The name of the study: Comparison of Kinematic and Temporal Parameters Between Different Pitch Velocity Groups
Overview: This research split up their subjects into either high or low velocity throwers based on their…. you guessed it – throwing velocity. They then analysed their mechanics to determine what were the main differences between the two groups in order to find out what allows certain pitchers to throw harder than others. This is a landmark study since they discovered some great information to pass along to anyone who wishes to throw harder and if you are reading this you are probably interested in throwing harder or you know someone who wants to increase their throwing velocity.
The authors: Tomoyuki Matsuo, Rafael F. Escamilla, Glenn S. Fleisig, Steven W. Barrentine, and James R. Andrews (that same Dr. Andrews that performs Tommy John surgery on all the big name guys)
Where to find it: Journal of Applied Biomechanics 2001; 17: 1-13
What they did: They looked at 127 healthy college and professional pitchers and had them throw in their lab with a bunch of reflective markers on specific points of their body in order to determine joint angles and body positions (kinematics parameters). They also used a high-speed camera to determine exactly when each pitcher got to certain joint angles like maximal external rotation during their deliveries (temporal parameters).
Of the 127 subjects 29 were classified as hard throwers because they could achieve speeds of 38 meters per second (m/sec) which is 85 mph while 23 were classified as slow throwers that topped out at 34.2 m/sec (76.5 mph).
Below are the main differences (aka significant factors) between the slow and hard throwers were:
1 – Physical differences – the hard throwers were signficantly taller (5cm) and had longer arms (4cm). This is just a matter of physics – being taller and having longer arms can allow you to throw harder but it doesn’t guarantee it. If fact having longer limbs means that you have to strong enough to control those long legs and arms. If you aren’t strong enough you will lose potential energy that you could have transmitted into that baseball. They call this an energy leak.
2- Maximum Shoulder External Rotation: the hard throwing group was able to get their arms back into 179 degrees of rotation whereas the slow group could only get 166.3 degrees.
Greater amounts of external rotation allows you to throw harder because you generate more of a stretch reflex in your internal rotators which act like springs allowing your arm to rotate forward at an incredibly fast rate. Another reason why more external rotation allows you to throw harder is that you are creating a bigger range of motion which means that you have more time to add force. Your muscles take time to build up force so by creating a bigger range of motion you give yourself a little bit of extra time to add an MPH or two.
3 – The lead knee: this was the major finding of this study and I go into greater detail in this article about the front leg:
What they found here was that the lower velocity group showed greater amounts of knee flexion (bending your leg at the knee) from between the time their front foot landed until they released the ball. The high velocity group did they opposite where their front legs extended (straightening your leg at the knee).
In the discussion portion of the reasearch paper the authors talk about how the front leg braces and stabilizes which enhances the ability of the trunk to rotate more effectively forward over the front leg. If the front leg collapses this creates a major energy leak and slows down your fastball big time.
Watch the video below of the newest Texas Ranger Darvish Yu throw back when he was pitching in the Japanese league. This guy throws hard and watch his front leg brace to the point where he hops backwards after releasing the ball.
Another study (Escamilla et al. 1998) showed that in collegiate pitchers began to extend their front leg just before the shoulders started to get into their externally rotated position and kept extending until the point of ball release.
Check out 2011’s best pitcher Justin Verlander and his front leg in this video
That front leg bracing enables you to transfer all that energy you build up from your lower half and transmit it up through your upper body.
This next video does a great job of slowing things down to show how that front leg stiffens up.
4- Forward trunk tilt at instant of ball release – this one is a by product of strong front leg. A stiff and strong front leg enable you tilt your upper body to a greater degree than a weak and sloppy one. The high velocity group had a forward trunk tilt of 36.7 degress while the slower throwing group were more upright with a trunk tilt of only 28.6 degrees.
Having a greater degree of trunk tilt allows you to hold onto the ball longer which again allows you to build up more force than someone who has to let go of the ball earlier because their standing more upright. When you couple this with more shoulder external rotation you really get to add some extra force to that baseball.
Forward trunk tilt also enables you to let go of the baseball closer to the plate which is always a good thing because it gives the hitter less time to decide whether or not they should take a swing or not. This may not add any MPH’s to the radar gun but it make it seem faster to the hitter which is what really matters.
Below are some examples of some great trunk tilts upon ball release from one of the hardest throwers ever and one of the best pitchers ever (in his prime).
I hope you found this information useful and the simple fact that you know these things are important will allow you to at least be aware of how far back your arm gets into external rotation, what your front leg does and how much trunk tilt you have upon release.
As far as the body height and arm length go be sure to pick the right parents and eat your Wheaties!!
Graeme Lehman, MSc, CSCS