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Background: Few studies have examined the association between the acute:chronic workload ratio (ACWR) and complaints/injuries in young tennis players. Primary aims of this study were to investigate if accumulated external workload “spikes” in ACWR of tennis training, match play, and fitness training, and to see if high or low workload/age ratio were associated with the rate of shoulder complaints/injuries in competitive adolescent tennis players. Additional aims were to report the incidence of complaints/injuries stratified by sex and level of play and to describe shoulder injury characteristics. Hypothesis: Rapid increases in external workload are associated with the incidence of shoulder complaints and injuries. Study Design: A cohort study. Level of Evidence: Level 3. Methods: At baseline, 301 adolescent competitive tennis players, 13 to 19 years, were screened and followed weekly for 52 weeks with questionnaires, in the years 2018 to 2019. Information about time-varying accumulated external workload spikes (uncoupled ACWR >1.3), and workload/age ratio, in 252 uninjured players were used in Cox regression analyses with the outcomes shoulder complaints (≥20) and injuries (≥40) (Oslo Sports Trauma Research Center Overuse Injury Questionnaire). Results: For each additional workload spike in tennis training/match play, the hazard rate ratio (HRR) was 1.26 (95% CI, 1.13-1.40) for a shoulder complaint and 1.26 (95% CI, 1.15-1.39) for a shoulder injury. The HRR for fitness training was 1.11 (95% CI, 1.02-1.20) for a shoulder complaint and 1.18 (95% CI, 1.09-1.27) for a shoulder injury. Workload/age ratio was not associated with the rate of shoulder complaints or injuries. Conclusion: Accumulated external workload spikes of tennis training, match play, and/or fitness training are associated with a higher rate of shoulder complaints and shoulder injuries in competitive adolescent tennis players. Clinical Relevance: Consistency in training load on a weekly basis is most likely more beneficial for adolescent tennis players regarding shoulder complaints/injuries than a training schedule comprising rapid increases (ie, spikes) in workload.

Background Glenohumeral internal rotation deficit (GIRD) and posterior shoulder stiffness have been associated with impingement symptoms in the overhead athlete. Stretching of the posterior shoulder is advised in injury prevention as well as rehabilitation programs. The purpose of the present study was to determine if stretching of the posterior shoulder improves ROM and reduces symptoms, and to compare angular with non-angular stretching techniques. Methods 60 overhead athletes with GIRD (age 25 ± 7.2 years, height 176 ± 8 cm, weight 69.8 ± 10.2 kg) participated to the study. Thirty athletes had no shoulder pain, 30 had impingement symptoms on the dominant shoulder. The subjects were randomly assigned into an “angular” or a “non-angular” treatment group. They were treated for 3 weeks (9 sessions) and followed for another period of 3 weeks after completion of the treatment. Treatment outcome variables were glenohumeral internal rotation range of motion, and, in the patient group, pain (VAS) scores and functional performance (ROWE-score). Results Statistical analysis showed a significant increase in ROM ( p < .05) in both treatment groups, in the patient as well as in the healthy control group. In addition, patients showed a significant improvement in pain assessment scores, and a significant increase in the Modified Rowe Score. There were no significant differences between both treatment techniques. Discussion Stretching, angular as well as non-angular techniques, increases internal rotation ROM in overhead athletes, and may decrease sport specific shoulder pain in overhead athletes with impingement symptoms.

The merger of the head offices of two public service organizations in Sweden was used to examine differences in the meanings that employees attach to the organizations involved and their expectations of the new merged organization, nine months prior to the merger. A two-stage methodology was used, combining the repertory grid method with a survey questionnaire based on the elicited constructs. Predictions from a social constructivist perspective on culture and social identity theory were largely confirmed. The results showed that both groups expected one of them to be dominant after the merger. Members of this organization expected to change very little, while employees in the non-dominant group felt themselves to be threatened by the prospect of merger and this led them to emphasize their own distinctiveness. The findings suggest that the success of the integration process after a merger is critically dependent on how employees of merger partners perceive the culture of the organizations involved and the expectations they have of the new organization. The study has practical implications for how to manage the merger integration process.

