For basketball technique elements to become stable and automated, the technique must be executed correctly from the initial stages of the learning process. The jump shot is considered the most ...crucial shooting action, equally effective in various on-court situations. Ideal techniques may not unconditionally be the best for every player because they differ in motor and morphological characteristics. One of the shooting methods is shot with one hand from the spot, which, in terms of complexity and required motor abilities, is at a lower level of demand when compared to the jump shot. The first aim of this research is to define the kinematic pattern of the jump shot and the shot with one hand from the spot and determine if there are differences between them. The second aim is to establish whether there is a significant difference in the level of motor skills between the two groups. The participant sample consists of 29 junior basketball players. They were divided into two groups: G1 = players who perform the shot with one hand from the spot (N = 14); G2 = players who execute the jump shot (N = 15). MANOVA was used to determine the differences in observed kinematic parameters between the group and in the measured tests assessing motor abilities. The kinematic parameters of the upper extremities, the parameters of the basketball player’s take-off, and the angle of the ball’s impact were analyzed. It was determined that the kinematic pattern of these two shooting techniques significantly differs (F = 12.86, p = 0.00). There was a statistically significant difference between the group of participants performing the jump shot and the group performing the one-handed chest shot from the spot (F = 5.51, p = 0.00) in motor ability tests. The group that performed the jump shot showed significantly better results in three of the five measured tests (PLANK, MED_THR, POL_BACK). Shooting with one hand from the spot is a technically correct shooting method recommended to be performed until the player possesses a certain level of motor skills that enables proper execution of the jump shot.
Alpine skiing is characterized by specific and dynamic conditions and demands constant processing of visual information and fast decision-making. A fast response time is necessary for protective ...movements which reduce the number and severity of additional head impacts. The apparent detriments to visual performance caused by protective headgear are concerning and should be considered moving forward in recreational alpine skiing. The aim of this study was to examine the effects of wearing the three most common combinations of protective headgear in skiing on the timing of visual stimuli perception and adequate response when simulating on-the-slope situations. The sample consisted of 45 recreational-level skiers (27 M, 18 F; age 30.6 ± 8.19 years) who had finished basic alpine skiing school, had been skiing 6–10 years continuously, and were students of Faculty of Kinesiology, University of Zagreb. They did not report any serious medical conditions regarding vision. The overall testing was conducted in the winter season during January and February of 2022. Reaction time on perceived visual stimuli was observed in a way that a skier was approaching behind a participant’s back from both the left and right side. A 2 × 3 (helmet*condition) mixed-model repeated-measures ANOVA was used to determine differences between helmet users and non-users in each tested condition. When observing the results, it was confirmed that the response time of the participants was the slowest when wearing a ski helmet and goggles combined. Furthermore, one of the most important findings was the determined differences in reaction time between helmet users and non-users, i.e., prior helmet users tended to react faster to the upcoming visual stimuli when wearing combined ski helmet and goggles. In the design and construction of the goggles, it is also necessary to pay attention to reducing the thickness of the frame in order to reduce the distance between the eye and the lens, which consequently reduces interference in the peripheral parts of the field of vision. In future studies, the same testing protocol with all the possible combinations of wearing a ski cap, a helmet, sunglasses, and goggles is necessary to gain a clearer insight into the effect of each item of headgear separately and in various combinations.
Nowadays, various programs are used in ski schools to teach beginners. All programs have the same goal, and that is to teach beginners specific body movements with which they will be able to manage ...their skis. Three programs are most commonly used in alpine skiing schools. According to one program, ski beginners are taught the basics of alpine skiing exclusively with elements of parallel skiing techniques. In the second program, ski beginners acquire knowledge using elements of snowplough and parallel ski technique. The third alpine skiing learning program combines these two methods. In addition to the program, in practice there are two approaches to learning alpine skiing. The first method involves a daily trip to a ski slope or a nearby winter tourist centre, where the skiing technique is adopted and beginners return to the place of residence the same day. The second way consists of an organized, usually seven-day, winter trip, during which the basics of alpine skiing are learned every day during the stay in the ski-resort. Regardless of the learning programs used, the safety of skiers is a priority in every alpine skiing school. Therefore, it is advisable for all beginner skiers to get involved in an alpine skiing school, as this is the best way to prevent injuries.
