Research carried out by Clifton Bradeley at the Sub-4 Human Performance lab has revealed that human asymmetry is responsible for the majority of repetitive injuries in runners and in many other sports.
95% of the world’s population has a leg length inequality (one leg that is longer than the other) and the body deals with this in very specific ways. We’ve put concrete and other hard surfaces down in much of our environment. And because concrete has 100% energy return, it sends a shock wave back up through the feet, legs and into the lower back increasing the risk of injury. Running with a leg length inequality on concrete can increase the risk of sports injuries. However, good quality running shoes help reduce this risk by absorbing shock.
Overcompensation Can Cause Injury
Your posture can deal with the leg length inequality by compensating in the feet, legs, pelvis and upper body. By using the legs as a series of levers and allowing the pelvis to compensate for asymmetry, our bodies can move around most environments effectively. But just because movement is possible, doesn’t negate the chance for injury. In fact, the overcompensation our bodies use to adapt can actually increase the risk of injury, especially if the overcompensation is too great.
If you notice any of the following signs you may wish to consult a podiatrist for a biomechanical assessment and gait analysis to check for a leg length inequality:
- One shoe wearing more than the other
- Recurrent foot, knee, hip or lower back pain when you run
- A sense of asymmetry in your posture
- A sense of drifting to one side when you run
- You swing one leg outwards when you run
- Recurrent injuries on one side of your body
- Lower back pain during activity, especially when flexing forwards
While some of the instances listed above may occur without any leg length inequality present, it’s best to remain mindful of how your body is performing while you train. The sooner you recognize any new changes in how your gear is wearing or how your body is feeling, the sooner you'll be able to address these issues before there is a bigger problem.
To also help avoid injury and improve athletic ability, make sure you have the right type of running gear and shop with ASICS today.