Latest research in football - week 8,5 - 2018

As previous literature updates, I have performed a PubCrawler search looking for football articles in NCBI Medline (PubMed) and GenBank databases.

Following studies were retrieved for this week:

#1 Normalized STEAM-based diffusion tensor imaging provides a robust assessment of muscle tears in football players: preliminary results of a new approach to evaluate muscle injuries
Reference: Eur Radiol. 2018 Feb 8. doi: 10.1007/s00330-017-5218-9. [Epub ahead of print]
Authors: Giraudo C, Motyka S, Weber M, Karner M, Resinger C, Feiweier T, Trattnig S, Bogner W
Summary: The purpose of the study was to assess acute muscle tears in professional football players by diffusion tensor imaging (DTI) and evaluate the impact of normalization of data. Eight football players with acute lower limb muscle tears were examined. DTI metrics of the injured muscle and corresponding healthy contralateral muscle and of ROIs drawn in muscle tears (ROItear) in the corresponding healthy contralateral muscle (ROIhc_t) in a healthy area ipsilateral to the injury (ROIhi) and in a corresponding contralateral area (ROIhc_i) were compared. The same comparison was performed for ratios of the injured (ROItear/ROIhi) and contralateral sides (ROIhc_t/ROIhc_i). ANOVA, Bonferroni-corrected post-hoc and Student's t-tests were used. Analyses of the entire muscle did not show any differences (p>0.05 each) except for axial diffusivity (AD; p=0.048). ROItear showed higher mean diffusivity (MD) and AD than ROIhc_t (p<0.05). Fractional anisotropy (FA) was lower in ROItear than in ROIhi and ROIhc_t (p<0.05). Radial diffusivity (RD) was higher in ROItear than in any other ROI (p<0.05). Ratios revealed higher MD and RD and lower FA and reduced number and length of fibre tracts on the injured side (p<0.05 each). DTI allowed a robust assessment of muscle tears in athletes especially after normalization to healthy muscle tissue.

#2 Sideline Concussion Assessment: The King-Devick Test in Canadian Professional Football
Reference: J Neurotrauma. 2018 Feb 8. doi: 10.1089/neu.2017.5490. [Epub ahead of print]
Authors: Naidu D, Mrazik M, Borza C, Kobitowich T
Summary: Reasons for Study: Sideline assessment tools are an important component of concussion evaluations. To date there has been little data evaluating the clinical utility of these tests in professional football. The purpose of this study was to evaluate the clinical utility of the King-Devick Test (KD) in evaluating concussions in professional football players. Baseline data was collected over 2 consecutive seasons in the Canadian Football League as part of a comprehensive medical baseline evaluation. A pilot study with the KD began in 2015 with 306 participants and the next year (2016) there were 917 participants. In addition, a sample of 64 participants completed testing after physical exertion (practice or game). Participants with concussion demonstrated significantly higher (slower) results compared with baseline and the exercise group (F[2,211] = 5.94, p = 0.003). The data revealed a specificity of 84% and sensitivity of 62% for our sample. Reliability from season to season was good (ICC2,1 = 0.88, 95% CI: 0.83, 0.91). On average participants improved performances by a mean of 1.9 seconds (range -26.6 to 23.8) in subsequent years. High reliability was attained in the exercise group. (ICC2,1 = 0.93, 95% CI: 0.89, 0.96). The K-D test presents as a reliable measure although sensitivity and specificity data from our sample indicate it should be used in conjunction with other measures for diagnosing concussion. Further research is required to identify stability of results over multiple usages.

