Gymnastik- och idrottshögskolan, GIH

Background: A cruciate ligament (CL) injury is a severe injury in soccer. Neuromuscular training programs have a well-documented preventive effect, but there are few studies on the effectiveness of such a program at a national level. The Swedish Knee Control Program (KCP) was found to be effective in preventing CL injuries in youth female soccer players. The KCP was implemented nationwide in Sweden in 2010.

Purpose: To evaluate the effectiveness of the Swedish KCP in reducing acute knee injuries in soccer players at a nationwide level.

Study Design: Descriptive epidemiology study.

Methods: All licensed soccer players in Sweden are covered by the same insurance company. Using this insurance database, around 17,500 acute knee injuries that were reported to the insurance company between 2006 and 2015 were included in the study. By matching the number of licensed soccer players with the number of reported injuries each year, the annual incidence of knee and CL injuries was able to be calculated. To evaluate the spread of the KCP nationally, a questionnaire was sent to all 24 Swedish district football associations (FAs) with questions regarding KCP education. The number of downloads of the KCP mobile application (app) was obtained.

Results: The incidence of CL injuries decreased during the study period for both male (from 2.9 to 2.4 per 1000 player-years) and female players (from 4.9 to 3.9 per 1000 player-years). The overall incidence of knee injuries decreased in both male (from 5.6 to 4.6 per 1000 player-years) and female players (from 8.7 to 6.4 per 1000 player-years). Comparing before and after the nationwide implementation of the KCP, there was a decrease in the incidence of CL injuries by 6% (rate ratio [RR], 0.94 [95% CI, 0.89-0.98]) in male players and 13% (RR, 0.87 [95% CI, 0.81-0.92]) in female players and a decrease in the incidence of knee injuries by 8% (RR, 0.92 [95% CI, 0.89-0.96]) and 21% (RR, 0.79 [95% CI, 0.75-0.83]), respectively (P < .01 for all). This trend corresponded to a reduction of approximately 100 CL injuries each year in Sweden. A total of 21 of 24 district FAs held organized KCP educational courses during the study period. The percentage of district FAs holding KCP courses was between 46% and 79% each year. There were 101,236 downloads of the KCP app.

Conclusion: The KCP can be considered partially implemented nationwide, and the incidence of knee and CL injuries has decreased in both sexes at a nationwide level.

Introduction: The purpose of this study was to evaluate healing frequency in different stages of stress reactions in the Pars Interarticularis (PI) using a classification system with MRI and CT. The intervention was 3-month rest from physical activity, without a brace, with the exception of activities of daily living.

Materials & Method: Twelve adolescent athletes with different stages of Spondolysis were included in the study. They had pathology in the Pars Interarticularis and were clinically examined with MRI and CT 3-6 weeks after debut of Low Back Pain (LBP) and re-evaluated after 3 months intervention with rest from physical activity.

Results: A combination of MRI and CT scanning to investigate suspected injuries to Pars Interarticularis in adolescent athletes revealed 6 different stages of Spondolysis that ranged from marrow oedema to pseudoarthrosis. After 3 months of rest from physical activity the early stages of Pars Interarticularis injuries healed significantly better than the later stages with rest from physical activity.

Conclusion: The combination of MRI and CT revealed 6 stages of stress reactions instead of 4 as in Hollenberg's staging with MRI only. In the 3 earliest stages, of these 6, rest from physical activity for 3 months can heal the stress reaction.

AIM: The purpose of this study was to investigate the effects of menstrual and oral contraceptive cycle based high frequency periodized leg resistance training in trained women, on squat and countermovement jump, isokinetic peak torque and lean body mass in a non- laboratory setting.

METHODS: Two groups performed high frequency leg resistance training for two weeks of each menstrual/oral contraceptive cycle for four months. The remaining part of the cycle they performed the leg training once a week. Group 1 (n=19) trained with high frequency (5 times∙w-1) during the first two weeks of each cycle, and group 2 (n=19) during the last two weeks of each cycle. A control group (n=21) performed regurlar (3 times∙w-1) leg resistance training for four months.

RESULTS: Significant increase in squat and countermovement jump, and peak torque values in hamstrings for group 1 were observed, but not in group 2. In the control group an increase in squat and countermovement jump, and peak torque (only left hamstring) was also observed. There was also a significant increase in lean body mass of the legs in group 1 only. There were no evident differences in the training effects between women with or without oral contraceptive.

