scholarly journals A comparison of two gluteus maximus EMG maximum voluntary isometric contraction positions

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.


Author(s):  
Marina Maren Reiner ◽  
Christoph Glashüttner ◽  
Daniel Bernsteiner ◽  
Markus Tilp ◽  
Gael Guilhem ◽  
...  

Abstract Purpose The purpose of the study was to investigate the effects of using a vibration foam roll (VFR) or a non-vibration foam roll (NVFR) on maximum voluntary isometric contraction peak torque (MVIC), range of motion (ROM), passive resistive torque (PRT), and shear modulus. Methods Twenty-one male volunteers visited the laboratory on two separate days and were randomly assigned to either a VFR group or a NVFR group. Both interventions were performed for 3 × 1 min each. Before and after each intervention, passive resistive torque and maximum voluntary isometric contraction peak torque of the leg extensors were assessed with a dynamometer. Hip extension ROM was assessed using a modified Thomas test with 3D-motion caption. Muscle shear modulus of the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) was assessed with shear wave elastography (SWE). Results In both groups (VFR, NVFR) we observed an increase in MVIC peak torque (+ 14.2 Nm, + 8.6 Nm) and a decrease in shear modulus of the RF (− 7.2 kPa, − 4.7 kPa). However, an increase in hip extension ROM (3.3°) was only observed in the VFR group. There was no change in PRT and shear modulus of the VL and VM, in both the VFR group and the NVFR group. Our findings demonstrate a muscle-specific acute decrease in passive RF stiffness after VFR and NVFR, with an effect on joint flexibility found only after VFR. Conclusion The findings of this study suggest that VFR might be a more efficient approach to maximize performance in sports with flexibility demands.


Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2349
Author(s):  
Stephen Keenan ◽  
Matthew B. Cooke ◽  
Regina Belski

Diets utilising intermittent fasting (IF) as a strategic method to manipulate body composition have recently grown in popularity, however, dietary practices involving fasting have also been followed for centuries for religious reasons (i.e., Ramadan). Regardless of the reasons for engaging in IF, the impacts on lean body mass (LBM) may be detrimental. Previous research has demonstrated that resistance training promotes LBM accrual, however, whether this still occurs during IF is unclear. Therefore, the objective of this review is to systematically analyse human studies investigating the effects of variations of IF combined with resistance training on changes in LBM in previously sedentary or trained (non-elite) individuals. Changes in body weight and fat mass, and protocol adherence were assessed as a secondary objective. This review followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. MEDLINE, CINAHL, PubMed and SportDiscus databases were searched for articles investigating IF, combined with resistance training that reported measures of body composition. Eight studies met the eligibility criteria. LBM was generally maintained, while one study reported a significant increase in LBM. Body fat mass or percentage was significantly reduced in five of eight studies. Results suggest that IF paired with resistance training generally maintains LBM, and can also promote fat loss. Future research should examine longer-term effects of various forms of IF combined with resistance training compared to traditional forms of energy restriction. Prospero registration CRD42018103867.


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.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2325 ◽  
Author(s):  
Andrew D. Vigotsky ◽  
Gregory J. Lehman ◽  
Chris Beardsley ◽  
Bret Contreras ◽  
Bryan Chung ◽  
...  

The modified Thomas test was developed to assess the presence of hip flexion contracture and to measure hip extensibility. Despite its widespread use, to the authors’ knowledge, its criterion reference validity has not yet been investigated. The purpose of this study was to assess the criterion reference validity of the modified Thomas test for measuring peak hip extension angle and hip extension deficits, as defined by the hip not being able to extend to 0º, or neutral. Twenty-nine healthy college students (age = 22.00 ± 3.80 years; height = 1.71 ± 0.09 m; body mass = 70.00 ± 15.60 kg) were recruited for this study. Bland–Altman plots revealed poor validity for the modified Thomas test’s ability to measure hip extension, which could not be explained by differences in hip flexion ability alone. The modified Thomas test displayed a sensitivity of 31.82% (95% CI [13.86–54.87]) and a specificity of 57.14% (95% CI [18.41–90.10]) for testing hip extension deficits. It appears, however, that by controlling pelvic tilt, much of this variance can be accounted for (r= 0.98). When pelvic tilt is not controlled, the modified Thomas test displays poor criterion reference validity and, as per previous studies, poor reliability. However, when pelvic tilt is controlled, the modified Thomas test appears to be a valid test for evaluating peak hip extension angle.


Author(s):  
Gabriel Sen ◽  
Albert Adeboye ◽  
Oluwole Alagbe

The paper was a pilot study that examined learning approaches of architecture students; variability of approaches by university type and gender and; influence of architecture students’ learning approaches on their academic performance. The sample was 349 architecture students from two universities. Descriptive and statistical analyses were used. Results revealed predominant use of deep learning approaches by students. Furthermore, learning approaches neither significantly differed by university type nor gender. Regression analysis revealed that demographic factors accounted for 2.9% of variation in academic performance (F (2,346) = 6.2, p = 0.002, R2 = 0.029, f2 = 0.029) and when learning approaches were also entered the model accounted for 4.4% of variation in academic performance (F (14,334) =2.2, p =0.009, R2 = 0.044, f2=0.044). Deep learning approaches significantly and positively influenced variation in academic performance while surface learning approaches significantly and negatively influenced academic performance. This implies that architectural educators should use instructional methods that encourage deep approaches. Future research needs to use larger and more heterogeneous samples for confirmation of results.


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