scholarly journals THE EFFECT OF LOCAL VIBRATION IN CROSS COUNTRY SKIING (DIAGONAL STRIDE)

2016 ◽  
Vol 3 ◽  
pp. 434
Author(s):  
Kalvis Ciekurs ◽  
Viesturs Krauksts ◽  
Daina Krauksta ◽  
Juris Grants ◽  
Aleksandras Alekrinskis
Keyword(s):  
Video Camera ◽  
Erector Spinae ◽  
Mathematical Statistics ◽  
Cycle Duration ◽  
Local Vibration ◽  
Cross Country Skiing ◽  
The Mean ◽  
Cross Country ◽  
The Difference ◽  
Moving Speed

Local vibration (LV) is innovation as a part of training method that helps athletes to regain the power and get ready for next training faster. There are many discussions about how to increase moving speed in cross-country skiing. Many scientists research the possibilities of increasing moving speed in this sport. Cycle duration in different moving strides along different course terrains is stated, including even stride cycle duration separately for the leg and arm movements. It is proved by many studies that moving speed depends on stride cycle duration. A pilot study was carried out. Two LASE specialization students participated in the study. The following methods were used in the study: videoanalysis, LV manipulations, the stating experiment and mathematical statistics. The videoanalysis was made with Panasonic digital video camera (50 Hz), and the obtained data were processed using a videoanalysis program. LV manipulations were done to the muscles m. Erector spinae, m. Latisimus dorsi, m. Deltoideus, m. Trapecius and m. Triceps Brachi using 100 Hz frequency and different pressure on the muscles. The total LV application time was 10 min. with 30 min. relaxation. The obtained data were processed using mathematical statistics. The results: having stated the result difference before LV and after it. The results testify significant improvement of diagonal stride results, what is showed by the difference of the mean results. The results: having stated the result difference before LV and after it, it was stated that the mean moving speed of both students (S1 and S2) in the cycle before LV was 4.14m/s (S1) and 3.97m/s (S2), but after the application of LV the mean moving speed in a cycle was 4.51m/s (S1) and 4.25m/s (S2), thus the difference of the means was 0.37m/s (S1) and 0.28m/s (S2). 

scholarly journals THE EFFECT OF LOCAL VIBROSTIMULATION ON ELECTROMYOGRAPHY PARAMETERS IN ROWERS

2017 ◽  
Vol 3 ◽  
pp. 325
Author(s):  
Kalvis Ciekurs ◽  
Viesturs Krauksts ◽  
Daina Krauksta ◽  
Baiba Smila ◽  
Aivars Kaupuzs
Keyword(s):  
Biceps Brachii ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Erector Spinae ◽  
Mathematical Statistics ◽  
Triceps Brachii ◽  
The Mean ◽  
Moving Speed

Local vibrostimulation (further in text - LV) is innovation as a part of training method that helps athletes to regain the power and get ready for next training faster. There are many discussions about how to increase moving speed in rowers. Many scientists research the possibilities of increasing moving speed in this sport. The following methods were used in the study: tests – Concept-2, LV manipulations, electromyography and mathematical statistics. The electromyography was made with Biometric LTD. LV manipulations were done to the muscles erector spinae, latisimus dorsi, teres major, teres minor, trapezius, infraspinatus, deltoideus, slenius capitis, triceps brachii, gluteus maximus, semitendinosus, biceps femoris, semimembranosus, castrocnemius, tendo calcaneus, rectus femoris, vastus lateralis, tensor fascia latae, vastus medialis, sarterius, ligamentum patellae, tibialis anterior, rectus abdominis, pectoralis major and biceps brachii. We using 100 Hz frequency, 2 – 4 mm amplitude and different pressure on the muscles. The total LV application time was 5 to 20  min. The obtained data were processed using mathematical statistics. The results: having stated the result difference before LV and after it. The results testify significant improvement of Concept-2 tests results and electromyography results, what is showed by the difference of the mean results. Comparing the results of the rowers of EG and CG they have differences in the left side muscle latissimus dorsi after the t-test where p>0.05, but stating the percentage of the mean result difference of this muscle it was found out that p>0.05 what also shows significant changes in the muscle biopotential (mV).

