Jim, good opening. So I want to talk about the kinetic chain. It's well known. Since 1964, there's never been a study that has not shown the basis of the kinetic chain in this integrated activity called throwing. Ever since I first was introduced to this in 1984 by Dr. Jack Groppel, he drew this on a napkin at a dinner at a restaurant. We made a cartoon out of it this way right here. This is from Mark Safran showing exactly what Jim Bradley was talking about, the transfer of forces so that at ball impact, we have the most force and the highest velocity, each segment sequentially summating the speed until you get your ball impact. You have your force generation area, your core stability and strength of your core. You have your force regulation and transfer, which is actually what the shoulder and the scapula is mainly designed to do. And then you've got your force delivery, which is your hand and whatever else you hold in the hand. Implications, the body works in these coordinated patterns to produce function. There are multiple degrees of freedom, as Jim mentioned, in the kinetic chain, and therefore multiple possible weak links that you have to check in the exam. The body fails, however, in certain patterns. And these are fairly common patterns that you can examine. And you can demonstrate to yourself and to the patient. This is a very interesting study here. A lot of this work here is showing the sequential activation of onset of muscle activity from the serratus, to the pec, to the deltoid, all the way out, and the peak time. Once again, there's a particular sequence that occurs. And if you do something wrong, then you've got to catch up. Mathematically, it's very difficult to catch up. If you drop your trunk kinetic energy by 20%, you have to increase your shoulder velocity 34%, shoulder mass by 80%, or you have to suffer the consequences of decreased function. This is a study done in tennis players from the 2000 Olympics. Once again, showing that if you don't bend your knees, you increase the torque at the shoulder and the elbow to maintain the same ball velocity. Just 10 degrees of your knee bending will increase 17% to 23% the requirements for catch up. Implications. Therefore, in these injuries, alterations exist and must be evaluated at least, from the literature, 50% hip, trunk, and core. Scapodiskinesis, 94%. Shoulder rotation, 90%. Therefore, you have to look at the entire kinetic chain in a victims and culprits situation. And the way we look at it, as Jim was talking about it, is that you take what I call them buckets. You take your core bucket, which is your leg stability, hip rotation, any damage you have in the lower extremity. You have your scapular bucket, where you do the scapular evaluation. And then you do your classical evaluation of the shoulder. But that comes at the end of the evaluation, not at the start. Shoulder scapula, as Jim mentioned, you look at static position. You look at dynamic motion. You look how well they can retract the scapula. It's called a low row position. Then you do these corrective maneuvers where you actually can mobilize the scapula. And you can change the symptoms. So this is an individual here. And you can see that he has the problem with his right shoulder, this quote unquote sick scapula, with a type 1 dyskinesis. And then that's at rest. Then motion, you have him elevate, depressed. And you see, once again, the loss of control of the serratus and low trap, creating that impingement problem. He comes to the clinic with an idea that he has an impingement and he needs a subacroma decompression. And then the effect of the scapular dyskinesis on pain, he has rotator cuff pain, anterior pain, and weakness. If you do this manual stabilization, then you correct every bit of the weakness and pain, demonstrating to you and the patient that the scapula is the source of the problem, not the rotator cuff. I've got a couple of cases to show some of this in practice. 30-year-old pro tennis player, he has allowed me to use his case. High ranking, gradual onset of pain, posterior pain in the shoulder. But it was at ball impact and follow through, not in cocking, where you get usually your labral injuries. Decreased ball velocity and strength so that he had some functional problems. He had to pull out of some tournaments. He had an MRI and showed a slap lesion and partial rotator cuff injury, and was told he needed to have a scope. However, if you keep on looking at him, his DLS test, which is very similar to that deep pit test, it's like I'm going to show this on Saturday. But he did have an internal rotation deficit. But he had no instability. He had normal strength. He had scapular dyskinesis. But in the leg, he had, as mentioned, the left hip internal rotation was 15 degrees less than the right hip. He had tight lateral iliotibial band, lateral patellar tilt with pain upon knee flexion. And no ankle dorsiflexion, absolutely none. If you looked at his video, you saw that he favored the left leg in the video from recent compared to the year before. So we get an x-ray. He's got a big old ankle bone spur, limiting his ability to generate the force and kinetic chain in the motions. So he got his scope, but he got a scope of his ankle. And he debrided this. We then took care of his hip and core problems with flexibility and strength. He did have a lot of scapular tracheal control and eccentric strengthening of the rotator cuff. Four months rehabilitation conditioning. He returned in four to five months. At a year, he's back in the top 10. And last summer, he competed in a tournament where he beat the number one player in the world and the number one United States player in the world. 500 serves over two days. Last serve to win 26-24 fifth set match was 125 miles an hour. So he doesn't have any shoulder problems, even though he still has the findings of the MRI. Second is 18-year-old college pitcher, high school senior. He pitched him to the state title. Over the summer, he worked on a tobacco farm doing a lot of lifting and carrying. Came to fall his freshman year, and he had shoulder pain every throw, decreased ball velocity, can't get loose, imaging, possible labral injury. So if you look at him, once again, he does have the scapular dyskinesis. He's got pain along the medial scapular border. You can see it right there, asymmetry. So you say, well, that's maybe the problem he's got. Well, he does. But if you look at his one-leg stability series, look at this strapping kid. This is what Jim's talking about. He can't stand on one leg. So he's on DL for four weeks, no throwing. Did hip and core stability, scapular traction control. Did the eccentric program and throwing progressions. Returned on a pitch count, off-season core stability. Returned in the spring. And progression pitch count, he did very well that freshman year, and then completed college play with no injury. So kinetic chain is a mechanism by which coordination of these segments works. The body works as a unit. That's the only way that it can work. If you don't allow that in your thought process, then you're missing a lot of the answers. The kinetic framework is the way that this all works. The body fails as a unit in certain patterns, most commonly hip and core, scapular dyskinesis, internal rotation deficits, et cetera. There are patterns of failure that you need to look at both proximal and distal with a screening exam that can be done very easily. The catch-up and compensations do exist. Sometimes you get by, a lot of times you don't. You have to look at those. There are victims and culprits, and you can demonstrate this in your exam, which will help you and help the patient and usually the players and the family and everybody else that are around on the exam. And therefore, you do an overview of the screening exam, detail exam. And remember that the labral injury on MRI does not necessarily, he calls it the bad slap. I'm going to, on Saturday, I'm going to talk about what we call it the Sisley lesion. And therefore, we need to understand the sports mechanics, whether it's tennis, baseball, swimming, a lot of those are the same things. Thank you very much.

kinetic chain

integrated activities

throwing

scapular dyskinesis

hip and core stability