Friday Interview: Dr. Lizzie Hibberd Discusses Swimmer's Shoulder Prevention

1. Please introduce yourself to the readers (how you started in the profession,
education, credentials, experience, etc.).

Hello all! My name is Lizzie Hibberd and I am currently serving as an Assistant Professor and the Director of the Athletic Training Research Laboratory in the Department of Health Science at The University of Alabama. I received my B.A. and M.A. degrees in Athletic Training from the University of North Carolina at Chapel Hill (2008 and 2010) and received a Ph.D. in Human Movement Science from the University of North Carolina at Chapel Hill in 2014.

My interest in athletic training began when I was in high school. After injuring my shoulder and relying on the help of athletic trainers for evaluation and rehabilitation, I began working as a student athletic trainer. From my experience as an injured athlete and working as a student athletic trainer, I chose to attend UNC-Chapel Hill and started in the Athletic Training Program. After undergrad, I stayed at UNC and worked as a graduate assistant athletic trainer for UNC’s Swimming and Diving and JV Basketball teams. As soon as I began working with the UNC Swim Team, I realized there was a huge gap in the literature about prevention, assessment, and treatment of swimming related shoulder injuries. In order to improve the quality of care for athletes and advance the profession through evidence-based medicine, I continued my education in the Human Movement Science Program. While in the program, my research focused on injury biomechanics and injury prevention in overhead athletes- primarily swimming and baseball.

2. You have been the predominant researcher in the US on swimming shoulder injuries. What have been your pieces and interest in the sport?
My interest in the sport developed when I was working as an athletic trainer with the UNC Swimming Team. This was really my first exposure to the sport, where I understood the demands that were placed on the athlete. The first few months were definitely a huge learning curve for me to really understand the training and the culture of the sport. During this time, I developed such an appreciation for a sport that very few people know anything about. As I was treating athletes and trying to develop injury prevention programs, I discovered that there was a huge gap in the literature related to swimming injuries. From this experience, I decided that I wanted to focus on clinically applicable research to improve the quality of care for swimmers and other overhead athletes and began my research career on injury biomechanics and injury prevention. During this time, I have worked with youth, collegiate, and masters swimmers both in clinical and research capacities.

3. For your paper regarding the general rehabilitation program and scapular stability (dyskinesia), what did you look at?
For this paper (Effect of a 6-Week Strengthening Program on Shoulder and Scapular-Stabilizer Strength and Scapular Kinematics in Division I Collegiate Swimmers), we looked at the effect of a shoulder injury prevention program on physical characteristics in collegiate swimmers during the training season. The injury prevention program that we used was adapted from exercises that have been shown to be effective for injury prevention or strengthening scapular stabilizing musculature in baseball players. The characteristics that we looked at as part of this project were glenohumeral range of motion, scapular kinematics, posture, shoulder and scapular stabilizer strength, and pain score.

4. What were the main results?
In this project, we found that overall all swimmers moved in to greater forward shoulder posture and altered scapular kinematics that promote impingement regardless of group assignment. The strengthening program that was used in this paper was not robust enough to counteract the demands of the training load during the training season.

5. How could the rehabilitation programs prescribed be improved?
From the results of this study, the biggest places for improvement is on the timing of implementation. While most swimmers take a short rest period before their training season, this may be the most beneficial time to complete an injury prevention program. During the training season, the fatigue they experience from high training loads increases their risk for the development of injury. Completing a strengthening program prior to this heavy training would put the athlete in better position to mitigate the demands of the training. During the training season, a maintenance program should be completed with a greater emphasis on stretching.

Also, the findings of this study highlighted the importance of research specific to swimmers. Many times all overhead athletes are grouped into the same category and programs that are effective for baseball players are automatically applied to swimming. The demands and adaptations are unique to each overhead sport, and research is needed specific to each sport to best help the athlete.

6. You had another study monitoring shoulder pain via questionnaire in club swimmers. What were the main results of this study?
In this study (Practice Habits and Attitudes and Behaviors Concerning Shoulder Pain in High School Competitive Club Swimmers), we looked at 13-18 year old competitive swimmers that are training on the top training level at their clubs in order to understand the culture of swimming. We found that these adolescent club swimmers have a high frequency of practices, comparable to collegiate and professional swimmers. They believe that shoulder pain is normal and should be tolerated to complete practice and are regularly taking pain medication in order to manage their pain so that they can complete practice yardage.

On the plus side, we found an association between the swimmers' attitudes and behaviors, which indicates that interventions that educate the swimmers, coaches and parents may be effective in changing their attitudes and ultimately their behaviors, and potentially changing these cultural norms.

7. As a PT, these results really upset me. What were your thoughts on the incidence of pain and current practice?
From working clinically with swimmers, I was not surprised that training with shoulder pain is the cultural norm in competitive swimmers. Currently, the training demands in these youth athletes are tremendous and so far, there is only anecdotal evidence that these training methods are effective. This high volume of training leads to alterations in physical characteristics that predispose swimmers to shoulder pain and injury. In the future, I hope coaches and researchers partner to identify training methods that maximize performance while minimizing injury risk. This will take a lot of collaborative work, but I will be imperative in preventing these injury and making evidence-based practice and injury prevention guidelines.

8. If a swimmer is having pain in their shoulder in practice, in your opinion, what should the coach do?
I think the biggest thing that the coach can do is make it known that injury prevention and awareness is a priority. It seems like many of the swimmers that I have previously worked with (across levels) are afraid to tell their coach or don’t even think that it is something they should report because shoulder pain has been normalized in the sport. It would be beneficial for coaches to have education sessions with their athletes, or even better bring in a sports medicine professional, to talk about shoulder pain and injury prevention.

