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Biomechanics of figure skating jump double axel performed in on ice and off ice conditions

Mazurkiewicz A., Iwańska D.

Aktualne Problemy Biomechaniki

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2015

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z. 9

83--88

EN

Figure skating is considered a highly technical discipline. Coaches and researchers are constantly looking for the most effective and safest movement model for jumps, especially Axel Paulsen, which is the hardest kind of all jumps. This research was taken to verify the usefulness of performing double Axel under off- ice conditions as a part of general figure skating training. Research was based on video analysis made in APAS 2000 programme. Parameters taken into account were: joints and take off angle, displacement of centre body mass, horizontal and vertical velocity. Results helped in finding out parameters which are trained during off-ice session.

2

Symmetry of proprioceptive sense in female soccer players

Iwańska D., Karczewska M., Madej A., Urbanik Cz.

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 2

155--163

EN

Purpose: The purpose of the study was to assess the symmetry of proprioceptive sense among female soccer players when trying to reproduce isometric knee extensions (right and left) and to analyze the impact of a given level of muscle force on proprioception. Methods: The study involved 12 soccer players aged 19.5 ± 2.65 years. Soccer players performed a control measurement of a maximum 3s (knee at the 90°) position in the joint. Subsequently, 70%, 50%, and 30% of the maximum voluntary contraction (MVC) were all calculated and then reproduced by each subject with feedback. Next, the players reproduced the predefined muscle contraction values in three sequences: A – 50%, 70%, 30%; B – 50%, 30%, 70%; C – 70%, 30%, 50% of MVC without visual control. Results: In every sequence, the participants found obtaining the value of 30% of MVC the most difficult. The value they reproduced most accurately was 70% of MVC. Both trial II and trial III demonstrated that the symmetry index SI significantly differed from values considered acceptable (SIRa). In each successive sequence the largest asymmetry occurred while reproducing the lowest values of MVC (30%) (p < 0.05). Conclusion: High level of prioprioceptive sense is important to soccer players due to the extensive overload associated with dynamics stops or changes in direction while running. Special attention should be paid to develop skills in sensing force of varying levels. It was much harder to reproduce the predefined values if there was no feedback.

3

The sense of position and movement in the knee joint during voluntary movements

Iwańska D., Urbanik C.

Acta of Bioengineering and Biomechanics

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2013

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Vol. 15, no. 3

11--17

EN

The aim of the paper was to assess body position reproduction as well as jump height during an intended movement, together with an assessment of the influence of factors that disturb this process. Factors disturbing the jump were related to with the reproduction of different knee joint angles (90° or 120°); different muscle activity in performed jumps: SJ with no countermovement and CMJ with countermovement; as well as with and without visual (VC) of control movement (nVC) – eyes covered. Nineteen subjects aged twenty-one years participated in the experiment. Jump height (h) was calculated on the basis of a reaction force (R) of the base, as registered with a tensometric platform. Two-dimensional cinematographic analysis was used to assess the reproduction of angular position in the knee joint. A significant factor determining the level of position reproduction during voluntary movements was the imposed angle as well as the character of muscle activity. The biggest difficulty of developing maximum heights occurred during jumps with disturbed visual control (eyes shut).

4

Evaluation of the effectiveness of training on a machine with a variable-cam

Urbanik C., Staniszewski M., Mastalerz A., Karczewska M., Lutosławska G., Iwańska D., Madej A., Ostrowska E., Gwarek L., Tkaczyk J.

Acta of Bioengineering and Biomechanics

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2013

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Vol. 15, no. 4

93--102

EN

The aim of the study was to assess the effectiveness of the training of elbow flexors through the use of 2 machines, one of which was equipped with a disc plate of constant radius, the other one with a variable-cam having a radius adjustable to muscle strength. The experiment included 45 men divided into 3 equal groups: training group A (variable-cam), training group B (circle), and control group C. The training lasted for 8 weeks, 3 times a week. In order to control the effects, the values of peak torque and power of the flexor muscles of the elbow were isokinetically measured for the angular velocities of 30°/s and 60°/s. Also taken were anthropometric measurements of the arm and the creatine kinase (CK) activity in the blood plasma. As a result of the training, significant increases of biomechanical values were noted only in group A: power increased over 20%, the peak torque over 14%. After the training, significant increases of arm circumference in the relaxed position were noted in group A (17 mm), as well as in group B (11 mm). Also, some changes in CK activity were observed between Monday and Friday in a training week. On the basis of the experimental measurements, it may be ascertained that training elbow flexor muscles on a machine with a variable-cam is more efficient for increases in strength and power, as well as for some anthropometric parameters, than training on a machine with a disc plate.

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The influence of training with two different intensities on the level of muscle strength and power of jump

Iwańska D., Mastalerz A., Ostrowska E., Madej A., Staniszewski M., Urbanik C.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2006

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z. 26

137-142

EN

The aim of the study was the evaluation of training with two different intensities on the level of muscle strength and power of lower extremities. There were twenty six students from the University of Physical Education investigated in thai experiment. They were divided into 2 groups. The training lasted four weeks (live days per week). The exercises consisted of four sets of ten take offs on the inclined plane. Each week started with research of muscle strength and power of CMJ jump measurements. These tests were also used to monitored trainings effects for the next 2 weeks.

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The effect of various types of power training on muscle torques and power levels of lower extremity

Ostrowska E., Mastalerz A., Urbanik C., Staniszewski M., Iwańska D., Madej A., Pędzich W.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2006

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z. 26

275-280

EN

The aim of this study was to determine the effects of two various types of power training on the muscle torques and power levels of lower extremities. During four weeks (five days a week) 27 students participated in this study. The training device consisted of an incline plane and a sliding seat. The varied types of power training were achieved by utilizing intermissions between the series of take offs. 4 series of 10 takes-offs with rest periods among series were carried out in A group (120s in length). Whereas the group B carried out the same number of take offs (40 take-offs) continuously. The interval training (group A) resulted in more effective dynamic values of the lower extremities than the continuous training adhered to by group B.

7

Lactic acid concentration and muscle strength level after 4-weeks power training

Madej A., Mastalerz A., Lutosławska G., Iwańska D., Malara M., Ostrowska E., Żołnowska M., Urbanik C.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2006

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z. 26

213-218

EN

Thirty one young men volunteered to the study. After pre-testing two groups completed 4 weeks (5 days per week) of two versions of power training programs (4x10 take-offs on a inclined plane; intervals 120 or 30s.). Additional external loads to increase external power were applied. Training effects were monitored by: maximal muscle torques (measured under static conditions for the knee, hip and ankle joints) and lactate concentration in the blood. Results of the study showed no significant differences between groups in increase of the sum of muscle torques nor in lactate. Significant differences (up to 26%) were revealed in lactic acid concentration in blood between groups in post training measurements (less while exercising with long intervals).

8

Force and power levels after 4-weeks of plyometric training

Mastalerz A., Ostrowska E., Iwańska D., Madej A., Pędzich W., Staniszewski M., Urbanik C.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2006

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z. 26

235-240

EN

Fifteen students from the Warsaw University of Physical Education participated in the experiment. After pre-testing, two groups completed 4 weeks of plyometric training with different time of rest periods among series (30 and 120 seconds) Four series of hops above ten hurdles were executed during the one training. Two different heights of hurdles and additional external loads were carried out for individualisation training loads. Our results proved that shorter time of rest period influenced on poor muscle toleration on load and possibilities to recover after a plyometric exercises.