Latest research in football - week 11 - 2014

#1 Thigh muscles injuries in professional soccer players: a one year longitudinal study
Reference: Muscles Ligaments Tendons J. 2014 Feb 24;3(4):331-6. eCollection 2013.
Authors: Corazza A, Orlandi D, Baldari A, Gatto P, Stellatelli M, Mazzola C, Galli R, Longo S, Sconfienza LM, Silvestri E.
Download link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3940508/pdf/331-336.pdf
Summary: Thigh muscles indirect injuries are common finding in soccer and represent a critical challenge for teams medical staffs. Indirect injuries are classified on the basis of their site and their clinical and radiological findings, but the assessment of a precise prognosis remains a crucial point. Both ultrasound (US) and magnetic resonance (MR) represent effective techniques not only to detect indirect injuries but also to accurately determine severity, location, and, consequently, the prognosis. In this setting, our aim is to review imaging findings of professional athletes muscle tears at three time points (3 days, 2 weeks, and 4 weeks after the time of injury) and, further, to investigate the correlation between tears extent and lay-off time of the athletes. Combined US-MR assessment could be helpful in the management of thigh muscles indirect injuries providing accurate information about the site, the extent, and the healing process.


#2 Reducing muscle injuries and reinjuries in one italian professional male soccer team
Authors: Melegati G, Tornese D, Gevi M, Trabattoni A, Pozzi G, Schonhuber H, Volpi P.
Reference: Muscles Ligaments Tendons J. 2014 Feb 24;3(4):324-30. eCollection 2013.
Download link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3940507/pdf/324-330.pdf
Summary: The incidence rate of muscle injuries and re-injuries in professional elite soccer players actually is very high and may interfere with the fate of a championship. The purpose was to investigate the effect of a two-tiered injury prevention programme on first injury and re-injury incidence in top level male soccer players. Muscle injuries and re-injuries sustained by a group of 36 soccer player of an italian elite soccer team have been collected during 2010-2011 season. These data have been compared with those collected during the previous season in the same elite soccer team. A total of 64 injuries occurred, 36 (56%) of which during practice and 28 (44%) during matches. Muscle injuries accounted for 31.3% of the total (n=20), 70% (n=14) of which occurred during practice and 30% (n=6) during matches. Hamstring were the muscles most often injured (n=11) In all, 3 re-injuries occurred (15% of muscle injuries). No early re-injuries occurred. The incidence was 2.5 injuries/1000 hours and the burden was 37 days absence/1000 hours. Through the implementation of a group and personalized injury prevention program, we were able to reduce the total number of muscle injuries and days absent because of injury, in a team of elite soccer players, as compared to the previous season. Specifically, muscle injuries accounted for 31% of all injuries, as compared to 59% of all injuries sustained by the team during the previous season. The number of injuries/1000 hours of exposure was reduced by half (from 5.6 to 2.5) and the days absent/1000 hours fell from 106 to 37.


#3 Compression garments to prevent delayed onset muscle soreness in soccer players
Authors: Valle X, Til L, Drobnic F, Turmo A, Montoro JB, Valero O, Artells R.
Reference: Muscles Ligaments Tendons J. 2014 Feb 24;3(4):295-302. eCollection 2013.
Download link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3940503/pdf/295-302.pdf
Summary: The purpose of this study was to evaluate the use of a compression garment as DOMS prevention. This was accomplished by provoking a DOMS in 15 athletes, running on a treadmill at 73% of their maximal aerobic velocity, during 40 minutes with a 10% negative slope; wearing the compression garments on one thigh, protected thigh (PT), and not in the contralateral thigh, control thigh (CT). A clinical and MRI diagnosis of DOMS was performed. Biopsies in both vastus lateralis were done, and the amount and severity of the DOMS was estimated by measuring intracellular albumin, and lymphocytes CD3+ and neutrophils intra/interfibrilar infiltrates, 48h after the induced damaging exercise. There was less total injury in the PT than in the CT, a 26.7% average. These data indicate that this compression garment is an effective method to reduce the histological injury in DOMS.


