scholarly journals Effects of Stance Width and Barbell Placement on Kinematics, Kinetics, and Myoelectric Activity in Back Squats

2021 ◽  
Vol 3 ◽  
Author(s):  
Stian Larsen ◽  
Eirik Kristiansen ◽  
Eric Helms ◽  
Roland van den Tillaar
Keyword(s):  
Body Mass ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
The Other ◽  
Knee Extensors ◽  
Myoelectric Activity ◽  
Plantar Flexors ◽  
Total Moment ◽  
Repetition Maximum ◽  
Back Squat

Barbell placement and stance width both affect lifting performance in the back squat around the sticking region. However, little is known about how these squat conditions separately could affect the lifting performance. Therefore, this study investigated the effects of stance width and barbell placement upon kinematics, kinetics, and myoelectric activity around the sticking region during a three-repetition maximum back squat. Nine men and nine women (body mass: 76.2 ±11.1, age: 24.9 ± 2.6) performed back squats with four different techniques, such as: high-bar narrow stance (HBNS), high-bar wide stance, low-bar narrow stance, and low-bar wide stance where they lifted 99.2 ± 23.6, 92.9 ± 23.6, 102.5 ± 24.7, and 97.1 ± 25.6 kg, respectively. The main findings were that squatting with a low-bar wide stance condition resulted in larger hip contributions to the total moment than the other squat conditions, whereas squatting with an HBNS resulted in greater knee contributions to the total moment together with higher vastus lateralis and less gluteus maximus myoelectric activity. Our findings suggest that training with an HBNS could be beneficial when targeting the knee extensors and plantar flexors, whereas a low-bar wide stance could be beneficial when targeting the hip extensors.

A Comparison of Gluteus Maximus, Biceps Femoris, and Vastus Lateralis Electromyography Amplitude in the Parallel, Full, and Front Squat Variations in Resistance-Trained Females

2016 ◽  
Vol 32 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Bret Contreras ◽  
Andrew D. Vigotsky ◽  
Brad J. Schoenfeld ◽  
Chris Beardsley ◽  
John Cronin
Keyword(s):  
Range Of Motion ◽  
Body Mass ◽  
Training Stimulus ◽  
Vastus Lateralis ◽  
Full Range ◽  
Gluteus Maximus ◽  
Biceps Femoris ◽  
Repetition Maximum ◽  
Training Adaptations ◽  
Back Squat

Front, full, and parallel squats are some of the most popular squat variations. The purpose of this investigation was to compare mean and peak electromyography (EMG) amplitude of the upper gluteus maximus, lower gluteus maximus, biceps femoris, and vastus lateralis of front, full, and parallel squats. Thirteen healthy women (age = 28.9 ± 5.1 y; height = 164 ± 6.3 cm; body mass = 58.2 ± 6.4 kg) performed 10 repetitions of their estimated 10-repetition maximum of each respective variation. There were no statistical (P = .05) differences between full, front, and parallel squats in any of the tested muscles. Given these findings, it can be concluded that the front, full, or parallel squat can be performed for similar EMG amplitudes. However, given the results of previous research, it is recommended that individuals use a full range of motion when squatting, assuming full range can be safely achieved, to promote more favorable training adaptations. Furthermore, despite requiring lighter loads, the front squat may provide a similar training stimulus to the back squat.

scholarly journals A Biomechanical Comparison of the Safety-Bar, High-Bar and Low-Bar Squat around the Sticking Region among Recreationally Resistance-Trained Men and Women

2021 ◽  
Vol 18 (16) ◽  
pp. 8351
Author(s):  
Eirik Kristiansen ◽  
Stian Larsen ◽  
Markus E. Haugen ◽  
Eric Helms ◽  
Roland van den Tillaar
Keyword(s):  
Body Mass ◽  
Gluteus Maximus ◽  
Knee Extension ◽  
The Other ◽  
Myoelectric Activity ◽  
Knee Valgus ◽  
Men And Women ◽  
Biomechanical Comparison

