Ask Mike Reinold Show

How Does Treatment Differ Between Posterior and Anterior Shoulder Instability?

On this episode of the #AskMikeReinold show we talk about some of the differences in how we would treat someone with anterior versus posterior shoulder instability. To view more episodes, subscribe, and ask your questions, go to

#AskMikeReinold Episode 200: How Does Treatment Differ Between Posterior and Anterior Shoulder Instability?

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Show Notes


Mike Reinold: On this episode of the Ask Mike Reinold show, we are stuck at home in self-quarantine, but still answering your questions for an amazing 200th episode special podcast from home, from all of us. But we’re going to answer one big question in addition to celebrating, and that is what is the difference between our treatment principles with somebody with anterior or posterior shoulder instability.

Mike Reinold: We have a question from James from New York (I feel like you need a prize for getting picked for the 200) “What is the key difference in nonoperative treatment for posterior versus anterior shoulder instability?” Now that there’s a pretty neat question, right? Because I think a lot of people just think instability is the same thing, right? Like you have a unstable shoulder, it’s the same thing, but does it matter if it’s anterior or posterior?

Mike Reinold: And I guess you could almost imply through the question there that this was probably a traumatic type of thing, or maybe not with posterior, but it’s a unidirectional one, which I think is a little different than a congenital multi-directional axis, which I think is really neat, but anterior versus posterior. So who wants to start? Maybe we’ll try to see somebody jump in and I can try to lead it if not, but we’ll see if we can do this from a distance. Dave, what do you got?

Dave Tilley: I just have one to share because it’s been something that comes up a lot with weightbearing and my population is somebody who has a posterior dislocation, obviously to be very cautious, getting back to weightbearing because of posterior translation versus someone who’s an anterior or maybe even a multi-directional if that comes up like you said. You want to get back to a little bit of weightbearing because it helps rebuild dynamic stability a little earlier. So I had to learn that lesson the hard way when I was a younger grad. I got back too soon and I irritated someone’s posterior cuff.

Mike Reinold: Yeah, and posterior instability, posterior capsule in and of itself is super thin. It’s real easy to be loose posteriorly so you’re absolutely right. You definitely go a little slower is that, that would almost be the first thing I would say, before we even talked about the weightbearing, but like I think the first thing is we go a little slower with posterior, right? And then second it comes into to close kinetic chain and weight bearing things. So Dave mentioned getting back to weight bearing activities, if you’re a wrestler or a gymnast or something like that, right, and you have weight bearing activities but also don’t forget it’s our selection of our closed chain. So, if this is my shoulder, right? Posterior translation going out the back. If we get into this closed chain position, I’m going to get that posterior translation.

Mike Reinold: So we usually delay the start of close chain. That’s a big one. And then when we start, then we make sure that we are super wide and almost in that scapular plane. So now that way that translation is going to be into my glenoid versus posteriorly and maybe out the back. So I like that. So that’s a good first one, right? We’re slower and then the second one is that we’re careful with our closed kinetic chain. Who else wants to add to that? I think there’s a bunch of the talk. What do you got Mike?

Mike Scaduto: Yeah, I think the first step for me would definitely be understanding the mechanism of injury. I think that would be a big thing. Is it a fall on an outstretched arm that caused the posterior instability episode or dislocation? Working with golfers, we see a lot of posterior instability in the lead shoulder from being cross body and then rotating the trunk towards the lead side can cause a little glide on the humeral head posteriorly. So that’s probably more of a microtrauma, repeated microtrauma. So kind of understanding the history of that person’s injury mechanism and the actual traumatic injury mechanism if it’s there I think would be very helpful. And then if they have posterior instability, I’m probably going to be careful with range of motion across their body moving into horizontal abduction and probably internal rotation, as well early on probably it, depending on the severity of the instability, maybe avoid those positions early on and then gradually reintroduce that range of motion and strength and into that range of motion over time.