THE EFFECT OF FITNESS EXERCISE ON ANAEROBIC POWER AND AEROBIC POWER

2019 ◽  
Vol 4 ◽  
pp. 65
Author(s):  
Kalvis Ciekurs ◽  
Voldemārs Arnis ◽  
Edgars Bernāns ◽  
Aivars Kaupuzs
Keyword(s):  
Aerobic Power ◽  
Anaerobic Power ◽  
Test Results ◽  
Power Capacity ◽  
Power Test ◽  
Study Test ◽  
Cross Country Skiing ◽  
The Mean ◽  
Cross Country ◽  
The Difference

There are many discussions about how to increase anaerobic power and anaerobic power capacity in cross-country skiing. Many scientists research the possibilities of increasing anaerobic power and anaerobic power capacity in this sport.  The aim was to research the possibilities of increasing anaerobic power and anaerobic power capacity. A pilot study was carried out. Two BJSS "Arkādija" cross-country skiing specialization participants (15 years old girl (G) and boy (B)) participated in the study. The following methods were used in the study: test exercises (bench press, leg press, push up, pull down, pull up), WO2 max, Skierg Concept-2, Skierg Thorax and mathematical statistics. Fitness exercises used one month after that three month period of endurance exercise and last month fitness exercises again. The results: having stated the result difference before fitness exercises and after it. The participant G and B results difference in anaerobic power test was 48,7% and 37,1% and aerobic power test results was 39,8% and 32,4%. Conclusions: the obtained data from both BJSS “Arkādija” specialization participants prove that after the fitness exercise periods the results have improved. The results testify significant improvement of double pooling results on skiergs, what is showed by the difference of the mean results.

scholarly journals LOCAL VIBRATION INFLUENCE OF ELECTROMYOGRAPHY PARAMETERS ON ANAEROBIC CAPACITY TEST IN ROWERS

2020 ◽  
Vol 6 ◽  
pp. 115
Author(s):  
Kalvis Ciekurs ◽  
Viesturs Krauksts ◽  
Daina Krauksta ◽  
Juris Grants ◽  
Žermēna Vazne
Keyword(s):  
Biceps Brachii ◽  
Vastus Lateralis ◽  
Anaerobic Capacity ◽  
Erector Spinae ◽  
Mathematical Statistics ◽  
Whole Body ◽  
Control Group ◽  
Triceps Brachii ◽  
Local Vibration ◽  
The Mean

Whole body vibration is a worldwide innovation as a part of training method that helps athletes to regain the power and get ready for next training faster. However less attention is paid to local vibration where an isolated muscle or muscle group is stimulated by the use of a vibration device. For the reason to determine the effect of local vibration on anaerobic capacity of rowers, two research groups were assembled from the students of Murjāņi Sport Gymnasium (MSG). The following methods were used in the study: tests – Concept-2, local vibration (LV) manipulations, electromyography and mathematical statistics. The electromyography was made with Biometric LTD. LV manipulations were done to the muscles erector spinae, latisimus dorsi, teres major, teres minor, trapezius, infraspinatus, deltoideus, slenius capitis, triceps brachii, gluteus maximus, semitendinosus, biceps femoris, semimembranosus, castrocnemius, tendo calcaneus, rectus femoris, vastus lateralis, tensor fascia latae, vastus medialis, sarterius, ligamentum patellae, tibialis anterior, rectus abdominis, pectoralis major un biceps brachii. We using 100 Hz frequency, 2 – 4 mm amplitude and different pressure on the muscles. The total LV application time was 5 to 20 min. The obtained data were processed using mathematical statistics. The results: having stated the result difference before LV and after it. The results testify significant improvement of Concept-2 tests results and electromyography results, what is showed by the difference of the mean results. Comparing the results of the rowers of experimental group (EG) and control group (CG) they have differences in the left side muscle latissimus dorsi after the t-test where p>0.05, but stating the percentage of the mean result difference of this muscle it was found out that p>0.05 what also shows significant changes in the muscle biopotential (mV). 

scholarly journals Performance and Participation in the ‘Vasaloppet’ Cross-Country Skiing Race during a Century

Sports ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 86 ◽  
Author(s):  
Nastja Romancuk ◽  
Pantelis T. Nikolaidis ◽  
Elias Villiger ◽  
Hamdi Chtourou ◽  
Thomas Rosemann ◽  
...  
Keyword(s):  
Gender Differences ◽  
Male Athletes ◽  
Small Magnitude ◽  
Public Health Policies ◽  
Race Time ◽  
Participation Of Women ◽  
Cross Country Skiing ◽  
The Mean ◽  
Cross Country