Barbell placement can affect squat performance around the sticking region. This study compared kinematics, kinetics, and myoelectric activity of the safety-bar squat with the high-bar, and low-bar squat around the sticking region. Six recreationally resistance-trained men (26.3 ± 3.1 years, body mass: 81 ± 7.7 kg) and eight women (22.1 ± 2.2 years, body mass: 65.7 ± 10.5 kg) performed three repetition maximums in all three squat conditions. The participants lifted the least load with the safety bar followed by the high-bar and then the low-bar squat. Greater myoelectric activity of the gluteus maximus was observed during safety-bar squats than high-bar squats. Also, larger knee extension moments were observed for the safety bar compared with low-bar squat. Men had higher myoelectric activity in the safety-bar condition for the gluteus maximus during all regions in comparison with women, and greater knee valgus at the second occurrence of peak barbell velocity. Our findings suggest that the more upright torso inclination during the safety-bar could allow greater gluteus maximus contribution to the hip extensor moment. Moreover, low-bar squats allowed the greatest loads to be lifted, followed by the high-bar and safety-bar squats, possibly due to the larger hip moments and similar knee moments compared to the other squat conditions. Therefore, when the goal is to lift the greatest load possible among recreationally trained men and women, they should first attempt squatting with a low-bar technique, and if the goal is to increase myoelectric activity in the gluteus maximus, a safety-bar squat may be the more effective than the high- bar squat.

scholarly journals Effects of the back-squat exercise on lower limb myoelectric activity in trained men: a systematic review

2021 ◽  
Vol 20 (1) ◽  
pp. 83-92
Author(s):  
Rogério Santos Aguiar ◽  
Juliana Brandão Pinto de Castro ◽  
Andressa Oliveira Barros dos Santos Santos ◽  
Giullio César Pereira Salustiano Mallen da Silva ◽  
Fabiana Rodrigues Scartoni ◽  
...  
Keyword(s):  
Systematic Review ◽  
Resistance Training ◽  
Lower Limb ◽  
Vastus Lateralis ◽  
Experimental Studies ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Myoelectric Activity ◽  
Back Squat ◽  
Squat Exercise

Aim: The aim of this study was to describe the effects of the back-squat exercise on the lower limb myoelectric activity in trained men. Methods: We conducted a systematic review following the recommendations of PRISMA. Medline (PubMed), Scielo, Scopus, SPORTDiscus, and Lilacs databases were searched. The search terms included electromyography, exercise, resistance training, and squat. We included experimental studies that described the back-squat exercise using surface electromyography (EMG) in men experienced in resistance training and back squat exercise at angles from 60º to 90º. Results: Eight studies met the inclusion criteria. The interventions of the included studies ranged from 2 to 7 days. The protocols demonstrated to improve the neuromuscular system and to provide greater acquisition of strength in the muscles involved in performing the back-squat exercise (p < 0.05). Thirty-seven muscles were analyzed, with a predominance of the vastus lateralis, vastus medialis, gluteus maximus, and rectus femoris muscles. Conclusion: The studies investigated in this review showed that the back-squat exercise at angles from 60º to 90º increased the lower limb myoelectric activity recorded in loads of 30% and 100% of 1RM in men experienced in resistance training. However, more studies with higher methodological quality are needed in the analysis of the squat exercise to reduce the risk of bias.

A Comparison of Gluteus Maximus, Biceps Femoris, and Vastus Lateralis Electromyography Amplitude for the Barbell, Band, and American Hip Thrust Variations

2016 ◽  
Vol 32 (3) ◽  
pp. 254-260 ◽  
Author(s):  
Bret Contreras ◽  
Andrew D. Vigotsky ◽  
Brad J. Schoenfeld ◽  
Chris Beardsley ◽  
John Cronin
Keyword(s):  
Experimental Study ◽  
Body Mass ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Biceps Femoris ◽  
Sport Performance ◽  
Repetition Maximum ◽  
Emg Amplitude ◽  
Healthy Female ◽  
Female Subjects

Bridging exercise variations are well researched and commonly employed for both rehabilitation and sport performance. However, resisted bridge exercise variations have not yet been compared in a controlled experimental study. Therefore, the purpose of this study was to compare the differences in upper and lower gluteus maximus, biceps femoris, and vastus lateralis electromyography (EMG) amplitude for the barbell, band, and American hip thrust variations. Thirteen healthy female subjects (age = 28.9 y; height = 164.3 cm; body mass = 58.2 kg) familiar with the hip thrust performed 10 repetitions of their 10-repetition maximum of each variation in a counterbalanced and randomized order. The barbell hip thrust variation elicited statistically greater mean gluteus maximus EMG amplitude than the American and band hip thrusts, and statistically greater peak gluteus maximus EMG amplitude than the band hip thrust (P ≤ .05), but no other statistical differences were observed. It is recommended that resisted bridging exercise be prescribed according to the individual’s preferences and desired outcomes.

