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Clinically relevant magnetic resonance imaging (MRI) findings in elite swimmers’ shoulders

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Background: Shoulder pain is the most common and well-documented site of musculoskeletal pain in elite swimmers. Structural abnormalities on magnetic resonance imaging (MRI) of elite swimmers’ symptomatic shoulders are common. Little has been documented about the association between MRI findings in the asymptomatic shoulder versus the symptomatic shoulder.Objective: To assess clinically relevant MRI findings in the shoulders of symptomatic and asymptomatic elite swimmers.Method: Twenty (aged 16–23 years) elite swimmers completed questionnaires on their swimming training, pain and shoulder function. MRI of both shoulders (n = 40) were performed and all swimmers were given a standardised clinical shoulder examination. Results: Both shoulders of 11 male and 9 female elite swimmers (n = 40) were examined. Eleven of the 40 shoulders were clinically symptomatic and 29 were asymptomatic. The most common clinical finding in both the symptomatic and asymptomatic shoulders was impingement during internal rotation, with impingement in 54.5% of the symptomatic shoulders and in 31.0% of the asymptomatic shoulders. The most common MRI findings in the symptomatic and asymptomatic shoulders were supraspinatus tendinosis (45.5% vs. 20.7%), subacromial subdeltoid fluid (45.5% vs. 34.5%), increased signal in the AC Joint (45.5% vs. 37.9%) and AC joint arthrosis (36.4% vs. 34.5%). Thirty-nine (97.5%) of the shoulders showed abnormal MRI features.Conclusion: MRI findings in the symptomatic and asymptomatic shoulders of young elite swimmers are similar and care should be taken when reporting shoulder MRIs in these athletes. Asymptomatic shoulders demonstrate manifold MRI abnormalities that may be radiologically significant but appear not to be clinically significant.
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SA Journal of Radiology
ISSN: (Online) 2078-6778, (Print) 1027-202X
Page 1 of 8 Original Research
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Authors:
Arno Celliers1
Fekade Gebremariam2
Gina Joubert3
Thami Mweli4
Husain Sayanvala5
Louis Holtzhausen6
Aliaons:
1Department of Diagnosc
Radiology, University of the
Free State, South Africa
2Department of Pelonomi
Radiology, University of the
Free State, South Africa
3Departement of Biostascs,
University of the Free State,
South Africa
4Dr Sulman and Partners,
Netcare Rosebank Hospital,
South Africa
5Locum Radiologist, Cape
Town, South Africa
6Department of Sport and
Exercise Medicine, University
of the Free State,
South Africa
Corresponding author:
Arno Celliers,
arnocelliers@gmail.com
Dates:
Received: 17 Aug. 2016
Accepted: 09 Nov. 2016
Published: 20 Jan. 2017
How to cite this arcle:
Celliers A., Gebremariam
F., Joubert G. et al. Clinically
relevant magnec resonance
imaging (MRI) ndings in
elite swimmers’ shoulders. S
Afr J Rad. 2017;21(1), a1080.
hps://doi.org/10.4102/sajr.
v21i1.1080
Introducon
Shoulder pain is the most common musculoskeletal complaint in competitive swimmers.1,2
Competitive swimmers registered with the USA Swimming national governing body average a
distance of 60–80 km per week and 1.56 million overhead rotations per year.3 Both the stroke
volume and multiple overhead rotations place tremendous stresses on the rotator cuff and
glenohumeral joint, eventually resulting in the ‘swimmer’s shoulder ’.3,4 Arthroscopic findings
suggest that the term swimmer’s shoulder covers a variety of pathologies, including labral wearing
and subacromial impingement.5 Connor et al. hypothesised that asymptomatic dominant shoulders
of elite overhead athletes may have a higher incidence of magnetic resonance imaging (MRI)
abnormalities than either their non-dominant shoulders or shoulders of asymptomatic volunteers.6
Elite swimmers demonstrate MRI changes of the shoulder similar to the imaging changes found on
MRIs of persons with painful clinical syndromes.2 There seems to be limited information regarding
MRI findings in overhead athletes who are asymptomatic. It has been suggested that these findings
may be unique to overhead athletes, and care must be taken to correlate clinical history and physical
examination with MRI findings in these patients with symptoms, as these changes might have been
present premorbidly.2 Therefore, symptoms should not necessarily be attributed to the MRI changes.
In a study by Sein et al., 84% of the swimmers studied had a positive impingement sign and 69% of
those demonstrated supraspinatus tendinopathy on MRI. They concluded that supraspinatus
tendinopathy was the major cause of shoulder pain in elite swimmers and this was induced by
intensive swimming training.4 However, it was not possible to draw conclusions in the asymptomatic
shoulders, as this portion of the studied group only constituted 9% of the total sample.
Background: Shoulder pain is the most common and well-documented site of musculoskeletal
pain in elite swimmers. Structural abnormalities on magnetic resonance imaging (MRI) of elite
swimmers’ symptomatic shoulders are common. Little has been documented about the
association between MRI findings in the asymptomatic shoulder versus the symptomatic
shoulder.
Objective: To assess clinically relevant MRI findings in the shoulders of symptomatic and
asymptomatic elite swimmers.
