Perhaps you went to the doctor because you were having knee pain, but the x-rays didn’t show anything unusual. Or maybe you’ve recently noticed nagging back or hip pain. Sometimes people attribute these aches and pains to the aging process or to increased activity levels. However, it’s possible your knee and back pain isn’t being caused by your knees or back. If that’s the case, then what’s the root cause of the pain, and what can you do about it?

The “Root” Cause

Your feet and ankles support your entire body. They form the foundation of your body’s “kinetic chain,” which is the system of interconnected muscles and joints of the body that all work together during movement. When you walk or run, your feet and ankles absorb and distribute the stress from the impact. If your feet and ankles can’t distribute that stress properly, they may become unstable. The stress caused by foot and ankle instability can move upward through the kinetic chain of the body resulting in knee, hip, and back pain. 

What causes foot or ankle instability?

Some common causes of foot or ankle instability include: 

  • Prior injury– An injury to a foot or ankle may heal, but sometimes there is residual ligament weakness in the area of the injury. That ligament weakness can cause instability, which increases the risk of reinjury. 
  • Overpronation – The term “pronation” refers to the natural side-to-side movement of the foot. Overpronation can weaken the ligaments of the foot and ankle and cause the foot to roll inward too much when you walk or run. This causes the arch to flatten resulting in foot and ankle instability, which can increase risk of injury. Pregnancy, obesity, and running/walking on hard surfaces for extend periods of time can all contribute to overpronation.   
  • Look at the wear pattern on the soles of your shoes. If there is more wear on the inner side of the sole, it’s likely caused by overpronation. 
  • Symptoms of overpronation may include heel pain, bunions, shin splints and/or hip, knee, and lower back pain, as well as stress fractures of the first and second toes.  
  • Underpronation (supination) – Underpronation occurs when your foot lands on the outer edges of your heel as you walk or run. This causes the foot to roll outward. Unlike overpronation, underpronation is associated with higher arches and stiffer feet. That stiffness transmits more of the stress of walking/running up to the ankle, knee, and hip. Common signs of underpronation include: 
  • More wear on the outside of the shoe sole than on the inside. 
  • Stress fractures of the fourth toe and pinky toe. 
  • Tight calf muscles and Achilles tendons. 
  • Pain along the arch of the foot or the middle of the heel.   
  • Weak ligaments – Some people have naturally weak ligaments, which can lead to foot and ankle instability. That instability increases the chances of getting foot and ankle injuries. 

How to Treat Foot and Ankle Instability

Due to the many causes of foot and ankle instability, seeking advice from a medical professional who specializes in injuries of the foot and ankle is recommended. They will conduct an examination to determine the root cause of the instability and will recommend the best way to correct it. Treatment may include custom orthotics (custom-designed shoe inserts), supportive taping or bracing, physical therapy, or a combination of therapies tailored to your specific needs.