to produce 20% of maximum voluntary isometric contraction. The muscle was tested before and after fatigue with a 6-pulse CFT and 6-pulse CITs that contained an initial doublet, triplet, or quadruplet. For prefatigue responses, the greatest isotonic performance was produced by CITs with initial doublets. When the muscles were fatigued, triplet CITs were best. CITs produce greater excursion, work, peak power, and average power than do CFTs, because CITs produced more rapid rates of rise of force. Faster rates of rise of force enabled the preload on the muscle to be exceeded earlier during the stimulation train.


2009 ◽  
Vol 41 ◽  
pp. 135
Author(s):  
Tiffany J. Patrick ◽  
David Bellar ◽  
Matt Muller ◽  
Meagan Williamson ◽  
Ellen L. Glickman

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