The purpose of this study was to investigate if there is a difference in performance and experienced mental workload between 2-D and 3-D simulations of airport tower air traffic control. The air traffic control task was to give aircraft take-off and landing clearances. A total of ten subjects, all university students, participated in the study. All subjects were exposed to both 2-D and 3-D simulations. The order between 2-D and 3-D was rotated to exclude order effects. Performance was judged using a rating form used by the Swedish Air Traffic Services Academy. After each simulation the subjects were required to rate their mental workload on NASA-TLX. The results show no statistically significant differences between 2-D and 3-D with respect to performance or experienced workload. When looking at the raw data tendencies can be found for the 3-D to yield better performance and less mental load. This merits further study with a larger number of subjects and scenarios.

This study aims at investigating the impact of a recently implemented short term conflict alert system in Swedish air traffic control. The main issue is whether controllers have changed their way of working after the introduction of the new system and to look for potential risk factors. Observations, questionnaires and semi-structured interviews were used to collect information from working controllers. Results show no change in work procedures except for the fact that controllers have increased the amount of information given to pilots. A tendency was found for experienced controllers to look more often at alerts in other sectors than less experienced controllers did, which might be a potential risk factor.

A total of 36 air traffic control incident investigation reports were analysed, identifying five main contributing factors: lack of concentration, methodology, handover, lack of training and fraseology. A number of background factors with possible relations to the occurance of incidents were also selected. The most important background factors were traffic intensity and work shift. Experience in terms of time as controller and time since the controller was checked out in his present position also seems to play a major role. A cluster analysis confirms the above conclusions as well as giving indications of effects of individualized ways of working.

Purpose: Revascularizing procedures like percutaneous transluminal coro nary angioplasty (PTCA) aim at reducing the incidence and severity of myocardial ischemia. To evaluate this, continuous Holter ST analysis is a possible method. Design: 41 patients (35 men, 6 women) with stable angina pectoris had continuous twenty-four-hour two-channel Holter registration (V5/aVF -analogous leads) recorded before and after PTCA. Transient myocardial ischemia (TM) was defined as 0.1 mV ST depression or more 80 msec after the J point for one minute or more. Findings: PTCA was successful for 37 patients (90%). Eleven of these had a total of 53 episodes of TM, 36 (68%) before and 17 (32%) after PTCA (p0.05). Implications: TM is common in patients with stable angina pectoris. The incidence significantly decreases after successful PTCA, but TM is seen also with a clinically uncomplicated course. In multivessel disease this is consistent with incomplete revascularization, whereas in single-vessel disease the most likely cause is intermittent spasm or thrombosis. TM after successful PTCA does not seem to be a predictor of restenosis.

The aim of the present study is to describe and analyze the preconditions for simultaneous development of productivity and work organization in a small company based on action research using the Hourglass model. The ongoing change process in the company is aiming at developing the competence of personnel and management in order to enhance relations with customers and the market. Its special focus is how external factors can improve productivity.

The individual constitutes meaning in and through his daily life activities. A careful analysis of meaning, as it is constituted by the individual, can give us indications for possible generalizations and formulations of typologies and classifications above the individual level. The concept of the individual is in this way of the highest scientific value, being the sole valid basis for all efforts of scientific conceptualizations. To affirm that meaning is individually constituted as a product of subjectivity, is also to affirm the necessity of reaching it with and through the concerned individual's own terms and expressions. This is accomplished by the MCA software.

Sex ratios in childhood in nineteenth-century America were skewed, with a relative excess of males in agricultural and frontier areas, and the reverse in urban and industrial areas. The pattern is consistent at the state, county, and (where data are available) community and household levels. The most likely con tributing causes are sex-specific migration of families according to the mix of their children, migration of children themselves, and mortality patterns arising from differential childcare based on the sex-specific economic value of children to the household in agricultural versus urban settings. These patterns confirm similar ones observed in developing countries and in the British Isles under condi tions of early agricultural modernization, in which the relative value of female labor declines in agricultural zones.

The detectability of one part of an illuminated field which has a straight edge as the border to the remaining part of the field was studied experimentally while the illumination of the total field had an irregular contrast based on a gaussian-noise spatial structure. The two parts of the field had different average illuminations. The detectability of the edge was studied for various illumination differences, field areas, edge lengths, and sharpnesses. The results are discussed in terms of the characteristics of the background noise and the visual system. The observations are interpreted in terms of a model that assumes spatial differentiation and spatial integration.