Friday, September 7, 2012

Low injury rate correlates with team success-Recent studies in football (part I)

Abstracts modified from PubMed
Eirale C, Tol JL, Farooq A, Smiley F, Chalabi H. Low injury rate strongly correlates with team success in Qatari professional football. Br J Sports Med. 2012 Aug 17. [Epub ahead of print]

Department of Sports Medicine, Aspetar-Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Using a prospective cohort study design, this study captured exposure and injuries in Qatar male elite football for a season. Club performance was measured by total league points, ranking, goal scored, goals conceded and number of matches won, drawn or lost. Lower injury incidence was strongly correlated with team ranking position (r=0.929, p=0.003), more games won (r=0.883, p=0.008), more goals scored (r=0.893, p=0.007), greater goal difference (r=0.821, p=0.003) and total points (r=0.929, p=0.003).
CONCLUSIONS: Lower incidence rate was strongly correlated with team success. Prevention of injuries may contribute to team success.

Dallinga JM, Benjaminse A, Lemmink KA. Which screening tools can predict injury to the lower extremities in team sports?: a systematic review. Sports Med. 2012 Sep 1;42(9):791-815

Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
The aim of this article is to determine the predictive values of anthropometric and/or physical screening tests for injuries to the leg, anterior cruciate ligament (ACL), knee, hamstring, groin and ankle in team sports. The analysis showed that different screening tools can be predictive for injuries to the knee, ACL, hamstring, groin and ankle. For injuries in general there is some support in the literature to suggest that general joint laxity is a predictive measure for leg injuries. The anterior right/left reach distance >4 cm and the composite reach distance <4.0% of limb length in girls measured with the star excursion balance test (SEBT) may predict leg injuries. Furthermore, an increasing age, a lower hamstring/quadriceps (H : Q) ratio and a decreased range of motion (ROM) of hip abduction may predict the occurrence of leg injuries. Hyperextension of the knee, side-to-side differences in anterior-posterior knee laxity and differences in knee abduction moment between both legs are suggested to be predictive tests for sustaining an ACL injury and height was a predictive screening tool for knee ligament injuries. There is some evidence that when age increases, the probability of sustaining a hamstring injury increases. Debate exists in the analysed literature regarding measurement of the flexibility of the hamstring as a predictive screening tool, as well as using the H : Q ratio. Hip-adduction-to-abduction strength is a predictive test for hip adductor muscle strain. Studies do not agree on whether ROM of the hamstring is a predictive screening tool for groin injury. Body mass index and the age of an athlete could contribute to an ankle sprain. There is support in the literature to suggest that greater strength of the plantar flexors may be a predictive measure for sustaining an ankle injury. Furthermore, there is some agreement that the measurement of postural sway is a predictive test for an ankle injury.
Conclusions: The screening tools mentioned above can be recommended to medical staff and coaches for screening their athletes. Future research should focus on prospective studies in larger groups and should follow athletes over several seasons.

Wilkerson GB, Giles JL, Seibel DK. Prediction of core and lower extremity strains and sprains in collegiate football players: a preliminary study. J Athl Train. 2012;47(3):264-72.

Graduate Athletic Training Education Program, University of Tennessee at Chattanooga, USA.
Poor core stability is believed to increase vulnerability to uncontrolled joint displacements throughout the kinetic chain between the foot and the lumbar spine. All team members (National Collegiate Athletic Association Division I Football Championship Subdivision football program ) who were present for a mandatory physical examination on the day before preseason practice sessions began (n = 83). Preparticipation administration of surveys to assess low back, knee, and ankle function; documentation of knee and ankle injury history; determination of body mass index; 4 different assessments of core muscle endurance; and measurement of step-test recovery heart rate. All injuries were documented throughout the preseason practice period and 11-game season. Receiver operating characteristic analysis and logistic regression analysis were used to identify dichotomized predictive factors that best discriminated injured from uninjured status. The 75th and 50th percentiles were evaluated as alternative cutpoints for dichotomization of injury predictors. Players with ≥2 of 3 potentially modifiable risk factors related to core function had 2 times greater risk for injury than those with <2 factors (95% confidence interval = 1.27, 4.22), and adding a high level of exposure to game conditions increased the injury risk to 3 times greater (95% confidence interval = 1.95, 4.98). Prediction models that used the 75th and 50th percentile cutpoints yielded results that were very similar to those for the model that used receiver operating characteristic-derived cutpoints.
CONCLUSIONS: Low back dysfunction and suboptimal endurance of the core musculature appear to be important modifiable football injury risk factors that can be identified on preparticipation screening. These predictors need to be assessed in a prospective manner with a larger sample of collegiate football players.

