Pole length and ground reaction forces during maximal double poling in skiing

The purpose of the investigation was to study the relationship between thrust phase duration, ground reaction force, velocity increase after pole thrust and pole angles versus pole length during double poling in roller skiing. Seven male regional elite cross-country skiers volunteered as subjects for the study. The subjects performed a maximal double pole thrust on roller skis with each of the three different pole lengths: 'short', self-selected (normal) and 'long'. The short and long poles were 7.5 cm shorter and 7.5 cm longer than the self-selected pole length. The subjects made seven maximal pole thrusts with each pole length, which were randomly selected during 21 trials. For each trial the subjects accelerated from a 1.2 m high downhill slope attaining a speed of 3.92 m.s-1 before making a maximal double pole thrust on a force plate placed at the bottom of the slope. The vertical (F2), anterior-posterior (Fy) and mediolateral (Fx) reaction forces of the left pole were measured by the force plate. The positions of the pole were recorded in 3-D by an opto-electronic system. Thrust phase duration, impulse, mean force, velocity increase after pole thrust and pole angles were calculated from the recorded data. Double poling with long poles produced a significantly larger propulsive anterior-posterior reaction force impulse and velocity increase than normal (p < .05) and short poles (p < .05). This was in spite of a larger mean anterior-posterior reaction force being produced with short poles. Thus, thrust phase duration was a primary factor in determining propulsive anterior-posterior impulse. For the practitioner, the results can be useful in the selection of pole length when the aim is to increase thrust phase duration, anterior-posterior force impulse and velocity.     

Socialization content in schools and education for sustainable development – II. A study of students’ apprehension of teachers’ companion meanings in ESD

Subject content is always studied within an educational context. This context is constituted by the socialization content, which can be regarded as an educational content beyond the subject content. This is the third article of three studies (this article; Sund and Wickman 2011; Sund 2008) that together form a triangulation of possible socialization content of environmental education. A common purpose for these three combined studies is to embrace and visualize the important value-laden content, which is often forgotten in discussions about the development of education for sustainable development. It is not sufficient to merely integrate more subject content matter – it may also be necessary to adapt to a changed teaching approach, which also develops content in the teaching process. Teachers’ changed approaches convey qualitatively different clusters of ‘meta-messages’ to students. The first study from authors in 2008 developed an analytical tool consisting of five important educational aspects and the second, also published in Environmental Education Research used the aspects to study teachers’ socialization content expressed in the interviews. The present study examines whether the qualitative differences in upper secondary teachers’ communicated socialization content in three selective traditions are apprehended by their students.     

The challenge of greening technologies—Environmental policy integration in Finnish technology policies

The integration of environmental principles into other policies is perceived as essential in order to combat environmental problems as efficiently as possible. Environmental policy integration in Finnish technology policies is assessed empirically by focusing on technological R&D support at all levels, from policy strategies to project funding decisions. The actors making and implementing technology policies have grasped the idea of environmental protection and environmental issues have been identified especially at the strategy level and in some technology programmes. However, the integration is not overarching and no assessment of environmental impacts is required in funding applications.     

Cross‐Country Skiing

The purpose was to study the adaptation to speed in the temporal patterns of the movement cycle and determine any differences in velocity, cycle rate and cycle length at the maximum speed level in the different classical style and freestyle cross‐country skiing techniques. Eight skilled male cross‐country skiers were filmed with a digital video camera in the sagittal plane while skiing on a flat cross‐country ski track. The skiers performed three classical style techniques the diagonal stride, kick double poling and the double poling technique and four freestyle techniques paddle dance (gear 2), double dance (gear 3), single dance (gear 4) and combiskate (gear 5) at four different self‐selected speed levels slow, medium, fast and their maximum. Cycle duration, cycle rate, cycle length, and relative and absolute cycle phase duration of the different techniques at the different speed levels were analysed by means of a video analysis system. The cycle rate in all tested classical and freestyle techniques was found to increase significantly (p < .01) with speed from slow to maximum. Simultaneously, there was a significant decrease in the absolute phase durations of all the investigated skiing techniques. A minor, not significant, change in cycle length, and the significant increase in cycle rate with speed showed that the classical and freestyle cross‐country skiing styles are dependent, to a large extent, on an increase in cycle rate for speed adaptation. A striking finding was the constant relative phase duration with speed, which indicates a simplified neural control of the speed adaptation in both cross‐country skiing styles. For the practitioner, the knowledge about the importance of increasing cycle frequency rather than cycle length in the speed adaptation can be used to optimise a rapid increase in speed. The knowledge about the decrease in absolute phase duration, especially the thrust phase duration, points to the need for strength and technique training to enable force production at a high cycle rate and skiing speed. The knowledge that the relative phase duration stays constant with speed may be used to simplify the learning of the different cross‐country skiing techniques.     

Knee angular displacement and extensor muscle activity in telemark skiing and in ski-specific strength exercises

