Drive Leg Valgus
Something I have seen lately with younger pitchers trying to get downhill faster or maybe have been told to be “tall and fall” is this collapsing drive leg knee. This is medically and kinematically called valgus, and it plagues more than just pitchers. On the right is an picture from the article I linked above that does a great job demonstrating what valgus collapse looks like form an anatomical standpoint. But what does it affect when we pitch? The simple answer is: your elbow.
This position is very ineffecient and leads to young and older pitchers placeing more stress through the arm/elbow in order to try and compensate for the lack of energy generated from the legs.
To the left is the graph that shows how and why we lose power from the legs. If you’re not into the science-y numbers, the easy way to think of it is you’re pushing your back leg toward the plate instead of trying to produce force into the rubber to drive you towards the plate. So basically if you were a car, you are trying to drive forward, but are stuck in reverse.
Now the part where it affects our elbow. Again for those not into stats, the more your pitcher’s knee collapses toward the plate, the more stress goes into their elbow. This is easily noted with the linear progression with increasing valgus of the knee (negative numbers to positive on the bottom), the increasing amount of torque the elbow sustains (negative numbers to positive on the left).
So how do we help cue or improve this if it is noted in a pitcher? The biggest cue I use is to think about rotating the foot into the rubber, or screwing the foot into the ground, but there are a number of ways to help improve performance. Another fantastic way to help them realize this common deficit is to put them on video and compare to higher level guys. Visual cues really help, but sometimes guys do well with internal cue to feeling it in the drive leg hip. The “lateral glutes” (Gluteus Medius and Minimus) will get activated and should feel a tension in the drive hip. The last way I like to link it is hitting, as the back leg in hitting should be holding the same tension, and this is more intuitive to younger players.
To sum up, as pitchers, we want to avoid a collapsed drive leg knee through the linear movement down the mound. A more efficient position is to hold hip external rotation and hip abduction to allow the full potential out of the ground to transition to the hip. If you are having problem identifying this or need help analyzing video feel free to reach out!