Injury Patterns in Overweight and Obese High School Athletes

In case readers are wondering whether the term “obese athlete” is an oxymoron, it is not: from my own practice I know that there are a number of high-performance athletes out there, who can have significant weight-related health problems including obstructive sleep apnea, hypertension and fatty liver disease. But that is NOT the topic of this post!

This post is about the findings of Ellen Yard and Dawn Comstock from the Centre for Injury Research and Policy, Columbus, Ohio, just published in the Journal of Physical Activity and Health, regarding the the relationship between injury pattern and BMI in US high school athletes.

This question is of considerable interest, as the authors note that about one-third of the over 7 million US high school athletes meet the BMI criteria for overweight or obesity.

The researchers analysed data from 100 nationally representative US high schools, which submitted athlete exposure (AE) and injury information during the 2005 to 08 school years via High School RIO (Reporting Information Online).

A total of 13,881 injuries during 5,627,921 athlete-exposures (2.47 injuries per 1000 AE) were reported, representing an estimated 4,339,247 injuries sustained nationally during the 2005–08 school years, for an average of 1,446,416 injuries sustained annually.

Injury rates were higher in competition (4.65 per 1000 AE) compared with practice (1.65 per 1000 AE).

Injury rates were highest in football (4.32 per 1000 AE), wrestling (2.43 per 1000 AE) and girls’ soccer (2.40 per 1000 AE). Injury rates were lowest in baseball (1.13 per 1000 AE), softball (1.19 per 1000 AE), and volleyball (1.39 per 1000 AE).

Two-thirds (61.4%) of these injuries occurred in normal weight athletes, with the exception of football, where 54% of injured athletes were overweight or obese. Specifically, in football, the majority of injured defensive tackles (65.2%), offensive tackles (64.7%), centers (63.1%), and offensive guards (58.4%) were obese.

Sport-specific overweight and obesity prevalence was also high in wrestling (31.7%), baseball (28.6%), and boys’ basketball (19.3%). Conversely, injured girls’ soccer athletes were least likely to be overweight or obese (13.5%). Other sport-specific positions with large proportions of obese athletes included first basemen in baseball (20.5%) and softball (17.2%).

The most common injury diagnoses were incomplete ligament sprains (28.2%), incomplete muscle strains (14.0%), contusions (13.2%), fractures (9.8%), and concussions (9.2%), with one in twenty (5.9%) injured athletes requiring surgery.

Compared with normal weight athletes, obese athletes sustained a larger proportion of knee injuries and their injuries were more likely to have resulted from contact with another person.

Interestingly, compared with normal weight athletes, underweight athletes sustained a larger proportion of fractures and a larger proportion of injuries resulting from ‘illegal’ activity.

With regard to the high prevalence of obesity amongst football players, the authors note:

“Although the use of BMI instead of body fat percentage may have classified some very muscular football players as overweight or obese, these findings are consistent with the previously reported epidemic of overweight and obesity in football. Football culture not only accepts but often encourages large body size, particularly among offensive and defensive linemen.

These results point to important differences in the pattern of injuries incurred by heavier compared to normal or underweight athletes – some of which may be accounted for by the propensities of heavier athletes to participate in different types of sports than their leaner counterparts.

While this study does not support the notion that higher BMI athletes are at greater risk for injury (reported in previous studies), it may point to an increased risk in underweight athletes:

“With high school athletes being bigger and faster today than in previous years, collisions between mismatched athletes may be putting smaller, underweight athletes at greater risk for severe injury.”

What the paper does not discuss is the long-term risk of athletics for future weight gain, in overweight and obese athletes who retire due to injury or other life events. As blogged before, there seems to be no shortage of patients in my adult bariatric clinic, who report having been competitive athletes in younger years.

Edmonton, Alberta

Yard E, & Comstock D (2011). Injury Patterns by Body Mass Index in US High School Athletes. Journal of physical activity & health, 8 (2), 182-91 PMID: 21415445