#4 Return to sport after anterior cruciate ligament reconstruction in professional soccer players
Authors: Zaffagnini S, Grassi A, Marcheggiani Muccioli GM, Tsapralis K, Ricci M, Bragonzoni L, Della Villa S, Marcacci M.
Reference: Knee. 2014 Feb 14. pii: S0968-0160(14)00016-7. doi: 10.1016/j.knee.2014.02.005. [Epub ahead of print]
Summary: The purpose was to investigate time to return to sport and rate of professional sport activity in a homogenous group of competitive soccer players 4years after anterior cruciate ligament (ACL) reconstruction and rehabilitation. Twenty-one male professional soccer players (mean age 22.9±5.4years) underwent non-anatomical double-bundle autologous hamstring ACL reconstruction and followed the same rehabilitative protocol. Clinical evaluation was performed preoperatively and at 3, 6 and 12-month follow-up. Data regarding return to train and official match, sport activity, complications and revision surgeries were collected at 4-year follow-up. Laxity test (KT-2000) and total KOOS mean score resulted in a significant improvement from the preoperative status to the 12-month follow-up (p<0.0001). The KOOS mean value showed a significant progressive improvement from the preoperative status to 6-month follow-up (p=0.0010) as well, while values collected at 6 and 12-month follow-up were comparable (p=0.2349). Returned to official matches 186±53days after surgery. After 12months, 95% came back to the same activity level performed before injury. Four years after ACL reconstruction, 15 patients (71%) were still playing competitive soccer. One patient (5%) underwent ACL failure and subsequent revision. The ACL reconstruction with the presented technique followed by patient-tailored rehabilitation, allowed 95% and 62% professional male soccer players to return to the same sport activity 1year and 4years after surgery respectively. However, 71% were still able to play competitive soccer at final follow-up. Clinical scores were restored after 6months. Level of evidence: IV, case series.


#5 Discrepancy between Exercise Performance, Body Composition, and Sex Steroid Response after a Six-Week Detraining Period in Professional Soccer Players
Authors: Koundourakis NE, Androulakis NE, Malliaraki N, Tsatsanis C, Venihaki M, Margioris AN.
Reference: PLoS One. 2014 Feb 19;9(2):e87803. doi: 10.1371/journal.pone.0087803. eCollection 2014.
Download link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3929557/pdf/pone.0087803.pdf
Summary: The aim of this study was to examine the effects of a six-week off-season detraining period on exercise performance, body composition, and on circulating sex steroid levels in soccer players. Fifty-five professional male soccer players, members of two Greek Superleague Teams (Team A, n = 23; Team B, n = 22), participated in the study. The first two weeks of the detraining period the players abstained from any physical activity. The following four weeks, players performed low-intensity (50%-60% of VO2max) aerobic running of 20 to 30 minutes duration three times per week. Exercise performance testing, anthropometry, and blood sampling were performed before and after the six-week experimental period. Our data showed that in both teams A and B the six-week detraining period resulted in significant reductions in maximal oxygen consumption (60,31±2,52 vs 57,67±2,54; p<0.001, and 60,47±4,13 vs 58,30±3,88; p<0.001 respectively), squat-jump (39,70±3,32 vs 37,30±3,08; p<0.001, and 41,05±3,34 vs 38,18±3,03; p<0.001 respectively), and countermovement-jump (41,04±3,99 vs 39,13±3,26; p<0.001 and 42,82±3,60 vs 40,09±2,79; p<0.001 respectively), and significant increases in 10-meters sprint (1,74±0,063 vs 1,79±0,064; p<0.001, and 1,73±0,065 vs 1,78±0,072; p<0.001 respectively), 20-meters sprint (3,02±0,05 vs 3,06±0,06; p<0.001, and 3,01±0,066 vs 3,06±0,063; p<0.001 respectively), body fat percentage (Team A; p<0.001, Team B; p<0.001), and body weight (Team A; p<0.001, Team B; p<0.001). Neither team displayed any significant changes in the resting concentrations of total-testosterone, free-testosterone, dehydroepiandrosterone-sulfate, Δ4-androstenedione, estradiol, luteinizing hormone, follicle-stimulating hormone, and prolactin. Furthermore, sex steroids levels did not correlate with exercise performance parameters. Our results suggest that the six-week detraining period resulted in a rapid loss of exercise performance adaptations and optimal body composition status, but did not affect sex steroid resting levels. The insignificant changes in sex steroid concentration indicate that these hormones were a non-contributing parameter for the observed negative effects of detraining on exercise performance and body composition.