If an athlete does report true shoulder pain, where they are having pain and altering their stroke mechanics in order to complete the necessary yardage, the coach should remove the athlete from practice for that session, have then kick (not with a kickboard because that is impingement position!), or have them do some type of cardio out of the water. Removing from practice is only one part of the solution, though. The coach should talk with the athlete to determine what bothers them and evaluate how dryland training, weights, or specific swimming drills may be contributing to their pain. Making these alterations would benefit that specific athlete, but also others who are not reporting their pain. It would also be imperative for this athlete to begin a rehab program- which is where a sports medicine professional (physician, athletic trainer, or physical therapist) would be crucial.

9. Recently, you were part of a study monitoring stroke biomechanics in college swimmers. What did this study look at and find?
In this study (Prevalence of Freestyle Biomechanical Errors in Elite Competitive Swimmers), we evaluated the prevalence of biomechanical stroke errors in collegiate swimmers using underwater cameras. We focused primarily on freestyle, because of the heavy training load in the freestyle stroke regardless of stroke specialty. Both coaches and an athletic trainer graded each swimmer based on the defined errors. The biomechanical errors that we defined were a dropped elbow during the pull-through phase, a dropped elbow during the recover phase, an eyes-forward head-carrying angle, incorrect hand position during hand entry, incorrect hand entry angle, incorrect pull-through patter, and inadequate body roll. We found a high prevalence of errors in these elite swimmers, with dropped elbow during the pull-through and the recovery phases with the highest prevalence. We also found relationship between dropped elbow during recovery and improper hand entry position and angle and eyes-forward heady carrying angle with incorrect pull-through pattern. This indicates that presence of one of these errors is related to having an additional error.
 
10. Did these results surprise you?
Not really. From previous work that we have done, most youth athletes believe that there is not enough time spent on technique work in practice. I think there is so much emphasis on the number of yards that the quality of the yards is sometimes put aside. Further, the errors that we identified were from a variety of coaching and biomechanical literature, but to our knowledge a comprehensive list of stroke errors related to injury had not previously been created. Finally, some of the coaches the evaluated the videos commented that while they understood why this was biomechanical error, performance-wise it was how they taught the stroke. This is another area of opportunity for biomechanists and coaches to work together to identify ways to maximize performance while minimizing injury risk.

11. What steps can be made for improving biomechanics in college swimmers?
In my opinion, the biggest way to improve biomechanics is to put an emphasis on it in age-group swimming. It is hard to change the motor patterns of a collegiate swimmer, who may have been swimming with a certain stroke for 13+ years. However, if you do have an athlete that you want to focus on changing their stroke, I believe video is one of the most important tools for the athlete. Many athletes, and especially swimmers because they rarely get to see their stroke, respond well underwater video where they see the problem in their stroke, as well as have their progress tracked as they make the change. While there are many expensive software and cameras out there for this, things like GoPros and even iPhones with an underwater case may be adequate as a beginning step in film evaluation.

12. Same question, but with age-group swimmers?
This is the place where there is the greatest opportunity for installing proper swimming mechanics and making changes! An emphasis on proper stroke regularly during practice, individual work if necessary, video analysis, and modeling of proper strokes is imperative at this age. Ensuring proper mechanics before moving on to high yardage is critical.

13. What research or projects are you currently working on or should we look from you in the future?
I recently completed a project tracking youth swimmers over the course of their training season to identify what physical characteristics change during the training season and how this relates to alterations in pain levels and another project tracking postural changes in collegiate swimmer during the season. The findings from this study will help in developing evidence based injury prevention programs.

My future research agenda includes: validation of an evidence-based injury prevention program, development of a swimming pain and function survey, prospective analysis of risk factors for injury in competitive swimmers, and research on training load and recovery. All of these areas/projects will hopefully help in maximizing performance while minimizing injury risk in competitive swimming!

Thank you for the opportunity to discuss my research with you! Please feel free to contact me with questions, research ideas, or comments.

Elizabeth Hibberd, PhD, ATC
The University of Alabama
483 Russell Hall
Box 870311
Tuscaloosa, AL 35487-0311
eehibberd@ches.ua.edu
205-348-7320

Post-Operative Prognosis for Swimmers

Take Home Points on Post-Operative Prognosis for Swimmers

    1. Many factors determine shoulder surgery outcomes
    2. Prognosis for return to prior levels of performance is bleak for overhead throwing athletes
    3. Limited research exists on post-op outcomes on swimmers
    Shoulder injuries are unfortunate realities of competitive swimming.  Most commonly, injuries can be treated with some combination of rest, treatment, and exercise.  Evidence favors conservative care before trying surgery and also encourages rehabilitation post-op for optimal function.  Unfortunately though, many injuries progress to needing invasive care (ie surgery). 

    Many factors go into surgery: surgical skill, injury mechanism, severity, patient status (Age, health, etc), patient motivation, among others variables.   But what are realistic expectations for surgical outcomes among swimmers?  At the extremes, some believe you can never return to prior performance, while others believe surgery cures all.  The truth likely exists somewhere in the middle. 

    Asking the right questions is imperative: what are the chances of returning to prior level of performance (or even higher)?  Surgeons may sometimes evaluate success based on a) the quality of their craftsmanship (it didn’t break!!!!) and b) whether the patient can resume normal activities of daily living.  The problem for swimmers is that the swimming shoulder has far greater demands than 99 pct of the general population. 

