Running on the Outside of Your Foot: Causes, Risks, and Solutions

Is it bad to run on the outside of your foot?

Running predominantly on the outside of your foot, a gait pattern known as excessive supination or underpronation, can indeed be problematic, potentially increasing your risk of certain injuries due to compromised shock absorption and altered biomechanics.

Understanding Foot Biomechanics in Running

To fully grasp the implications of running on the outside of your foot, it's essential to understand the natural motion of the foot during gait. This motion involves two key phases:

• Pronation: This is the natural inward rolling of the foot after landing. It's a crucial mechanism for shock absorption, allowing the arch to flatten slightly to distribute impact forces and providing flexibility for the foot to adapt to uneven terrain.
• Supination: This is the outward rolling motion of the foot, which occurs primarily as the foot pushes off the ground. During supination, the foot becomes a rigid lever, providing stability and propulsion for the next stride.

A healthy running gait involves a balance between pronation and supination, allowing for efficient shock absorption upon landing and effective propulsion during push-off.

What Does "Running on the Outside of Your Foot" Mean?

When someone describes running on the outside of their foot, they are typically referring to excessive supination or underpronation. This means that during the gait cycle:

• The foot lands with the weight concentrated on the outer edge.
• The foot rolls minimally or not at all inward (pronates insufficiently) to absorb shock.
• The weight continues to be borne along the lateral (outer) aspect of the foot throughout the stance phase, from landing to toe-off.

This lack of inward roll means the foot remains rigid, failing to adequately flatten and distribute forces across the entire foot.

Is It "Bad"? The Implications of Excessive Supination

Yes, excessive supination can be detrimental for several reasons:

• Compromised Shock Absorption: The primary concern with excessive supination is the reduced ability of the foot to absorb impact. The foot's natural pronation acts as a shock absorber. When this mechanism is limited, impact forces are transmitted up the kinetic chain (ankle, knee, hip, lower back), leading to increased stress on bones, joints, and soft tissues.
• Reduced Flexibility and Adaptability: A foot that remains overly rigid struggles to adapt to uneven surfaces, increasing the risk of ankle sprains.
• Altered Kinetic Chain Mechanics: The rigid foot can lead to compensatory movements higher up the leg, potentially affecting knee tracking, hip stability, and even lumbar spine mechanics.

Causes of Excessive Supination

Excessive supination can stem from a combination of anatomical, biomechanical, and external factors:

• Foot Structure:
  • High Arches (Pes Cavus): Individuals with high, rigid arches are naturally predisposed to supination as their arches do not flatten sufficiently.
  • Forefoot Varus: An anatomical alignment where the forefoot is inverted relative to the rearfoot.
• Biomechanical Factors:
  • Limited Ankle Dorsiflexion: Tight calf muscles or anatomical limitations can restrict the ankle's ability to bend, forcing the foot to supinate to achieve ground clearance or accommodate landing.
  • Muscle Imbalances: Weakness in muscles responsible for pronation (e.g., tibialis anterior, tibialis posterior) or excessive tightness in supinator muscles (e.g., tibialis posterior, gastrocnemius, soleus) can contribute.
  • Gait Pattern: Some individuals naturally adopt a gait that favors the outside of the foot, possibly due to habit or compensation for other issues.
• Footwear:
  • Worn-Out Shoes: Shoes with excessive wear on the outer sole can perpetuate or exacerbate supination.
  • Inappropriate Shoe Type: Motion control shoes, designed for overpronators, can be detrimental for supinators by further restricting their already limited pronation. Neutral shoes are generally recommended for supinators.