#6 Detraining in young soccer players
Authors: Melchiorri G, Ronconi M, Triossi T, Viero V, De Sanctis D, Tancredi V, Salvati A, Padua E, Alvero Cruz JR.
Reference: J Sports Med Phys Fitness. 2014 Feb;54(1):27-33.
Summary: Two types of detraining can be described: short-term detraining with a period of less than 4 weeks, and long-term detraining (period longer than 4 weeks). The purpose of this study is to verify the presence and eventually the magnitude of physiological cardiorespiratory changes in young team sport players after a period of long-term detraining. Fourteen young soccer players (15±1 year) were studied with two incremental tests at the end of the regular season and after a six-week total break period from training activities. Physiological variables were evaluated: heart rate (HR), oxygen uptake (VO2), volume of ventilation (VE), aerobic (VA) and anaerobic (Van) running speed at thresholds and maximum effort were recorded. This study shows the magnitude of the physiological changes in young players after a period of long-term detraining. The results showed significant decreases at the end of the detraining period of VO2 at VA of 22.7% (44.54±4.56 vs. 34.41±4.57 mL/kg/min, P<0.05), of 25.8% of VO2 at VAn (54.60±5.81 vs. 40.48±5.07 mL/kg/min, P<0.05) and of 21.2% in VO2max (62.83±5.77 vs. 49.46±6.51 mL/kg/min, P<0.05). Speed at VA (11.5±0.96 vs. 10.7±0.97 km/h; P<0.05), speed at VAn (15.3±1.05 vs. 14.2±1.48 km/h; P<0.05), peak running speed (18.8±1.20 vs. 17.2±1.1 km/h; P<0.05). It is likely that alteration of metabolic parameters may significantly affect the range of physical condition and especially, aerobic-anaerobic resistance and maintenance training would be advisable in young athletes during the transition period. Given the relevance of worsening demonstrated by our data, coaches should avoid very long periods of complete rest (no more than 15 days) at the end of the season.


#7 A Cam Deformity Is Gradually Acquired During Skeletal Maturation in Adolescent and Young Male Soccer Players: A Prospective Study With Minimum 2-Year Follow-up
Authors: Agricola R, Heijboer MP, Ginai AZ, Roels P, Zadpoor AA, Verhaar JA, Weinans H, Waarsing JH.

Reference: Am J Sports Med. 2014 Feb 28. [Epub ahead of print]
Summary: A cam deformity is a major risk factor for hip osteoarthritis, and its formation is thought to be influenced by high-impact sporting activities during growth. The purpose was (1) prospectively study whether a cam deformity can evolve over time in adolescents and whether its formation only occurs during skeletal maturation and (2) examine whether clinical or radiographic features can predict the formation of a cam deformity. Preprofessional soccer players (N = 63; mean age, 14.43 years; range, 12-19 years) participated both at baseline and follow-up (mean follow-up, 2.4 ± 0.06 years). At both time points, standardized anteroposterior and frog-leg lateral radiographs were obtained. For each hip, the α angle was measured, and the anterosuperior head-neck junction was classified by a 3-point visual system as normal, flattened, or having a prominence. Differences between baseline and follow-up values for the α angle and the prevalence of each visual hip classification were calculated. Additionally, the amount of internal hip rotation, growth plate extension into the neck, and neck shaft angle were determined. Overall, there was a significant increase in the prevalence of a cam deformity during follow-up. In boys aged 12 and 13 years at baseline, the prevalence of a flattened head-neck junction increased significantly during follow-up (13.6% to 50.0%; P = .002). In all hips with an open growth plate at baseline, the prevalence of a prominence increased from 2.1% to 17.7% (P = .002). After closure of the proximal femoral growth plate, there was no significant increase in the prevalence or increase in severity of a cam deformity. The α angle increased significantly from 59.4° at baseline to 61.3° at follow-up (P = .018). The amount of growth plate extension was significantly associated with the α angle and hip classification (P = .001). A small neck shaft angle and limited internal rotation were associated with cam deformities and could also significantly predict the formation of cam deformities (α angle >60°) at follow-up. In youth soccer players, cam deformities gradually develop during skeletal maturation and are probably stable from the time of growth plate closure. The formation of a cam deformity might be prevented by adjusting athletic activities during a small period of skeletal growth, which will have a major effect on the prevalence of hip osteoarthritis.