    To my knowledge, there has been no formal study on post-op outcomes on return to level of performance in swimming.  Designing these studies can be difficult too, with the temptation of surgeons to cherry pick cases with a likelihood of a favorable outcome.  Though swimming has unique demands, research from other sports can offer some clues. 

    One recent study (Fedoriw 2014) examined professional baseball players who suffered superior labrum anterior posterior (SLAP) tears.  Of the pitchers, 22% who attempted conservative (non-surgical care) returned to a prior level of performance or higher, with level marked by the level of league in which they competed (A, AA, AAA, Majors).  Only 7% who underwent surgery returned to prior performance levels though 48% returned to play at all.  However, among non-pitchers, 54% returned to prior performance levels.

    A similar study by Van Kluenen (2012) focusing only on pitchers revealed another low rate of return to prior performance.   All players studied underwent surgery (no conservative care in this study) but only 6 of the 17 players in the sample returned to their same or higher level of play following their procedure.  Notably, all the patients in this study presented with Glenohumeral Internal Rotation Deficit (GIRD). 

    Another review (Sayde 2012) expanded the inquiry beyond baseball players and found
    better results among non-overhead athletes.  Overall, 83% had "good-to-excellent" patient satisfaction and 73% returned to their previous level of play whereas only 63% of overhead athletes returned to their previous level of play.”  Though the results seem more favorable when expanded beyond pitchers, it’s still unclear where swimming falls on the continuum between non-overhead athletes to pitchers.

    Conclusion

    Shoulder surgery is a very personal choice.  While favorable outcomes are very possible in high level athletes, the prognosis gets bleaker with greater overhead demands on the shoulder.  If we equate swimming shoulder demands to baseball pitchers, at best we can say that return to prior performance levels is unlikely.  That said, there can be many confounding variables at work.  Better surgical skill and deeper athlete motivation can make or break and outcome.  Ultimately, know that swimmers who return to higher levels of performance after shoulder surgery have done so against long odds. 

    References

    1. Fedoriw WW1, Ramkumar PMcCulloch PCLintner DM.  Return to play after treatment of superior labral tears in professional baseball players.Am J Sports Med. 2014 May;42(5):1155-60. doi: 10.1177/0363546514528096. Epub 2014 Mar 27.
    2. Van Kleunen JP1, Tucker SAField LDSavoie FH 3rd.  Return to high-level throwing after combination infraspinatus repair, SLAP repair, and release of glenohumeral internal rotation deficit.  Am J Sports Med. 2012 Nov;40(11):2536-41. doi: 10.1177/0363546512459481. Epub 2012 Oct 10.
    3. Sayde WM1, Cohen SBCiccotti MGDodson CC.  Return to play after Type II superior labral anterior-posterior lesion repairs in athletes: a systematic review.  Clin Orthop Relat Res. 2012 Jun;470(6):1595-600. doi: 10.1007/s11999-012-2295-6.
    Written by Allan Phillips is a certified strength and conditioning specialist (CSCS) and owner of Pike Athletics. He is also an ASCA Level II coach and USA Triathlon coach. Allan is a co-author of the Troubleshooting System and was selected by Dr. Mullen as an assistant editor of the Swimming Science Research Review. He is currently pursuing a Doctorate in Physical Therapy at US Army-Baylor University.

    Are Ice and NSAIDs Beneficial for Recovery?

    Take Home Points on Are Ice and NSAIDs Beneficial for Recovery?
    • Ice helps decrease pain, but does increase muscle damage.
    • NSAIDs restore function, but improve bone, but not soft tissue healing.
    The use of non-steroid anti-inflammatory drugs (NSAIDs) and ice are common staples in
    sports medicine. Yet, the use of these modalities has recently received resistance from some online experts (Kelly Starrett, Dr. Gabe Mirkin). Despite this criticism, these modalities are still frequently used, sometimes ad libium. Now, before I make a notion on these modalities, it is important to understand the injury process, below is an exert from the COR Swimmer's Shoulder System.

    Everyone is familiar with inflammation. The inflammatory process occurs within seconds of every injury, but can linger for weeks or months with bad injuries or poor management.

    Inflammation is stemmed by the infiltration of cells, entitled neutrophils, during the first 6-24 hours; they are replaced by other cells (monocytes) in 24-48 hours. These cells will try to attack the inflammation and remove injurious agents. Phagocytosis is involved in the process of engulfing foreign particles and releasing the enzymes of neutrophils and macrophages which are responsible for eliminating the injurious agents. These are two major benefits derived by the accumulation of leukocytes at the inflammatory site.

    Chronic inflammation is a different warrior. The key player is another type of cell, the macrophage. Macrophages are large cells that can remain for weeks to months, perpetuating injuries.

    The classic signs and symptoms of inflammation are swelling, redness, throbbing, radiating heat, and constant pain. These pains especially occur when you wake up in the morning and last between thirty and sixty minutes. Also, just because you had the initial injury four months ago doesn’t mean inflammation has resolved or hasn’t returned, so pay closer attention to the signs and symptoms as opposed to the duration.

    Once again, the inflammtory process initiates every injury. This process is beneficial in restoring the body, but does decrease strength. This decrease in strength is why many seek improvement [well and the pain]. This has resulted in the use of the two most common modalities NSAIDs and ice. Unfortunately, these two modalities may prevent the normal physiological reaction of an injury. This impairment is thought to alter long-term improvement. However, many people take NSAIDs and ice for short-term gains. If someone needs improvement, for a quick return to the pool, then NSAIDs and ice are beneficial. However, the use of these modalities likely decreases long-term recovery, perhaps increasing the risk of re-injury. Unfortunately, most of this research is based on rodents, not humans and as I've mentioned before, rodents have different inflammatory processes! This makes the research nontransferable to humans ... oh well! Nonetheless, lets look at the research we have!