Method: Twenty (aged 16–23 years) elite swimmers completed questionnaires on their
swimming training, pain and shoulder function. MRI of both shoulders (n = 40) were performed
and all swimmers were given a standardised clinical shoulder examination.
Results: Both shoulders of 11 male and 9 female elite swimmers (n = 40) were examined.
Eleven of the 40 shoulders were clinically symptomatic and 29 were asymptomatic. The most
common clinical finding in both the symptomatic and asymptomatic shoulders was
impingement during internal rotation, with impingement in 54.5% of the symptomatic
shoulders and in 31.0% of the asymptomatic shoulders. The most common MRI findings in the
symptomatic and asymptomatic shoulders were supraspinatus tendinosis (45.5% vs. 20.7%),
subacromial subdeltoid fluid (45.5% vs. 34.5%), increased signal in the AC Joint (45.5% vs.
37.9%) and AC joint arthrosis (36.4% vs. 34.5%). Thirty-nine (97.5%) of the shoulders showed
abnormal MRI features.
Conclusion: MRI findings in the symptomatic and asymptomatic shoulders of young elite
swimmers are similar and care should be taken when reporting shoulder MRIs in these
athletes. Asymptomatic shoulders demonstrate manifold MRI abnormalities that may be
radiologically significant but appear not to be clinically significant.
Clinically relevant magnec resonance imaging (MRI)
ndings in elite swimmers’ shoulders
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Copyright: © 2017. The Author(s). Licensee: AOSIS. This work is licensed under the Creave Commons Aribuon License.
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Fredericson et al. evaluated asymptomatic overhead athletes
and all of the athletes studied had MRI findings that could be
considered abnormal, despite the fact that they were clinically
asymptomatic.2 They concluded that MRI changes could be
interpreted as evidence of a previous subclinical injury
unknown to the athlete and that perhaps accumulation of
multiple micro traumas has an additive effect in the absence
of a significant single injury.2 Our study serves to underline
the important message that findings on imaging always need
to be correlated with symptoms, as radiological abnormalities
often do not correspond with clinical problems.
Screening or pre-injury MRI is rarely available for comparison
when an athlete develops clinical symptoms. An improved
understanding of the baseline signal changes in a pre-injury
setting may lead to targeted injury-prevention training
strategies.7 Miniaci et al. advocated baseline shoulder MRI
for all baseball pitchers owing to the difficulty in interpreting
signal changes in these athletes.7 Improved understanding of
subclinical or clinically irrelevant findings in the overhead
athlete may decrease the number of unnecessary medical or
surgical interventions.
According to the researcher’s literature search, this study is
one of the largest studies investigating both shoulders in the
symptomatic as well as the asymptomatic elite swimming
population (Table 1).
Research method and design
For this cross-sectional study, the study population was
voluntarily selected from the University of the Free State’s
swimming team located in Bloemfontein, South Africa. The
clinical examinations were conducted at the Department of
Sport and Exercise Medicine at the University of the Free
State and the imaging (MRI) was done at the Pelonomi
Regional Hospital in Bloemfontein.
The sample included 20 volunteers, both male and female
elite swimmers between the ages of 16 and 25 years, with
symptomatic and asymptomatic shoulders. An elite
swimmer was defined as a swimmer with the ability to
perform a 100 m freestyle race at or faster than 75% of a
national record swimming time.8 Exclusion criteria were:
previous shoulder surgery, previous fracture of the shoulder,
inability or unwillingness to participate in the MRI and
clinical shoulder examination. None of the swimmers were
excluded from the study.
A standardised, self-administered swimming training
questionnaire was completed by each study participant on
the day of the MRI study. Descriptive characteristics were
obtained for each swimmer using a standardised Shoulder
Service Questionnaire.4 Items pertaining to the subject
included age, gender, birth date, occupation, arm dominance
(right, left or ambidextrous) and an overview of general
health. Clinical parameters of the shoulder condition included
the affected shoulder (right, left or both), date of injury onset,
mechanism of onset (whether traumatic or insidious).
Frequency and severity of the shoulder pain, stiffness of the
shoulder, difficulty in reaching behind the back, difficulty
with activities above the head, overall shoulder status,
current level of activity and highest level of sport at the time
of examination were obtained by the sports physician in the
clinical shoulder questionnaire.
All of the 20 participants (n = 40 shoulders) were examined
clinically by a sports physician (M Phil (Sports Medicine),
University of Cape Town), with a special interest in the
swimmer’s shoulder. The clinical examination included
examination of shoulders (symptomatic and asymptomatic),
rotator cuff tests, impingement tests, instability tests as well
as evaluation for local tenderness (sternoclavicular joint,
acromioclavicular joint, biceps, subacromial). The findings
of these tests were recorded on a standardised clinical form.
Materials
The MRIs were performed, using a MAGNETOM Aera
1.5-tesla MRI scanner (Siemens), utilising high-resolution
technique with a dedicated shoulder coil in a standardised
protocol with fixed sequence parameters (time of repetition,
time of echo, slice thickness, matrix, field of view).
Procedure
MRI without arthrography was performed on both shoulders
of all 20 participants (n = 40) with the arm placed in adduction
and neutral rotation. The following sequences were performed:
(1) Coronal plane: T2-weighted FSE and a PD FSE sequence
with fat saturation; (2) Sagittal oblique plane: T2-weighted
FSE and a PD FSE sequence with fat saturation; (3) Axial plane:
T2* GRE and a PD FSE sequence with fat saturation.