#8 The perceptions of professional soccer players on the risk of injury from competition and training on natural grass and 3rd generation artificial turf
Authors: Poulos CC, Gallucci J Jr, Gage WH, Baker J, Buitrago S, Macpherson AK.
Reference: BMC Sports Sci Med Rehabil. 2014 Mar 1;6(1):11. doi: 10.1186/2052-1847-6-11.
Summary: The purpose of this study was to describe professional soccer players' perceptions towards injuries, physical recovery and the effect of surface related factors on injury resulting from soccer participation on 3rd generation artificial turf (FT) compared to natural grass (NG). Information was collected through a questionnaire that was completed by 99 professional soccer players from 6 teams competing in Major League Soccer (MLS) during the 2011 season. The majority (93% and 95%) of the players reported that playing surface type and quality influenced the risk of sustaining an injury. Players believed that playing and training on FT increased the risk of sustaining a non-contact injury as opposed to a contact injury. The players identified three surface related risk factors on FT, which they related to injuries and greater recovery times: 1) Greater surface stiffness 2) Greater surface friction 3) Larger metabolic cost to playing on artificial grounds. Overall, 94% of the players chose FT as the surface most likely to increase the risk of sustaining an injury. Players believe that the risk of injury differs according to surface type, and that FT is associated with an increased risk of non-contact injury. Future studies should be designed prospectively to systematically track the perceptions of groups of professional players training and competing on FT and NG.


#9 Alteration of immune function in women collegiate soccer players and college students
Authors: Putlur P, Foster C, Miskowski JA, Kane MK, Burton SE, Scheett TP, McGuigan MR.
Reference: J Sports Sci Med. 2004 Dec 1;3(4):234-43. eCollection 2004.
Summary: The purpose of this study was to monitor the stress-induced alteration in concentrations of salivary immunoglobulin (S-IgA) and cortisol and the incidence of upper respiratory tract infections (URTI) over the course of a 9-week competitive season in college student-athletes and college students. The subjects consisted of 14 NCAA Division III collegiate female soccer athletes (19.8 ± 1.0 years, mean ± SD) and 14 female college students (22.5 ± 2.6 years). Salivary samples were collected for 9 weeks during a competitive soccer season. S-IgA and cortisol concentrations were determined by enzyme linked immunosorbent assay (ELISA). A training and performance questionnaire was given to the subjects every week, to record the subjects' session rating of perceived exertion (RPE) for all the training, load, monotony and strain, as well as any injuries or illnesses experienced. The between groups ANOVA procedure for repeated measures showed no changes in salivary concentrations of IgA and cortisol. Chi-square analysis showed that during the 9-week training season injury and illness occurred at a higher rate among the soccer players. There was a significant difference at baseline between soccer and control S-IgA levels (p≤0.05). Decreased levels of S-IgA and increases in the indices of training (load, strain and monotony) were associated with an increase in the incidence of illness during the 9-week competitive soccer season. Key PointsThere was a significant difference at baseline between soccer and control S-IgA levelsEighty-two percent of illnesses could be explained by a preceding decrease in S-IgA.Increases in the indices of training (load, strain and monotony) were associated with an increase in the incidence of illness.