    NSAIDs on Healing

    The authors reviewed the effectiveness of NSAIDS and selective (COX-2 inhibitors) NSAIDS on soft tissue and bone healing. A total of 44 articles reviewed (9 on soft tissue and 35 on bone healing). Thirty-nine of these articles were on animals and 5 on humans.

    No humans studies have been done on humans assessing the interaction between NSAIDS and soft tissue healing. Of the studies reviewed, there is a controversy between the administration of selective and non-selective NSAIDS after surgery, as many studies suggest detrimental effects on bone and soft tissue healing. However, the literature on this subject in humans is minimal.

    It appears inflammation mediated by prostaglandins is necessary to improve bone healing. However, in soft tissue injury, growth factors are more important and prostaglandins less involved. This suggest NAIDS are likely beneficial in soft tissue, but potentially not bone healing.

    Improving inflammation is necessary to decrease symptoms, however the use of NAIDS during bone repair may impair recovery, therefore only use NSAIDs in soft tissue injuries. However, more human clinical trials are necessary before a definitive answer is possible.

    NSAIDs on Gut Bacteria

    One potential hazardous result of NSAID consumption is the potential loss of integrity of bacteria, making the gut permeable to harmful substance.

    Nine male trained cyclists underwent small intestine lining permeability in four different conditions (Van Wijck 2012):

    1) during and after cycling after intake of ibuprofen

    2) during and after cycling without ibuprofen

    3) rest with prior intake of ibuprofen

    4) rest with prior ibuprofen intake

    The small intestinal lining was evaluated by providing the subjects a sugary drink, then assessing the amount of human intestinal fatty acid binding protein (I-FABP).

    The ibuprofen conditions took 400 mg of ibuprofen the night before and 1-hour prior to cycling on a fasted stomach. The cyclist performed roughly 90 minutes of cycling at moderate/hard cycling.

    In both exercise conditions, the I-FABP levels gradually increased with cycling. However, cycling with ibuprofen ingestion resulted in even high levels of I-FABP.

    These results show cycling alone increases both gastroduodenal and small intestinal permeability. This difference increased with ibuprofen intake. This is thought to be from splanchic hypoperfusion, reducing the blood to the gut and including injury to the enterocytes. One of the major pathways suspected for GI damage is:

    “to be involved is the inhibition of COX isotypes 1 and 2, resulting in local inflammation and vascular dysregulation, ultimately reducing perfusion and promoting mucosal integrity loss within the splanchnic area (Van Wijck 2012)”.

    Unless ergogenic benefits from NSAIDs exists, swimmers should not use these medications prior to exercise. Moreover, inflammation may yield greater results in endurance sports. One flaw with the study is the fact the athletes were fasted while taking NSAIDs. However, one note is the athletes were fasted during this test, this may have increased the intestinal lining to susceptibility.

    For rehabilitation, NSAIDs may still be beneficial, but at this time it is not certain if the benefits outweigh the risks.

    Ice and Muscle Damage Healing

    Eleven male college baseball players underwent two trials: sham application and topical cooling. Each trial was used five sessions of 15-min cold pack application to the exercised muscles 0 hours, 3 hours, 24 hours, 48 hours, and 72 hours after eccentric exercise training.

    The eccentric training protocol consisted of 6 sets of 5 eccentric contractions with 2 min rest between sets at 85% of their maximal strength. Muscle hemodynamics (hemoglobin most notably), inflammatory cytokines (multiple interleukins), muscle damage markers (Creatine kinase), visual analog scale (VAS), and muscle isometric strength.

    After topical cooling, rapid and sustained elevations in total hemoglobin and tissue oxygen saturation were noted. Also, creatine kinase was noted in both trials, but was elevated after topical cooling. Inflammatory markers were not changed following cooling. VAS was not different between groups, however topical cooling significantly increased rating of fatigue post-exercise. No significant differences were noted in strength between groups.

    Increased muscle damage, most notably the creatine kinase increase, was apparent in the topical cooling group. This is thought to occur from the rapid deviation in blood supply to the muscle.

    Using ice after practice improves muscular soreness, but appears to increase muscle damage due to rapid changes in ischemia. Therefore, unless injured topical cooling should be avoided.

    Ice and Blood Flow

    Nineteen subjects participated in this single-blinded, where the clinician was blinded. There was no history of lower extremity injuries for the past 6 injuries. Each participant visited the laboratory four separate times where baselines were measured at the first two visits, then the next two visits a trial of ice (750-g of crushed ice placed on the medial gastrocnemius) and a control trial.

    “There was a significant correlation (r = 0.49) between subcutaneous tissue thickness and change in intramuscular temperature immediately after treatment (P = 0.05) for the cryotherapy condition. Significant correlations were also found for change in temperature during the rewarming period and change in blood volume at rewarming (r = 0.53, P = 0.033) and change in blood flow at rewarming (r = 0.56, P = 0.025) for cryotherapy (Selkow 2012)”.

    Microvascular perfusion of the gastrocnemius did not decrease from baseline with cyrotherapy was applied, despite the decrease in subcutaneous temperature. The result was different than past studies, as many think cryotherapy decreases blood flow. This may be from no alterations noted in the microvascular.

    In the healthy population, cryotherapy appears not to alter blood-flow. Therefore, benefits and risks associated with cryotherapy application for inflammation may be negligible. However, next research must look at inflammation specifically. Until then, the effects of ice for injuries seem purely for slowing nerve conduction to gate pain.