The images were reviewed by three consultant radiologists,
one with a musculoskeletal radiology subspecialty and two
TABLE 1: Comparison with similar studies.
Date Source of study MRI sample size Sample populaon Mean age (years) Asymptomac (%) Symptomac (%) Unilateral or Bilateral MRI
2016 This study 40 Elite swimmers 18.9 72.5 27.5 Bilateral
2014 Klein et al. (10) 56 Water polo 24 100.0 0.0 Bilateral
2010 Sein et al. (5) 52 Elite swimmers 16 9.0 91.0 Unilateral
2009 Fredericson et al. (2) 33 Swimmers(n6), volley ball
players and gymnasts
19.6 100.0 0.0 Unilateral
2008 Reuter et al. (11) 23 Triathletes 37 30.4 69.6 Unilateral
2003 Connor et al. (7) 40 Tennis players and baseball
pitchers
26.4 100.0 0.0 Bilateral
2002 Miniaci et al. (9) 28 Baseball pitchers 20.1 100.0 0.0 Bilateral
MRI, magnec resonance imaging.
Page 3 of 8 Original Research
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with experience in musculoskeletal radiology. The radiologists
were blinded to grouping, dexterity, as well as clinical history
and examination. Their findings were documented on a
standardised self-administered assessment form that was
compiled from Stoller’s textbook of MRI in orthopaedics and
sports medicine.9 The checklist consisted of 135 variables that
had to be evaluated in the three different planes. There was
some overlap in the different planes between the anatomical
structures that had to be evaluated, and the findings of the
same anatomical structures were collated in the statistical
analysis of the data. The following anatomical structures had
to be evaluated and commented on: Coronal plane (1) rotator
cuff, (2) AC joint, (3) biceps tendon (longhead), (4) labrum, (5)
IGHL, (6) glenohumeral joint cartilage, (7) osseous structures
(humeral head, glenoid, scapula, suprascapular notch), (8)
deltoid, (9) subacromial subdeltoid bursa; Axial plane: (1) AC
joint, (2) subscapularis and biceps tendon, (3) labrum, (4) joint
capsule structures, (5) glenohumeral joint cartilage, (6) osseous
structures (Hill-Sachs deformities, posterolateral humeral
head, glenoid, coracoid process, spinoglenoid notch), (7)
supraspinatus and infraspinatus tendons, (8) pectoralis major
muscle and deltoid; Sagittal oblique plane: (1) rotator cuff, (2)
acromion, (3) AC joint, (4) rotator interval, biceps tendon,
coracohumeral ligament and SGHL, (5) glenoid fossa, (6)
MGHL,IGHL, (7) subacromial subdeltoid bursa.9
For each item, a yes or no had to be indicated by the
radiologists. For analysis, consensus between the radiologists
was used (i.e. the answer given by two or more of the
radiologists).
Analyses
Results were summarised by frequencies and percentages
(categorical variables) and means, standard deviations or
percentiles (numerical variables). Statistical comparison of
subgroups was done using Fisher’s exact test owing to sparse
cells. P-values of less than 0.05 were considered statistically
significant.
Ethical consideraons
The study was conducted in accordance with the principles
of the Declaration of Helsinki and Good Clinical practice
guidelines.10 All participants signed an informed consent form
and consent was obtained from legal guardians for participants
younger than 18 years. The Ethics Committee of the Faculty of
Health Sciences, University of the Free State approved the
study, with ethical clearence number: ECUFS NR 117/2014.
Results
The demographics, symptoms and clinical examination were
compared with the methods and questions as performed in a
previous study evaluating elite swimmers.4
Demographics of the swimmers
Eleven (55%) of the elite swimmers were male and 9 (45%)
were female. The mean age was 18.9 years and all swimmers
had been coached for at least 5 years, with a median time of
11.5 years. Nineteen swimmers (95%) represented their
country at an international level and one swimmer (5%) was
competing at the national level. Median training time spent
on a specific stroke was 60% freestyle, 14% butterfly stroke,
12.5% backstroke and 20% breaststroke. The median time the
swimmers practised in the water was 13.5 h/week (range:
3 h/week – 18 h/week) and the median distance swum was
40 km/week (range: 9 h/week – 60 km/week).
Clinical symptoms
Of the 40 shoulders studied, 11 (27.5%) were symptomatic.
Two swimmers (n = 4 shoulders) reported bilateral shoulder
pain and 7 (n = 7 shoulders) reported unilateral shoulder
pain. All 11 symptomatic shoulders were painful during
activity (27.3% always, 18.2% daily, 27.3% weekly and 27.3%
monthly). In 2 of the 11 symptomatic shoulders (18.8%),
severe pain with activities above their head was stated.
In 6 (54.6 %) of the 11 symptomatic shoulders, the complaint
was that of a stiff shoulder (severe: 36.4%, moderate: 9.1%,
mild: 9.1%). The participants with symptomatic shoulders
(n = 11 shoulders) were asked to grade their shoulder pain
into none, mild, moderate, severe or very severe. In five
shoulders (45.5%), the self-assessed shoulder pain was found
to be mild. All symptomatic shoulders (n = 11) received
physiotherapy, 9 (81.8%) previously received corticosteroid
injections and 8 (72.7%) previously received acupuncture.