#10 Alteration of immune function in women collegiate soccer players and college students
Authors: Putlur P, Foster C, Miskowski JA, Kane MK, Burton SE, Scheett TP, McGuigan MR.
Reference: J Sports Sci Med. 2004 Dec 1;3(4):234-43. eCollection 2004.
Summary: The purpose of this study was to monitor the stress-induced alteration in concentrations of salivary immunoglobulin (S-IgA) and cortisol and the incidence of upper respiratory tract infections (URTI) over the course of a 9-week competitive season in college student-athletes and college students. The subjects consisted of 14 NCAA Division III collegiate female soccer athletes (19.8 ± 1.0 years, mean ± SD) and 14 female college students (22.5 ± 2.6 years). Salivary samples were collected for 9 weeks during a competitive soccer season. S-IgA and cortisol concentrations were determined by enzyme linked immunosorbent assay (ELISA). A training and performance questionnaire was given to the subjects every week, to record the subjects' session rating of perceived exertion (RPE) for all the training, load, monotony and strain, as well as any injuries or illnesses experienced. The between groups ANOVA procedure for repeated measures showed no changes in salivary concentrations of IgA and cortisol. Chi-square analysis showed that during the 9-week training season injury and illness occurred at a higher rate among the soccer players. There was a significant difference at baseline between soccer and control S-IgA levels (p≤0.05). Decreased levels of S-IgA and increases in the indices of training (load, strain and monotony) were associated with an increase in the incidence of illness during the 9-week competitive soccer season. Key PointsThere was a significant difference at baseline between soccer and control S-IgA levelsEighty-two percent of illnesses could be explained by a preceding decrease in S-IgA.Increases in the indices of training (load, strain and monotony) were associated with an increase in the incidence of illness.


#11 The efficacy of the fifa 11+ program in the collegiate male soccer player (USA)
Authors: Silvers H, Mandelbaum B, Bizzini M, Dvorak J.
Reference: Br J Sports Med. 2014 Apr;48(7):662. doi: 10.1136/bjsports-2014-093494.272.
Summary: Can the FIFA 11+ effectively reduce injury in the competitive male soccer player?
Prospective randomized controlled trial conducted in the NCAA. Every institution (N=411) was contacted via a formal letter, email and phone call. Sixty-one institutions consented to participate. Human ethics approval was acquired through Quorum IRB, Seattle, WA, USA. The intervention group received an instructional DVD, manual and placards. A injury surveillance database was utilized (HealtheAthlete(TM), Kansas) for data collection. Every exposure, injury, and compliance data was entered weekly. 61 institutions completed the study: 34 control (N=850 athletes) and 27 intervention (N=675 athletes). The FIFA 11+ injury prevention program served as the intervention program. It was utilized three times per week for the duration of the season. Specific injuries, athletic exposures, program compliance and time loss were recorded.In the intervention Group (IG), 285 injuries were reported (mean=10.56 injuries/team+/- 3.64) compared to 665 injuries (mean=20.15 +/- 11.01) in the control group (CG). The number of athletic exposures was 35,226 (Games: 10 935 AE, Practice: 24 291AE) for the IG and 44 212 (Games: 13 624 AE, Practice: 30 588 AE) in the CG). The incidence rate (IR) was 8.09/1000 AE (95% CI) in the IG compared to 15.04/1000 AE (95% CI) in the CG (P=.00117). Total days missed due to injury was 2 824 (mean=9.94) in the IG compared to 8776 days (mean=13.20) in the CG. The FIFA 11+ was shown to reduce injury rates and time loss in the male collegiate soccer player in a statistically significant manner.


#12 Lower limb functional asymmetries in young soccer players: do differences exist between different age groups?
Authors: Sannicandro I, Quarto A, Piccinno A, Cofano G, Rosa R.
Reference: Br J Sports Med. 2014 Apr;48(7):657. doi: 10.1136/bjsports-2014-093494.260.
Summary: Functional asymmetries of the lower limbs(FA) have been recognised as a potential source of injury risk of in soccer players;moreover a difference in strength performance between the lower limbs exceeding 15% is considered an injury risk factor. Preventative strategies should be integrated into young football player training regimes. Table 1.Young soccer players: mean age 9.1±0.1 years. n.athletes>15%Total%>15%% othersHop2522711,288,8Triple192278,491,6Side3322714,585,5 Table 2.Young soccer players: mean age 11.2±0.1 years *p>0.05. n.athletes>15%Total%>15%% othersHop2720013,786,3Triple162008,391,7Side3720018,581,5 OBJECTIVE: To assess the presence of FA in the lower limbs and evaluate whether the percentage of subjects presenting asymmetries exceeding 15% increases with age. 427 young soccer players: 9.1±0.1 years, 36.3±6.5 kg, 137.9±7.1cm (n=227) and 11.2±0.1 yrs, 43.8±9.7 kg, 148.9±9.1 cm (n=200) participated in this stud. Monopodalic jump were used as asymmetry measurement; all three versions were employed: Single (SI), Triple (TR) and Side hop(SE) is considered a valid indicator of FA in the lower limbs. Strength in each of the lower limbs was assessed by means of the SI, TR and SE test; the percentage of FA between the lower limbs was calculated using the formula proposed by Yamamoto, 1993: (jump dominant-limb-jump non-dominant limb)/jump dominant-limb*100.  The highest percentage of subjects presenting asymmetries was detected in the 11yr-olds. Comparing the results for the two age groups revealed a statistically significant difference for the SideHop test.