Mike Reinold: That’s great. And what I like about what you said was you talked about the mechanism of it, right? Which I think is super important, but then you talked about the movements. So what stresses posteriorly is obviously internal rotation and cross body abduction and adduction across, right? So we want to be careful with those motions, with posterior instability obviously because that causes that stress in the posterior aspect, right? But then when you combine it with the mechanism, I think it’s really important, right? If it’s a golfer for example, versus a gymnast for Dave, right? Dave is going to probably be a little bit more cautious with weightbearing and you’re going to be a little bit more cautious with cross body range of motion. Right? So you put those together. So I liked that. So posterior, probably slower. We’re going to be careful with closed kinetic chain and then we’re going to be really cautious with specific movements, cross body and internal rotation. So I don’t know based on that Lisa then what’s the opposite of that for anterior? What motions are we careful? Or what do we need to be more careful with anterior?

Lisa Russell: So the patient I think of when I’m thinking of interior dislocations and interior cuff stuff is our capsule. I had this tennis player a while ago who was really probably just a very loose person but she dislocated her shoulder probably, I don’t know, seven or eight times before she came to PT. And I mean so just literally teaching her the movement patterns of not going overhead and keeping her shoulder up in its joint. I mean rowing wise, there’s not a ton of shoulder dislocation stuff. So generally, I haven’t treated a ton of it and-

Mike Reinold: That’s a good thing with rowers, that we don’t have to –

Lisa Russell: You get a little bit if it’s like a very freak traumatic thing-

Mike Reinold: Do you ever capsize rowing and you’re like –

Lisa Russell: I do and it legitimately when that kind of a thing happens or there’s something in rowing called catching a crab where you like catch your oar handle in the water weird and it like makes you kind of fall back or like it go over your head and like that’s what does it like if you’re a full speed going, you know like in race and all of a sudden the oars overhead.

Mike Reinold: That would be bad.

Lisa Russell: But otherwise there’s not like a ton of capsular injury.

Mike Reinold: Yeah. But that’s a good thing. So to go to the flip side of what Mike said with crossbite internal, so with anterior we’re probably going to be more cautious with external, that’s probably one. And then going behind the body, which is the two opposite. But again I think that goes back to what Mike said too, as well as the mechanism of injury. Right? Lisa has had some anterior instability when we go up overhead, which makes sense. That happens. It’s like anterior inferior. But a lot of times you can just get pulled back this way or this way into an episode and you’re actually pretty stable up overhead. Right. It’s more of behind the body and into, into external rotation. So you know, I think that also plays a big part of it. But if this is an issue with posterior, then this is an issue with anterior.

Mike Reinold: And that’s, that’s a big thing we kind of work on. Let me see. Well before we go on, I got to ask, Len, what are you typing?

Lenny Macrina: Nothing.

Mike Reinold: Yeah, you were.

Lenny Macrina: No, that wasn’t me.

Mike Scaduto: He’s just nervously tapping his fingers on the keys.

Lenny Macrina: No I hear it but it’s not me. I’m just sitting here.

Mike Reinold: It sure looked like, like I was like Lenny, like answering emails right now. Like this is the problem with working from home, by the way. You’re in video conference. All right. So Len, how about this? So how about like, exercise? So we talked about range of motion, I think, which was be careful with different directions.

Lenny Macrina: All great answers. Yeah, so I think for exercise, very similar, no doubt, very similar. The core program is going to be very similar where you’re going to do a lot of full camp stuff like Mike said, the scapular plane, you’re going to do sideline external rotation. That’s in all my shoulder programs. I think I’m going to limit the amount of range of motion for the anterior instability. If we started doing maybe some T’s, so like a prone T or prone horizontal abduction, I may limit them to not go in full range of motion initially if they feel unstable. I’m going to probably maybe consider a little bit more subscap strengthening for the anterior instability cause we know the subscap crosses right over the front of the humeral head, so it’s a great dynamic stabilizer of the humeral head anteriorly. So if you think about subscap and infraspinatus, we talked about force factors.

