Tag: sEMG

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
Pobierz/Download/下載/Cкачиваете   免費下載（僅限英文版）

sEMG assessment of the activity of the rectus abdominis and multifidus muscles in different sitting postures

Wojciech Kiebzak, Michał Dwornik, Justyna Żurawska, Arkadiusz Żurawski

W. Kiebzak, M. Dwornik, J. Żurawska, A. Żurawski – sEMG assessment of the activity of the rectus abdominis and multifidus muscles in different sitting postures. FP 2017; 17(3); 52-62

Abstract

Aim. To assess the activity of the rectus abdominis (RA) and multifidus (MF) muscles during slump and active sitting.
Material and method. The study involved 30 participants aged 19-23 years. The activity of the rectus abdominis (RA) and multifidus (MF) muscles was assessed by surface electromyography in four different sitting postures. A questionnaire was also used to assess the degree of difficulty associated with maintaining a particular position. The results were subjected to a statistical analysis.
Results. The highest RA tone of 2.34 was recorded in the adjusted position with backward tilting of the trunk, and the lowest of 1.16 in the slump position. The MF muscle was most active (33.01) in the adjusted position with forward tilting of the trunk, and least active (18.66) in the slump position. The highest proportion of the participants considered the adjusted position with forward tilting of the trunk to be the easiest, followed by the slump position (86.67% and 83.33%, respectively). The adjusted position with backward tilting of the trunk turned out to be the most difficult to maintain (for 90% of the participants). T1 scores indicate a normal distribution of the empirical data.
Conclusions
1. The adjusted sitting position with forward tilting of the trunk is compatible with the clinical assumptions of correct body posture.
2. The adjusted sitting position with forward tilting of the trunk should become an element of national programmes of back overload prevention.

Key words:
sitting posture, sEMG, RA & MF activity, T1 scores

Pobierz/Download/下載/Cкачиваете 免費下載（僅限英文版）

Usability of sEMG analysis for the evaluation of the muscles stimulation sequence in the lumbosciatic area in patients suffering from pain in lumbar spine

Karolina Kleist-Lamk, Rita Hansdorfer-Korzon, Stanisław Bakuła, Elżbieta Rajkowska-Labon

K. Kleist-Lamk, R. Hansdorfer-Korzon, S. Bakuła, E. Rajkowska-Labon – Usability of sEMG analysis for the evaluation of the muscles stimulation sequence in the lumbosciatic area in patients suffering from pain in lumbar spine. FP 2014; 14(3); 56-64

Abstract

Aim of the study: 1.  Evaluation of the relationship between the change in the stimulation sequence of muscles in the lumbosciatic area and the occurrence of functional pain in the L section of the vertebral column, as compared to the Janda’s model.
2. Analysis of the differences in the superficial electromyography (sEMG) record of a correct and disturbed pattern of muscle recruitment during the prone hip extension test in two sub-groups of patients: suffering from pain (sub-group A) and without pain (sub-group B).
3. Evaluation of the suitability of the sEMG measurement for making diagnoses in patients with pains in the lumbar section of the vertebral column.
The material and method: For the research, 61 persons were qualified, aged 20-35 years, with the average age 25 years (+/- 6). The tested group was divided into two sub-groups. 33 persons were qualified to sub-group A, and to sub-group B (reference group) 28 persons were qualified. Among the participants, a questionnaire was spread, prepared for the needs of the survey, to be filled in. For testing the sequence of stimulations, the measurements were used which had been obtained from the sEMG record during the Prone Hip Extension (PHE )Test.
Results: The results obtained during the examination of the muscles recruitment pattern in PHE test showed a changed sequence of muscles activation in the Patients from sub-group A vs. these from sub-group B. The results of chi-square test (χ²) confirmed the statistically significant dependence: the persons with pain symptoms in the lumbar spine statistically less frequently showed the correct sequence of muscles engagement:  χ²=5.05,  p=0.041, R= – 0.59 (strong negative dependence).
Conclusions: Changes in the pattern of muscles recruitment during the hip joint extension lead to overloads in the lumbosciatic area, consequently causing pain in the lumbar section. Superficial electromyography, because of the possibility of obtaining the quantitative outcome, is a useful method of evaluating muscles performance.

Key words:
The Janda test, Prone Hip Extension Test, PHE, sEMG, LBP, pain in the lower part of back

Pobierz/Download/下載/Cкачиваете 免費下載（僅限英文版）