#13 Explosive strength capacity in the lower limbs and speed performance in young soccer players
Authors: Sannicandro I, Piccinno A, Cofano G, Lupelli N, Rosa R.
Reference: Br J Sports Med. 2014 Apr;48(7):656-7. doi: 10.1136/bjsports-2014-093494.259.
Summary: The explosive strength capacity of each limb influences acceleration capacity in soccer players. The purpose was to investigate whether a relationship exists between the individual strength capacities of the lower limbs and performances in sprinting in a straight line and with a change of direction(CoD) in young soccer players. 205 young soccer players (11.3±0.2 yrs, 180.1±2.6 cm, 78.5±2.2 kg) participated in the study. All subjects performed the Hop test (HT), the Triple hop test (THT) and the Side hop test (SHT) (testing strength capacity); the 5m and 10m sprint test, the Foran test, and the 10×5m shuttle sprint test (tests to assess sprinting capacity in a straight line and with CoD) were executed using a photocell. The correlation between the results of the three strength tests and sprinting performance was assessed.  The results show that the athletes with high values of lower limb strength as assessed using the HT obtain significantly better performances in a straight line sprinting. However, the correlation coefficients indicate that the strength of the relationship is only moderate: 0.35 to 0.44 for performances in the HTvs sprinting in a straight line; and 0.12 to 0.26 for performances in the SHTvs sprinting with a CoD.


#14 The effect of exposure to the fifa 11+ warm-up program on injury risk knowledge and prevention beliefs in elite female youth soccer
Authors: McKay C, Steffen K, Romiti M, Finch C, Emery C.
Reference: Br J Sports Med. 2014 Apr;48(7):637. doi: 10.1136/bjsports-2014-093494.207.
Summary: Injury knowledge and beliefs influence uptake of injury prevention programs. The effect of exposure to prevention programs on knowledge and beliefs is not well understood. The purpose was to explore the effect of exposure to the FIFA 11+ program on the injury knowledge and beliefs of female youth soccer coaches and players. 31 female teams [coaches n=29, players (ages 13-18) n=258] participated in the study. Teams recorded FIFA 11+ adherence during the season and the main outcome measurements were pre-season and post-season questionnaires to assess changes in injury knowledge and prevention beliefs after FIFA 11+ exposure completed by coaches and players. At baseline, 62.8% (95% CI: 48.4-77.3) of coaches and 75.8% (95% CI: 71.5-80.1) of players considered "inadequate warm-up" a risk factor for injury. There was no effect of 11+ adherence on this belief (odds ratio=1.0; 95% CI: 0.9-1.1), although more players (78.7%; 95% CI: 73.77-83.7) than coaches (51.7%; 95% CI: 33.55-69.9) considered "inadequate warm-up" a risk factor at post-season. At baseline, 13.8% (95% CI: 1.3-26.4) of coaches believed a warm-up could prevent muscle injuries, but none believed it could prevent knee and ankle injuries. For players, 9.7% (95% CI: 6.1-13.3), 4.7% (95% CI: 2.1-7.3), and 4.7% (95% CI: 2.1-7.3) believed a warm-up would prevent muscle, knee, and ankle injuies, respectively. There was no effect of adherence on post-season beliefs that a warm-up could prevent an injury, for coaches or players. Exposure to the FIFA 11+ appears insufficient for changing injury risk or prevention beliefs over a single season. This could have implications for program delivery strategies and may influence sustained program use.