Lenny Macrina: Those are two great muscles that are going to stabilize anteriorly and posteriorly. So you really, when they contract they basically contract them together and causing the humeral head to basically get suctioned into the glenoid. So my focus is on anything subscap in anything infraspinatus. And then obviously trying to get, you know, scapulothoracic type stuff. So lower traps, mid traps, even up traps, but probably more so lower traps, mid traps, they’re going to be huge for me. So the prone Y’s, T’s prone 90/90 like all the prone U or W whatever, call them for prone up. And again, watching them at end range external rotation because you will get some humeral head translation at that end range of motion. And if they’re loose they’ll know, they’ll kind of freak out by, it’ll have some pain. So you get to kind of give them confidence and also let them know you don’t have to go through the full range of motion. And usually it, you know, you can get through that phase and then you can go through full range of motion shortly after that.

Mike Reinold: Yeah, I like it. So exercise selection, I mean it’s pretty similar between the two because they all have the same principle of: I want to help stabilize the glenohumeral joint and center the humeral head. So exercise selection is going to be really similar. But I like what you did there though. You took the range of motion things that we talked about earlier and you said like, “Well, hey, maybe we’re just going to limit the range of motion a little bit to that little last bit that like 80% of the range of motion from there.”

Lenny Macrina: Right.

Mike Reinold: So I think this leads us really well. So Dan Pope, So Dan I mean, so with it, I guess the question is Lenny just talked about limiting end range based on some of those range of motions. When you’re returning somebody back to their activities, when do you start working on now some stability and some strength in their end range, maybe in their unstable position. And do you do anything different between anterior and posterior with that lat, that later phase trying to get people back?

Dan Pope: Yeah, I think it’s going to depend entirely on the athlete, right? I mean I see a bunch of people that are in the fitness world, so it’s not as necessarily like these guys are trying to throw a baseball and getting into end range exo rotation arms way far behind them. So for me it’s a case by case basis. I don’t see a whole lot of traumatic injuries where they have like a severe capsular tear, labral tear and then they’re having a hard time getting back from that position. Generally it’s more kind of multidirectional instability. But I think it’s probably going to be very similar from sport to sport. So one you just have to start slowly and it’s going to be on an individual basis. So some folks are probably going to progress really quickly and some people are going to be quite a bit slower. But I would just say you have to introduce this positions really slowly, gradually, and appropriately. Monitor for symptoms, why it’s happening and then the next day on if things are progressing well and just keep on pushing along until you’re back to doing what you want to get back to. So-

Mike Reinold: I like it.

Dan Pope: So, kind of general answer.

Mike Reinold: No, but I mean I think, I think that’s right. It’s just like what we said before with like the direction of instability. Now when you need to do is take the range of motion things, take the activities that they’re doing and think like, all right, what, what do I need to get them back to and are there any vulnerable positions and how do we start getting into that. So Mike, did you have a little more, yeah?

Mike Scaduto: Yeah, one big thing I think about when I’m particularly thinking about anterior instability is getting people back to pressing activities like bench press type things. So I, so in my mind I typically want to limit the range of motion into horizontal abduction or have the elbow dropping below the thorax. So I usually start them off with a floor press, but I was kind of wondering Dan, like what, what’s your typical progression getting people back into the bench press particularly?

Mike Reinold: You know what, before you answer Dan, bench press is a good one because it’s bad for both anterior and posterior in different ways. So yeah, no, I’m eager to hear Dan.

Dan Pope: Yeah, good one. Well again, I just don’t see it a ton in my world it’s not like people are having a whole lot of traumatic injuries where they have a lot of anterior stability and you can’t bench press because of it. The other thing to keep in mind is if you’re doing an aggressive powerlifting bench press or you’re really bring your chest up quite a bit, there’s a little bit of extension, there’s a little bit of horizontal abduction it’s not like your arms come way far behind you. Plus you’re also in kind of a neutral rotation position. So something like a bench press isn’t too tough for most folks. But yeah, you have a really good idea, progression in mind. So you can do partial range of motion presses. Maybe you have an athlete we’re doing floor press or maybe doing some board press.