Clinical examinaon of the shoulder
Of the 40 shoulders examined, the most common positive
findings were: a positive impingement sign in internal
rotation elicited with the Hawkins-Kennedy test (n = 15;
37.5%), positive O’ Brien’s sign (n = 12; 30.0%), biceps
tenderness (n = 11; 27.5%), as well as AC joint tenderness (n = 9;
22.5%). Sternoclavicular tenderness (18.2% vs. 17.2%) was
slightly more common in the symptomatic group.
None of the shoulders demonstrated muscle wasting of the
rotator cuff or supporting muscles. Of the 11 symptomatic
shoulders, one (9.1%) had reduced power of four out of five
for rotator cuff strength testing, as well as mild anterior
instability. None of the asymptomatic shoulders demonstrated
loss of power or instability. Details regarding the clinical
examination findings in swimmers are shown in Tab le 2.
TABLE 2: Clinical examinaon ndings.
Clinical ndings
Posive
Symptomac shoulderAsymptomac shoulder
n%n%
Drop arm 0 0 1 3.4
Impingement (ER) 2 18.2 310.3
Impingement (IR) 654.5 9 31.0
Apprehension 218.2 413.8
O’ Brien’s sign 654.5 620.7
Paxinos 0 0 1 3.4
SC joint tenderness 218.2 517.2
AC joint tenderness 654.5 310.3
Biceps tenderness 545.5 620.7
Subacromial tenderness 327.3 310.3
, n = 11; , n = 29.
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Magnec resonance imaging ndings
Of the 29 asymptomatic shoulders studied, 25 (86.2%) had
MRI changes which could be viewed as abnormal. Ten (91%)
of the 11 symptomatic shoulders had abnormal MRI findings.
The most common MRI findings (Figures 1–3) in the
symptomatic shoulders were supraspinatus partial tear (45.5%
in symptomatic shoulders vs. 20.7% in asymptomatic
shoulders), subacromial subdeltoid fluid (45.5% vs. 34.5%),
increased signal in the AC Joint (45.5% vs. 37.9%), supraspinatus
tendinosis (36.4% vs. 10.3%) and AC joint arthrosis (36.4% vs.
34.5%). Supraspinatus tendinosis (36.4% vs. 10.3%) and partial
tear of the supraspinatus (45.5% vs. 20.7%) were much more
common in the symptomatic shoulders compared with the
asymptomatic shoulders. Biceps tendinosis was common in
both symptomatic and asymptomatic shoulders (18.2% vs.
6.9%). Degeneration in the proximal bicipital groove (18.2% vs.
0%) was more common in the symptomatic population.
Thickening of the inferior glenohumeral ligament was more
common in the asymptomatic shoulders (13.8% vs. 0.0%).
Increased signal of the labrum and labral tears were comparable
in the two groups (10.0% vs. 10.3%).
Twenty (50%) of the shoulders in this study (n = 40) had a
positive impingement sign with the Hawkins-Kennedy
impingement test. Of these, 8 (72.7%) were clinically
symptomatic shoulders (n = 11) and 12 (41.4%) were clinically
asymptomatic shoulders (n = 29). In both groups, 25% of the
shoulders had positive clinical signs of impingement that
were correlated with MRI features of supraspinatus
tendinosis (2 of 8 asymptomatic, 3 of 12 symptomatic).
In the clinically symptomatic group (n = 11), three (27.3%)
shoulders tested negative for impingement but still
demonstrated MRI features consistent with supraspinatus
tendinosis. In the clinically asymptomatic group (n = 29), 17
(58.6%) tested negative for impingement clinically, but only
four of these (23.5%) demonstrated MRI features consistent
with supraspinatus tendinopathy.
Discussion
Shoulder pain in overhead athletes is a common problem
owing to tremendous repetitive stresses.6
We examined elite swimmers clinically and with bilateral
shoulder MRI. Most of these young elite swimmers aspire to
compete at the senior international level. They spend on
average 13.5 hours a week in the pool and swim an average
of 40 km/week. The emphasis of the study was on
differentiating clinically insignificant MRI findings in elite
athletes from those that are clinically and radiologically
significant (Figure 4). It is paramount to provide a baseline of
what might be considered clinically irrelevant signal changes
and findings in this population, in order to reduce further
morbidity by limiting over-diagnosis and preventing
unnecessary surgical interventions. Miniaci et al. advocated
baseline shoulder MRI for all baseball pitchers owing to the
difficulty in interpreting signal changes in these athletes.7
We aimed to evaluate the overlap of MRI findings in the
symptomatic and asymptomatic shoulders in order to
0.0%5.0%10.0%15.0%20.0%25.0%30.0%35.0%40.0%45.0%50.0%
Asymptomatic
Symptomatic
Supraspinatus tear
Supraspinatus paral tear
Supraspinatus tendinosis
Infraspinatus tendinosis
Subscapularis tear
Subscapularis paral tear
Subscapularis tendinosis
Subscapularis increased signal
Biceps tendinosis
Long head of biceps: Thinned
FIGURE 1: Magnec resonance imaging ndings in the rotator cu.
