Dr Alex Eade (Osteopath)
Many long distance runners commonly experience knee pain or heel pain. 
What is Running Cadence?
A useful way to reduce impact and injuries when you run is to increase the cadence or steps per minute. It’s the most common metric used to measure running form and remains important for several reasons.
How does it work?
For starters, the shorter your stride length and the quicker your stride rate, the faster and better you run. If you have a low cadence, you likely also have a long stride. Runners who have a long stride lock their knees and slam their heels to the ground on most steps. This slows you down, creates a choppy, bouncy gait, and puts extra pressure on muscles and bones, making you more prone to injury.
By increasing your cadence, you are doing more than moving your feet faster. You are changing the positioning of where your feet land. Rather than having your foot land in front of your hips, with a higher cadence, it lands underneath you, closer to the centre of gravity. This can help the variability between each stride and not favour one leg more than the other.
When you increase your cadence, you reduce the force with which your body hits the ground. If you have a low cadence, you spend more time up in the air. Hitting the ground harder with your bodyweight, where if the cadence is high you are propelling your body forward. This is easy to see if your head is bobbing up and down.
What is a good cadence?
A rule of thumb for an optimal running cadence is around 180. With that in mind the ideal running cadence is more specific for the individual.
How can I measure?
Using a stopwatch count the amount of steps you take in a minute, going at a pace you would normally run. That number is the cadence.
If you have a running watch like a Garmin, they will have it as a feature built in to measure the average cadence of your run.
What can I use to help improve my Cadence?
Find roughly 5-10% of your cadence and then add it to your current level
Music or a metronome – You can find songs with 180 beats per minute to time and synchronise foot strikes.
Hill Sprints or quick knees – Forces faster turnover and lower ground contact time
References:
Hafer, J. F., Freedman Silvernail, J., Hillstrom, H. J., & Boyer, K. A. (2016). Changes in coordination and its variability with an increase in running cadence. Journal of sports sciences, 34(15), 1388–1395. https://doi.org/10.1080/02640414.2015.1112021
Hunter, I., & Smith, G. A. (2007). Preferred and optimal stride frequency, stiffness and economy: changes with fatigue during a 1-h high-intensity run. European journal of applied physiology, 100(6), 653–661. https://doi.org/10.1007/s00421-007-0456-1