Dan Pope: Another thing I like for those folks, are band presses and also chain presses just because if you’re doing a press and for the people who don’t know this is you put bands or chains around the bar attached to the floor or just hanging for the chains. So when you go deeper and deeper and deeper into your bench press, less weight is your…More weight is on the floor so you don’t have to work quite as hard. So when the shoulder is at its max point of, I don’t know, potentially anterior translation of the humeral head, there’s a little less stress in the shoulder. And as you press, press, press, press, press towards lockout, there’s more and more weight or the shoulders in a position where it’s not quite as unstable. So again, good ideas, but the other part is I tend not to see it that much and stuff like a bench press doesn’t really put you into an extreme end range.

Mike Reinold: Right.

Lenny Macrina: I liked the concept. I think it’s a good exercise and I use that a lot for my particularly anterior instability people just because of the closed chain nature of it and the co-contraction, so it’s kind of like flipping and doing a pushup, like starting with a pushup on a table where, you know you start out on a wall push up, to a table push up, to a floor pushup. I like the closed chain aspect because of the co-contraction and it’s a nice stable position. That’s my daughter. And it’s a nice stable position for the shoulder joint, especially if somebody gets hurt posteriorly I’m a little hesitant because of that effect that Mike talked about, Scaduto talked about. But for some of the interior, I like the closed chain aspect because I think it’s a really good way to get co-contraction and really give somebody confidence in that humeral head is not going to feel like shifting.

Mike Reinold: I’m glad you noted that was your daughter. If you were in like Starbucks or something with some random little girl came up and hugged you that would have been super weird. All those reporter videos, your wife’s crawling in the background trying to get her. That’s awesome. Well another great question. Thanks so much. I mean our 200th question actually more because we used to answer a bunch of questions in there. Wow, we might be, we might be like well over 500 questions at this point. We probably are. So anyway, thank you so much. Before we have our final sendoff, if you’re that much of a fan and you’ve watched this much of the episode, which I know not everybody does, I just want to highlight one thing. Len, is there anything odd on Dave Tilley’s desk right now before Dave has to go? Is there anything that’s odd?

Lenny Macrina: We love Dave, and we love Dave, but Dave has a collection of blue and black pens that I am very jealous of because at Champion, we barely have any pens. I think I found all of our pens right there next to his monitor. So hey, next time we open when this pandemic ends, can you bring us some pens? Buy some off of you.

Mike Reinold: Just quickly tell us about the need for 100 pens, both 50 black and 50 blue for easy, easy access on your desk.

Dave Tilley: First of all, you will have no pens ever for the rest of your life. And I will, I will hoard them all. No.

Lenny Macrina: Apparently.

Dave Tilley: So the reason that I got a large chunk of pens is because I’ve been using them, but I was tired of paying shipping on smaller amounts of pens and so I figured I’m probably going to write for the rest of my life so I might as well just buy them in bulk.

Mike Reinold: So do you like throw them away after each use or do you need easy access to all one hundred?

Dave Tilley: I’ve had these for like eight months, so I use them all.

Mike Reinold: Just mix them up.

Dave Tilley: I don’t, I also don’t have like drawers. I have a standing desk. So there’s no drawers, there’s only shelves.

Mike Reinold: But you look like you’re sitting right now.

Dave Tilley: I’m sitting in a big chair.

Mike Reinold: At a standing desk. I like it. We should, we could almost have like home office tours with this. So I just-

Dave Tilley: Come on, I’m like, I’m a gymnast. I’m like five feet tall. You think I’m as tall as my book shelf?

Mike Reinold: Awesome. Well, hey, thank you so much everybody again, please asking. Let’s do another 200 of these episodes, right? If you have a question, head to click on that podcast link and we will do our best to get through all these answers. Anything you want to talk about, you know, PT, fitness, business, sports performance, anything you guys, you guys want, we’re happy for you guys, and thank you again so much for our 200th episode. Thank you so much. See you on the next episode.