Does BMI Affect Injury Incidence?

World Aquatics Championships - Women 3m Synchronised - Finals - OCBC Aquatic Centre, Singapore - July 29, 2025 Italy’s Elisa Pizzini and Chiara Pellacani in action REUTERS/Hollie Adams.

Practitioners use the Body Mass Index (BMI) to classify individuals according to their body weight relative to height⁽¹⁾. However, debate remains regarding the influence of BMI on musculoskeletal (MSK) injuries in both the general population and athletes. A higher BMI, often associated with obesity, is thought to contribute to an increased injury risk due to increased mechanical load, altered biomechanics, and chronic inflammation⁽²⁾. However, evidence is mixed, with some studies demonstrating strong correlations and others suggesting minimal or non-significant associations. 

BMI and MSK Injuries

Musculoskeletal injuries include damage to bones, joints, ligaments, tendons, muscles, and nerves⁽¹⁾. Researchers at the King Saud Bin Abdulaziz University for Health Sciences College of Medicine in Saudia Arabia found that while a higher BMI is generally associated with an increased risk of injury, the specific site of injury is not influenced by BMI. Their study emphasized that age and gender are more predictive of injury location, particularly showing that younger individuals (≤35 years) are more prone to upper extremity injuries due to increased participation in sports activities compared to their older counterparts⁽¹⁾.

Interestingly, the researchers found that individuals with higher BMI, particularly those categorized as obese (BMI > 35) are three times more likely to sustain MSK injuries compared to individuals with lower BMI⁽¹⁾. However, despite this elevated risk, the researchers concluded that the anatomical location of injury (e.g., lower back vs. lower extremities) did not differ significantly across BMI categories, challenging the assumption that body composition uniformly dictates injury type or site⁽¹⁾.

“…debate remains regarding the influence of BMI on musculoskeletal injuries in both the general population and athletes.”

BMI and Chronic Back Pain

Another dimension of injury related to BMI is chronic pain and disability, particularly in the lower back. Researchers from Monash University in Australia showed a clear link between increases in BMI over five years and high-intensity back pain and disability ten years later. Specifically, a one-unit increase in BMI, equivalent to a 3.1 kg weight gain, increased the odds of high-disability outcomes by 63% in older adults aged 60 years or older⁽²⁾.

Lean mass (LM) plays a protective role in preventing high-intensity pain, suggesting that muscle composition, rather than body weight alone, plays a crucial role in injury prevention⁽²⁾. The researchers propose that increased mechanical loading and reduced neuromuscular adaptation in obese individuals exacerbate spinal stress and accelerate tissue degeneration⁽²⁾.

Sport-Specific

In elite sports contexts, practitioners scrutinize BMI as both a risk and protective factor. Researchers from Liverpool Football Club aimed to identify the correlation between preseason body composition and injury burden throughout the season in their elite cohort. They found a weak but notable association between injury burden and preseason body composition variables, such as BMI and waist circumference⁽³⁾. Although these correlations were statistically non-significant, they suggest that players with lower BMI, waist circumference, and bone mineral density (BMD) may be more prone to longer injury recovery periods⁽³⁾. On the other hand, collegiate ice hockey players with a BMI ≥25 have over twice the odds of injury compared to their peers with a BMI <25, highlighting a potential dose-response relationship⁽⁴⁾. 

Obese adolescents have a 34% higher risk of sport-related injuries compared to healthy-weight peers⁽⁵⁾. These injuries were particularly common in the lower extremities, including the knees and ankles, likely due to increased soft tissue loading and joint stress⁽⁵⁾. However, Canadian researchers found that overweight or obese active adolescents do not appear to be at increased risk of sports injury⁽⁶⁾. The decreased odds among obese adolescents may be due to differences in the intensity of sport participation or the type of sporting activity⁽⁶⁾.