#15 Using the health action process approach (hapa) model to predict adherence to the fifa 11+ program in elite female youth soccer
Authors: McKay C, Meeuwisse W, Emery C.
Reference: Br J Sports Med. 2014 Apr;48(7):636. doi: 10.1136/bjsports-2014-093494.206.
Summary: The FIFA 11+ warm-up program can significantly reduce injury risk in youth soccer, but community uptake of the program has been suboptimal. A health behaviour theory, the Health Action Process Approach (HAPA) model, may identify predictors of program uptake that can inform targeted promotion strategies. The purpose was to determine whether HAPA constructs (risk perceptions, outcome expectancies, self-efficacy, action and coping plans, facilitators and barriers) predict uptake intention and adherence to the FIFA 11+ in elite female youth soccer. Elite (Tier 1 and 2) female soccer teams (ages 12-16) competing in Calgary, Canada participated in the study. 12 teams (coaches n=12, players n=200) who were randomly recruited prior to the 2013 season as wave 1 of the larger trial were assessed. Participants completed a baseline questionnaire assessing risk perceptions, outcome expectancies and self-efficacy associated with the FIFA 11+, and barriers/facilitators to program use.
Intention to follow the FIFA 11+ (from the HAPA questionnaire) and prospectively reported adherence during the season were used as main outcome measures. Preliminary analyses demonstrate that for coaches, risk perceptions, outcome expectancies, and task self-efficacy accounted for 92.7% of uptake intention variance [F(3,3)=12.71, P=.0327, R(2)=0.9271]. The most commonly identified facilitator was access to FIFA 11+ materials (videos, manuals). The largest barrier was not having enough time to complete the program. For players, the HAPA model accounted for only 41.4% of intention variance [F(7, 154)=15.53, P<.001, R(2)=0.4139]. Identified facilitators included having adequate time, personal effort, and enjoying the program. Barriers included poor team leadership, uncooperative teammates, and lack of time. Relationships between HAPA constructs and adherence will also be presented. The HAPA model appears to strongly predict coach, but not player, intentions to uptake the FIFA 11+. The development of role-targeted promotion strategies may improve program uptake.


#16 The preventive effect of the nordic hamstring exercise on hamstring injuries in amateur soccer players: a randomized controlled trial
Authors: van der Horst N, Wouter Smits D, Petersen J, Goedhart E, Backx F.
Reference: Br J Sports Med. 2014 Apr;48(7):609-10. doi: 10.1136/bjsports-2014-093494.135.
Summary: Hamstring injuries are the most common muscle injuries in male amateur soccer. Eccentric strength of the hamstrings is recognized as an important modifiable risk factor, leading to the development of preventive exercises such as the Nordic Hamstring Exercise. This study aims to investigate the preventive effect of the Nordic Hamstring Exercise on the incidence and severity of hamstring injuries in male amateur soccer players. Dutch first class amateur field soccer including male amateur soccer players (mean age 24.5 years, SD 3.8 years) from 40 teams were allocated to intervention (n=309 players) or control group (n=310 players). The intervention group was instructed to perform 25 sessions of the Nordic Hamstring Exercise within a period of 13 weeks during the first months of 2013. Both the intervention group and control group performed regular soccer training and were followed for hamstring injury incidence and severity during the calendar year 2013. At baseline, personal characteristics (e.g. age, injury history, field position) were gathered from all participants via.
Primary outcomes are initial and recurrent hamstring injury incidence (number of hamstring injuries) and injury severity (number of days injured). Interim analysis after intervention (2 months follow-up) show a total of 2 hamstring injuries in intervention group vs 12 hamstring injuries in control group (χ(2)=7.5, P<.05). Regarding injury severity, no difference was found between intervention and control group (t=0.3, P=.77). Preliminary analyses during the summer break show substantial hamstring injury incidence reduction by incorporating the Nordic Hamstring Exercise in regular training. With a total follow-up of 9 months, final analyses (survival analyses including the number of injuries per 1000 playing hours) will be performed in January 2014.