Football is one of the most popular sports worldwide. Unfortunately, football players are highly exposed to injuries and muscle injuries are the most common ones. The aim was to study possible differences of muscle injuries regarding type, localization and the extent of injury between the dominant and non-dominant leg in elite male football players. Another aim was to study the injury incidence of muscle injuries of the lower extremity during match and training. Data were consecutively collected between 2007 and 2013 in a prospective cohort study based on fifty-four football players from one team of the Swedish first league. The injury incidence was calculated for both match and training and injuries to the hip adductors, quadriceps, hamstrings and triceps surae were diagnosed and evaluated with ultrasonography and their length, depth and width were measured to determine the extent of structural muscle injuries. Fifty-four players suffered totally 105 of the studied muscle injuries. Out of these 105 injuries the dominant leg was affected in 53% (n=56) of the cases. A greater extent of the injury was found in the dominant leg when compared to the non-dominant leg with regards to structural injuries of the hamstrings. No other significant differences were found. Structural hamstring muscle injuries were found to be of greater extent in the dominant leg when compared to the non-dominant leg. This new finding should be taken into consideration when allowing the football player to return to play after leg muscle injuries.

IV.

Injuries to the hamstring muscles are common in athletes. Track and field, Australian football, American football and soccer are examples of sports where hamstring injuries are the most common. The purpose of this study was to investigate whether there is a correlation between a hamstring injury prognosis and its characteristics of imaging parameters. The literature search was performed in the databases PubMed and CINAHL, and eleven articles were included. Seven out of the 11 articles showed a correlation between the size of the hamstring injury and length of time required before returning to sports. Different authors have reported contrasting results about length of time required before returning to sports due to location of injury within specific muscle. Majority of the articles found hamstring strain correlated to an extended amount of time required before returning to sports.

Context: The physical and mental demands of an elite football player are complex, which may explain why injuries are common in football. At elite level, muscle injuries of the lower-extremity are the most common among male football players, and the research hitherto is limited. Objective: To investigate whether personality traits affect the incidence of muscle injuries among male football players from the first league in Sweden. Design: Prospective cohort study. Participants: A male football team from the first league in Sweden was prospectively followed, in terms of muscle injuries of the lower-extremity during 8 seasons, between 2007 and 2015. Intervention: All muscle injuries included in this study were evaluated and diagnosed with ultrasonography. Players from the team filled out the Swedish Universities Scales of Personality questionnaire. Swedish Universities Scales of Personality questionnaire consists of 91 items and is divided into 13 categories. Main Outcome Measures: The raw values of each scale were linearly transformed to T scores, having a mean (SD) of 50 (10). All variables were summarized with standard descriptive statistics, such as frequency, mean, and SD. As data were of interval scale and no variable distribution was severely skewed, differences between noninjured players, rarely injured players, and frequently injured players were analyzed with 1-way analysis of variance with post hoc tests by Tukey honestly significant difference test. Results: No significant difference in personality traits were observed between noninjured players, rarely injured players, and frequently injured players regarding number of muscle injuries (P > .05). However, a trend (P = .07) was seen, where frequently injured players scored higher on stress susceptibility than rarely injured players. Conclusion: A player’s stress susceptibility should be taken into consideration by the player, coaches, and medical staff when assessing the risk of a muscle injury. Also, preventive measures available for these players may need to be considered.