The biomechanical relationship between footwear, foot function and running related pain and injuries can be visualised nicely from the video:
As you can see, the runner on the left is wearing conventional running footwear and the great toe is not aligned with the direction of travel of the runners body weight due to the narrow, symmetrical toe box which forces the great toe inwards creating what is known as a ‘hallux angle’. This means that the bones, muscles and tendons of the great toe can no longer assist in providing stability for the forefoot or participate in weight bearing, forcing the runner to compensate for the lack of toe function and forefoot stability by increasing the activity of the shin, knee and hip muscles in an attempt to control the increased postural instability which in turn increases the risk of fatigue and injury to these muscle groups.
Where as the runner on the right is wearing footwear with a wide, asymmetrical toe box ( functional footwear) which allows the great toe to align itself with the direction of travel of the runner’s body weight and encourages the muscles and tendons of the great and lesser toes to participate in weight bearing and provide the foot with the stability and strength required for the all important propulsive phase of running.
4 out of the 5 Running Related Pains are related to a lack of toe function
The function of the toes during running cannot be overstated, in fact, 4 out of the 5 most common Running Related Pains are directly related to a lack of toe function and the increased demands placed on the muscles and tendons of the lower leg as they attempt to control an unstable foot.