While recreational running is a great way to stay fit, it comes with a very high risk of injury, particularly injuries to the knee that may account for 50% of running related injuries. Recently, minimalist footwear and forefoot gait patterns have been suggested to reduce the risk of running injuries. These two alterations result in an increased step rate. Previous research has shown that increasing step rate by 10% or more (and decreasing step length proportionally) reduces impact loading and decreases the amount of energy the lower extremity joints must absorb.
Researchers in this study compared the biomechanics of runners at their preferred speed, 5% greater than their preferred speed, and 10% above preferred speed. Their results were that with increased step rate there was a decrease in step length (as would be expected), vertical displacement of the body, and braking impulse. Specifically to the knee joint, 20% less energy was absorbed when step rate was increased by five percent and 34% less energy when step rate was increased by ten percent. Rating of perceived exertion (how hard participants thought they were working) was only increased when step rate was increased 10%. Energy absorption at the hip was also decreased with an increased step rate.
In conclusion, while forefoot gait patterns and minimalist footwear have been shown to decrease lower extremity force absorption during running, these same effects may be achieved by increasing step rate 5-10% above one’s preferred speed.
Heiderscheit, Chumanov, Michalski, Wille, and Ryan (2010). Effects of Step Rate Manipulation on Joint Mechanics during Running. Medicine & Science in Sports & Exercise.