Pitching Injuries and Performance: Understanding Stride Foot Contact and Full External Rotation
Posted Oct 02 2012 3:53pm
At the end of the day yesterday, I took a quick glance at my Facebook feed and was quickly drawn to a "highlight" video from a baseball strength and conditioning program. The athletes' energy was great, and there was a ton of camaraderie. The only problem was that if you had watched the video without first seeing the word "baseball" in the title, you would have never known it was a baseball team training. The exercises - and the way that they were/weren't coached - clearly didn't reflect the unique demands of the sport.
With that in mind, I thought I'd use today's post to quickly highlight the most important positions you need to understand when you're training throwing athletes: stride foot contact/full external rotation.
Stride foot contact occurs just before maximum external rotation takes place. As the foot touches down, the pelvis has started rotating toward home plate while the torso is still rotated in the opposite direction to create the separation that will enhance velocity. Maximum external rotation - or "lay-back" - signifies the end of this separation, as the energy generated in the lower extremity is already working its way up the chain. Nissen et al. (2007) presented this tremendous diagram to illustrate the separation that takes place. This image represents a right handed picture, where the top image is the hips, and the bottom image is the torso (right and left shoulder joint centers of rotation).
Source: Nissen et al.
Based on this image alone, you should be able to see where most oblique strains and lower back pain originate; this is ridiculous rotational stress. Additionally, you can appreciate why hip injuries are higher in throwers than they ever have been before; it takes huge hip rotation velocities to play "catch up" so that the pelvis and thorax are squared up at maximum external rotation (if they aren't, the arm drags). This just refers to what's happening at the lower extremity and core, though. Let's look at the shoulder.
At full lay-back (maximum external rotation), we encounter a number of potentially traumatic and chronic injuries to the shoulder. In a pattern known as the peel-back mechanism, the biceps tendon twists and tugs on the superior labrum. The articular side (undersurface) of the rotator cuff may impinge (internal impingement) on the posterior-superior glenoid, leading to partial thickness cuff tears. Finally, as the ball externally rotates in the socket, the humeral head tends to glide forward, putting stress on the biceps tendon and anterior ligamentous structures.
Likewise, at the elbow, valgus stress is off the charts. That can lead to ulnar collateral ligament tears, flexor/pronator strains, medial epicondyle stress fractures, lateral compressive injuries, ulnar nerve irritation, and a host of other isssue. I don't expect most of you to know what much of this means (although you can learn more from Everything Elbow ), but suffice it to say that it's incredibly important to train throwers to be functionally strong and mobile in these positions.
And, this brings to light the fundamental problem with most strength and conditioning programs for overhead throwing athletes; they commonly don't even come close to training people to be "safe" in these positions. "Clean, squat, deadlift, bench, chin-up, sit-up" just doesn't cut it. You need to be strong in single-leg stance to accept force on the front side with landing.
You need to be able to apply force in the frontal and transverse planes.
You also need to transfer this force to powerful movements.
You need to have plenty of rotary stability to effectively transfer force from the lower to upper body.
You need to be strong eccentrically in the 90/90 position.
You need to have outstanding hip mobility in multiple planes of motion.
You need to attend to soft tissue quality in areas that other athletes rarely have to consider.
These demands are really just the tip of the iceberg, though, as you have to see how all the pieces fit together with respect to throwing and hitting demands at various times of year. Training for baseball isn't as simple as doing the football strength and conditioning program and then showing up for baseball practice; there are far more unique challenges when dealing with any rotational sport, particularly those that also integrate overhead throwing. Watch the sport, talk to the players, appreciate the demands, and evaluate each individual before you try to write the program; otherwise, you're simply fitting athletes to existing programs.
Sign-up Today for our FREE Baseball Newsletter and Receive a Copy of the Exact Stretches used by Cressey Performance Pitchers after they Throw!