Lower Extremity Muscle Functions during Full Squats

2008 ◽  
Vol 24 (4) ◽  
pp. 333-339 ◽  
Author(s):  
D.G.E. Robertson ◽  
Jean-Marie J. Wilson ◽  
Taunya A. St. Pierre
Keyword(s):  
Inverse Dynamics ◽  
Vastus Lateralis ◽  
Muscle Length ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Knee Extensors ◽  
Plantar Flexors ◽  
Lower Extremity Muscle ◽  
Length Changes

The purpose of this research was to determine the functions of the gluteus maximus, biceps femoris, semitendinosus, rectus femoris, vastus lateralis, soleus, gastrocnemius, and tibialis anterior muscles about their associated joints during full (deep-knee) squats. Muscle function was determined from joint kinematics, inverse dynamics, electromyography, and muscle length changes. The subjects were six experienced, male weight lifters. Analyses revealed that the prime movers during ascent were the monoarticular gluteus maximus and vasti muscles (as exemplified by vastus lateralis) and to a lesser extent the soleus muscles. The biarticular muscles functioned mainly as stabilizers of the ankle, knee, and hip joints by working eccentrically to control descent or transferring energy among the segments during ascent. During the ascent phase, the hip extensor moments of force produced the largest powers followed by the ankle plantar flexors and then the knee extensors. The hip and knee extensors provided the initial bursts of power during ascent with the ankle extensors and especially a second burst from the hip extensors adding power during the latter half of the ascent.

scholarly journals New Insights About the Sticking Region in Back Squats: An Analysis of Kinematics, Kinetics, and Myoelectric Activity

2021 ◽  
Vol 3 ◽  
Author(s):  
Stian Larsen ◽  
Eirik Kristiansen ◽  
Roland van den Tillaar
Keyword(s):  
Reaction Force ◽  
Gluteus Maximus ◽  
Biceps Femoris ◽  
Knee Extensors ◽  
Myoelectric Activity ◽  
Force Output ◽  
Total Moment ◽  
Joint Kinetics ◽  
Moment Arms ◽  
Kinetics Of

The aim of this study was to investigate barbell, joint kinematics, joint kinetics of hip, knee, and ankle in tandem with myoelectric activity around the sticking region in three-repetition maximum (3-RM) back squats among recreationally trained lifters. Unlike previous literature, this study also investigated the event of first-peak deacceleration, which was expected to be the event with the lowest force output. Twenty-five recreationally trained lifters (body mass: 70.8 ± 10.5, age: 24.6 ± 3.4, height: 172 ± 8.5) were tested in 3-RM back squats. A repeated one-way analysis of variance showed that ground reaction force output decreased at first peak deacceleration compared with the other events. Moreover, torso forward lean, hip moment arm, and hip contribution to total moment increased, whereas the knee moment arms and moment contribution to total moment decreased in the sticking region. Also, stable moment arms and moment contributions to total moment were observed for the ankle in the sticking region. Furthermore, the knee extensors together with the soleus muscle decreased myoelectric activity in the post-sticking region, while the gluteus maximus and biceps femoris increased myoelectric activity in the post-sticking region. Our findings suggest that the large hip moment arms and hip contributions to total moment together with a lower myoelectric activity for the hip extensors contribute to a poor biomechanical region for force output and, thereby, to the sticking region among recreationally trained lifters in 3-RM back squats.

