Super Shoes, World Records & Navicular Bone Injuries

Picture by Getty images from BBC

On Friday night, Faith Kipyegon set another world record in the women's one mile by almost 5 seconds with her 4:07.64 min timing. Track fans were stunned since previous world records often were improved by mere tenths of seconds. Earlier in June last month, she broke both the 1500 and 5000 meters world record as well while Lamecha Girma set a new mark in the men's 3000 m steeplechase.

Picture by Marta Gorczynska

The ever evolving breeds of super shoes and spikes (have a look above) - those thick springy midsoles with a carbon fiber foot plate by giving higher rebound / energy return must definitely play a part.

Since both elite and recreational runners wear these super shoes in races, almost all of them use super shoes in training too to get a good feel for them too.

Super shoes may store and return more energy than standard footwear so your legs are fresher thus leading to improved running economy. This energy return is possibly from the compression of the midsole cushioning material and the lever effects of the carbon foot plate and a higher toe spring.

Previous studies have demonstrated different biomechanical demands on the foot and lower extremities between super shoes compared to standard competitive running footwear. Runners using super shoes were observed to have decreased cadence, correspondingly longer steps and a longer flight time. 

Red arrows outline the carbon plate

Peak vertical ground reaction forces and vertical impulse per step were also higher when running in super shoes. There were no changes in hip or knee mechanics but differences were observed in ankle and the metatarsophalangeal (foot) joint mechanics. Ankle range (dorsiflexion) during stance phase was found to be reduced during running in super shoes compared to standard competitive footwear (racing flats in the study).

This change in foot and ankle biomechanics introduced by the super shoes may contribute to the navicular bone injuries as previous studies have shown that reduced ankle dorsiflexion and subtalar range are risk factors.

I have written about how an ankle sprain can trigger navicular bone pain in your ankle if you have an accessory navicular bone. Well, there are also runners who get much more serious navicular bone injuries from using super shoes.

A published article documented 5 cases of navicular bone injuries in both elite teenage runners and older professional triathletes that arose from the atypical stresses on the bones and soft tissue from using super shoes.

In all cases, the athletes developed acute pain during or after running in super shoes. 2 out of the 3 teenage runners were steeplechasers while the other ran middle distance. The 2 older athletes were triathletes. They were quickly diagnosed by the experienced healthcare providers that they saw and this hastened their recovery time. Otherwise navicular bone stress injuries can take up to 9 months to diagnose (Saxena et al, 2000). 

Recognizing possible associations of navicular bone stress injuries in runners who present with vague midfoot or ankle pain especially if they use super shoes may be important to identify this high risk injury.

The performance benefits of super shoes are definitely considerable. If you do use super shoes to train and race and do have foot or ankle pain near the navicular bone region, show this article to your health care provider or come and see us at our clinics.

I'm looking forward to see if any more word records are broken at next month's track and field World Championships in Budapest.

References

Saxena A, Fullem B and Hannaford D (2000). Results Of Treatment Of 22 Navicular Stress Fractures And A New Proposed Radiographic Classification System. DOI: 10.1016/s1067-2516(00)80083-2

Tenforde A, Hoenig T, Saxena A et al (2023). Bone Stress Injuries In Runners Using Carbon Fiber Plate Footwear. Sports Med. 53: 1499-1505. DOI: 10.1007/s40279-023-91818-z.