Page 5 of 8 Original Research
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10.3%
10.3%
6.9%
13.8%
10.3%
0.0%
3.5%
3.5%
3.5%
6.9%
3.5%
0.0%2.0%4.0%6.0%8.0%10.0%12.0%14.0%16.0%
Labrum high signal
Labrum tear
SLAP
IGHL thickened
IGHL increased signal
SGHL thickened
MGHL thickened
Coracohumeral ligament thickened
Coracohumeral ligament increased signal
Joint capsule thickening
Axillary pouch thickening
Asymptomac
Symptomac
FIGURE 3: Magnec resonance imaging ndings in the joint capsule.
0.0%5.0%10.0%15.0%20.0%25.0%30.0%35.0%40.0%45.0%50.0%
AC joint osseous spurring
AC joint subchondral
cysc change
AC joint subchondral
oedema
Subacromial subdeltoid fluid
AC joint capsule tear
AC Joint increased signal
Os acromiale
AC joint Arthrosis
AC joint oedema across
the synchrondosis
Asymptomac
Symptomac
FIGURE 2: Magnec resonance imaging ndings in and around the AC Joint.
Page 6 of 8 Original Research
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elucidate the fact that asymptomatic shoulders may
demonstrate manifold MRI abnormalities that may be
radiologically significant but appear not to be clinically
significant.
Of the asymptomatic shoulders studied, 86.2% had MRI
changes which could be viewed as abnormal. This
corresponds to previous studies that showed that MRI
abnormalities in asymptomatic overhead athletes are
common.2,4,11 The most common findings in both the
symptomatic and asymptomatic shoulders were subacromial
subdeltoid fluid (Figure 5), increased signal at the AC joint
(Figure 6), AC joint arthrosis, supraspinatus tendinosis
(Figure 7) and biceps tendinosis (Figure 8). There were 11
symptomatic shoulders in our sample group with the most
common clinical findings being impingement, AC joint
tenderness, positive O’ Brien’s sign and biceps tenderness.
The asymptomatic group also demonstrated positive clinical
findings, with subacromial impingement, biceps tenderness
and sternoclavicular tenderness being the most common
findings. AC Joint tenderness was less common in the
asymptomatic group. The studied group consisted of a
slightly smaller symptomatic group than Sein et al., but our
athletes more frequently demonstrated local AC joint
tenderness and positive O’Brien’s sign. Increased signal at
the AC joint is a common finding in both the symptomatic
and asymptomatic shoulders of overhead athletes and does
not correlate with patient symptomatology as also noted in
agreement with Reuter et al.12 In this study, type 1 acromion
0%
10%
20%
30%
40%
50%
Supraspinatus tendinosis
Supraspinatus
paral tear
Subscapularis
tendinosis
Biceps tendinosisSubacromial subdeltoid fluid
AC Joint increased
signal
AC Joint arthrosis
Symptomac
Asymptomac
FIGURE 4: Summary of the most common magnec resonance imaging ndings.
FIGURE 5: Subacromial subdeltoid uid in the asymptomac dominant shoulder
of a 16-year-old swimmer.
FIGURE 6: Increased signal in the AC joint in the asymptomac non-dominant
shoulder of a 17-year-old swimmer.
FIGURE 7: Supraspinatus tendinosis in the asymptomac non-dominant
shoulder of a 19-year-old swimmer.
Page 7 of 8 Original Research
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shape was most common followed by type 2 and type 3.
There was no direct correlation between shoulder pain and
acromion shape.
Supraspinatus tendinopathy was a common finding in both
the symptomatic and asymptomatic shoulders, with it being
nearly twice as common in the symptomatic shoulders.
Previous studies also found supraspinatus tendinopathy to
be a dominant finding.4 Biceps tendinosis was approximately
twice as common in the symptomatic shoulder. Connor et al.
showed that subacromial subdeltoid fluid was a common
finding in the asymptomatic shoulder.6 This study
demonstrated similar results with subacromial and/or
subdeltoid fluid found in 34.5% of the asymptomatic
shoulders. In a study where Reuter et al. evaluated shoulder
MRI changes in 23 triathletes, 57% of the asymptomatic
group and 31% of the symptomatic group demonstrated AC
joint arthrosis.12 The current study demonstrated nearly
equal percentages of AC joint arthrosis (36.4% symptomatic
vs. 34.5% asymptomatic).
Most of our findings correlate with previous studies done,
demonstrating multiple abnormal MRI signal changes in the
asymptomatic shoulder.4,11
Limitaons of the study
The majority of the studied population was from the same
training facility with the same coaching staff. Therefore, the
analysis may suffer from sampling errors related to local
factors and/or the fact that clinical symptoms were based on
subjective self-reporting. The study sample consists of
volunteers; therefore, there is a lack of randomisation.
Another limitation is that previous studies7 referred to the
possibility that owing to the young age of the athletes, some
of the observed MRI findings might become symptomatic
later in their professional career. Further studies with
long-term follow-up are required. MRI was done without
arthrography as complications could not be justified.
