Minor leg injuries like ankle sprains and muscle ruptures may increase the risk of blood clots in the legs or lungs.
Previous studies revealed that major injuries increased the risk for venous thrombosis. The disorder included deep vein thrombosis, or blood clots in the leg, and pulmonary embolism, or a blood clot that has travelled to the lungs.
"However, apart from the injury itself, other risk factors for venous thrombosis will be present because of the major injury, such as surgery, a plaster cast, hospitalization and extended bed rest," the authors write.
"The risk of so-called minor injuries that do not lead to these additional factors is unknown."
A study led by Karlijn J. van Stralen at Leiden University Medical Centre, Leiden, the Netherlands, examined 2,471 patients who developed venous thrombosis between 1999 and 2004.
They were asked to complete a questionnaire about any injuries, surgical procedures, plaster casts or immobilizations they had within one year of developing blood clots, as well as their height, weight, family history and sports participation.
The patients were then compared to 3,534 controls that did not have venous thrombosis.
A total of 289 patients had a minor injury in the three months prior to developing venous thrombosis, while 154 controls had a minor injury in the three months before completing the questionnaire.
"Minor injuries that do not require surgery, a plaster cast or extended bed rest were associated with a three-fold greater relative risk of venous thrombosis," wrote authors.
"The association appeared local because injuries in the leg were associated strongly with thrombosis, while injuries in other locations were not associated with thrombosis. The association was strongest for injuries that occurred in the month before the venous thrombosis, suggesting a transient effect," they added.
According to the authors, because minor injuries are common, they can be major contributors to the occurrence of venous thrombosis
"Many individuals with minor injuries will have contacted the general practitioner first. Therefore, there may be an important task for general practitioners to identify subjects who are at high risk of developing venous thrombosis and subsequently to provide prophylactic measures," they concluded.
The report appears in Archives of Internal Medicine, a JAMA journal.