As we know, running places high forces on the patellofemoral joint, making patello-femoral pain syndrome (PFPS) the most common diagnosis in runners, hence why the condition has been popularised as ‘runner’s knee’ 🏃♀️
Lenhart, et al. (2014) investigated the effect that step rate had on patellofemoral joint force in 23 experienced runners. She used body kinematics to measure joint force while participants ran at 90%, 100% & 110% of their normal/preferred step rate on a treadmill 🏃🏿♂️
The study found that increasing step rate by 10% of participants’ preferred step rate decreased patellofemoral joint force by 15.4%. On the other hand, decreasing step rate by 10% of their preferred step rate actually increased patellofemoral joint force by 17.3% 📚
This study demonstrates that a simple running form modification (e.g. increasing step rate) can be used to diminish peak patellofemoral joint force, however please note it is likely that there will be a number of different factors contributing to patellofemoral pain other than joint force 📉