Therefore, there is no arthroscopic correlation with MRI
findings. Another possible limitation is that the study did not
make use of T1W MR sequences. Sequences used were
derived from Stoller textbook of muskulosceletal MRI, which
did not include T1W sequences. Although it is not essential
for this study, T1W sequences may be utilised in future
studies.
Conclusion
The importance of this study lies in the fact that supraspinatus
abnormalities on MRI are common in asymptomatic
shoulders. Asymptomatic shoulders demonstrate manifold
MRI abnormalities that may be radiologically significant but
appear not to be clinically significant. The researcher suggests
a pre-season baseline MRI for all elite swimmers with follow-
up imaging if supraspinatus pathology was identified on
the baseline MRI. An improved understanding of the
baseline signal changes in a pre-injury setting may lead to
targeted injury-prevention training strategies. Improved
understanding of subclinical or clinically irrelevant findings
in this population may lead to avoidance of unnecessary
medical or surgical intervention.
Acknowledgements
The authors would like to thank Melvin, Sam and Joshua for
performing the imaging.
Compeng interests
The authors declare that they have no financial or personal
relationships that may have inappropriately influenced them
in writing this article.
Authors’ contribuons
F.G. was the project leader and A.C. was the lead author. G.J.
made conceptual contributions and did the biostatistical
analysis. L.H. performed the clinical examinations and also
made conceptual contributions. H.S. and T.M. identified the
necessity for this research analysis and assisted in the
finalisation of this article.
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... 7 MRI investigations of competitive swimmers with shoulder pain report the most commonly injured structure to be the supraspinatus tendon with 45%-69% identified with tendinosis. 5,8 Excessive tissue load remains the most substantial causative factor in the development of rotator cuff (RC) tendinopathy, as reflected by the fact that RC tendinopathy occurs more frequently in the dominant limb 9 and in occupations and sports with high rates of upper-limb loading. 5,10 Diagnostic ultrasound is an accessible, portable, valid, and reliable tool to study supraspinatus tendon thickness (STT) and the acromiohumeral distance (AHD). ...
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Objectives To assess if swimming practice results in changes in supraspinatus tendon thickness, acromiohumeral distance and occupational ratio in shoulders of elite swimmers with and without a history of shoulder pain. Design Case‐Control study. Methods A convenience sample of fifty elite swimmers (14‐22 years) were recruited for this study. Groups were defined by the presence (history of pain, N=37) or absence (pain free, N=63) of significant interfering shoulder pain within the previous 6 months. The current study analysed supraspinatus tendon thickness, acromiohumeral distance and the occupational ratio, through the use of ultrasound. Measures were taken prior to swim practice; immediately after practice; and 6 hours post practice. Results No statistically significant difference in supraspinatus tendon thickness, acromiohumeral distance or ratio between shoulders with and without a history of pain were found at rest. Following a swimming practice, both shoulders with and without a history of pain had a significant increase in tendon thickness (0.27 & 0.17mm; p=<0.001 & <0.001). The increase in thickness was significantly greater in the history of pain shoulders compared to pain free shoulders (p=0.003). At 6 hours post practice, the history of pain shoulders were still significantly thicker than their pre practice (rested) levels (p=0.007). Despite changes in tendon thickness, the occupational ratio remained non significant between groups. Conclusion Shoulders with a history of pain show an altered response to swimming practice. The results of the current study have implications for training load and injury management. It should prompt investigation into how the tendon reacts under varying load conditions.
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Objectives The aim of this study is to determine the prevalence of abnormal anatomical change present on MRI in elite swimmers' shoulders compared to age-matched controls. Design Descriptive epidemiological study. Methods Sixty (aged 16–36 years) elite Australian swimmers and 22 healthy active, age and gender matched controls (aged 16–34 years). All participants completed a demographic, and training load and shoulder pain questionnaire and underwent shoulder MRI. Tests for differences in the population proportion was used for comparison between swimmers dominant and non-dominant shoulders and those of the controls. Results Subscapularis and supraspinatus tendinopathy was the most common tendon abnormality identified in swimming participants, being reported in at least one shoulder in 48/60 (73 %) and 46/60 (70 %) swimmers, respectively. There was no significant difference between dominant and non-dominant shoulders for either tendinopathy, however, grade 3 tendinopathy was significantly more prevalent in subscapularis than in supraspinatus (P < 0.01). Compared with controls, significantly more abnormalities were reported in swimmers' shoulders in both subscapularis and supraspinatus tendons along with the labrum and acromioclavicular joint. Pathology was not a predictor of current pain. Conclusions This data confirms that tendon abnormality is the most common finding in elite swimmers' shoulders. Furthermore, that subscapularis tendinopathy is not only as common as supraspinatus but has a greater prevalence of grade 3 tendinopathy. With significant varied abnormalities including tendinopathy being so common in both symptomatic and asymptomatic shoulders of swimming athletes', clinicians should consider imaging findings alongside patient history, symptom presentation and clinical examination in determining their relevance in the presenting condition.
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»: Swimming is a popular activity with numerous health benefits. »: Swimming involves complex biomechanical movements that, especially if performed incorrectly, can lead to musculoskeletal injuries. »: The shoulder is the most commonly affected joint, although lower-extremity and spine injuries have also been reported.