Mills A, Butt J, Maynard I, Harwood C. Identifying factors perceived to influence the development of elite youth football academy players. J Sports Sci. 2012 Aug 13. [Epub ahead of print]

Centre for Sport and Exercise Science, Sheffield Hallam University , UK.

Based on the developmental theory presented by Gagné (2009), we examined the factors perceived to influence the development of elite youth football players at a critical stage in their progression to the professional level. Transcribed interviews with ten expert development coaches were inductively and deductively content analysed. Conceptualisation of the data revealed six interrelated higher-order categories that represented the factors perceived to either positively or negatively influence player development. These were: awareness (e.g. self-awareness, awareness of others); resilience (e.g. coping with setbacks, optimistic attitude); goal-directed attributes (e.g. passion, professional attitude); intelligence (e.g. sport intelligence, emotional competence); sport-specific attributes (e.g. coachability, competitiveness); and environmental factors (e.g. significant others, culture of game). In this investigation, awareness emerged as a fundamental and mediating element for understanding how young players are able to transition to the professional level.
Conclusions: The findings underline the multidimensional nature of talent development and suggest that an intricate combination of stage-specific factors must manifest for gifted young players to translate their potential into excellence. Mechanisms by which academies could be helped to shape the characteristics and conditions associated with effective development are discussed.

Aguiar M, Botelho G, Gonçalves B, Sampaio J. Physiological responses and activity profiles of football small-sided games. J Strength Cond Res. 2012 Jul 18. [Epub ahead of print]

Research Center for Sport Sciences, Health and Human Development, University of Trás-os-Montes e Alto Douro and CERNAS Research Unit, Coimbra College of Agriculture, Polytechnic Institute of Coimbra, Bencanta, Portugal
The aim of this study was to identify the acute physiological responses and activity profiles of football small-sided games (SSG) formats. Ten professional football players participated in four variations of SSG (2-, 3-, 4- and 5-a-side) with an intermittent regime involving 3 × 6 minute bouts with 1 minute of passive planned rest in which the heart rate (30), rating of perceived exertion (40), activity profile and body load were recorded. The higher % HRmax values were found in 2- and 3-a-side formats (p ≤ 0.05). The lowest RPE value was found at the 5-a-side and the highest was found at the 2-a-side (13.48 ± 2.67 and 17.01 ± 1.80, respectively, p ≤ 0.05). The distance covered in the 2-a-side format (598.97 ± 78.91 m) was smaller than in all other formats. The 2-a-side format presented the lowest number of sprints (0.71 ± 0.86) and the 3-a-side the highest (2.50 ± 1.65). Statistically significant differences were found across SSG in the total body load. The 4-a-side presented the highest and the 5-a-side the lowest values (95.18 ± 17.54 and 86.43 ± 14.47, respectively). The body load per minute declined each 2 minutes of play.
Conclusions: Maintaining a constant area:player ratio, coaches can use lower number of players (2- and 3-a-side) to increase cardiovascular effects, but use higher number of players (4- and 5-a-side) to increase variability and specificity according to the competition demands.

1 comment:

Meniscus surgery said...

There is some evidence that when age increases, the probability of sustaining a hamstring injury increases. Debate exists in the analysed literature regarding measurement of the flexibility of the hamstring as a predictive screening tool,