Footwear traction and lower extremity non-contact injury

Abstract

For the past forty years footwear traction has been thought to be one of the causes of noncontact lower extremity injury in sport. Previous studies have shown that rotational traction was associated with ACL injury, however, no studies have determined the relationship between footwear traction, both translational and rotational, and all lower extremity non-contact injuries. Therefore, the purposes of this thesis were to 1) determine if a relationship exists between an athlete's specific footwear traction (both translational and rotational) and lower extremity non-contact injury and 2) determine how independently altering translational and rotational traction affects ankle and knee joint loading.Over the course of three years, 555 athletes had their footwear traction tested on the actual playing surface; either an artificial or natural grass field. The athletes were followed over each season and any injury that they sustained during a game was recorded by certified athletic therapists on site at the field.No differences in injury rate were seen between the artificial and natural grass surfaces.A relationship was found between rotational traction and lower extremity non-contact injury, with increases in rotational traction leading to an increase in injury rate. A relationship was also seen between translational traction and injury with the mid-range of translational traction leading to a higher injury rate. PrefaceThe following three chapters are based on scientific manuscripts:

The effect of translational and rotational traction on lower extremity joint loading

“…Increases in translational traction do increase joint loading for certain movements, which could lead to an increase in injury risk. However, the injury study showed that after a certain value, further increases in translational traction were associated with a drop off in the injury rate (Wannop et al, 2013). The results of the current study cannot explain the drop in injury rate with increasing translational traction, but the results do provide support to the fact that translational traction can influence joint loading and potentially joint injury.…”

“…Additionally, these studies did not speculate why or how rotational traction may affect injuries. The results from Wannop et al (2013) indicate that not only rotational traction but also translational traction can have an effect on lower extremity non-contact injuries. This study revealed that the individual components of both rotational traction as well as translational traction can influence joint loading, indicating that both components are important when related to injury risk.…”

“…Relating back to the injury study of Wannop et al (2013), the injury results showed that increases in rotational traction Table III. Mean (standard deviation of the difference from the control) ground reaction force and joint moment/impulse data during the s-cut movement in the low rotation, control and high rotation shoes.…”

“…A landmark study by Lambson et al (1996) indicated that footwear that had significantly greater rotational traction were associated with significantly higher anterior cruciate ligament injury rates in grid-iron football. In addition, Wannop, Luo, and Stefanyshyn (2013) indicated that significant increases in rotational traction lead to a significantly greater number and rate of non-contact lower extremity injuries in high school grid-iron football players; however, a relationship was also present between translational traction and injury, which has not been investigated previously. The majority of past studies have focussed solely on rotational traction and how it relates to injury without taking into account translational traction (Lambson et al, 1996;Torg et al, 1974).…”

“…The majority of past studies have focussed solely on rotational traction and how it relates to injury without taking into account translational traction (Lambson et al, 1996;Torg et al, 1974). Based on the results of Wannop et al (2013) translational traction is associated with injury and should not be ignored.…”