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 t-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.
Traditionally used methods for kinematic analysis of alpine skiing has limitations regarding data collecting and data processing. Also, analysis of measured parameters, interpretation, and implementation to practice are postponed. Therefore, aim of this paper was to determine differences in the performance of slalom turns between three conditions using a relatively new technology that allows fast data collecting and analysis. Twenty kinematic variables were analysed for each turn (both the left and right) and 26 turns were executed in each condition. All turns were performed by a national skiing demonstrator. Differences were determined by MANOVA (F=71.3; p=.00). Tukey's post-hoc test showed that the turns performed on the ski simulator differed in every variable from the turns performed in other two condition, and the free skiing turns differed from the corridor turns in the following variables: hip joint angle of abduction of the right leg in the left turn, p=.00; distance of the projection of the centre of mass relative to the right foot in the left turn, p=.00; hip joint angle of flexion of the left leg in the left turn, p=.02; hip joint angle of abduction of the left leg in the left turn, p=.01; distance of the projection of the centre of mass relative to the left foot in the left turn, p=.00; knee angle of flexion of the left leg in the right turn, p=.04). The kinematic parameters obtained using the XSENS suit during slalom turns performed on the ski simulator and ski slope suggested significant differences in the position of the lower extremities, which might be important for situational efficiency and technical performance. Our results can be used to improve the alpine skiing technique. They suggest more precise relations between space parameters, such as body position and the angles between different body segments during a slalom turn. Methodology of research and technology used could contribute to the development of new scientific approaches in biomechanical research of top-level sports.
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.
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.
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.
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.