Assessment of changes in the electrical activity of muscles in classic squat with a barbell in powerlifting athletes and people training Crossfit

Bartosz Ruta, Wojciech Walczak. Kamila Pasternak-Mnich, Krzysztof Bortnik


Bartosz Ruta, Wojciech Walczak. Kamila Pasternak-Mnich, Krzysztof Bortnik – Assessment of changes in the electrical activity of muscles in classic squat with a barbell in powerlifting athletes and people training Crossfit. Fizjoterapia Polska 2022; 22(1); 134-151

Abstract
Aim. Assessment of the degree of muscle involvement during a squat with a barbell in powerlifters and Crossfit trainers using surface electromyography (sEMG).
Material and methods. The study included two groups of 30 people exercising Crossfit and powerlifting, with an average age of 24 ± 2.8 years. Inclusion criteria: male gender, age range-22 to 28 years and a minimum of two years of training experience. Muscle tension measurements were made using the EMG FREEEMG300 electromyograph, in accordance with the SENIAM guidelines. The study consisted of a total of twelve repetitions of squats with a barbell, in two series of frontsquat and backsquat techniques.
Results. The mean and mean maximum muscle tone, each time statistically significant differences were noted – in the Crossfit group it was higher than in powerlifting.
Conclusions. The involvement of muscles during the squat with the bar and with the load equal to the body weight, performed using the “back squad” and “front squat” techniques is significantly higher in competitors training Crossfit. The analysis of the subjective assessment of difficulties in performing the exercises showed that the level of difficulty depends on the technique of performing the exercises. Reported difficulties of exercises – 50% of crossfiters using the “back squat” technique and 100% of powerlifters using the “front squat” technique.
Key words:
powerlifting, crossfit, muscle tone, sEMG
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The method of evaluation of biomechanical parameters of human lower limbs in the jump from steps of different heights

Aleksandra Melińska, Andrzej Czamara, Łukasz Szuba, Romuald Będziński

Aleksandra Melińska, Andrzej Czamara, Łukasz Szuba, Romuald Będziński – The method of evaluation of biomechanical parameters of human lower limbs in the jump from steps of different heights. Fizjoterapia Polska 2011; 11(4); 327-340

Abstract
Background. The aim of this study was to identify the loads that occur when landing from different heights, achieved through analysis of selected kinetic and dynamic parameters in men without injuries of the musculoskeletal system. Understanding the characteristics of this type of transportation can play an important role in assessing the progress of rehabilitation after lower limb injuries.Material and methods. The sample comprised 26 men aged 20 to 26 years without lower limb injuries, who performed landing at three heights: 0.1, 0.2 and 0.3 m. For quantitative and qualitative assessment biomechanical studies were performed using motion measurement system, a dynamometric platform for ground reaction force measurement for the vertical component and a module for electromyography.Results. The maximum value of the ground reaction forces for the vertical component during the jump down on both lower limbs from 0.3 m increased to about 2.2 weight. The most active muscles during landing were: m. vastus medialis of the thigh (both limbs) and gastrocnemius, as demonstrated in the study of surface electromyography.Conclusions. 1. No statistically significant (up to 4%) differences were found in the values of maximum ground reaction forces for the vertical component between the left and right lower limb. 2. A positive correlation was found between the ground reaction force, and the height from which the subjects jumped and between the ground reaction force and muscle tension. 3. Muscle tone apparently increased during free standing before landing compared to the jump phase.
Key words:
Methodology, jump down, ground reaction force, muscle tension
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不同频率的静电场按摩对肩胛骨特定骨骼肌张力的影响

Patryk Kiljański, Joanna Kałuża-Pawłowska, Krzysztof Gieremek, Marek Kiljański

P. Kiljański, J. Kałuża-Pawłowska, K. Gieremek, M. Kiljański – The effect of massage with an electrostatic field of different frequency on the tension of selected skeletal muscles of the shoulder girdle. Fizjoterapia Polska 2018; 18(4); 138-158

 

摘要
研究目的。该研究的目的在显示静电场按摩是否对斜方肌上部的静息张力降低有影响。
材料和方法。共20名年龄在23-29岁间的男性与女性加入研究,其生活方式各不相同,受试组中有做休闲运动者、长时间在电脑前工作者或阅读书籍者,也有非全职工作者,其共同特性为生活方式活跃。
测量肌肉张力时使用“Szirmai“肌张力测量器,进行静电场按摩治疗时使用Physiomed品牌的深度振荡仪器,按摩分两阶段进行,两阶段分别使用50 Hz (测试1) i及150 Hz (测试2) 等不同频率。测试间隔为2-3周。
结果和结论。研究结果显示50 Hz及150 Hz频率的静电场按摩对肌肉张力下降有影响,而50 Hz及150 Hz的按摩对肌肉张力降低无统计学上的显著差异。

关键词:
按摩、肌肉张力、频率、深度振荡

 

 

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