This study investigated gender differences in performance and participation and the role of nationality during one century in one of the largest cross-country (XC) skiing events in the world, the ‘Vasaloppet‘ in Sweden. The total number of female and male athletes who finished (n = 562,413) this race between 1922 and 2017 was considered. Most of the finishers were Swedish (81.03% of women and 88.39% of men), followed by Norwegians and Finnish. The overall men-to-women ratio was 17.5. A gender × nationality association was observed for participation (χ2 = 1,823.44, p < 0.001, φ = 0.057), with the men-to-women ratio ranging from 6.7 (USA) to 19.1 (Sweden). For both genders, the participation (%) of Swedish decreased, and that of all other nationalities (except Swiss) increased across years. Regarding the mean race time, men were faster than women by 14.5% (7 h 52 min 17 s versus 9 h 00 min 55 s, respectively). A trivial gender×nationality interaction regarding the race time was observed (p < 0.001, η2 < 0.001), with gender differences ranging from 4.4% (USA) to 22.0% (Iceland). The race time increased across calendar years for both women (r = 0.45, p = 0.006, moderate magnitude) and men (r = 0.25, p = 0.015, small magnitude). On the basis of these findings, we concluded that a relatively small number of women pariticipates in XC skiing. Therefore, the development of public health policies targeting the participation of women in XC skiing should be a concern in the countries with a tradition of this sport.

A Portrait of Pacing Profile of Cross-Country Skiers in the Vasaloppet 2004–2017

2018 ◽  
Vol 39 (11) ◽  
pp. 875-880
Author(s):  
Pantelis Nikolaidis ◽  
Elias Villiger ◽  
Thomas Rosemann ◽  
Beat Knechtle
Keyword(s):  
Race Time ◽  
Performance Group ◽  
Pacing Strategies ◽  
Main Effect ◽  
The Mean ◽  
Cross Country ◽  
The Difference ◽  
And Performance

AbstractThe aim of the study was to examine the effect of performance group by race time (10 groups;<3 h, 3–4 h, and so on up to>12 h) on pacing in women (n=19,465) and men (n=164,454) finishers in the ‘Vasaloppet’ cross-country (XC) skiing race from 2004 to 2017. The speed in the fastest and slowest split was analysed as a percentage of the mean race speed and pacing was defined as the difference (%) between the fastest and slowest split. Women had a larger pace range than men (44.0±10.6% versus 41.1±12.5%, respectively, p<0.001, d=0.25). An almost perfect relationship between performance group and pacing was observed in women (r=0.900, p<0.001) and men (r=0.908, p<0.001). A large main effect of performance on pacing was observed in women (p<0.001, η2=0.292), where the smaller range was in the<4 h group (22.8±3.3%) and the largest in the 10–11 h group (49.2±9.9%). In men, the corresponding values were 21.6±2.2% (<3 h group) and 51.6±11.2% (10–11 h group; p<0.001, η2=0.474). Based on these findings, it was concluded that fast XC skiers had relatively the most even pacing and pacing became less even with decreasing performance. This information is of practical value for coaches working with XC skiers to develop optimal sex- and performance-tailored pacing strategies.

Effects of Temperature Changes on the Mechanical and Ballistic Responses in Biathlon Shooting

2006 ◽  
Vol 74 (5) ◽  
pp. 1037-1041 ◽  
Author(s):  
Christelle Grebot ◽  
Alain Burtheret
Keyword(s):  
Room Temperature ◽  
Negative Temperature ◽  
Trigger Mechanism ◽  
Temperature Changes ◽  
Mechanical Responses ◽  
Cross Country Skiing ◽  
Mechanical Factors ◽  
Effects Of Temperature ◽  
Cross Country ◽  
The Difference

