Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

4 Acta of Bioengineering and Biomechanics

Znaleziono wyników: 4

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Relative power of the lower limbs in drop jump

100%

Pietraszewski B. , Rutkowska-Kucharska A.

tom Vol. 13, no. 1

13-18

The purpose of this paper was to determine the power produced by the lower limbs in the take-off phase in drop jumps (DJ) and the correlation between the power and load measured by dropping height after take-off. The research group (N = 17) contained students practicing football, volleyball, basketball, athletics, high jump, swimming and fencing. The individual characteristics "power-load" of the players and the observation of the changes during the training process enable the coaches to choose precise loads and at the same time to improve the training. The criterion of choosing loads in the plyometric training may be relative power output of lower limbs referred to the DJ height. While the condition allowing player to perform this type of training may depend on obtaining greater power in drop jump than in counter movement jump.

Symmetry of muscle activity during abdominal exercises

80%

Rutkowska-Kucharska A. , Szpala A. , Pieciuk E.

2009

tom Vol. 11, nr 1

25-30

In this study, the symmetry of EMG activity of right and left parts of rectus abdominis, erector spinae, rectus femoris has been tested during isometric exercises. Subjects (N = 3) were selected from the university population. In each of nine isometric exercises, the position of lower and upper extremities is different in relation to the upper body. Electromyographic signals were recorded from left and right parts of selected muscles at 1000 Hz sampling frequency. Differences in EMG activity between specific exercises for left and right parts of each muscle were tested for significance with a one-way ANOVA. It was concluded that EMG activity of left and right sides of rectus abdominis and rectus femoris does not differ significantly; nevertheless statistically important differences were noticed between left and right sides of erector spine. These findings provide more detailed knowledge and understanding of different forms of abdominal exercises.

Magnetic resonance imaging (MRI) for assessment of differences in geometrical parameters in muscles stabilizing vertebral column in young and older persons. Case study

71%

Dziuba A. , Rutkowska-Kucharska A. , Hadzik A. , Rudziński M. , Garcarek J.

tom Vol. 12, no. 3

41-51

Today non-traumatic low back pain (LBP) is a social disease being attributed to weakening the function of abdominal and back muscles. Condition of deep muscles, inaccessible to non-invasive examinations, can be assessed by means of magnetic resonance imaging (MRI). The method allows for the assessment of cross-sections, muscle girths, as well as their intensity (brightness). The aim of the investigations was to determine the opportunities to employ MRI technique for assessing the geometry of muscles which stabilize spinal column. The study covered 4 women without LBP symptoms. The cross-sectional area, thickness and brightness of abdominal and back muscles were measured at the level of L3–L4. Measurement of geometrical parameters in the positions studied was aimed at setting such measurement conditions that would force higher isometric contraction in the muscles examined. As a result of measurements it can be inferred that other conditions of the experiment affect neither an increase in cross-sectional surface area nor the thickness of the muscles examined. The differences observed in geometrical parameters of the muscles testify to different coordination of muscle activation in the positions studied, both in young and older subjects, and to the purposefulness of continuing this type of measurements.

Asymmetry of electromechanical delay (EMD) and torque in the muscles stabilizing spinal column

71%

Szpala A. , Rutkowska-Kucharska A. , Drapała J. , Brzostowski K. , Zawadzki J.

tom Vol. 12, no. 4

11-18

Stabilization of the spinal column is ensured by the activity of trunk flexor and erector muscles, including rectus abdominis (RA) and erector spinae (ES). The goal of this study was to evaluate the symmetry of action potential and electromechanical delay (EMD) in RA and ES during generation of maximal muscle torque. In the present study, the symmetry of EMG activity in the right and left parts of RA and ES was tested under isometric conditions. The subjects (N = 13) were selected from the university population. Electromyographic signals and muscles torques were recorded with the sampling frequency of 1000 Hz. Lack of significant differences in EMD between left and right sides in both muscles studied and lack of correlation between EMD and maximal muscle torque were observed. Analysis aimed at assessing the symmetry of EMG signals amplitude revealed crossed laterality characterized by increased activity in the right side of RA muscle and left side of ES. The proportion of maximal muscle torque in ES to RA in the women examined amounted to 1.7:1.