Toe in or toe out ... what's the verdict?

We’ve talked about the way some of our female athletes land when jumping as a risk factor for ACL injury. It turns out, it may be more than just whether or not the knee turns inward.

One of the past Fellows from here in Vail, Dr. Jason Dragoo, is now a professor at Stanford and doing some amazing work in the field of sports medicine.

This risk was much more pronounced in the female athletes than in their male counterparts. ​- Dr. Sterett

In this article, he and his co-investigators were able to show that the position of the foot, not just of the knee when our athletes land, may play a big role in the risk of sustaining an injury to the ACL.

They were able to show that, when the foot is externally rotated when landing (pointing out), the ACL is at much less risk than when somebody lands internally rotated or pigeon-toed.

This risk was much more pronounced in the female athletes than in their male counterparts.

So many factors leading to the risk of these “non-contact” ACL injuries from twisting, jumping landing and muscle strength. There is lots we know, but lots more to learn.

Read below for the details!

J Exp Orthop. 2016 Dec;3(1):13. doi: 10.1186/s40634-016-0049-1. Epub 2016 Jun 18.

The effect of foot landing position on biomechanical risk factors associated with anterior cruciate ligamentinjury.

Tran AA1,2,3, Gatewood C2,3, Harris AH2, Thompson JA2,4,3, Dragoo JL5,6,7.

Author information

• 1Stanford University School of Medicine, Stanford University, Stanford, CA, USA.

• 2Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA.

• 3Human Performance Lab, Stanford Sports Medicine Center, 341 Galvez Street, Stanford, CA, 94305, USA.

• 4Department of Bioengineering, Stanford University, Stanford, CA, USA.

• 5Stanford University School of Medicine, Stanford University, Stanford, CA, USA. jdragoo@stanford.edu.

• 6Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA. jdragoo@stanford.edu.

• 7Human Performance Lab, Stanford Sports Medicine Center, 341 Galvez Street, Stanford, CA, 94305, USA. jdragoo@stanford.edu.

ABSTRACT

BACKGROUND:

Identification of biomechanical risk factors associated with anterior cruciate ligament (ACL) injury can facilitate injury prevention. The purpose of this study is to investigate the effects of three foot landing positions, "toe-in", "toe-out" and "neutral", on biomechanical risk factors for ACL injury in males and females.

The authors hypothesize that

1. Relative to neutral, the toe-in position increases the biomechanical risk factors for ACL injury,

2. The toe-out position decreases these biomechanical risk factors, and

3. Compared to males, females demonstrate greater changes in lower extremity biomechanics with changes in foot landing position.

METHODS:

Motion capture data on ten male and ten female volunteers aged 20-30 years (26.4 ± 2.50) were collected during double-leg jump landing activities. Subjects were asked to land on force plates and target one of three pre-templated foot landing positions: 0° ("neutral"), 30° internal rotation ("toe-in"), and 30° external rotation ("toe-out") along the axis of the anatomical sagittal plane. A mixed-effects ANOVA and pairwise Tukey post-hoc comparison were used to detect differences in kinematic and kinetic variables associated with biomechanical risk factors of ACLinjury between the three foot landing positions.

RESULTS:

Relative to neutral, landing in the toe-in position increased peak hip adduction, knee internal rotation angles and moments (p < 0.01), and peak knee abduction angle (p < 0.001). Landing in the toe-in position also decreased peak hip flexion angle (p < 0.001) and knee flexion angle (p = 0.023). Landing in the toe-out position decreased peak hip adduction, knee abduction, and knee internal rotation angles (all p < 0.001). Male sex was associated with a smaller increase in hip adduction moment (p = 0.043) and knee internal rotation moment (p = 0.032) with toe-in landing position compared with female sex.

CONCLUSIONS:

Toe-in landing position exacerbates biomechanical risk factors associated with ACL injury, while toe-out landing position decreases these factors.