Sports Medicine Research: In the Lab & In the Field: Can the Sleeper Stretch Increase Range of Motion and the Sub-Acromial Space? (Sports Med Res)
Monday, September 10, 2012

Can the Sleeper Stretch Increase Range of Motion and the Sub-Acromial Space?

Quantifying Acromiohumeral Distance in Overhead Athletes With Glenohumeral Internal Rotation Loss and the Influence of a Stretching Program

Maenhout A, Van Eessel V, Van Dyck L, Vanraes A, Cools A.  Am J Sports Med. 2012 Aug 6. [Epub ahead of print]

It is well known that overhead athletes develop a loss of internal rotation (IR; also called glenohumeral internal rotation deficit or GIRD) and a gain of external rotation (ER).  Recently, it has been demonstrated that baseball players with GIRD are more likely to develop shoulder injuries.  It has been suggested that GIRD is caused by a tight posterior capsule and during ER the tight capsule may alter the arthrokinematics of the shoulder by moving the head of the humerus in a posterior-superior direction thereby decreasing the acromiohumeral distance (AHD).  However, it currently unknown if this occurs and if stretching of the posterior shoulder improves motion and the AHD.  Therefore, the purpose of the study was to compare bilateral AHD in overhead athletes with GIRD (> 15° loss of IR) and to examine the effect of the sleeper stretch on AHD and IR.  The authors assessed bilateral range of motion (IR, ER, and horizontal adduction) in the supine position with the scapula stabilized among sixty-two overhead athletes with GIRD.  AHD was measured using diagnostic ultrasound at rest, 45°, and 60° of abduction.  Athletes were then randomly divided into a stretching (n = 30) or a control (n = 32) group.  The stretching group performed the sleeper stretch daily (3 reps of 30 sec holds) for 6 weeks on the dominant arm.  All stretching was performed by the athletes with no sessions from physical therapists or athletic trainers.  The control group did not perform the sleeper stretch but were asked to maintain normal activities.  Range of motion and AHD were reassessed after the 6-week intervention period.  At baseline, the authors found that dominant arms’ IR and horizontal adduction were significantly less and ER was greater compared to the non-dominant for both groups.  Also, AHD was smaller on the dominant arm compared to the non-dominant.  When examining the effect of stretching there was a significant increase on the dominant arm for IR, horizontal adduction, and AHD at all positions.  There were no changes on the dominant arm of the control group. 

This study is the first to demonstrate that the dominant shoulders of overhead athletes with GIRD have reduced AHD compared to the contralateral shoulder and that sleeper stretching improves the AHD in just 6 weeks.  Clinically, this is a very important finding which gives support for both the hypothesis that GIRD will cause a decrease in AHD and that stretching not only improves ROM but also increases the AHD.  A loss of AHD has been suggested to cause impingement of the rotator cuff and lead to tendon degeneration or even tears.  Maximizing the AHD may minimize the risk of impingement and maintain the health of the rotator cuff.  Previous research has found that GIRD can increase the chance of shoulder injury.  By performing the sleeper stretch the athlete can eliminate GIRD and increase AHD thereby reducing the likelihood of injury; however, more research may be needed to verify the reduce risk of injury.  One limitation of the study was that AHD was not assessed at 90° of abduction which is the functional position of overhead athletes.  However, based on their data there was a significant improvement at all of the tested shoulder positions up to 60°.  This may suggest that a similar finding would have occurred at the 90° position.  It would also be interesting to examine other methods to increase IR in overhead athletes (posterior joint mobilizations, active release, etc).  A nice follow-up to this study would be to follow these athletes over the season to evaluate injury rates.  What are your thoughts on this study?  Do you currently use the sleeper stretch or do you have other ways to reduce GIRD?  Do you think a decrease in the AHD contributes to shoulder injuries in overhead athletes with GIRD?

Written by:  Stephen Thomas
Reviewed by:  Jeffrey Driban

Related Posts:
Maenhout A, Van Eessel V, Van Dyck L, Vanraes A, & Cools A (2012). Quantifying acromiohumeral distance in overhead athletes with glenohumeral internal rotation loss and the influence of a stretching program. The American Journal of Sports Medicine, 40 (9), 2105-12 PMID: 22869627

10 comments:

Anonymous said...

I use the sleeper stretch and it's great to have evidence that it increases AHD. My only question is if they have excess ER of the shoulder already due to their sport, have we now promoted a hypermobile shoulder at risk for instability?
-BN

Stephen Thomas, PhD, ATC said...

This is an excellent question and unfortunately one that doesn't have a clear answer. We do know that recent research has demonstrated that decreased internal rotation and loss of total motion on the dominant arm has been associated with an increased risk of shoulder injury. The cause of this increased risk is still not know. Based on that alone, improving internal rotation seems very important to decrease the risk of shoulder injuries. However, as you point out now the athlete may be mobile in both the posterior and anterior directions. Anecdotally speaking, I think as long as you increase total motion so there is no bi-lateral difference then you arent making the athlete hypermobile in the posterior direction and overall decreasing the risk of shoulder injuries. More research is clearly required in this area to determine the cause or causes of shoulder injuries as they relate to decreased internal rotation. Once we identify the true anatomical or biomechanical changes that are leading to injuries then we can examine specific treatments to target that adaptation.

Mark A. Rice said...