CONCLUSION: The high frequency periodized leg resistance training during the first two weeks of the menstrual cycle is more beneficial to optimize training, than the last two weeks. Resistance training during the first two weeks of the menstrual cycle even resulted in a larger gain of lean body mass than regular training.

BACKGROUND: An improved muscle strength are of great importance in many sports, hence an increased understanding on how to generate optimal strength training programs in women without negative side effects that may lead to the female athlete triad are essential. The purpose of this study was to investigate potential negative effects of high frequency periodized menstrual/OC cycle based leg resistance training on components in the female athlete triad.

METHODS: Fifty-nine women, with experience of resistance training and with regular menstrual/OC cycles were included in the analyses. The participants were randomly assigned a training program consisted of high frequency leg resistance training, periodized to the first two weeks (group 1) or the last two weeks (group 2) of each cycle, or to a control group performing regular training, during four consecutive menstrual/OC cycles. The main analysis was the pre-to-post change of sex and growth hormones, cortisol, total body fat mass, bone mineral density in the spine. We further examined the participants' own experience of the training programs.

RESULTS: No significant negative impact on sex and growth hormones, cortisol, total body fat mass and bone mineral density in the spine, was detected in any of the groups. Moreover, the women in group 1 experienced their training program as positive.

CONCLUSIONS: The high frequency periodized leg resistance training was not associated with exercise-related negative consequences on components in the female athlete triad. Moreover, the training was well accepted when performed during the first two weeks of each cycle.

This is Part 2 of 5 in the series of evidence statements from the IOC expert committee on exercise and pregnancy in recreational and elite athletes. Part 1 focused on the effects of training during pregnancy and on the management of common pregnancy-related symptoms experienced by athletes. In Part 2, we focus on maternal and fetal perinatal outcomes.

When athletes optimize their physical performance, an imbalance could occur between the strain of training, time for recovery and the athlete’s individual tolerance of stress that could lead to overreaching and overtraining syndrome. Cortisol has been suggested to be a biological, diagnostic marker to detect overreaching and overtraining syndrome, since it is thought to indicate stress. This study aimed to provide normative data on cortisol levels, hence investigate seasonality and impact of oral contraceptive use to elucidate if cortisol could be used as a diagnostic marker to detect overreaching and overtraining syndrome in female athletes. The women, divided in two groups, oral contraceptive users (n = 15) and non-users (n = 18), were followed over a nine-month period with monthly blood sampling for cortisol testing and a Profile of Mood State questionnaire (POMS) as a subjective measure of overreaching and overtraining syndrome.Findings indicated seasonal variations in cortisol levels, with different pattern in oral contraceptive users to non-users and moreover, higher cortisol levels in users to nonusers irrespective of season. No differences in seasonal variation in Global POMS score within the groups and no differences in Global POMS score between the groups were detected. Due to seasonality, impact of oral contraceptive use on cortisol levels, methodological considerations and standardization, as well as due to no convincing relationship to Global POMS score, cortisol is not suggested to be an optimal biological, diagnostic marker to detect overreaching and overtraining syndrome in physically active women.

Acute injuries in sport are still a problem where limited knowledge of incidence and severity in different sports at national level exists. In Sweden, 80% of the sports federations have their mandatory injury insurance for all athletes in the same insurance company and injury data are systematically kept in a national database. The aim of the study was to identify high-risk sports with respect to incidence of acute and severe injuries in 35 sports reported to the database. The number and incidences of injuries as well as injuries leading to permanent medical impairment (PMI) were calculated during 2008–2011. Each year approximately 12 000 injuries and 1 162 660 licensed athletes were eligible for analysis. Eighty-five percent of the injuries were reported in football, ice hockey, floorball, and handball. The highest injury incidence as well as PMI was in motorcycle, handball, skating, and ice hockey. Females had higher risk of a PMI compared with males in automobile sport, handball, floorball, and football. High-risk sports with numerous injuries and high incidence of PMI injuries were motorcycle, handball, ice hockey, football, floorball, and automobile sports. Thus, these sports ought to be the target of preventive actions at national level.