In this study, the removal of cadmium (Cd) by free-living Oscillatoria sp. was studied. Our results showed that maximal Cd removal efficiency (~60%) by the cyanobacterial culture was achieved within ...12–24 h in the presence of 5.0 or 25.0 mg/L of Cd. The mechanisms underlying this phenomenon were explored by elemental analysis and FTIR-ATR spectroscopy. It was found that metal adsorption by negatively charged functional groups in the cyanobacterial biomass was the main mechanism used by Oscillatoria sp. to remove metal from the aqueous medium, followed by Cd bioaccumulation into living cells. Additionally, Cd-exposed microalgae showed increased oxidative stress (MDA formation), a decreased dehydrogenase activity, a higher amount of soluble carbohydrates and a decreased total carotenoid concentration, as compared to the control cells. These results suggest that Oscillatoria sp. improved its antioxidative defense system under stressful conditions, through carotenoid-mediated ROS quenching and induction of carbohydrate catabolism, in order to counteract the oxidative damage and preserve the photosynthetic machinery and cellular energetics. In fact, no significant reduction in Oscillatoria sp. cell density, total protein amount, and chlorophyll a content was observed after 24-h Cd exposure, even at the highest metal concentration tested (i.e., 25.0 mg/L). Hence, the presented results are the first to describe some new insights about the metabolic and physiological behavior of living Oscillatoria sp. during Cd remediation, and open up the possibility of finding an equilibrium that maximizes metal removal performance with an active cyanobacterial metabolism, to achieve a rewarding and sustainable management of industrial metal-polluted wastewater.
The benefit of protective headgear for recreational skiers is an ongoing debate in the snow sports industry, and there are a lot of opposing opinions. Due to the dynamic conditions in which winter ...sports are performed, athletes demand rapid and constant processing of visual information. A sufficient level of anticipation helps athletes to properly position themselves to reduce the forces transferred to the head or even move to avoid a collision. To objectively identify the impact of protective headgear on the visual field when skiing, it is necessary to conduct suitable measurements. The sample consisted of 43 recreational-level skiers (27 M, 16 F; age 31.6 ± 8.23 years). A predefined testing protocol on an ortoreter was used to assess the visual field for three conditions of wearing protective headgear. Differences in perceived visual stimuli between the three conditions were evaluated by repeated measures analysis of variance (ANOVA). Based on the observed results, it can be concluded that the combination of wearing a ski helmet and ski goggles significantly negatively influences visual performance in a way that the visual field is narrowed, for both helmet users and non-users, only when comparing the tested conditions. When comparing helmet users and non-users, there are no differences in the amount of visual impairment; therefore, the habit of wearing a helmet does not influence the ability of perceiving visual stimuli.
There are numerous programs worldwide adapted for alpine ski beginners and they all share the same primary goal-inclusion of skiing beginners in alpine ski schools. The final elements of ski school ...taught in the parallel skiing technique are parallel turn and short turn. Synchronized analysis of kinetic and kinematic parameters of the parallel turn (PT) and short turn (ST) was conducted to determine the main biomechanical differences from a standpoint of foot pressure and lower limb angles. Both elements were performed by nine male ski instructors (age 33.4 ± 8.62, height 179.52 ± 5.98 cm, weight 78.6 ± 8.88 kg). Kinetic and kinematic analysis was conducted on 180 turns, 90 for each element. Differences in kinetic and kinematic parameters between parallel and short turns were tested by a paired
-test. The main findings of our study are determined differences in the ratio of pressure distribution on the inside and the outside foot and differences in kinematic parameters of the outside leg between elements. The mentioned analysis can provide an objective insight into the complexity of each element and provide guidelines for teaching process of those elements. This study determined the reasons for higher complexity of ST compared to PT based on the objective evaluation of biomechanical factors.
