Shoulders open when

The moment when you plant your foot should your shoulders still be closed?

shoulders should be starting to open at foot plant i believe

At foot plant, the hips will have started to open in order to allow the front foot and leg to open (as dictated by your flexibility). After the front leg firms up and braces, then the hips rotate the rest of the way. After the hips have fully rotated, then the shoulders rotate.

Well, this is what we want to happen. But it takes good mechanics and timing and many pitchers have issues that prevent this from happening.

hey roger but when the hips rotate shouldnt the shoulders be rotating as well like at the same time?

If the shoulders rotate at the same time as the hips, then you don’t take advantage of the stretch-shortening cycle (SSC) of the muscles in the core.

Also, when the NPA does a motion analysis of a pitcher, they capture the rotational velocities of the hips, shoulders, and hand. Their data shows that the shoulder typically rotate faster than the hips when they rotate after the hips. I believe the shoulders will slow down if they rotate with the hips.

[quote=“timmyg123”]… but when the hips rotate shouldnt the shoulders be rotating as well like at the same time?[/quote]Not at the beginning. Roger’s correct. You want the hips rotating without the shoulders until they can’t do it any more without pulling the shoulders with them. This “hip/shoulder separation” stretches the muscles and connective tissues across the torso. As a protective mechanism, they contract at the same time as they are lengthening. This is called an “eccentric” contraction. It’s sometimes described as a “load” of the muscles. Now you need to “unload” them to do the work you want them to do in what’s called a “concentric” contraction. A muscle’s most powerful concentric contraction is immediately following a rapid eccentric one. There can be no pauses in this “load and unload” process. If you do, the energy stored in the muscle will be lost as heat. This is what Roger was referring to when he mentioned the Stretch Shortening Cycle.

So, it’s a load and unload process across the torso. Hips rotate, shoulders don’t. Then, at some point, the hips can’t go further without affecting the shoulders. This is the stretching we’re speaking of. If the shoulders begin to turn at the same time as the hips do, you don’t get that stretch, or load. Your contractions are now not as powerful as if you had used this load and unload process.

Thanks, DM. Great explanation!

The shoulders are LIGHTER than the hips so when you do this stretching, the unwinding results in the shoulders moving faster than the hips were… same thing for shoulder>arm.

Precisely, Spencer. It’s a fortunate arrangement that things get lighter and lighter as you progress through the kinetic chain.

There’s one thing that I’ve seen mis-understood about the load/unload. “Loading”, to be most effective, must utilize the SSC. This is a very different animal than simply stretching the muscle. Lengthening it, pausing, then contracting is not the SSC. Everything I’ve read about the SSC indicates that it’s a dynamic process, taking into account the speed of the stretch, the magnitude of the lengthening and the direction of the load as compared to the unload. So, a faster, longer (within tolerance, of course) stretch, and in the direct opposite direction of the unload to come, is the most effective.

This is a “risk/reward” issue as well. I’ve very often said that I believe that velocity and tissue injury risk are directly related and I also suggest that there’s pretty much an exponential relationship there, not just a linear one. The reason I believe this is because of the nature of the SSC. It is very effective at increasing force but it does so by pushing the involved tissues to the limits of their abilities to tolerate. We’re on a razor’s edge with this. Then we take this concept and apply it to some very fragile tissues around joints, such as the shoulder.

OK. I’ll stop my diatribe now.

But it was very good diatribe. :wink:

So this when the moment the foot plants, the shoulder should be closed like this and the hips will begin to rotate until it can no longer rotate without rotating the shoulders? Thanks for all the comments guys :slight_smile:

Almost. Actually, the hips begin to open just prior to landing. You want that stretch across the torso to be at it’s maximum velocity just as the front foot plants, so that the shoulders are ready to fire just then. In order to have hip/shoulder separation at foot plant, the hips would have to be opening earlier than that.

ok thanks dm and if I were to stay closed longer and at the last moment open the hips followed by footplant would that increase by shoulder rotation speed (velocity) ?

Also what do you mean by that?

I think of there being two parts to hip rotation. The first part occurs right before foot plant and it consists of only that rotation that is necessary to open up the front foot and leg into foot plant. The second part of hip rotation occurs after foot plant and after the front leg has firmed up and braced. This is when the hips rotate the most and the most explosively.

So, at foot plant, you want the first part of hip rotation to have occurred but not the second part.

In that picture a few posts back, it’s not clear to me whether “part 2” has just occurred or if only “part 1” has occurred.

Hey, DM. I’ve been wondering about the relationship between the magnitude of the stretch, the amount of muscle tissue, and flexibility. It seems like more muscle mass you have, the less flexibility you’ll have and that will limit the magnitude of the stretch. However, with more muscle being stretched, the effect is the same or maybe even greater.

What do you think? Have you read anything about this?

ok so this would part one ?

Yes, that would be what I call “part 1”. Although the front foot hasn’t planted yet in that picture, the front leg and foot have opened up to point at home plate and the hips have rotated a bit to enable the opening of the front leg and foot.