Background: Biathlon is a nordic sport that combines cross-country skiing with rifle marksmanship. It was reported that standing shooting was significantly affected because skiing exercise usually decreased the postural control of biathletes and increased the shooting time. Another hypothesis that may explain the decrease of one’s shooting accuracy after a cession of cross-country skiing could be linked with mechanical factors. The goal of the present study was to examine the influence of negative temperatures on the trigger mechanism and on the ballistic responses of the bullet. Method of approach: In order to determine the possible variations of the force required for triggering, five biathlon rifles were equipped with strain gauges fixed on the trigger. A thermostat vessel was used to control the temperature changes at room temperature (+20°C)(+68°F) until −20°C(−4°F). Concerning the ballistic measurements, eight series of five shots were performed at +20°C(+68°F), at −3°C(+26.6°F), at −10°C(+14°F), and at −20°C(−4°F). The shooting precision was assessed by determining the group diameter (GD) and the shooting score (Sc). Results: The results showed that from +20°C(+68°F) until −8°C(+17.6°F), the triggering force was equal to 5N(1.12lb), whereas at −20°C(−4°F), a triggering force of 8N(1.8lb) was required. The increase of the triggering force that was found under −8°C(+17.6°F) could be caused by the difference between the coefficients of expansion of the different materials constituting the trigger mechanism. Concerning the ballistic measurements, GD at room temperature was significantly lower (P<0.05) than −3°C(+26.6°F), −10°C(+14°F), and −20°C(−4°F). Furthermore, Sc was significantly better at +20°C(+68°F)(P<0.05) compared to −3°C(+26.6°F), −10°C(+14°F), and −20°C(−4°F) conditions. Conclusion: It can be supposed that the degradation of GD and Sc could be due to the formation of frost in the barrel and by the difference of the expansion coefficient of the bullet-barrel materials. Consequently, both mechanical responses could partly explain the shooting accuracy impairment observed in negative temperature shooting conditions.

scholarly journals Comparisons of Macro-Kinematic Strategies During the Rounds of a Cross-Country Skiing Sprint Competition in Classic Technique

2021 ◽  
Vol 2 ◽  
Author(s):  
Finn Marsland ◽  
Judith Mary Anson ◽  
Gordon Waddington ◽  
Hans-Christer Holmberg ◽  
Dale Wilson Chapman
Keyword(s):  
Kinematic Data ◽  
Pacing Strategies ◽  
Classical Technique ◽  
Micro Sensor ◽  
Classic Technique ◽  
Cross Country Skiing ◽  
The Mean ◽  
Cross Country ◽  
The Individual ◽  
Mean Cycle

This study was designed to examine macro-kinematic parameters of six female cross-country skiers during the qualifying, semi-final and final rounds of a 1.1 km sprint competition in classical technique. During each round these skiers were monitored continuously with a single micro-sensor, and their cycle parameters and relative use of these two sub-techniques calculated. Within each round six sections of the course, during which all skiers employed either double pole (DP) or diagonal stride (DS) sub-technique, were chosen for additional analysis. The mean macro-kinematic cycle parameters and relative usage of sub-techniques over the full course did not differ significantly between rounds. On average 54% of the course was covered employing DP and 13% using DS, while 32% was covered utilizing a non-cyclical or irregular technique. With DP, the mean racing speed and cycle rate (CR) on the starting, middle and finishing sections of the course differed significantly, with no differences in mean cycle length (CL) between the last two sections. At the finish, higher DP speed was achieved by increasing CR. On the three hills, where all athletes utilized DS, mean racing speed and CL, but not mean CR, differed significantly. On these sections DS speed was increased by utilizing longer cycles. The individual skiers utilized a variety of macro-kinematic strategies during different rounds and on different sections of the course, depending on individual strengths, preferences and pacing strategies, as well as the course topography and tactical interactions with other skiers. Such collection of macro-kinematic data during competitions can help to identify an individual skier's strengths and weaknesses, guiding the testing of different cycle rates, and lengths on different terrains during training in order to optimize performance.

Ratio imaging of intracellular ion concentration

1992 ◽  
Vol 50 (2) ◽  
pp. 1160-1161
Author(s):  
Stephen R. Bolsover
Keyword(s):  
Individual Cell ◽  
Video Camera ◽  
Field Of View ◽  
Ion Concentration ◽  
Fluorescence Signal ◽  
Ion Imaging ◽  
Ratiometric Fluorescence ◽  
Ratio Imaging ◽  
The Mean ◽  
The Many

The field of intracellular ion concentration measurement expanded greatly in the 1980's due primarily to the development by Roger Tsien of ratiometric fluorescence dyes. These dyes have many applications, and in particular they make possible to image ion concentrations: to produce maps of the ion concentration within living cells. Ion imagers comprise a fluorescence microscope, an imaging light detector such as a video camera, and a computer system to process the fluorescence signal and display the map of ion concentration.Ion imaging can be used for two distinct purposes. In the first, the imager looks at a field of cells, measuring the mean ion concentration in each cell of the many in the field of view. One can then, for instance, challenge the cells with an agonist and examine the response of each individual cell. Ion imagers are not necessary for this sort of experiment: one can instead use a system that measures the mean ion concentration in a just one cell at any one time. However, they are very much more convenient.

The Effect of Vocabulary Intervention on Text Comprehension: Who Benefits?

