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Rehabilitation of Scapular Muscle Balance Which Exercises to Prescribe?

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Strengthening exercises for the scapular muscles are used in the treatment of scapulothoracic dysfunction related to shoulder injury. In view of the intermuscular and intramuscular imbalances often established in these patients, exercises promoting lower trapezius (LT), middle trapezius (MT), and serratus anterior (SA) activation with minimal activity in the upper trapezius (UT) are recommended. Of 12 commonly used trapezius strengthening exercises, a selection can be performed for muscle balance rehabilitation, based on a low UT/LT, UT/MT, or UT/SA muscle ratio. Controlled laboratory study. Electromyographic activity of the 3 trapezius parts and the SA was measured in 45 healthy subjects performing 12 commonly described scapular exercises, using surface electromyography. For each intramuscular trapezius ratio (UT/LT, UT/MT), 3 exercises were selected for restoration of muscle balance. The exercises side-lying external rotation, side-lying forward flexion, prone horizontal abduction with external rotation, and prone extension were found to be the most appropriate for intramuscular trapezius muscle balance rehabilitation. For the UT/SA ratio, none of the exercises met the criteria for optimal intermuscular balance restoration. In cases of trapezius muscle imbalance, some exercises are preferable over others because of their low UT/LT and UT/MT ratios. In the selection of rehabilitation exercises, the clinician should have a preference for exercises with high activation of the LT and MT and low activity of the UT.
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Medicine
American Journal of Sports
DOI: 10.1177/0363546507303560
2007; 35; 1744 originally published online Jul 2, 2007; Am. J. Sports Med.
Cagnie and Erik E. Witvrouw
Ann M. Cools, Vincent Dewitte, