Freelap Friday Five with Dr. Emily Splichal
Dr. Emily Splichal, podiatrist and human movement specialist, is the founder of the Evidence Based Fitness Academy, creator of the Barefoot Training Specialist®, BarefootRx®, and BARE® Workout Certifications, and inventor of Naboso Barefoot Technology. With over 16 years in the fitness industry, Dr. Splichal has dedicated her medical career towards studying postural alignment and human movement as it relates to barefoot science, foot-to-core integration, and from-the-ground-up training.
She is active in barefoot training research and barefoot education as it relates to athletic performance, injury prevention, and movement longevity. Dr. Splichal has presented her research and barefoot education both nationally and internationally, with her Barefoot Training Specialist® Program in over 35 countries worldwide and translated into 12 languages.
Freelap USA: What constitutes a “well-functioning” foot for running? What are some things that would lead you to see someone who can apply force to the ground well?
Dr. Emily Splichal: A well-functioning foot is one that is meeting the demands of running from both a biomechanical and neuromuscular perspective. Biomechanically, with every step we take, a well-functioning foot must be able to dance back and forth between supination and pronation very quickly—and within a small range of motion. The closer a foot is towards neutral, the easier it is to lock and unlock with each foot contact.
Neuromuscularly, a well-functioning foot must be sensory sensitive and myofascially integrated. This means that the plantar foot must be able to perceive the rapid onset of impact forces while creating a fascial tension response that happens before the foot even contacts the ground. This can be observed in a foot that has rapid contact time, which is through rapid stiffness before foot contact.
In a foot that can meet the demands of running, both biomechanically and neuromuscularly, you would notice shortened contact time, faster speed, and a fluidity and flow to their movement patterns.
Freelap USA: How do running shoes affect the natural function of the foot?
Dr. Emily Splichal: If we stick with biomechanical and neuromuscular aspects of the foot, running shoes can positively or negatively affect both characteristics. From a biomechanical perspective, a shoe with a heel toe drop will shift the natural mechanics of the foot. Now, if the foot needs more stability, the heel toe drop may be a positive effect. However, in most cases a heel toe drop interrupts the natural unlocking mechanism of the foot, thereby creating an increase in supination of the foot. This alters the window of range of motion the foot moves through during impact.For optimal propulsion, our rearfoot needs to be able to spiral relative to the fixed forefoot. Click To Tweet
Another feature of footwear that alters natural foot mechanics is a shank, often presented as a plastic shell in the shoe that runs from heel to sulcus. It forces the foot to shift forward in a lever movement; however, due to the rigidity of this structure, it blocks torsion of the shoe and foot. Restricted torsion in footwear is one of the most common causes of insufficient stiffness and push-off. For optimal propulsion, our rearfoot needs to be able to spiral relative to the fixed forefoot.
From a neuromuscular perspective, cushioning in footwear is one of the most controversial topics. From a natural foot function perspective, we need the sensory stimulation of impact forces and the cushions in shoes dampen or block them. Our nervous system uses the vibratory stimulation of impact forces to determine how hard we are striking the ground and to maintain dynamic balance. If the foot is not strong enough to absorb the impact forces entering the foot, then less cushioning in shoes can cause an increased risk for impact-related injuries. The best way to keep feet strong enough to offset impact forces is to integrate foot strengthening exercises into the athlete’s programming.
Freelap USA: Could you expand on the importance of the rearfoot, how torsion works, and how we can assess this? What are some training modalities to help improve this area of function?
Dr. Emily Splichal: All joints in the body move in an integrated and coupled fashion, and the foot is no different. When we look at the mechanics of the rearfoot, every time our ankle dorsiflexes, it creates an eversion moment in the subtalar joint. This eversion of the subtalar joint creates an internal rotation of the tibia. Conversely, every time we plantarflex the ankle, it leads to inversion of the subtalar joint and external rotation of the tibia.
It is these coupled joint movements that allow for integrated power and the release of energy. When it comes to runners, the foot needs to achieve sufficient inversion and tibial external rotation at push-off. If footwear restricts this, it can limit the runner’s speed and contact time.
You can train this integrated joint coupling with the following exercise.
Video 1. A variation on the short foot exercise, this foot-to-core movement strengthens the muscles of the feet and lower leg up into the deep abdominals and glutes. This helps train the integrated joint coupling needed by runners for power and energy.
Freelap USA: What’s your take on “toe strength” and mobility, and how do we know if this is something our athletes should look at?
Dr. Emily Splichal: Toe flexor strength is extremely important to a runner’s performance. Research has shown that there is a direct relationship between toe flexor strength and acceleration and vertical jumps. Push-off, whether in running, walking, or jumping, requires a force going downward into the ground. This downward force creates a stable base and eliminates shifting during acceleration and power release. Force application would be greatly compromised if there was no downward force—for instance, think about running on ice.
The long toe flexors and plantar fascia play a critical role in toe purchase and this downward force during push-off, with both being the most active during the lever phase of the foot or propulsion. You should integrate exercises that strengthen this action of the foot into all runners’ programming. These all target the long flexors. Short foot is a long flexor exercise, as it targets the Deep Front Fascial Line, which includes the long flexors.
Freelap USA: What are some of the best exercises we can use to improve foot strength as it relates to the running cycle?
Dr. Emily Splichal: My three favorite exercises for strengthening the foot for running include short foot, a ball between the heel raise, and short foot single leg training—all done barefoot and ideally on the Naboso Proprioceptive Mat. The unique texture of the Naboso Proprioceptive Mat is designed to enhance foot stimulation, which will help runners tune into their feet.
Short foot is an activation exercise that I use to coordinate the timing of the foot engagement with core engagement. It also strengthens toe flexor strength, which we just discussed as important for the push-off phase of running.
Video 2. The short foot exercise strengthens the small muscles of the feet, helping the body absorb impact and thus, helping prevent running injuries. Use it to coordinate the timing of foot engagement with core engagement, and to strengthen toe flexor strength.
The ball between the heel exercise that I mentioned earlier combines the power of short foot with a targeted posterior tibialis exercise. Myofascially, the posterior tibialis connects to our core muscles and therefore plays a role in the integrated stability of the foot.Runners need exercises that integrate foot activation with core activation and breathing patterns. Click To Tweet
You can combine all of these into a series of exercises that integrate foot activation with core activation and breathing patterns. I advise my patients who are runners to do five minutes of these short foot single-leg exercises before they run. The impact on their rate of stabilization and force production is powerful.
Video 3. These short foot single-leg exercises have a powerful impact on a runner’s rate of stabilization and force production. I advise my patients who are runners to do five minutes of these before they run.