Great write-up, Steve. There's a few points that I'd like to make regarding this post. First, i do believe that there is some association between posterior shoulder capsule length and GIRD and injury. However, I believe that one item that isn't looked at or appreciated is the IR loss that is resultant from the inherent osseous adaptations that occur in the throwing shoulder. We see these young throwers coming in all the time with nebulous shoulder pain during their baseball seasons right in the midst of skeleteal development. Then people want to just hammer IR stretching, when in fact they need to compare ER gain to IR loss. This is especially important in the younger athletes that are still developing. Stretching IR in these individuals without comparing to ER could conceivably be a waste of time if the motion differentials are equal and the shoulder pain is rooted in bony changes. There is no question that bone adapts to the mechanical stresses placed upon it, and I contend that IR loss starts first at the bony level as the humeral head retroversion angle increases. Many clinicians don't think about osseous component to a decrease in IR, and that's why it's imperative to understand how the "total arc of motion" works. Future longitudinal research needs to be done to quantify shoulder pain, ROM changes and humeral version radiographic changes to prove this theory. Whoever does that, could make a career out of it.

MEShiresATC said...

When evaluating a throwing shoulder, total motion is a secondary concern as compared to GIRD. Where the ER arc is the distance that forces can be applied to the arm/ball the IR arc is the distances that deceleration has to take place. If that IR arc is deficient something has to give or change.
Example in real life - we all know that using a hammer with wrist action will lead to medial epicondylitis, that is why "swinging" a hammer is more efficient (whole arm). What if you can't swing it, you don't have the IR to do it? You are going to have to make some sort of an accommodation: anterior tip the scap, forward flex the trunk, swing the hammer across your body, or use more wrist action. ie why we are seeing such a high correlation between GIRD and elbow.
Second, if you are comparing total motion, and >IR and <ER - where and how are you going to affect change? IR stretching and perturbation in ER? That is all fine and good, but as soon as they go back to throwing ER increases(usually a Dx of posterior impingement). This change will need to be made in mechanics, but you still will have to address the lack if IR.
I do enough shoulder assessments where total motion is so skewed because of the excessive ER gains and IR gains (stretching) are present without a Hx of injury to know the total motion is less important.
And on the flip side, for some reason with left hand pitchers the total motion, ER and IR is LESS than their right side (cannot account for hand dominance) that total motion is not as big a factor as GIRD.

Mark A. Rice said...

All great points, Mark. I was specifically referencing the skeletally imature, with the older more developed athlete, i couldn't agree with you more. My point being, that with young throwers lets be sure to truly identify where IR changes are coming from and not be too quick to assume that it's just a result from soft tissue changes. Love having baseball guys weigh in. Thanks!

BJ Maack said...

Love the discussion....

I always look first at how the scapula moves before I focus too much on IR/ER. If the scap doesn't allow proper ROM, then it really doesn't matter what IR/ER is. More of my throwers get symptom relief when their scap is mobilized (superior/inferior glides, then rotating the tip).
The scapula is the foundation of the whole shoulder

Mark Shires, ATC said...

The more shoulder work I do, the more important controlled upward rotation becomes apparent.

If you cannot control the scap, everything else is worthless, lower trap and serratus play the ultimate role.

Tasher said...

Good study! Just wondering- what can we expect to find in tennis players? They aren't overhead athletes per se, but in the case of men in particular who may play 4-5 hours, there is a significant number of overhead movement as they serve. These serves are constantly above 100mph. They follow the serve with a predominantly internal rotation as the follow through across the body with the forehand. Thoughts on the AHD distance, IE and ER in that case?

Stephen Thomas, PhD, ATC said...

Great discussion! I will try to hit on everybody's comments here. I do agree GIRD is very important however it is very important to know the amount of humeral retroversion that exists in each player. Without this information we may be going beyond physiological limits with stretching. I know in most cases you are fighting an up hill battle with throwers especially during the season so this may not ever be a concern. In addition we currently don't know which of the three adaptations that lead to GIRD actually cause shoulder and elbow injuries. It is thought that during external rotation the humeral head shift in a posterior superior direction and this shift is a major cause for several injuries. However, which adaptation causes this? Is it humeral retroversion? Is it rotator cuff tightness? Or is the posterior capsule tightness/thickness? Or all three? Clearly we cant do anything to the bony changes but we could address the soft tissue adaptations but which soft tissue adaptation do we address? If we mob the shoulder and reduce GIRD but its not the capsule then that may actually be detrimental to the athlete. If we stretch the rotator cuff and reduce GIRD but its not the cuff then we didnt address the necessary tissue adaptation. We need to determine this in research to better treat these athletes. In terms of the scapula I agree that if the scapula isnt mobile then that will cause shoulder issues but with the scapula and the glenohumeral joint its still the chicken or the egg. Which alteration came first? If we never let GIRD occur will the scapula experience alterations? We don't really know. Finally tennis players are overhead athletes and this information implies to them as well. Ben Kiblers shoulder work all started with high level tennis players and these motion changes have been demonstrated in tennis players serving arm. Thanks for all the comments and keep them coming! This is how new ideas and research is created!

Becca Feuerherd said...

I agree with Stephen Thomas' point that it is necessary to know the amount of humeral retroversion present in the athletes we are treating. It is extremely important to know whether the internal rotation deficit is a true capsular or muscular restraint, or if the decreased internal rotation is merely an adaptive bony response to overhead activity. Without this knowledge, it is almost impossible to have clear rehabilitation goals for GH ROM.

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