    NSAIDs or Corticosteroids for Recovery


    Zheng (2014) performed a systematic review of all the high-quality studies comparing NSAIDs and corticosteroid injections, a total of ten full articles. Overall, 267 patients were analyzed and of the six studies two focuses on rotator cuff tendonitis patients, two on shoulder impingement syndrome, one studied frozen shoulder of diabetes and the other investigated shoulder pain.

    Of these studies, NSAIDs and corticosteroids did not have a significant difference in pain improvement. Corticosteroids were significantly better for remission of symptoms. Five of the studies reported range of active shoulder abduction and note NSAIDs did not significantly improve the active shoulder abduction compared to corticosteroids. The studies assessed were 4 – 6 weeks in length.

    Compared to NSAIDs, corticosteroid injections provide faster relief. However, comparisons of other therapies and conjunctions of therapy are needed, as well as longer study periods and follow-ups.

    My Recommendations


    If you are injured, stop exercising. If the pain is non-stop, see a rehabilitation specialist like a physical therapist. At this time, apply ice, as it does reduce pain and doesn't seem to alter blood flow. However, apply the ice for a short period, as it may increase muscular damage. I suggest applying the ice for up to 10 minutes and remove it for 20 minutes. Only ice immediately after the injury, ~6 hours after the injury. If you are competing at a meet and must perform, NSAIDs can help decrease pain and restore function. However, if you are not in a rush for return, try not to ice and consider compression instead. Compression helps naturally clear the fluid from the joint, facilitating recovery. When you are able to move comfortably without pain, do so. Movement also helps move fluid out of the joint and restore function. However, do not move into pain, as this can alter movement patterns and impair function. 

    Try and prevent using NSAIDs, unless unrelenting pain exists and the injury appears muscular. If recovering from an injury, a corticosteroid injection is likely better than just NSAIDs, but remember other rehabilitation is needed. 

    We have much more research needed on the subject, but it isn't clear that ice and NSAIDs are a “no brainer”. Until more research is performed, I'll continue the suggestions I've made for years, if you're in no rush, let the inflammation naturally make it's way throughout the body, giving yourself rest and compression for improvement. Once you're able to move naturally do so! However, if you are in a rush, like at a big competition and need to get in the pool, NSAIDs and ice can help!

    References

    By Dr. G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University where he swam collegiately. He is the owner of COR, Strength Coach Consultant, Creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.

    Does Spinal Manipulation Help with Shoulder Pain?

    Before we get to the article today, some big news! The popular COR Swimmer's Shoulder System now has a digital version! Purchase today for only $39.99! This incredible product has helped many improve shoulder pain and many teams have integrated these techniques into their prevention programs.

    Order your copy today!


    Take Home Points on Does Spinal Manipulation Help with Shoulder Pain?
    1. Spinal manipulation appears to reduce pain in patients with shoulder impingement through the placebo effect.
    2. However, spinal manipulation does seem to improve scapular upward rotation. 
    This question was received from one of our readers. If you have a question for the
    Swimming Science team, e-mail us today or tweet @swimmingscience #swimsciq! What are you waiting for? Send us a question today!

    Question: 
    I'm a high school senior and have been relatively healthy until this summer when I started having shoulder pain. I went to our local chiropractor and he has been giving me spinal manipulation therapy. Is this helpful for shoulder pain and if so, how?

    Answer: 
    Great question! Well, like a lot of aspects of science, we don't have a precise answer for your individual case, as more information is required. However, a recent study in the Journal of Sports Physical Therapy (JOSPT) looked at the effects of thoracic spine manipulation for those with and without shoulder pain. 

    A little bit of background on the shoulder first, and if you want more, check out some of my previous work on this website, Swimming World Magazine, About.com, USA Swimming, Swimming World Magazine, and in my product the COR Swimmer's Shoulder System.
    The shoulder is the second most commonly injured joint, only behind low back pain. Shoulder pain is extremely common in overhead athletes, especially swimmers.  In swimmers and the general population, shoulder impingement is the most common cause of shoulder pain.  

    Previous reports suggest excessive internal rotation combined with less scapular upward rotation and posterior tilt are associated with shoulder pain.

    Thoracic spine manipulations are most commonly associated with chiropractic treatment. However, physical therapists and other health care professionals can also provide high-velocity, low-amplitude movements in the same manner. This cracking and popping of the mid-back has been consider a beneficial treatment by many patients in the past. However, how manipulation therapy effects shoulder pain and those without pain is not well known.

    Now, this recent study was out of Brazil and Haik (2014) split ninety-seven subjects, 47 asymptomatic and 50 with shoulder impingement into 1 of 4 groups:
    1)    Thoracic spine manipulation impingement group
    2)    Sham impingement group
    3)    Thoracic spine manipulation asymptomatic group
    4)    Sham asymptomatic group

    More or less, some with shoulder impingement and some without shoulder impingement received either a thoracic manipulation or a sham manipulation.

    Measurements of 3-D scapular motion were assessment before and after the treatment sessions.

    For the manipulation, a therapist provided a seated thoracic thrust up to four times until cavitation (audible crack) was heard.

    The sham intervention involved the same protocol and same force, without applying a thrust.

    Did Spinal Manipulation Improve Shoulder Pain and Function
    Shoulder pain while elevating or lowering the arm after thoracic spine or a sham manipulation resulted in similar improvements for patients with shoulder impingement. No clinically relevant changes in scapular motion were observed in the shoulder impingement group. A significant increase in scapular motion was observed after spinal manipulation in the impingement group, but this did not reach clinical significance.

