Four distinct patterns of anterior cruciate ligament injury in women's professional football (soccer): a systematic video analysis of 37 match injuries.

BACKGROUND: To identify mechanisms and patterns of anterior cruciate ligament (ACL) injury in adult women's professional football by means of video match analysis. METHODS: ACL match injuries sustained in Germany's first women's league during the 2016-2017 to 2022-2023 seasons were prospectively analysed by three expert raters using a standardised observation form. Epidemiological and injury data, as well as the medical history of ACL tears, were obtained from media reports and the statutory accident insurance for professional athletes. RESULTS: Thirty-seven ACL injuries sustained in official football matches were included in the video analysis, of which 24 (65%) had associated knee injuries, mainly meniscus and collateral ligament injuries. According to the categorised contact mechanisms, 17 (46%) were non-contact injuries, 14 indirect contact injuries (38%) and six direct contact injuries (16%). Of the 17 non-contact injuries, seven (41%) occurred during the first 15 min of the match. Contact mechanisms did not differ between primary and secondary ACL injuries to the same or the contralateral side. Most injuries (80%) of field players occurred during horizontal movements such as sprinting (n=9, 26%), change-of-direction manoeuvres (n=7, 19%), stopping (n=5, 14%) and lunging (n=5, 14%). Four distinct repetitive patterns of ACL match injuries were identified: (1) non-contact 'pressing ACL injury' (n=9), (2) indirect contact 'parallel sprinting and tackling ACL injury' (n=7), (3) direct contact 'knee-to-knee ACL injury' (n=6) and (4) non-contact 'landing ACL injury' (n=4). CONCLUSION: Most of the identified patterns of ACL injuries in women's professional football have great potential for prevention.

High triacylglycerol turnover is required for efficient opening of stomata during heat stress in Arabidopsis.

Heat stress triggers the accumulation of triacylglycerols in Arabidopsis leaves, which increases basal thermotolerance. However, how triacylglycerol synthesis is linked to thermotolerance remains unclear and the mechanisms involved remain to be elucidated. It has been shown that triacylglycerol and starch degradation are required to provide energy for stomatal opening induced by blue light at dawn. To investigate whether triacylglycerol turnover is involved in heat-induced stomatal opening during the day, we performed feeding experiments with labeled fatty acids. Heat stress strongly induced both triacylglycerol synthesis and degradation to channel fatty acids destined for peroxisomal ß-oxidation through the triacylglycerol pool. Analysis of mutants defective in triacylglycerol synthesis or peroxisomal fatty acid uptake revealed that triacylglycerol turnover and fatty acid catabolism are required for heat-induced stomatal opening in illuminated leaves. We show that triacylglycerol turnover is continuous (1.2 mol% per min) in illuminated leaves even at 22°C. The ß-oxidation of triacylglycerol-derived fatty acids generates C2 carbon units that are channeled into the tricarboxylic acid pathway in the light. In addition, carbohydrate catabolism is required to provide oxaloacetate as an acceptor for peroxisomal acetyl-CoA and maintain the tricarboxylic acid pathway for energy and amino acid production during the day.