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#128 – Irene Davis, Ph.D.: The evolution of the foot, running injuries, and minimalist shoes

Sep 14, 2020 1h 53m 18 insights
<p>Irene Davis is the founding Director of the Spaulding National Running Center at the Harvard Medical School. In this episode, Irene describes how her research of biomechanics and clinical work with running injuries, as well as research by others, has shaped her views on maintaining body alignment and foot health. Irene discusses her argument for the role of modern footwear in running-related injuries and how minimalist footwear helps resolve the subsequent biomechanical issues.</p> <p>We discuss:</p> <ul type="disc"> <li>Irene's path to her Ph.D., her entry into physical therapy, and her interest in biomechanics [3:20];</li> <li>How Irene's thinking about the use of orthotics has changed [7:15];</li> <li>The evolution of the human foot and the transition from walking to running [10:30];</li> <li>The evolution of shoes and its impact on running injuries [17:30];</li> <li>An overview of running injuries [26:00];</li> <li>Cushioned running shoes, heel striking and impact forces [29:30];</li> <li>Shin splints [33:45];</li> <li>How heel strike patterns promotes knee stress through rate of loading [35:30];</li> <li>The critical importance of exercise [42:15];</li> <li>Impact forces and injury potential [45:45];</li> <li>How shoe cushioning alters impact forces despite forefoot striking [49:00];</li> <li>An overview of minimalist shoes [52:30];</li> <li>Irene's protocol for transitioning people out of orthotics [58:45];</li> <li>Transitioning to minimalist shoes and a forefoot strike [1:05:30];</li> <li>Foot muscle volume, minimalist shoes, and orthotics [1:07:00];</li> <li>The recognition of the importance of foot strength in podiatry [1:09:45];</li> <li>Minimalist shoes across the lifespan—from children to adults [1:12:30];</li> <li>Why learning to forefoot strike on soft surfaces is not the best approach [1:20:00];</li> <li>Knee valgus and factors related to knee injury [1:21:45];</li> <li>IT band syndrome [1:28:30];</li> <li>Physics and ground reaction forces [1:33:15];</li> <li>Irene's approach to retraining a runner's gait [1:36:00];</li> <li>Case study—How the transition to minimalist shoes decreased injury and improved performance [1:42:15];</li> <li>Importance of proper movement patterns and the negative influence of our modern environment [1:45:30]; and</li> <li>More.</li> </ul> <p>Learn more: <a href="https://peterattiamd.com/">https://peterattiamd.com/</a><br /> <br /> Show notes page for this episode: <a href="https://peterattiamd.com/irenedavis">https://peterattiamd.com/irenedavis</a> <br /> <br /> Subscribe to receive exclusive subscriber-only content: <a href="https://peterattiamd.com/subscribe/">https://peterattiamd.com/subscribe/</a><br /> <br /> Sign up to receive Peter's email newsletter: <a href="https://peterattiamd.com/newsletter/">https://peterattiamd.com/newsletter/</a><br /> <br /> Connect with Peter on <a href="http://Facebook.com/PeterAttiaMD"><u>Faceboo</u></a><u>k</u> | <a href="http://Twitter.com/PeterAttiaMD"><u>Twitter</u></a> | <a href="http://Instagram.com/PeterAttiaMD"><u>Instagram</u></a>.</p>
Actionable Insights

1. Strengthen Foot Muscles Intrinsically

Recognize that your feet contain 10 muscles in four layers, capable of strengthening just like your quads or biceps. Challenge the mindset that feet inherently require permanent external bracing, as continuous support can weaken these muscles.

2. Gradually Wean Off Orthotics

If using orthotics, slowly reduce their use over two to three weeks, starting with short periods (e.g., an hour) without them. Simultaneously, perform foot strengthening exercises and listen to your body, reinserting orthotics if feet become sore, to allow intrinsic muscles to adapt and strengthen.