    In the asymptomatic group, scapular upward rotation was also improved.

    For your second question, it appears the positive effects of spinal manipulation are mainly through a placebo mechanism. Now, the use of thoracic manipulation is not well understood, but believed that a sudden stretch could impact neurons in the paraspinal tissues resulting in pain reduction.

    The improvements in upward rotation are potentially from increased muscular activation of the lower trapezius following spinal manipulation.

    More or less, we aren't sure how spinal manipulation helps (if it does) for shoulder impingement. 

    Practical Implication
    If seeking improvements in scapular upward rotation, spinal manipulation is helpful. However, it seems the placebo effect is the main cause of pain reduction after spinal manipulation in those with shoulder impingement. Remember, this was not a study in athletes and only looked at range of motion, not high level exercise. Also, it didn't include other treatments like exercise therapy or massage, common adjuncts with spinal manipulation.

    Reference
    1. Haik MN, Alburquerque-Sendín F, Silva CZ, Siqueira-Junior AL, Ribeiro IL, Camargo PR. Scapular kinematics pre- and post-thoracic thrust manipulation in individuals with and without shoulder impingement symptoms: a randomized controlled study. J Orthop Sports Phys Ther. 2014 Jul;44(7):475-87. doi: 10.2519/jospt.2014.4760. Epub 2014 May 22.
    By Dr. G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University where he swam collegiately. He is the owner of COR, Strength Coach Consultant, Creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.

    Subacromial Bursa Thickness and Swimming Shoulders

    Take Home Points on Subacromial Bursa Thickness and Swimming Shoulders
    1. Changes to subacromial bursa thickness correlate poorly with painful symptoms
    2. Always consider imaging changes in their full context of structure, symptoms, and training load
    3. Certain changes may be a natural adaptation to repetitive movements in swimming
    Shoulder injuries are an unfortunate reality in swimming.  We’ve written about this general topic before (Radiologic Imaging and the Asymptomatic Athletic Shoulder), but have additional information to add based on recent studies and with a focus on a particular shoulder area, the subacromial bursa. 

    One “en vogue” diagnosis in rehabilitation has been bursitis.  For non-radiating pain with generalized pain symptoms, many providers will simply diagnose the condition as bursitis when they can’t figure out the underlying cause.  It might be harsh to call this a throwaway diagnosis, but in some cases that’s the unfortunate reality.   While this may in fact be correct in some cases, in others it may overlook the underlying problems entirely. 

    The diagnosis is only part of the story without addressing overall function (that a whole topic unto itself).  But the focus in this post will be the significance of whether changes to the subacromial bursa are meaningful indicators for painful shoulders. 

    Most recently, Couainis (2014) studied 22 open water marathon swimmers competing in a 19.7km event.  Ultrasounds were taken four months and two weeks prior to the race and one week after.  Authors noted the following findings:
    • SAB (subacromial bursa) thickness is significantly correlated with kilometres swum in the pool in the preceding week.
    • SAB thickness was not significantly correlated with pain when measured prior to the race.
    • At 1 week post-race, SAB thickness of shoulders with pain were significantly greater than those without pain
    Now does this mean SAB thickness is a meaningful pain indicator?  Maybe but maybe not.  Authors conclude that painless SAB thickening may be a natural adaptation to repetitive swim mechanics when viewed chronically and thus not a cause of painful symptoms.  But when viewed acutely after a triggering event, increases in SAB thickness may in fact be meaningful.  Ultimately, “these two entities can only be differentiated by clinical history and examination.”  Also consider training factors.  Although most pool swimmers won’t swim 19.7km continuous, a series of hard training bouts may cause changes to structure and trigger painful symptoms.  (See, Hell Weeks and Swimming; Hell Weeks and Swimming Revisited)   

    Appreciating the connection (or lack thereof) between SAB thickness and symptoms is especially important in determining whether to have surgery and in evaluating post-op outcomes.  Remember that many clinicians, though highly competent and well meaning, may not always appreciate the specialized demands of swimming and may not be aware of structural changes that accompany swimming biomechanics.

    Hodgson (2012) studied patients with full thickness rotator cuff tears detected by ultrasound, with 18 having pain and 15 having no pain.  After finding no relationship between SAB thickness, rotator cuff tears, and pain, authors concluded, “Although enhancement of the subdeltoid/subacromial bursa was common, no evidence was found to support the hypothesis that bursal enhancement is associated with pain in rotator cuff tears. It is therefore unlikely to determine reliably which patients would benefit from rotator cuff repair. Advances in knowledge Bursal enhancement and thickening does not reliably correlate with symptoms or presence of rotator cuff tear.”

    Studying post-op shoulder patients after rotator cuff surgery, Tham (2013) found short term increases in SAB thickness up to six months (along with increases in tendon vascularity and posterior glenohumeral capsule thickness), but noted these changes normalized after six months.  Ultimately, there was no significant connection between structural changes and pain. 

    Conclusion

    Nothing here is a new message, but recent literature reinforces what had already been suggested in prior findings.  Changes to structure observed through advanced imaging are only one piece of the puzzle in evaluating painful swimming shoulders.  Key take home point is to not only to correlate imaging with clinical findings but also to appreciate how modulations to training load may affect the swimmer’s condition, as both recent and long term training may determine what is normal and what is abnormal for each individual swimmer’s shoulder.  