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Background Shoulders of throwing and swimming athletes are highly stressed joints that often show structural abnormalities on magnetic resonance imaging (MRI). However, while water polo players exhibit a combination of throwing and swimming movements, a specific pattern of pathological findings has not been described. Purpose To assess specific MRI abnormalities in shoulders of elite water polo players and to compare these findings with a healthy control group. Study Design Cross-sectional study; Level of evidence, 3. Methods After performing a power analysis, volunteers were recruited for this study. Both shoulders of 28 semiprofessional water polo players and 15 healthy volunteers were assessed clinically (based on the Constant score) and had bilateral shoulder MRIs. The shoulders were clustered into 3 groups: 28 throwing and 28 nonthrowing shoulders of water polo athletes and 30 shoulders of healthy control subjects. Results Twenty-eight male water polo players with an average age of 24 years and 15 healthy subjects (30 shoulders) with an average age of 31 years were examined. Compared with controls, significantly more MRI abnormalities in the water polo players' throwing shoulders could be found in the subscapularis, infraspinatus, and posterior labrum ( P = .001, P = .024, and P = .041, respectively). Other structures showed no statistical differences between the 3 groups, including the supraspinatus tendon, which had abnormalities in 36% of throwing versus 32% of nonthrowing shoulders and 33% of control shoulders. All throwing shoulders showed abnormal findings in the MRI, but only 8 (29%) were symptomatic. Conclusion The shoulders of semiprofessional water polo players demonstrated abnormalities in subscapularis and infraspinatus tendons that were not typical abnormalities for swimmers or throwing athletes. Clinical Relevance The throwing shoulders of water polo players have specific MRI changes. Clinical symptoms do not correlate with the MRI findings.
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Competitive swimming has become an increasingly popular sport in the United States. In 2007, more than 250 000 competitive swimmers were registered with USA Swimming, the national governing body. The average competitive swimmer swims approximately 60 000 to 80 000 m per week. With a typical count of 8 to 10 strokes per 25-m lap, each shoulder performs 30 000 rotations each week. This places tremendous stress on the shoulder girdle musculature and glenohumeral joint, and it is why shoulder pain is the most frequent musculoskeletal complaint among competitive swimmers. Articles were obtained through a variety of medical search sources, including Medline, Google Scholar, and review articles from 1980 through January 2010. The most common cause of shoulder pain in swimmers is supraspinatus tendinopathy. Glenohumeral instability and labral tears have also been reported, but a paucity of information remains regarding prevalence and treatment in swimmers. Because of the great number of stroke repetitions and force generated through the upper extremity, the shoulder is uniquely vulnerable to injury in the competitive swimmer. Comprehensive evaluation should include the entire kinetic chain, including trunk strength and core stability.
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The present study aimed to investigate the effects of a high-intensity swim test among top-level swimmers on (i) the spatial and temporal parameters of both the stroke and the 3-D fingertip pattern and (ii) the mechanical, muscular, and physiological parameters. Ten male international swimmers performed a 4 x 50 m swim at maximal intensity. Isometric arm flexion force with the elbow at 90 degrees (F90 degrees ), EMG signals of right musculus biceps brachii and triceps brachii and blood lactate concentrations were recorded before and after the swim test. Kinematic stroke (stroke length, rate, and velocity) and spatiotemporal parameters of the fingertip trajectory were measured by two underwater cameras during the first and last 50 m swims. After the swim test, F90 degrees and mean power frequencies of the EMG decreased significantly when blood lactate concentration increased significantly, attesting the reaching of fatigue. From the first to the last 50 m, stroke rate, stroke velocity, and temporal parameters of the fingertip trajectory exhibited significant increases although stroke length and spatial fingertip trajectory remained unchanged. General and individual adaptations were observed among the top-level swimmers studied. The present findings could be useful for coaches in evaluating fatigue effects on the technical parameters of swimming.
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Shoulder pain is the most common musculoskeletal complaint in competitive swimmers. Problems with the shoulders of swimmers resemble that of the disabled thrower's shoulder, but the clinical findings and associated dysfunctions are not quite the same. Therefore, swimmers with shoulder pain should be evaluated and treated as a separate clinical entity, aimed toward underlying pathology and dysfunction. Balanced strength training of the rotator cuff, improvement of core stability, and correction of scapular dysfunction is central in treatment and prevention. Technical and training mistakes are still a major cause of shoulder pain, and intervention studies that focus on this are desirable. Imaging modalities rarely help clarify the diagnosis, their main role being exclusion of other pathology. If nonoperative treatment fails, an arthroscopy with debridement, repair, or reduction of capsular hyperlaxity is indicated. The return rate and performance after surgery is low, except in cases where minor glenohumeral instability is predominant. Overall, the evidence for clinical presentation and management of swimmer's shoulder pain is sparse. Preliminary results of an intervention study show that scapular dyskinesis can be prevented in some swimmers. This may lead to a reduction of swimmer's shoulder problems in the future.