3. Adopt Minimalist Footwear

Transition to minimalist shoes (no midsole, no arch support, flexible heel/upper, rollable) for walking and eventually running. This choice strengthens foot muscles and allows feet to function as they evolved, potentially reducing injury risk across the lifespan.

4. Transition to Forefoot Strike Pattern

Aim to land on the ball of your foot when running, as this reduces impact forces and shifts load from the knee to the stronger ankle and calf muscles. This pattern is associated with a smoother, more gentle application of force, which can lower the risk of running-related injuries.

5. Slowly Transition Running Mechanics

When changing to minimalist shoes or a forefoot strike, allow ample time (e.g., 1-3 months) for your feet and ankles to adapt. Start by walking briskly for 30 minutes in minimalist shoes before slowly interjecting short periods of running, to prevent overuse injuries like plantar fasciitis or metatarsal stress fractures.

6. Avoid Forefoot Striking in Conventional Shoes

If attempting a forefoot strike, do so in minimalist shoes. Forefoot striking in conventional shoes can lead to increased plantar flexion, greater load on the Achilles and calf, and increased medial-lateral forces, potentially causing injuries to the Achilles or peroneal tendons.

7. Use Cushioned Shoes for Heel Striking

If you continue to be a heel striker, ensure your shoes have adequate cushioning under the heel. This helps to attenuate the hard impacts associated with heel striking, which can otherwise lead to a quicker application of force (higher load rate) and increased injury risk.

8. Train on Hard Surfaces for Compliance

Incorporate training on hard surfaces to teach your legs to be compliant and attenuate shock effectively. While starting on grass is acceptable, training predominantly on hard surfaces helps develop the necessary leg stiffness modulation for most running environments.

9. Get Fit Before Running

If you are not currently fit, prioritize developing strength and motor control before starting a running regimen. Running without adequate fitness can lead to injuries because your body lacks the muscular control to cushion and manage impact forces.

10. Address IT Band Syndrome Mechanics

If experiencing IT band syndrome, investigate and address mechanical issues such as inward angulation of the thigh, pelvic drop, and internal rotation of the tibia. These factors can excessively stretch the IT band, contributing to pain and inflammation.

11. Be Patient with Gait Retraining

Understand that changing established gait patterns requires significant practice and patience. Utilize feedback (e.g., visual, proprioceptive) to learn correct movements, gradually fade external feedback, and commit to consistent practice over an extended period (months) for lasting change.

12. Gradually Ramp Up Post-Retraining

After completing gait retraining, increase running intensity and distance very slowly. Even with improved mechanics, tissues need time to adapt to new loading patterns, and rushing this process can lead to re-injury.

13. Consider Preventative Gait Training

Even if uninjured, consider gait training focused on landing softer, as studies show it can significantly reduce running injuries (e.g., 62% reduction in novice runners). This proactive approach can help maintain mechanics that keep you below your injury threshold.

14. Encourage Minimalist Footwear for Children

Provide children with minimalist footwear from an early age to allow their feet to develop naturally. This approach supports the development of strong, functional feet, potentially preventing future musculoskeletal issues.

15. Promote Varied Movement & Less Sitting for Children

Encourage children to engage in diverse physical activities and adopt varied postures like squatting or sitting on logs, rather than prolonged sitting in chairs. This fosters physical literacy, core stability, and overall musculoskeletal health, aligning with evolutionary movement patterns.

16. Advocate for Comprehensive Physical Education

Support and encourage daily physical education in schools that includes calisthenics, upper body strength exercises (e.g., monkey bars), and varied movement, beyond just team sports. This helps children build fundamental strength and physical literacy.

17. Encourage Multi-Sport Participation for Kids

Advise children to participate in multiple sports and varied physical activities rather than specializing in a single sport. This reduces the risk of burnout and injury, promoting healthier overall physical development.

18. Develop Protective Foot Calluses

Go barefoot frequently to allow your feet to develop natural calluses. These calluses provide a protective layer against elements, similar to how other animals’ feet are adapted to their environments.