Why Forefoot Flexion In Shoes Plays A Key Role In Foot Function

We discussed the American Academy of Podiatric Sports Medicine’s hands-on shoe evaluation process last month.¹ This month, I want to specifically discuss the test for forefoot flexion in shoes and why I think it is so important to overall foot function.

I have always used sample shoes in my office that have good forefoot flexion right out of the box. I also have used sample shoes that flex easily in the middle of the shoe and some that do not flex much, if at all, at the forefoot/metatarsophalangeal joint (MPJ) area of the shoe. The “bad” examples of forefoot flexion, the shoes that do not flex well at the forefoot, quite often make more of an impact on my patients than the shoes that are exactly what I want patients to buy, in other words, the shoes with more forefoot flexion.

I will also explain to patients that blockage of forefoot flexion in a shoe that is too “stiff” in the forefoot/MPJ area can block or delay vital motions at the forefoot that are necessary to minimize the risks of plantar fasciitis, Achilles tendon issues and metatarsalgia issues, etc.

Howard Dananberg, DPM, has long discussed the issues of functional hallux limitus and how that issue can prolong midfoot and rearfoot pronation because the foot is unable to rotate properly through the first MPJ.²

That said, blocking forefoot stiffness in football players can be both beneficial and detrimental, depending on what issue the players may be currently suffering from or have experienced in the past.

In U.S. football, a shoe with increased forefoot flexion stiffness is often considered a protection for linemen and other athletes who have suffered a turf toe injury. Obviously, minimizing first MPJ extension after a hyperextension injury is usually a good thing during the acute phases of the injury.

For those with chronic pain after a turf toe injury, I do not necessarily agree on keeping that forefoot area stiff. At least one study has shown that blocking the first MPJ’s normal extension motion can lead to increased external rotation of the foot and ankle.³ This along with any limitation in internal range of motion of the hip and coupled with prolonged foot pronation can really put the knee at higher risk for injury.^4–7

Several authors have discussed how bending stiffness of shoes can affect foot function and other issues as well. I’ll discuss those articles and studies in a DPM Blog post sometime in the next few months.

Suffice to say, how a shoe functions, where it is stiff and where it flexes easily all can affect our patients’ segmental and overall foot function. Shoes can lead to acute and chronic issues for our patients. It is imperative that we know as much as we can about how to assess shoes and how to make the most evidence-based decisions on what makes a bad shoe and a potentially good shoe.

See you next month!

References

1.    Williams B. How to do a hands-on shoe evaluation. Podiatry Today DPM Blog. Available at https://www.podiatrytoday.com/blogged/how-do-hands-shoe-evaluation . Published Feb. 6, 2019.
2.    Dananberg HJ. Functional hallux limitus and its relationship to gait efficiency. J Am Podiatr Med Assoc. 1986; 76(11):648-652.
3.    Lafuente G, Munuera PV, Dominguez G, et al. Hallux limitus and its relationship with the internal rotational pattern of the lower limb. J Am Podiatr Med Assoc. 2011; 101(6):467-474.
4.    Powers CM. The influence of abnormal hip mechanics on knee injury: a biomechanical perspective. J Orthop Sports Phys Ther. 2010; 40(2):42–51.
5.    Tainaka K, Takizawa T, Kobayashi H, Umimura M. Limited hip rotation and non-contact anterior cruciate ligament injury: a case-control study. Knee. 2014;21(1):86-90.
6.    VandenBerg C, Crawford EA, Sibilsky Enselman E, et al. Hip rotation is correlated with an increased risk for anterior cruciate ligament injury. Arthroscopy. 2017;33(2):317-325.
7.    Alentorn-Geli E, Myer GD, Silvers HJ, et al. Prevention of non-contact anterior cruciate ligament injuries in soccer players. Part 1: Mechanisms of injury and underlying risk factors. Knee Surg Sports Traumatol Arthrosc. 2009;17(7):705-29.