Friday, January 8, 2016

Intoeing Part II: The Pluses and Minuses of Pigeon-toed Anatomy in Athletes

Last blog we went over the different causes of intoeing in kids. Now we review what intoeing means for athletes.

Studies have shown that low to normal thigh-foot angles and intoeing while sprinting correlate with sprinting ability. Meaning, if your anatomy is such that your thigh-foot angle is low and makes you prone to intoeing and you continue to intoe while you sprint, you may be a better sprinter than those who don’t! Or, you may just be overcoming your anatomy and sprinting well despite your intoeing. It is hard to say which the case is. Have observational studies shown more sprinters who do well because they are pigeon-toed, or do sprinters just happen to have some pigeon-toers who sprint well? Usain Bolt has been noted not to intoe while sprinting. Andre Agassi and Michael Jordan, two athletes who have excelled in sports that require lateral movement (i.e. tennis and basketball) are pigeon-toed. Biomechanically speaking, lateral movement is easier when done with toes turned inward. Is this the case with sprinting?
Violet can't figure out if her rain/snow
boots make her intoe more or not.
She runs pretty fast in them!

The theory to explain the mechanism based on biomechanics and physics from the leading exercise physiologists goes something like this – runners land on the outside of the foot and roll their foot inward from heel-strike to toe-off. People with intoeing have less of this maneuver because they already land partially rotated due to their anatomy. They have less give in the foot and ankle joint when they strike, and the stiffer foot means less energy is absorbed and more energy is dissipated. Running speed is increased when an athlete’s body has the capacity to handle the impact of the forces that occur when the foot strikes the ground, forces that are 3 to 6 times bodyweight. A stiffer foot enables the athlete to absorb these forces and quickly accelerate in the opposite direction.

Some folks propose that intoeing, associated with having flat feet (pes planus) and bow legs, may lead to being faster, but it also leads to more ankle, knee, and hip injuries. The theory being that intoeing feet don’t cushion the force, so even though they are faster, the musculoskeletal system incurs the consequences of that impact. A recent literature review actually showed that there is a low association between pes planus and lower extremity musculoskeletal injury. I haven’t found anything that directly reviewed intoeing with lower extremity injuries, but since the theory is based on the association between intoeing and pes planus, I think we can safely say that there is low evidence to support it. So, dream on, athletes, for those pigeon-toes.
Violet checking out a runner's gait
and trying to decide if they are
hyperpronating or not. There's a lot
less entertainment during winter jogging
stroller runs because fewer people and
fewer animals are out. Why aren't they
as crazy as us, sweet girl?


References

Budt et al. The relationship between foot posture and lower limb kinematics during walking: A systematic review. Gait Posture. 2013 Jul;38(3):363-72.

Feigenbaum et al. The association of foot arch posture and prior history of shoulder or elbow surgery in elite-level baseball pitchers. J Orthop Sports Phys Ther. 2013 Nov;43(11):814-20.

Fuchs R and Staheli L. Sprinting and Intoeing. Journal of Pediatric Orthopaedics. July/Aug 1996: 16;4 – 489-491.

Tong et al. Association between foot tye and lower extremity injuries: systematic literature review with meta-analysis. J Orthop Sports Phys Ther. 2013 )ct;43(10):700-14.


Zafiropoulos et al. Flat food and femoral anteversion in children—a prospective study. Foot (Edinb). 2009 Mar;19(1):50-4.