May the force be with you

Work, money, family, friends; all of the may cause stress in our lives, but there is nothing like the ultimate stressor amity.  With every movement and every step we are battling the force of gravity.  When running, this force is even greater.  The vertical motion of the body as you run is balanced out by ground reaction force from the surface through your leg.  GRF is related to tibial stress which can manifest into injury.  A high step rate will decrease the time you spend going up and down (vertical force) and will decrease your change of injury.  In high school and young runners,  shin injuries are 48% of new injuries and 59% f re-injury.  There is a 10% increase in step rate can decreased the load thru the anterior patella femoral joint by 14%.
68 high school cross country runners were evaluated and followed thru their season.  They were all pain free at the start of the season.   Each runner was tested in an 800m on a track with a pacer at a fixed speed and at a self selected speed.  This was done within the first 3 weeks of the season.  At the end of the season, each runner was given a questionnaire about their pain during the season.  Runners with the lower step rate (<164 S/m) when running it's the pacer were more likely to have a shin injury than the runners with a higher step rate (>174s\m).
If you are experiencing shin or knee pain and maybe you just increased. Your mileage or started back to Running, this might be helpful for you.  Step rate or cadence is not easy to work on especially if you don't like to run on a treadmill.  First you need to find out what your normal step rate is by counting the number of steps you take in a minute.  Then suck it up, go on a treadmill with a metronome.  Start by trying to increase your step rate by 5-10 percent.  Everyone gets obsessed with the idea of 180-190 b/m but this is not always the most efficient for your specific build.  Having a gait analysis done by a professional can make a serious difference in your efficiency, form and injury prevention.  

Lace, L., Heiderscheit, B., Williams, D., Rauh,M.  Influence of Step Rate on Shin Injury and Anterior Knee Pain on High School Runners.  Medicine & Science in Sports & Exercise.  January 2016.48(7)1244-1250.

Kathleen Leninger, DPT