    References

    1. Tham ER1, Briggs L, Murrell GA.  Ultrasound changes after rotator cuff repair: is supraspinatus tendon thickness related to pain?  J Shoulder Elbow Surg. 2013 Aug;22(8):e8-15. doi: 10.1016/j.jse.2012.10.047. Epub 2013 Jan 23.
    2. Couanis G, Breidahl W, Burnham S.  The relationship between subacromial bursa thickness on ultrasound and shoulder pain in open water endurance swimmers over time.  J Sci Med Sport. 2014 May 20. pii: S1440-2440(14)00087-5. doi: 10.1016/j.jsams.2014.05.004. [Epub ahead of print]
    3. Hodgson RJ1, O'Connor PJ, Hensor EM, Barron D, Robinson P.  Contrast-enhanced MRI of the subdeltoid, subacromial bursa in painful and painless rotator cuff tears. Br J Radiol. 2012 Nov;85(1019):1482-7. doi: 10.1259/bjr/45423226.
    Written by Allan Phillips is a certified strength and conditioning specialist (CSCS) and owner of Pike Athletics. He is also an ASCA Level II coach and USA Triathlon coach. Allan is a co-author of the Troubleshooting System and was selected by Dr. Mullen as an assistant editor of the Swimming Science Research Review. He is currently pursuing a Doctorate in Physical Therapy at US Army-Baylor University.

    Forgotten Aspect of Swimmer's Shoulder Prevention/Rehabilitation: Motor Control Training!

    Take Home Points on the Forgotten Aspect of Swimmer's Shoulder Prevention/Rehabilitation: Motor Control Training!

    1. Overhead sports increase shoulder laxity and decrease motor control.
    2. Shoulder impingement decreases motor control of the shoulder.
    3. A complete shoulder injury prevention program must include motor control training.
    Recently, I've been writing extensively for About.com about the shoulder injury rate in
    swimming and the future injury rate. Overall, the exact prevalence of shoulder pain in swimmers was 3% in a study published in 1974 and has increased in recent publications: 42% in 1980 (Richardson 1980; Neer 1983), 68% in 1986 (McMaster 1987), 73% in 1993 (McMaster 1993), 40 – 60% in 1994 (Allegrucci 1994), 5 – 65% in 1996 (Bak 1996), 38% (Walker 2012). These rates in frequent surgeries for the swimmer's shoulder.

    Even more disturbing is the prevalence of shoulder pain. Eighty-five percent of high school-aged swimmers reported mild shoulder pain in the past year, 61% reported moderate shoulder pain, and 21% reported severe shoulder pain. Of these, only 14% had been to a physician (Hibberd 2013). Also, 47% of these swimmers report using pain medication one or more times per week (Hibberd 2013). These unsafe and improper practices increase burnout, prevent swimming improvement, ending many swimmer's careers.

    This results in many swimming programs performing elongated shoulder injury prevention
    programs. Despite their best intentions, traditional shoulder prevention programs do not improve shoulder blade strength and control, termed motor control (Hibberd 2012). Even worse, many programs incorporate dangerous shoulder stretching programs which further increase instability at the shoulder, leading to worse shoulder motor control [consider mobility for swimmers, a more practical use of mobility training and static shoulder stretches].

    I commonly refer to motor control as timing, a simpler way of understanding the importance of timing between various muscles at the joint. 

    Shoulder impingement is thought to be the most common cause of shoulder pain in swimmers. There are several causes of shoulder impingement, one is poor motor control of the peri-scapular muscles. Overhead athletes undergo high levels of stress at their shoulder during maturation.  This high force is thought to cause microtrauma that over time causes adaptive changes which increase one's injury risk. One adaptive change is adapting the soft tissue around the shoulder, causing an increased range of motion which is thought to affect the shoulder motor control. However, as the motor control decreases, so does an athlete's ability to maintain correct biomechanics. Does high volume of overhead motions decrease motor control?

    Motor Control in Healthy Overhead Athletes

    Launder (2012) analyzed thirty collegiate baseball players (13 pitchers and 17 position players) without a history of shoulder injury for the past two year.

    Shoulder motor control was tested on the throwing arm with the participant in the seated position with the shoulder and elbow flexed 90 degrees. Then, the shoulder was moved into 75 degrees external rotation, 30 degrees external rotation, or 30 degrees internal rotation. With the participant blindfolded, the shoulder was moved into one of these three positions, then the arm was held there for 10 seconds. After this, the arm was moved into a different position and then asked to return to the last position. The mean error for each position was measured.

    The mean anterior shoulder deviation was 14.1 mm. There was no relationship between anterior glenohumeral laxity with 30 degrees internal an external rotation. However, there was a moderate association between anterior glenohumeral laxity with 75 degrees external rotation.

    This study suggests as the amount of shoulder range of motion increases, the greater decrease in shoulder motor control. 

    “This is most likely due to the increased tension placed on the static restraints and potentially increased activity of the mechanoreceptors at the higher range of shoulder external rotation (Launder 2012)”.

    These findings suggest prevention programs should focus on improving motor control at the end-range of motion. However, it can not be concluded increased joint laxity causes altered joint proprioception.

    In swimming, high amounts of shoulder range of motion are used for swimming success. Unlike baseball, swimming uses high amounts of shoulder internal rotation during the catch. This study showed 30 degree internal and external rotation did not find association with altered position sense, but did not assess full internal range of motion. However, this reviewer hypotheses large internal rotation results in similar motor control deficits. This suggests proprioception training at full range internal range of motion is required for prevention of injury of swimmers.

    Motor Control and Shoulder Impingement

    Worsley (2012) matched sixteen young adults with shoulder pain with 16 healthy controls. All those with shoulder pain were assessed for shoulder impingement manually and with ultrasound. Then, the group received motor control training where alignment, coordination, proper scapular orientation at rest, specific muscle (trapezius and serratus anterior), and manual therapy. The intervention was performed at home twice a day for 10 weeks, with 5 follow-up appointments.