The complexity of skiing movements urges recreational alpine skiers and competitors to undertake many specific skill trainings not only during the season but also during the off-season using ...alternative sports. In AS, the role of the outside leg is crucial for successful turn performance. By measuring kinematic and kinetic parameters, we could define whether there is an objective similarity of the role and the movements of the outside leg while performing a turn in AS to those in the most used additional activity, IS. The sample consisted of ten female alpine ski instructors (age 31.6 ± 8.23, height 170.66 ± 7.32 cm, weight 60.16 ± 7.58 kg). Overall, 280 turns were analyzed (140 for AS and 140 for IS). For the purposes of this study, the variable sample consisted of 14 variables in total. For the detection of differences between short turn performance in AS and IS, MANOVA was used. The main findings of our study are defined similarities in pressure distribution during IS and AS and noticeable differences in the kinematic parameters of the outside leg between the mentioned activities. Based on the gathered results, recreational alpine skiers should be aware that IS cannot be used for the purpose of AS adoption, but rather as a dry-land additional activity for AS preparation.
Danas se u skijaškim školama primjenjuju različiti programi po kojima se uče skijaški početnici. Svi programi imaju isti cilj, a to je naučiti početnike specifične pokrete tijela pomoću kojih će moći ...upravljati skijama.Tri se programa najčešće koriste u školama alpskoga skijanja. Po jednom programu skijaške početnike se uči osnovama alpskoga skijanja isključivo elementima paralelne skijaške tehnike. Drugim programom skijaški početnici usvajaju znanja pomoću elemenata plužne i paralelne skijaške tehnike. Treći program učenja alpskoga skijanja kombinira navedena dva načina. Osim programa, u praksi postoje dva pristupa učenja alpskoga skijanja. Prvi način uključuje svakodnevni odlazak do skijaškog poligona ili obližnjeg zimskog turističkog centra, na kojemu se usvaja skijaška tehnika te se isti dan vraća u mjesto stanovanja. Drugi način sastoji se u organiziranom, najčešće sedmodnevnom, odlasku na zimovanje u sklopu čega se svaki dan uče osnove alpskoga skijanja. Neovisno o korištenim programima učenja, sigurnost skijaša prioritet je u svakoj školi alpskoga skijanja. Stoga je savjet svim skijašima početnicima uključiti se u školu alpskoga skijanja, jer na taj način čine najbolju prevenciju nastanka ozljeda.
Danas se u skijaškim školama primjenjuju različiti programi po kojima se uče skijaški početnici. Svi programi imaju isti cilj, a to je naučiti početnike specifične pokrete tijela pomoću kojih će moći ...upravljati skijama.Tri se programa najčešće koriste u školama alpskoga skijanja. Po jednom programu skijaške početnike se uči osnovama alpskoga skijanja isključivo elementima paralelne skijaške tehnike. Drugim programom skijaški početnici usvajaju znanja pomoću elemenata plužne i paralelne skijaške tehnike. Treći program učenja alpskoga skijanja kombinira navedena dva načina. Osim programa, u praksi postoje dva pristupa učenja alpskoga skijanja. Prvi način uključuje svakodnevni odlazak do skijaškog poligona ili obližnjeg zimskog turističkog centra, na kojemu se usvaja skijaška tehnika te se isti dan vraća u mjesto stanovanja. Drugi način sastoji se u organiziranom, najčešće sedmodnevnom, odlasku na zimovanje u sklopu čega se svaki dan uče osnove alpskoga skijanja. Neovisno o korištenim programima učenja, sigurnost skijaša prioritet je u svakoj školi alpskoga skijanja. Stoga je savjet svim skijašima početnicima uključiti se u školu alpskoga skijanja, jer na taj način čine najbolju prevenciju nastanka ozljeda.
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