Lack of eye discipline during headers in high school girls soccer: A possible mechanism for increased concussion rates

Differences in the technical performance of heading between men and women football players during FIFA World Cup 2022 and FIFA Women's World Cup 2023 matches

Objectives

To compare the incidence of headers, attempted headers, and other head impacts, and the difference in heading descriptors, including technical performance, between men and women in a purposive sample of FIFA World Cup 2022 (FWC22) and FIFA Women's World Cup (FWWC23) matches.

Methods

Video analysis of all observed headers, attempted headers and other head impacts during eight FWC matches (FWC22 (n=4); FWWC23 (n=4)) where the same national teams competed. Heading descriptors (including ball delivery method, purpose of the header and involvement of other players) and technical performance of each header (including controlled or uncontrolled header, use of upper body, point of head contact) were analysed using negative binomial regression analyses with men as the reference group (reported as incidence rate ratios (IRR)). Timing of eye closure was analysed using a t-test; α-error, p=<0.05.

Results

From 973 head impacts, 845 (87%) were headers (FWC22 mean 5.0 headers/player/match, FWWC23 mean 4.6 headers/player/match), 93 (10%) were attempted headers and 35 (4%) were unintentional head impacts. When compared with men, women were less likely to perform controlled headers (73% vs 83%, IRR 1.20, p=0.01), use their foreheads (IRR 2.36, p=<0.001) and their upper body during the header (80% vs 88%, IRR 1.29, p=0.005). Women also closed their eyes earlier before the header (1.91 vs 1.56 frames, d=0.41, p=0.002).

Conclusion

There were significant differences in heading technique between women and men, which could be important to address in training to improve heading performance and potentially reduce short-term and long-term burden of heading.

Identification of Neural Mechanisms in First Single-Sweep Analysis in oVEMPs and Novel Normative Data

BACKGROUND

Bone-conducted (BC) VEMPs provide important tools for measuring otolith function. However, two major drawbacks of this method are encountered in clinical practice-small n10 amplitude and averaging technique. In this study, we present the results of a new VEMP setup measuring technique combined with a novel single-sweep analysis.

METHODS

The study included BC oVEMP data from 92 participants for the evaluation of normative data using a novel analysis technique. For evaluating test-retest reliability, the intraclass correlation coefficient (ICC) was used.

RESULTS

We found significant n10 amplitude differences in single-sweep analyses after the first and second measurements. Thereby, mathematical analyses of the head movement did not show any differences in the first or second measurements. The normative n10 amplitude was 20.66 µV with an asymmetric ratio (AR) of 7%. The new value of late shift difference (LSD) was 0.01 ms. The test retest-reliability showed good to excellent ICC results in 9 out of 10 measurements.

CONCLUSIONS

Our results support a phenomenon in single-sweep analysis of the first stimuli independent of head movement and signal morphology. Furthermore, the values obtained with the new measurement method appear to be more sensitive and may allow an extended diagnostic range due to the new parameter LSD.

Why are female soccer players experiencing a concussion more often than their male counterparts? A scoping review

BACKGROUND

The risk of concussion is particularly high in female soccer players. There is no consensus as to why female soccer players are at an elevated risk.

OBJECTIVE

To synthesise current evidence investigating reasons for the increased concussion rate in female soccer players.

SOURCES

Searching of six databases (MEDLINE, Scopus, CINAHL, SportDiscus, Web of Science and the Cochrane Library) and grey literature was performed between 13/07/2020-31/07/2020. Keywords were concussion-related terms, terms relating to female football/soccer and terms relating to the mechanism/cause. No constraints were placed on publication date and quantitative or exploratory studies meeting inclusion criteria were eligible. Exclusion criteria were studies not published in English and qualitative studies.

RESULTS

Several hypotheses were identified to explain increased concussion rates in female soccer players, these include, reduced neck strength/anthropometrics, increased head acceleration, increased ball-to-head concussions, differences in hormones and brain structure/function, and reduced visual awareness.

CONCLUSION

Promising ideas/reasons have been identified for increased concussion rates in female soccer players. Despite hypothesis generation there is scarce high-level evidence which is required to guide injury prevention and/or rule changes to protect female soccer players. The level of evidence for included studies is level 2-3 with most being observational cross-sectional or cohort studies.