#3 Multivariate analysis of factors related to radiographic knee osteoarthritis based on the comparison between football players and matched nonsportsmen
Reference: Int Orthop. 2018 Feb 6. doi: 10.1007/s00264-018-3797-y. [Epub ahead of print]
Authors: Lv H, Chen W, Yuwen P, Yang N, Yan X, Zhang Y
Summary: Knee osteoarthritis (KOA) is the most common joint pathology worldwide and a major cause of later disability. It is unknown if the bone mass density (BMD) is correlated with KOA. This study aimed to investigate the prevalence of radiographic KOA among retired professional football players by comparing with matched nonsportsmen, and assess the correlation between BMD and KOA. A cross-sectional, descriptive study was performed on a group of retired professional football players without history of knee injury. A control group of nonsporting volunteers was matched to the football player group in terms of age, height, weight, and body mass index (BMI). Uni- and multivariate analyses were performed to identify risk factors for KOA and predictors for knee function. Eighty-six retired male professional football players, with a mean age of 53 (51-58) years and an average period of professional career of 19.8 ± 6.3 years, were enrolled into the study group. Eighty-six subjects were included in the control group. Radiographic KOA was more common in the control group (45.3%) than in the study group (15.1%; χ 2  = 18.633, P < 0.001). While the HSS, IKS score, and BMD of spine, femoral neck, and trochanter were all higher among sportsmen than the nonsportsmen (z = 10.250, z = 10.450, z = 7.237, z = 8.826, z = 8.776, all P < 0.001). Independent risk factors for ROA were age (55-60 + years, aOR 9.159, P < 0.001) and BMD (decrease, aOR 16.226, P = 0.001; osteoporosis, aOR 8.176, P = 0.005). The mathematical model of multiple linear regression for the HSS and IKS score were Y = 127.217-3.334 age + 8.971 BMD + 4.752 occupation and Y = 57.784-3.022 age + 7.241 BMD + 4.730 occupation, respectively. This study reveals that low BMD and advanced age are independent risk factors for KOA. High BMD and regular exercise have a positive impact on knee function as evaluated with the use of HSS and IKS. Our findings guarantee further study to investigate the possibility that KOA may be caused by low BMD.

#4 Structural differences in the lower extremities in children aged 7-9 years, caused by playing football: A cross-sectional study
Reference: Foot (Edinb). 2017 Nov 17;34:78-82. doi: 10.1016/j.foot.2017.11.004. [Epub ahead of print]
Authors: Diaz-Miguel S, Lopezosa-Reca E, Benhamu-Benhamu S, Ortega-Avila AB, Garcia-De-La-Pena R, Gijon-Nogueron G
Summary: Physical activity during childhood can be beneficial in the long term. However, this practice can influence the child's physiological development. The aim of this study was to determine whether the practice of soccer, in moderation, could be a risk factor for the inadequate development of the lower limb. The study group was composed of 115 children, of whom 59 (mean age 8.03±0.89years) practised soccer 3 times a week and had a positive Physical Activity Questionnaire for Adolescents (PAQ-A) score, while a further 56 (mean age 7.96±0.87years) did not perform any additional physical activity and had a negative PAQ-A score. A foot posture analysis, based on the foot posture index (FPI), the valgus index, the orientation of the subtalar joint (STJ) and the Q angle of the knee, was carried out. For the group of soccer players, the following results were obtained: FPI 4.79±2.38 (R) and 3.95±2.31 (L); valgus index 13.56°±1.66° (R) and 13.42°±1.48° (L); STJ test 79% pronated; Q angle 13.13°±2.06° (R) and 13.18°±1.93° (L). For the non-players, the corresponding values were: FPI 3.62±2.82 (R) and 3.74±2.77 (L); valgus index 12.76°±1.71° (R) and 12.84°±1.72° (L); STJ test 50% pronated; Q angle 13.87°±3.01° (R) and 13.86°±2.94° (L). There is a degree of difference between the two groups, but the values do not vary greatly from those considered normal for this age group. Any alterations in this respect can be assumed to be caused at older ages than those analysed.