Muscle coordination in cycling: effect of surface incline and posture

1998 ◽  
Vol 85 (3) ◽  
pp. 927-934 ◽  
Author(s):  
Li Li ◽  
Graham E. Caldwell
Keyword(s):  
Lower Extremity ◽  
High Speed ◽  
Vastus Lateralis ◽  
Activity Patterns ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Knee Extensors ◽  
Emg Activity ◽  
Muscle Coordination

The purpose of the present study was to examine the neuromuscular modifications of cyclists to changes in grade and posture. Eight subjects were tested on a computerized ergometer under three conditions with the same work rate (250 W): pedaling on the level while seated, 8% uphill while seated, and 8% uphill while standing (ST). High-speed video was taken in conjunction with surface electromyography (EMG) of six lower extremity muscles. Results showed that rectus femoris, gluteus maximus (GM), and tibialis anterior had greater EMG magnitude in the ST condition. GM, rectus femoris, and the vastus lateralis demonstrated activity over a greater portion of the crank cycle in the ST condition. The muscle activities of gastrocnemius and biceps femoris did not exhibit profound differences among conditions. Overall, the change of cycling grade alone from 0 to 8% did not induce a significant change in neuromuscular coordination. However, the postural change from seated to ST pedaling at 8% uphill grade was accompanied by increased and/or prolonged muscle activity of hip and knee extensors. The observed EMG activity patterns were discussed with respect to lower extremity joint moments. Monoarticular extensor muscles (GM, vastus lateralis) demonstrated greater modifications in activity patterns with the change in posture compared with their biarticular counterparts. Furthermore, muscle coordination among antagonist pairs of mono- and biarticular muscles was altered in the ST condition; this finding provides support for the notion that muscles within these antagonist pairs have different functions.

Back Squat vs. Hip Thrust Resistance-training Programs in Well-trained Women

2020 ◽  
Vol 41 (05) ◽  
pp. 306-310 ◽  
Author(s):  
Matheus Barbalho ◽  
Victor Coswig ◽  
Daniel Souza ◽  
Julio Cerca Serrão ◽  
Mário Hebling Campos ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Muscle Hypertrophy ◽  
Training Programs ◽  
Gluteus Maximus ◽  
Muscle Thickness ◽  
Quadriceps Femoris ◽  
Repetition Maximum ◽  
Back Squat ◽  
Before And After ◽  
Gluteus Maximus Muscle

AbstractThe study compared the effects of back squat (BS) and hip thrust (HT) exercises on muscle strength and hypertrophy in well-trained women. Twenty-two participants were divided in two groups: BS group (n=12, 26.4±1.32 years, 171.8±3.79 cm, and 69.5±4.9 kg) performed the BS exercise and HT group (n=10, 27.5±1.42 years, 170.8±4.4 cm, 67.5±4.7 kg) performed the HT exercise. Training was performed for 12 weeks. Before and after the training period, participants were assessed for quadriceps femoris and gluteus maximus muscle thickness (MT) and 1 repetition maximum (1RM) test on the BS and HT. Both groups significantly increased hip extensors MT and HT 1RM; however, the improvements in BS group were higher than in HT group on quadriceps femoris (12.2% for BS and 2% for HT, P<0.001) and gluteus maximus MT (9.4% for BS and 3.7% for HT, P=0.001) and BS 1 RM (35.9% for BS and 4.3% for HT, P<0.001). BS was more efficient than HT, since it resulted in greater muscle hypertrophy of the quadriceps femoris and gluteus maximus, increases in BS 1RM and similar increases in HT.

scholarly journals Returners Exhibit Greater Jumping Performance Improvements During a Peaking Phase Compared With New Players on a Volleyball Team

2018 ◽  
Vol 13 (6) ◽  
pp. 709-716 ◽  
Author(s):  
Caleb D. Bazyler ◽  
Satoshi Mizuguchi ◽  
Ashley A. Kavanaugh ◽  
John J. McMahon ◽  
Paul Comfort ◽  
...  
Keyword(s):  
Peak Power ◽  
Perceived Exertion ◽  
Vastus Lateralis ◽  
Rating Of Perceived Exertion ◽  
Training Experience ◽  
Cross Sectional ◽  
Repetition Maximum ◽  
Jumping Performance ◽  
Performance Improvements ◽  
Back Squat