    Before and after the intervention scapular kinematics and surface electromyography of the shoulder muscles were assessed. Subjective questions of function were also provided before and after the intervention.

    Before the intervention, the impingement group demonstrated  significant muscle delays in both the serratus anterior and lower trapezius. However, these muscles also had early termination during arm lowering in all planes. Imagine a swimmer having a delay of their muscles rotating the their shoulder for 1,500 strokes during a practice!

    After the intervention, the subjective exam (shoulder pain and disability index, SPADI) improved significantly, on an average of 3.4 points [not a huge drop, but not bad for the intervention applied]. Also, post-intervention the delayed onset of muscle activation reduced significantly for these muscles.

    This study further suggests improving motor control or muscle timing of the periscapular muscles for shoulder rehabilitation. 

    Further studies the blinding of athletes is necessary, as well as a comparison intervention group, and more subjects. Moreover, the use of surface EMG increases the amount of cross-talk between muscles, further confirmation studies should utilize fine wire EMG. Unfortunately, until this research is performed all those seeking ideal shoulder injury prevention and rehabilitation should include shoulder motor control or timing exercises. I've been advocating these forms of exercises for swimmers for the past three years with limited acceptance in the shoulder prevention community. Let's change the course of shoulder injury in swimmers and start adding shoulder motor control training today! 

    Check out this motor control exercise:

    If looking for a complete shoulder injury prevention and rehabilitation program for swimmers including muscle length, strength, timing and improved biomechanics, check out the COR Swimmer's Shoulder System!

    References:

    1. Worsley P, Warner M, Mottram S, Gadola S, Veeger HE, Hermens H, Morrissey D, Little P, Cooper C, Carr A, Stokes M. Motor control retraining exercises for shoulder impingement: effects on function, muscle activation, and biomechanics in young adults. J Shoulder Elbow Surg. 2012 Sep 1.
    2. Laudner KG, Meister K, Kajiyama S, Noel B. The Relationship Between Anterior Glenohumeral Laxity and Proprioception in Collegiate Baseball Players. Clin J Sport Med. 2012 Aug 14. [Epub ahead of print]
    3. Hibberd EE, Oyama S, Spang JT, Prentice W, Myers JB. Effect of a 6-week strengthening program on shoulder and scapular-stabilizer strength and scapular kinematics in division I collegiate swimmers. J Sport Rehabil. 2012 Aug;21(3):253-65. Epub 2012 Mar 2.
    4. Hibberd EE, Myers JB. Practice Habits and Attitudes and Behaviors Concerning Shoulder Pain in High School Competitive Club Swimmers. Clin J Sport Med. 2013 Sep 13. [Epub ahead of print]
    5. McMaster WC, Troup J. A survey of interfering shoulder pain in United States competitive swimmers. Am J Sports Med. 1993; 21:67-70.
    6. McFarland EG, Wasik M. Injuries in female collegiate swimmers due to swimming and cross training. Clin J Sport Med. 1996 Jul; 6(3):178-82.
    7. Muth S, Barbe MF, Lauer R, McClure PW. The effects of thoracic spine manipulation in subjects with signs of rotator cuff tendinopathy. J Orthop Sports Phys Ther. 2012 Dec;42(12):1005-16. doi: 10.2519/jospt.2012.4142. Epub 2012 Aug 17.
    8. Travell, J. Simons, D. Myofascial Pain and Dysfunction The Trigger Point Manual. Williams and Wilkins 1983.
    9. Tucker, Ross. "Training, Talent, 10000 Hours and the Genes."The Science of Sport. 11 Aug. 2011. Web. 08 Jan. 2012. .
    10. Weir PL, Leavitt, JL. Effects of model's skill level and model's knowledge of results on the performance of a dart throwing task. Human Movement Science. 1990 Sept; 9(3): 369-383.
    11. Wilk, KE, Reinold, MM, Andrews JR. The Athlete's Shoulder. Elsevier Health Sciences, 2008
    12. Kenal KA, Knapp LD. Rehabilitation of injuries in competitive swimmers. Sports Med. 1996 Nov;22(5):337-47. Review.
    13. McMaster WC, Roberts A, Stoddard T. A correlation between shoulder laxity and interfering pain in competitive swimmers. Am J Sports Med. 1998 Jan-Feb;26(1):83-6.
    14. Stocker D, Pink M, Jobe FW. Comparison of shoulder injury in collegiate- and master's-level swimmers.Clin J Sport Med. 1995;5(1):4-8.
    15. Ruwe PA, Pink M, Jobe FW, Perry J, Scovazzo ML. The normal and the painful shoulders during the breaststroke. Electromyographic and cinematographic analysis of twelve muscles.Am J Sports Med. 1994 Nov-Dec;22(6):789-96.
    16. Bak K. Nontraumatic glenohumeral instability and coracoacromial impingement in swimmers. Scand J Med Sci Sports 1996;6(3):132-144.
    17. Richardson AB, Jobe FW, Collins HR. The shoulder in competitive swimming. Am J Sports Med 1980;8(3):159-163.
    18. Neer CS, 2nd. Impingement lesions. Clin Orthop 1983(173):70-77.Allegrucci, Whitney SL, Irrgang JJ. Clinical implications of secondary impingement of the shoulder in freestyle swimmers. J Orthop Sports Phys Ther 1994:20(6):307-18.

    By Dr. G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University where he swam collegiately. He is the owner of COR, Strength Coach Consultant, Creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.