Much of the training of competitive telemark skiers is performed as dry-land exercises. The specificity of these exercises is important for optimizing the training effect. Our aim here was to study the activation of the knee extensor musculature and knee angular displacement during competitive telemark skiing and during dry-land strength training exercises to determine the specificity of the latter. Specificity was analysed with respect to angular amplitude, angular velocity, muscle action and electromyographic (EMG) activity. Five male telemark skiers of national and international standard volunteered to participate in the study, which consisted of two parts: (1) skiing a telemark ski course and (2) specific dry-land strength training exercises for telemark skiing (telemark jumps and barbell squats). The angular displacement of the right knee joint was recorded with an electrogoniometer. A tape pressure sensor was used to measure pressure between the sole of the foot and the bottom of the right ski boot. Electromyographic activity in the right vastus lateralis was recorded with surface electrodes. The EMG activity recorded during maximum countermovement jumps was used to normalize the EMG activity during telemark skiing, telemark jumps and barbell squats. The results showed that knee angular displacement during telemark skiing and dry-land telemark jumps had four distinct phases: a flexion (F1) and extension (E1) phase during the thrust phase of the outside ski/leg in the turn/jump and a flexion (F2) and extension (E2) phase when the leg was on the inside of the turn/jump. The vastus lateralis muscle was activated during F1 and E1 in the thrust phase during telemark skiing and telemark jumps. The overall net knee angular amplitude was significantly greater (P<0.05) for telemark jumps than for telemark skiing. Barbell squats showed a knee angular amplitude significantly greater than that in telemark skiing (P<0.05). The mean knee angular velocity of the F1 and E1 phases during telemark skiing was about 0.47 rad?·?s^?1; during barbell squats, it was about 1.22 rad?·?s^?1. The angular velocity during telemark jumps was 2.34 and 1.59 rad?·?s^?1 in the F1 and E1 phase, respectively. The normalized activation level of the EMG bursts during telemark skiing, telemark jumps and barbell squats was 70–80%. In conclusion, the muscle action and level of activation in the vastus lateralis during the F1 and E1 phases were similar during telemark skiing and dry-land exercises. However, the dry-land exercises showed a larger knee extension and flexion amplitude and angular velocity compared with telemark skiing. It appears that an adjustment of knee angular velocity during barbell squats and an adjustment of knee angle amplitude during both telemark jumps and barbell squats will improve specificity during training.     

Alternative Pathways to Chronic Depressive Symptoms in Young Adults: Gender Differences in Developmental Trajectories

Personality and intelligence associated with depressive symptoms in 23-year-olds were evaluated using prospective data from preschool through adolescence. Gender moderated the prospective relations between personality/intelligence and age-23 depressive symptoms. Young men with elevated age-23 General Behavior Inventory (GBI) scores manifested as early as in preschool allocentric behaviors: undersocialization and interpersonal antagonism. This pattern remained highly stable over the following 15 years. Prospective correlates of depressive symptoms in young women—not reliably identified until adolescence—were more likely than in young men to express autocentric concerns: oversocialization and introspective concern with self. These gender differences continued to persist but decreased in strength after puberty. Intellectual competence displayed significantly stronger negative correlations with age-23 GBI scores in males than in females. Findings were discussed in terms of gender differences in the development of chronic depressive symptoms, with special emphasis on equifinality in developmental pathways.     

Teachers’ objects of responsibility: something to care about in education for sustainable development?

Answers to questions about good teaching in environmental education can be expressed in different selective traditions. Questions as to what should be included in good teaching tend to be addressed by both teachers and researchers on an ideological basis. This qualitative study uses a pragmatist approach, and aims to make an empirical contribution to the debate. Rather than telling teachers what they should teach, this interview study involved listening to ten upper secondary school teachers in Sweden, and their arguments concerning their long‐term teaching purposes. Why should students learn particular things? The teachers’ answers revealed habits and frequently used the same arguments. These arguments recurrently dealt with what teachers particularly cared about, and five objects of responsibility were identified in the interviews. These objects of responsibility constitute the starting points of teachers’ actions and can be seen as personal anchor points within a selective tradition. These points of departure remind the teachers of their teaching aims and objectives, and at the same time, keep them within a tradition. While they help the teachers in their everyday practice, they could just as easily be seen as tacit obstacles to efforts to change environmental education into Education for Sustainable Development. The results are also relevant for science education in general. Issues identified in the study include how the same scientific knowledge could be used for different purposes in education, and the different personal anchor points for long‐term purposes of teaching based on teachers’ own ideas of good teaching. These results can be important in developing a reflection tool for teachers, which in turn can help them to reflect more deeply about how they might change their teaching practices.     

Moral motivation and the battle for students: The case of studies in nursing and social work in Norway

This paper presents data from a project onmoral motivation. It is more pragmaticallyframed on what it is that attracts students to`untrendy' fields and makes them want to do agood job. As the value structure in societychanges and the battle for students hardens,there is a growing concern that fields crucialto the development of society may lose out inthe competition for the best students. Amongthe fields that have received attention inthese debates are nursing and social work. Inpart, this is due to the fact that these fieldshave already experienced a decline inapplicants which merits concern, and in partdue to the image these studiesproject. In the debate on intake qualitiesfocus has primarily been on the academicquality of the students, and less on themotivational qualities that work of this typeimplies. The data presented here highlightsqualities related to this dimension ofprofessional work.     

Introducing a symbolic interactionist approach on teaching mathematics: the case of revoicing as an interactional strategy in the teaching of probability

This study examines an interactional view on teaching mathematics, whereby meaning is co-produced with the students through a process of negotiation. Further, teaching is viewed from a symbolic interactionism perspective, allowing the analysis to focus on the teacher’s role in the negotiation of meaning. Using methods inspired by grounded theory, patterns of teachers’ interaction are categorized. The results show how teachers’ actions, interpretations and intentions form interactional strategies that guide the negotiation of meaning in the classroom. The theoretical case of revoicing as a teacher action, together with interpretations of mathematical objects from probability theory, is used to exemplify conclusions from the proposed perspective. Data are generated from a lesson sequence with two teachers working with known and unknown constant sample spaces with their classes. In the lessons presented in this article, the focus is on negotiations of the meaning of chance. The analysis revealed how the teachers indicate their interpretations of mathematical objects and intentions to the students to different degrees and, by doing so, create opportunities for the students to ascribe meaning to these objects. The discussion contrasts the findings with possible interpretations from other perspectives on teaching.