The role of pre-season health characteristics as injury risk factors in female adolescent soccer players

[Purpose] Determine if female adolescent soccer players with a history of concussion, impaired K-D scores, and pre-season subjective complaints of neck pain, dizziness, and headache were predisposed to additional risk of musculoskeletal or concussive injury during 10-weeks of competitive play. [Participants and Methods] Twenty-three female high school soccer athletes provided concussion history and reported pre-season subjective complaints. K-D testing was performed pre and postseason. During the 10-week season, all injuries, preventing participation in practice or game, were recorded. [Results] Six reported a history of concussion. Of those six, three injuries were reported, including two concussions and a hamstring strain. Baseline K-D scores were worse in athletes that had two or more pre-season subjective factors compared to those that did not have any. Moderate positive correlations were found between a history of concussion and the number of injuries and a history of concussion and K-D post-test scores. [Conclusion] Findings indicate that pre-season subjective factors of neck pain, dizziness and headache, history of concussion, and K-D potentially increased injury risk. Combining pre-season metrics both at baseline and during the course of the season may assist in better injury risk screening in-season or indicate suboptimal function due to cumulative effects.

The Association of Visual Impairments of Elite Soccer Players with Concussion and Sports Injuries: A Prospective Cohort Study

Background: Visual skills play a pivotal role in athletic performance. However, in a professional setting, visual assessment is limited to a brief examination of visual acuity by the Snellen chart. This is while visual skills in sport comprise several other components. Objectives: This study aimed to evaluate the potential relationship between visual skills and sports injuries in professional soccer players. Methods: Through a prospective cohort study between September 2017 and October 2018, professional soccer league players were recruited for a complete eye examination including visual acuity, field of vision, and color discrimination as pre-competition examination. Any possible relationship between an abnormal eye finding and sports injury during the upcoming season was investigated. Results: A total of 386 male soccer players in 4 different playing positions were recruited from 16 league teams. Myopia, visual field defects, and green/blue/red color blindness were the most common visual impairments. Overall, there was no significant relationship between abnormal visual skills and the incidence of low back and upper extremity injuries among soccer players. However, a logistic regression model showed that the odds of quadriceps injury is 1.92 times higher (P-value: 0.005) for one diopter increase in both eyes' sum of refractive error. There is also an increased risk of concussion in players who have visual field defects (P-value < 0.005). Conclusions: Visual field defects can put soccer players at a higher risk for concussion. Moreover, uncorrected refractive eye errors will increase the incidence of lower limb injuries, mostly quadriceps injuries.

The Effects of Anticipation and Visual and Sensory Performance on Concussion Risk in Sport: A Review

Sports-related concussions pose a significant public health concern, and preventative measures are needed to help reduce risk in sport. Vision training could be a suitable prevention strategy for sports-related concussion to help improve athletes’ abilities to scan the visual field for oncoming objects or opponents and thus anticipate head impacts. By accurately anticipating impacts, athletes can prepare for impact or attempt to avoid the collision altogether. The purpose of this review is to explore the relationships between anticipation, visual and sensorimotor performance and head accelerations, as well as to examine the efficacy of vision training programmes in reducing concussion risk in sport. Anticipation of head impacts has been shown to help reduce linear and rotational head accelerations, particularly for mild-to-moderate severity head impacts, but less so for severe head impacts. There is conflicting evidence regarding the influences visual and sensorimotor performance and oculomotor behaviour have on concussion risk. However, preliminary research indicates vision training may help reduce concussion rates in collegiate American Football players. Therefore, this promising area of research warrants further investigation, particularly the role of anticipation and visual and sensory performance on reducing concussion risk in non-helmeted contact sports.

Female Athlete and Sports-Related Concussions

Female athletes are participating in collision sports in greater numbers than previously. The overall incidence of concussion is known to be higher in female athletes than in male athletes participating in similar sports. Evidence suggests anatomic, biomechanical, and biochemical etiologies behind this sex disparity. Future research on female athletes is needed for further guidance on prevention and management of concussion in girls and women.

The effects of vision training, neck musculature strength, and reaction time on concussions in an athletic population

A concussion is a major concern across the athletic population. Prevention of concussions can lead to a decrease of 3.8 million concussions that occur annually in the United States. Vision training, increasing neck musculature strength and quick reaction times are thought to be ways to prevent concussions. The purpose of this study is to review the literature on vision training, neck musculature, and reaction time, and how these interventions can prevent concussions. Upon review of the literature, vision training is proven to prevent concussions in a collegiate football setting, but there is no literature on different levels or sports. There are inconclusive results on whether neck musculature strength prevents concussions. There are substantial results concluding reaction time does prevent concussions by allowing the athlete to protect and anticipate head impact lessening the severity of the blow to the head. More research needs to be done for all three interventions to prove across all ages and levels of every sport that vision training, neck musculature strength, and reaction time prevent concussions in an athletic population. If proven true, practitioners in an athletic setting can use vision training, increasing neck musculature strength, and increasing reaction time as interventions to help prevent concussions in an athletic population.