Common Injuries Associated with Supination

Due to the increased stress and reduced shock absorption, excessive supination can contribute to a range of running-related injuries:

• Lateral Ankle Sprains: The rigid foot and outward weight bearing make the ankle more susceptible to rolling outward.
• Plantar Fasciitis: While often associated with overpronation, the rigid foot of a supinator can also suffer from excessive tension on the plantar fascia due to lack of arch flexibility.
• Stress Fractures: Particularly in the metatarsals (bones in the forefoot) or tibia (shin bone), due to repeated high-impact forces.
• Iliotibial (IT) Band Syndrome: The altered mechanics can lead to increased tension and friction in the IT band along the outer thigh.
• Shin Splints (Medial Tibial Stress Syndrome): Though more common with overpronation, the repetitive impact of a rigid foot can also contribute.
• Peroneal Tendinopathy: Inflammation or irritation of the tendons on the outside of the ankle, which are often overworked in supinators.
• Knee Pain: Often on the lateral (outer) side, due to altered force transmission through the kinetic chain.

Identifying if You Supinate Excessively

Several indicators can suggest excessive supination:

• Shoe Wear Pattern: Look at the outsole of your running shoes. If you are an excessive supinator, you will typically see significant wear on the outer edge of the heel and forefoot.
• Wet Foot Test: Dip your foot in water and step onto a piece of dark paper or cardboard.
  • Normal arch: Shows about half the arch filled in.
  • High arch (supinator): Shows only the heel and the ball of the foot, with a very narrow or absent connection between the two.
• Observational Gait Analysis: Have someone watch you run from behind. Do your ankles appear to roll outwards? Does your weight seem to stay predominantly on the outside of your feet?
• Physical Symptoms: Persistent pain on the outside of your foot, ankle, shin, or knee, especially after running.

Strategies to Address Excessive Supination

Addressing excessive supination typically involves a multi-faceted approach:

• Appropriate Footwear:
  • Neutral Running Shoes: These shoes offer cushioning without motion control features, allowing the foot's natural (albeit limited) pronation to occur. Avoid stability or motion control shoes.
  • Regular Replacement: Replace running shoes every 300-500 miles, or sooner if you notice significant wear on the outer sole.
• Orthotics/Insoles:
  • Custom Orthotics: A podiatrist can prescribe custom orthotics designed to provide cushioning and gentle support to encourage more natural pronation and improve shock absorption.
  • Over-the-Counter Insoles: Look for insoles specifically designed for high arches or supination, focusing on cushioning rather than aggressive arch support.
• Strengthening and Flexibility Exercises:
  • Ankle Mobility: Work on increasing ankle dorsiflexion through calf stretches (gastrocnemius and soleus).
  • Foot Intrinsic Muscles: Strengthen the small muscles within the foot to improve arch control.
  • Hip Abductor Strengthening: Strengthening the gluteus medius and minimus can improve hip stability and reduce compensatory movements.
  • Peroneal Stretching: Gently stretch the muscles on the outside of the lower leg.
• Gait Retraining:
  • Cadence Adjustment: Increasing your step rate (cadence) can reduce impact forces and encourage a more midfoot strike.
  • Running Form Drills: Working with a running coach to analyze and modify your stride to encourage a more balanced foot strike and improve overall running economy.
• Cross-Training: Incorporate low-impact activities like swimming, cycling, or elliptical training to maintain fitness while reducing repetitive stress on the feet and lower limbs.

When to Seek Professional Help

If you suspect you are an excessive supinator and are experiencing persistent pain, recurring injuries, or significant discomfort, it is highly recommended to consult a professional:

• Sports Medicine Physician: For diagnosis of injuries and medical management.
• Physical Therapist: For a comprehensive gait analysis, individualized exercise prescription, and manual therapy to address muscle imbalances and mobility restrictions.
• Podiatrist: Specializes in foot and ankle issues, can assess foot structure, and recommend appropriate footwear or custom orthotics.
• Certified Running Coach: Can provide expert guidance on running form and training adjustments.

Conclusion

While not inherently "bad" in the same way as an acute injury, running on the outside of your foot (excessive supination) is a biomechanical pattern that can significantly increase your risk of chronic pain and various running-related injuries due to impaired shock absorption and altered load distribution. Understanding your foot type, choosing appropriate footwear, and incorporating targeted exercises can help mitigate these risks. For persistent issues, professional guidance is crucial to ensure a safe and sustainable running practice.