Purpose: To determine if jumping-performance changes during a peaking phase differed among returners and new players on a female collegiate volleyball team and to determine which variables best explained the variation in performance changes. Methods: Fourteen volleyball players were divided into 2 groups—returners (n = 7) and new players (n = 7)—who completed a 5-wk peaking phase prior to conference championships. Players were tested at baseline before the preseason on measures of the vastus lateralis cross-sectional area using ultrasonography, estimated back-squat 1-repetition maximum, countermovement jump height (JH), and relative peak power on a force platform. Jumping performance, rating of perceived exertion training load, and sets played were recorded weekly during the peaking phase. Results: There were moderate to very large (P < .01, Glass Δ = 1.74) and trivial to very large (P = .07, Δ = 1.09) differences in JH and relative peak power changes in favor of returners over new players, respectively, during the peaking phase. Irrespective of group, 7 of 14 players achieved peak JH 2 wk after the initial overreach. The number of sets played (r = .78, P < .01) and the athlete’s preseason relative 1-repetition maximum (r = .54, P = .05) were the strongest correlates of JH changes during the peaking phase. Conclusions: Returners achieved greater improvements in jumping performance during the peaking phase compared with new players, which may be explained by the returners’ greater relative maximal strength, time spent competing, and training experience. Thus, volleyball and strength coaches should consider these factors when prescribing training during a peaking phase to ensure their players are prepared for important competitions.

Prohormone supplement 3β-hydroxy-5α-androst-1-en-17-one enhances resistance training gains but impairs user health

2014 ◽  
Vol 116 (5) ◽  
pp. 560-569 ◽  
Author(s):  
Jorge Granados ◽  
Trevor L. Gillum ◽  
Kevin M. Christmas ◽  
Matthew R. Kuennen
Keyword(s):  
Body Composition ◽  
Resistance Training ◽  
Lean Body Mass ◽  
Body Mass ◽  
Muscular Strength ◽  
Fat Body ◽  
Resistance Training Program ◽  
Repetition Maximum ◽  
Back Squat ◽  
Fat Body Mass

Prohormone supplements (PS) are recognized not to impart anabolic or ergogenic effects in men, but the research supporting these conclusions is dated. The Anabolic Steroid Control Act was amended in 2004 to classify androstenedione and 17 additional anabolic compounds as controlled substances. The viability of PS that entered the market after that time have not been evaluated. Seventeen resistance-trained men (23 ± 1 yr; 13.1 ± 1.5% body fat) were randomly assigned to receive either 330 mg/day of 3β-hydroxy-5α-androst-1-en-17-one (Prohormone; n = 9) or sugar (Placebo; n = 8) per os and complete a 4-wk (16 session) structured resistance-training program. Body composition, muscular strength, circulating lipids, and markers of liver and kidney dysfunction were assessed at study onset and termination. Prohormone increased lean body mass by 6.3 ± 1.2%, decreased fat body mass by 24.6 ± 7.1%, and increased their back squat one repetition maximum and competition total by 14.3 ± 1.5 and 12.8 ± 1.1%, respectively. These improvements exceeded ( P < 0.05) Placebo, which increased lean body mass by 0.5 ± 0.8%, reduced fat body mass by 9.5 ± 3.6%, and increased back squat one repetition maximum and competition total by 5.7 ± 1.7 and 5.9 ± 1.7%, respectively. Prohormone also experienced multiple adverse effects. These included a 38.7 ± 4.0% reduction in HDL ( P < 0.01), a 32.8 ± 15.05% elevation in LDL ( P < 0.01), and elevations of 120.0 ± 22.6 and 77.4 ± 12.0% in LDL-to-HDL and cholesterol-to-HDL ratios, respectively (both P < 0.01). Prohormone also exhibited elevations in serum creatinine (19.6 ± 4.3%; P < 0.01) and aspartate transaminase (113.8 ± 61.1%; P = 0.05), as well as reductions in serum albumin (5.1 ± 1.9%; P = 0.04), alkaline phosphatase (16.4 ± 4.7%; P = 0.04), and glomerular filtration rate (18.0 ± 3.3%; P = 0.04). None of these values changed (all P > 0.05) in Placebo. The oral PS 3β-hydroxy-5α-androst-1-en-17-one improves body composition and muscular strength. However, these changes come at a significant cost. Cardiovascular health and liver function are particularly compromised. Given these findings, we feel the harm associated with this particular PS outweighs any potential benefit.

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