2019 ◽  
Vol 50 (4) ◽  
pp. 562-578 ◽  
Author(s):  
Dawna Duff
Keyword(s):  
Middle School ◽  
Reading Comprehension ◽  
Text Comprehension ◽  
Classroom Instruction ◽  
Vocabulary Instruction ◽  
Clinical Intervention ◽  
Vocabulary Knowledge ◽  
Vocabulary Intervention ◽  
The Mean ◽  
The Difference

Purpose Vocabulary intervention can improve comprehension of texts containing taught words, but it is unclear if all middle school readers get this benefit. This study tests 2 hypotheses about variables that predict response to vocabulary treatment on text comprehension: gains in vocabulary knowledge due to treatment and pretreatment reading comprehension scores. Method Students in Grade 6 ( N = 23) completed a 5-session intervention based on robust vocabulary instruction (RVI). Knowledge of the semantics of taught words was measured pre- and posttreatment. Participants then read 2 matched texts, 1 containing taught words (treated) and 1 not (untreated). Treated texts and taught word lists were counterbalanced across participants. The difference between text comprehension scores in treated and untreated conditions was taken as a measure of the effect of RVI on text comprehension. Results RVI resulted in significant gains in knowledge of taught words ( d RM = 2.26) and text comprehension ( d RM = 0.31). The extent of gains in vocabulary knowledge after vocabulary treatment did not predict the effect of RVI on comprehension of texts. However, untreated reading comprehension scores moderated the effect of the vocabulary treatment on text comprehension: Lower reading comprehension was associated with greater gains in text comprehension. Readers with comprehension scores below the mean experienced large gains in comprehension, but those with average/above average reading comprehension scores did not. Conclusion Vocabulary instruction had a larger effect on text comprehension for readers in Grade 6 who had lower untreated reading comprehension scores. In contrast, the amount that children learned about taught vocabulary did not predict the effect of vocabulary instruction on text comprehension. This has implications for the identification of 6th-grade students who would benefit from classroom instruction or clinical intervention targeting vocabulary knowledge.

Efficacy and Safety of Oral Ivermectin and Topical Permethrin in the Treatment of Scabies

2020 ◽  
Vol 33 (1) ◽  
pp. 41-47
Author(s):  
Mohsena Akhter ◽  
Ishrat Bhuiyan ◽  
Zulfiqer Hossain Khan ◽  
Mahfuza Akhter ◽  
Gulam Kazem Ali Ahmad ◽  
...  
Keyword(s):  
Skin Diseases ◽  
Close Contact ◽  
Randomized Study ◽  
Sarcoptes Scabiei ◽  
Efficacy And Safety ◽  
Common Skin ◽  
Group A ◽  
The Mean ◽  
The Difference ◽  
Group B

Background: Scabies is one of the most common skin diseases in our country. It is caused by the mite Sarcoptes scabiei var hominis, which is an ecto-parasite infesting the epidermis. Scabies is highly contagious. Prevalence is high in congested or densely populated areas. Individuals with close contact with an affected person should be treated with scabicidal which is available in both oral and topical formulations. The only oral but highly effective scabicidal known to date is Ivermectin. Amongst topical preparations, Permethrin 5 % cream is the treatment of choice. Objective: To evaluate the efficacy & safety of oral Ivermectin compared to topical Permethrin in the treatment of scabies. Methodology: This prospective, non-randomized study was conducted at the out-patient department of Dermatology and Venereology of Shaheed Suhrawardy Medical College & Hospital over a period of 6 months, from August 2016 to January 2017. The study population consisted of one hundred patients having scabies, enrolled according to inclusion criteria. They were divided into two groups. group A was subjected to oral Ivermectin and the group B to Permethrin 5% cream. Patients were followed up on day 7 and 14 for assessment of efficacy and safety. Result: The mean scoring with SD in group A (Ivermectin) and group B (Permethrin) were 8.26 ± 2.22 and 7.59 ± 2.01 respectively at the time of observation. The difference between the mean score of the two group is not significant (p=0.117) the mean scoring with SD in group A and group B were 4.54 ± 2.05 and 1.64 ± 1.84 respectively at 7thdays. The difference between the mean score of the two group is significant (p<0.001). The mean scoring with SD in group A and group B were 2.68± 2.35 and .36± 1.10 respectively at 14th day difference between the mean score of the group is significant (p<0.001). Conclusion: Topical application of permethrin 5% cream is more effective and safer than oral Ivermectin in the treatment of scabies. TAJ 2020; 33(1): 41-47

Sign in / Sign up

Export Citation Format

Share Document