A recent research article in the Medicine & Science in Sports & Exercise, December 2009 studied the effects of increased stride length and the incidence of tibial stress fractures in runners. The authors of "Effects of Stride Length and Running Mileage on a Probabilistic Stress Fracture Model" found that by reducing stride length by 3%-6% decreased the probability of stress fracture. Increasing the running mileage increased the probability of stress fracture by 4%-6%. They also concluded that if a runner decreases their stride length by 10%, he or she can run an additional 2 miles/day and maintain the same probability of stress fracture.
It is very important to understand the difference between stride length
and stride angle
as we do not advise runners to reduce their stride angle. Stride length is the distance from initial contact of one foot to the subsequent contact of the same foot. There are stride calculators on the web to determine your stride length such as http://www.tech4o.com/stridecalc.htm
measures the greatest angle your legs create during the running stride.
An example of stride angle
We would like to see the stride angle increase without the stride length increasing as we do not want the runner to land too far out in front of her body.
Heel strike far in front of body
To increase stride angle, we would do ART (Active Release Techniques) to the hip flexor group and hamstring group as well as other related structures inhibiting range of motion as well as prescribe various stretches and exercises. To reduce over striding, we work on technique and running drills. To receive a video analysis of your stride angle and running gait, please email email@example.com.