#5 Prevalence of dermatomycoses in professional football players : A study based on data of German Bundesliga fitness check-ups (2013-2015) compared to data of the general population.
[Article in German]
Reference: Hautarzt. 2018 Feb 7. doi: 10.1007/s00105-017-4120-3. [Epub ahead of print]
Authors: Buder V, Augustin M, Schafer I, Welsch G, Catala-Lehnen P, Herberger K
Summary: The prevention, early diagnosis and treatment of onychomycosis is of great importance for professional athletes to avoid physical limitations by complications. So far, there is only little data on the prevalence of dermatomycosis in professional athletes. The aim of the study was to detect the prevalence of dermatomycosis in professional football players compared to the general population. The prospective, non-interventional, controlled study on the prevalence of dermatomycosis in professional football players was carried out on football players of a German Bundesliga team compared with a previously studied, equivalently aged German working population. A questionnaire survey, a dermatological check-up and a microbiological detection of pathogens in cases of suspicion were performed. Data of 84 football players (n = 45 in 2013; n = 39 in 2015) were compared to data of n = 8186 male employees between 17 and 35 years of age. In the group of athletes, there were findings of 60.7% onychomycosis, 36.9% of tinea pedis and 17.8% of pityriasis versicolor. In the group of the age-equivalent general German working population the findings were: onychomycosis 3.3%, tinea pedis 3.2%, pityriasis versicolor 1.4%. Our study shows a clearly higher risk for fungal diseases of the skin especially on the feet of professional football players. The results show a necessity for elucidation within prevention and the establishment of an appropriate therapy of dermatomycosis for professional football players.

#6 Depression and anxiety symptoms in 17 teams of female football players including 10 German first league teams
Reference: Br J Sports Med. 2018 Feb 2. pii: bjsports-2017-098033. doi: 10.1136/bjsports-2017-098033. [Epub ahead of print]
Authors: Junge A, Prinz B
Summary: Information on the prevalence of mental health problems of elite athletes is inconclusive, most probably due to methodological limitations, such as low response rates, heterogeneous samples. The aim of the study was to evaluate the prevalence and risk factors of depression and anxiety symptoms in high-level female football players. Female football players of 10 German first league (Bundesliga) and 7 lower league teams were asked to answer a questionnaire on players' characteristics, the Center of Epidemiologic Studies Depression Scale (CES-D) and the Generalised Anxiety Disorder (GAD-7) scale. A total of 290 players (184 first and 106 lower league players) took part in the study. The CES-D score indicated mild to moderate symptoms of depression in 48 (16.6%) and severe symptoms in 41 (14.1%) players. The GAD-7 score indicated an at least moderate generalised anxiety disorder in 24 (8.3%) players. The prevalence of depression symptoms and generalised anxiety disorders was similar to the female general population of similar age. However, significantly more second league players reported symptoms of depression than first league players, and thus the prevalence of depression symptoms in second league players was higher than in the general population. Only a third of the 45 (15.7%) players who stated that they currently wanted or needed psychotherapeutic support received it. The prevalence of depression and generalised anxiety symptoms in elite football players is influenced by personal and sport-specific variables. It is important to raise awareness of athletes' mental health problems in coaches and team physicians, to reduce stigma and to provide low-threshold treatment.

#7 Using Cartilage MRI T2-Mapping to Analyze Early Cartilage Degeneration in the Knee Joint of Young Professional Soccer Players
Reference: Cartilage. 2018 Feb 1:1947603518756986. doi: 10.1177/1947603518756986. [Epub ahead of print]
Authors: Waldenmeier L, Evers C, Uder M, Janka R, Hennig FF, Pachowsky ML, Welsch GH
Summary: The objective was to evaluate and characterize the appearance of articular cartilage in the tibiofemoral joint of young professional soccer players using T2-relaxation time evaluation on magnetic resonance imaging (MRI). Design In this study, we included 57 male adolescents from the youth academy of a professional soccer team. The MRI scans were acquired of the knee joint of the supporting leg. An "early unloading" (minute 0) and "late unloading" (minute 28) T2-sequence was included in the set of images. Quantitative T2-analysis was performed in the femorotibial joint cartilage in 4 slices with each 10 regions of interest (ROIs). Statistical evaluation, using Wilcoxon signed-rank tests, was primarily performed to compare the T2 values of the "early unloading" and "late unloading." Results When comparing "early unloading" with "late unloading," our findings showed a significant increase of T2-relaxation times in the weightbearing femoral cartilage of the medial ( P < 0.001) and lateral ( P < 0.001) compartment of the knee and in the tibial cartilage of the medial compartment ( P < 0.001). Conclusion In this study, alterations of the cartilage were found with a maximum in the medial condyle where the biomechanical load of the knee joint is highest, as well as where most of the chronic cartilage lesions occur. To avoid chronic damage, special focus should be laid on this region.