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To characterize abnormalities on magnetic resonance images (MRI) in the shoulder and wrist joints of asymptomatic elite athletes to better define the range of "normal" findings in this population. Cohort study. Academic medical center. Division IA collegiate volleyball players (n=12), swimmers (n=6), and gymnasts (n=15) with no history of injury or pain and normal physical examination results. None. Grade of severity of MRI changes of the shoulder and wrist joints. A 3- to 4-year follow-up questionnaire was administered to determine the clinical significance of the asymptomatic findings. All athletes demonstrated at least mild imaging abnormalities in the joints evaluated. Shoulder: Volleyball players had moderate and severe changes primarily in the labrum (50% moderate, 8% severe), rotator cuff (25% moderate, 17% severe), bony structures (33% moderate), and tendon/muscle (25% moderate, 8% severe). Swimmers had moderate changes primarily in the labrum (83% moderate) and ligament (67% moderate). Wrist: All gymnasts had changes in the wrist ligaments (40% mild, 60% moderate), tendons (53% mild, 47% moderate), and cartilage (60% mild, 33% moderate, 7% severe). Most gymnasts exhibited bony changes (20% normal, 47% mild, 26% moderate, 7% severe), the presence of cysts/fluid collections (80%), and carpal tunnel changes (53%). Swimmers had no wrist abnormalities. At follow-up interview, only 1 swimmer and 1 volleyball player reported shoulder problems during the study. Additionally, only 1 gymnast reported a wrist injury during their career. Asymptomatic elite athletes demonstrate MRI changes of the shoulder (swimmers and volleyball players) and wrist (gymnasts) similar to those associated with abnormalities for which medical treatment and sometimes surgery are advised. Given the somewhat high frequency of these asymptomatic findings, care must be taken to correlate clinical history and physical examination with MRI findings in these patients with symptoms.
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The purpose of this study was to evaluate the magnetic resonance imaging findings in both shoulders of asymptomatic professional baseball pitchers. Fourteen pitchers who were without significant prior injury underwent a blinded clinical assessment and magnetic resonance imaging of both shoulders. All images were interpreted by two experienced musculoskeletal radiologists. The appearance of the rotator cuff tendons was graded, with additional evaluation of the biceps, labrum, and osseous structures. Ten athletes were found to have stable shoulders and painless full range of motion. Clinically, four athletes had at least a 40 degrees loss in internal rotation as compared with the nonthrowing arm. There were no significant differences in magnetic resonance imaging findings of the supraspinatus and infraspinatus tendons between the throwing and nonthrowing shoulders. The labrum was abnormal in 79% of the 28 shoulders. Enthesopathic changes of the posterior glenoid labrum were identified in the four pitchers who had loss of internal rotation. We conclude that unenhanced magnetic resonance imaging of the shoulder in asymptomatic high performance throwing athletes reveals abnormalities that may encompass a spectrum of "nonclinical" findings. These data can be useful in separating symptomatic pathologic findings from these variants. Enthesopathic changes of the posterior glenoid labrum in the throwing arm may represent an early Bennett-type lesion. The cause may be excessive traction on the posterior capsule during the pitching motion, with subclinical injury to this area.
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Although several studies have described magnetic resonance imaging findings in shoulders of asymptomatic volunteers, no such investigation has been performed on asymptomatic dominant and nondominant shoulders of elite overhead athletes. Asymptomatic dominant shoulders of elite overhead athletes may have a higher incidence of magnetic resonance imaging abnormalities than either their nondominant shoulder or shoulders of asymptomatic volunteers. Prospective cohort study. Detailed magnetic resonance imaging scans of asymptomatic dominant and nondominant shoulders of elite overhead athletes were obtained. Three experienced musculoskeletal radiologists interpreted each scan for multiple variables, including rotator cuff appearance. Images from a surgical control group were intermixed to assess accuracy and control for observer bias. A 5-year follow-up interview was performed to determine whether magnetic resonance imaging abnormalities found in the initial stage of the study represented truly clinical false-positive findings or symptomatic shoulders in evolution. Eight of 20 (40%) dominant shoulders had findings consistent with partial- or full-thickness tears of the rotator cuff as compared with none (0%) of the nondominant shoulders. Five of 20 (25%) dominant shoulders had magnetic resonance imaging evidence of Bennett's lesions compared with none (0%) of the nondominant shoulders. None of the athletes interviewed 5 years later had any subjective symptoms or had required any evaluation or treatment for shoulder-related problems during the study period. Magnetic resonance imaging alone should not be used as a basis for operative intervention in this patient population.
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Shoulder pain is the most common musculo-skeletal complaint in competitive swimmers. It remains one of the shoulder pain syndromes in overhead athletes where no golden standard of treatment exists. Eighteen competitive swimmers who all had undergone shoulder arthroscopy for therapy-resistant shoulder pain were retrospectively evaluated with respect to operative findings and ability to return to their sport after the operation. The most common finding at arthroscopy was labral pathology in 11 (61%) and subacromial impingement in five shoulders (28%). Operative procedures included debridement in 11 swimmers, partial release of the coraco-acromial ligament in four, and bursectomy in four. Sixteen (89%) responded to the follow-up evaluation. Nine swimmers (56%) were able to compete at preinjury level after 4 (2–9) months. Findings at arthroscopy suggest that the term “Swimmer's shoulder” covers a variety of pathologies including labral wearing and subacromial impingement. Arthroscopic debridement of labral tears or bursectomy in swimmers with shoulder pain has a low success rate with regard to return to sport. Further understanding and investigation of this syndromes complex pathophysiology is needed.