#8 A Trunk Stabilization Exercise Warm-up May Reduce Ankle Injuries in Junior Soccer Players
Reference: Int J Sports Med. 2018 Feb 15. doi: 10.1055/s-0044-100923. [Epub ahead of print]
Authors: Imai A, Imai T, Iizuka S, Kaneoka K
Summary: The aim of this study was to investigate the efficacy of a trunk stabilization exercise warm-up program in reducing the incidence of lower extremity injuries among male junior soccer players. Two junior soccer teams participated in this study. The intervention (INT) team performed three trunk stabilization exercises before practice sessions and games, while a control (CON) team performed their usual warm-up without trunk exercises. Both teams engaged in regular soccer training and games, and were followed for the incidence of injury. As a result, overall injury incidence rates (IRs) were 2.65 injuries/1,000 h and 4.94 injuries/1,000 h in the INT and CON teams, respectively (incidence rate ratio [IRR]=0.54, 95% confidence interval [CI]=0.32-0.89, p=0.013). The IR of acute injuries was significantly lower in the INT team (1.91 injuries/1,000 h) than in the CON team (4.06 injuries/1,000 h) (IRR=0.47, 95%CI=0.26-0.84, p=0.009). Regarding injury sites, the IRs of ankle injuries in the INT team (0.32 injuries/1,000 h) were significantly lower than that in the CON team (2.28 injuries/1,000 h) (IRR=0.14, 95%CI=0.04-0.47, p<0.001). These results suggest that a warm-up program comprising trunk stabilization exercises alone can prevent acute injuries, especially ankle injuries.

#9 Effect of oxygen therapy on chest pain in patients with ST elevation myocardial infarction: results from the randomized SOCCER trial
Reference: Scand Cardiovasc J. 2018 Feb 13:1-5. doi: 10.1080/14017431.2018.1439183. [Epub ahead of print]
Authors: Khoshnood A, Akbarzadeh M, Carlsson M, Sparv D, Bhiladvala P, Mokhtari A, Erlinge D, Ekelund U
Summary: Oxygen (O2) have been a cornerstone in the treatment of acute myocardial infarction. Studies have been inconclusive regarding the cardiovascular and analgesic effects of oxygen in these patients. In the SOCCER trial, we compared the effects of oxygen treatment versus room air in patients with ST-elevation myocardial infarction (STEMI). There was no difference in myocardial salvage index or infarct size assessed with cardiac magnetic resonance imaging. In the present subanalysis, we wanted to evaluate the effect of O2 on chest pain in patients with STEMI. Normoxic patients with first time STEMI were randomized in the ambulance to standard care with 10 l/min O2 or room air until the end of the percutaneous coronary intervention (PCI). The ambulance personnel noted the patients´ chest pain on a visual analog scale (VAS; 1-10) before randomization and after the transport but before the start of the PCI, and also registered the amount of morphine given. 160 patients were randomized to O2 (n = 85) or room air (n = 75). The O2 group had a higher median VAS at randomization than the air group (7.0 ± 2.3 vs 6.0 ± 2.9; p = .02) and also received a higher median total dose of morphine (5.0 mg ± 4.4 vs 4.0 mg ± 3.7; p = .02). There was no difference between the O2 and air groups in VAS at the start of the PCI (4.0 ± 2.4 vs 3.0 ± 2.5; p = .05) or in the median VAS decrease from randomization to the start of the PCI (-2.0 ± 2.2 vs -1.0 ± 2.9; p = .18). Taken together with previously published data, these results do not support a significant analgesic effect of oxygen in patients with STEMI.

#10 The Trainability of Adolescent Soccer Players to Brief Periodized Complex Training
Reference: Int J Sports Physiol Perform. 2018 Feb 12:1-25. doi: 10.1123/ijspp.2017-0763. [Epub ahead of print]
Authors: Chatzinikolaou A, Michaloglou K, Avloniti A, Leontsini D, Deli CK, Vlachopoulos D, Gracia-Marco L, Arsenis S, Athanailidis I, Draganidis D, Jamurtas AZ, Williams CA, Fatouros IG
Summary:  The purpose was to investigate the effect of a complex, short-term strength/power training protocol on performance and body composition of elite early-adolescent soccer players. Twenty-two players (14-15 years) were randomly assigned to (a) an experimental (EG, n=12, participated in a 5-week training protocol with traditional multi-joint power resistance exercises, Olympic-style lifts, plyometric drills and speed work, four times/week) or (b) a control group (CG, n=10). Strength and power performance [jumping, speed, change of direction, repeated sprint ability, endurance, isokinetic strength of knee flexors and extensors, maximal strength in various lifts, speed-endurance) were evaluated pre- and post-training. Cessation of training for five weeks in the CG induced a marked performance deterioration (~5-20%). Training not only prevented strength performance deterioration but also increased it (~2-30%). Endurance and RSA declined to a smaller extent in EG compared to CG (15% vs. 7.5%). Isometric strength, and body composition remained unaltered in both groups. Results demonstrate that (i) young players exhibit a high level of trainability of their strength/power performance (but not endurance) in response a short-term complex training protocol during early adolescence, (ii) Olympic-style lifts are characterized by increased safety in this age group and appear to be highly effective, (iii) it appears that lifts incorporating a hip thrust result in increased strength of both knee extensors and flexors, (iv) cessation of training for only five weeks results in marked deterioration of strength/power and endurance performance and (v) improvement of strength/power performance may be related to neural-based adaptation since body composition remained unaffected.

#11 Osteochondral lesion of the distal tibial plafond in an adolescent soccer player: a case report
Reference: J Can Chiropr Assoc. 2017 Dec;61(3):261-268.
Authors: Corso M, DeGraauw C, Hsu W
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Summary: Osteochondral lesions of the tibial plafond account for approximately 2.6% of osteochondral lesions in the ankle. There are few cases describing this lesion in the literature, with little information on mechanism of injury, history/physical findings or recommendations for management. A 17-year-old male competitive soccer player presented with a 6-7 month history of medial ankle pain after an inversion sprain. He presented with locking and giving way of the ankle with weight-bearing and pushing off the foot to the contralateral side. Radiographs were negative for fracture or osteochondral involvement. Magnetic resonance imaging revealed an osteochondral lesion of the tibial plafond with no injury to the talar dome. This case discusses the clinical presentation, imaging findings, management and outcomes of this osteochondral lesion of the distal tibial plafond.

#12 Modelling the impact of players' workload on the injury-burden of English Premier League football clubs
Reference: Scand J Med Sci Sports. 2018 Feb 23. doi: 10.1111/sms.13078. [Epub ahead of print]
Authors: Fuller CW
Summary: The loss of players through injury is known to affect team performance in many sports; it is important therefore for professional teams to be able to quantify the likely injury-burden that will be encountered throughout a season. A kinetic model, based on the rates at which match and training injuries are sustained and resolved, a team's squad size and the 2017/18 season fixture schedule for teams competing in the English Premier League, is used to produce daily forecasts of injury-burden experienced by a typical team. The incidences and median severities of match (incidence: 26.9 injuries/1000 player-match-hours, 95% CI: 21.5 to 33.7; severity: 17.5 days, 95% CI: 13.0 to 28.0) and training (incidence: 4.3 injuries/1000 player-training-hours, 95% CI: 3.4 to 5.5; severity: 14.0 days, 95% CI: 11.0 to 22.0) injuries were determined using data collected from four English Premier League football clubs during the 2016/17 season. Time-to-recovery curves for the match and training injuries sustained in the Premier League closely matched the time-to-recovery curves predicted by the kinetic model used in this study. The kinetic model predicted higher match and lower training injury burdens and a higher overall injury burden for successful teams competing in both national and European club competitions compared to teams competing only in national competitions. The model also showed that, in terms of injury-burden, there were no benefits in adopting a 4-week mid-season break during the season: reducing the number of clubs competing in the Premier League would, however, reduce the overall injury burden during a season. This article is protected by copyright. All rights reserved.

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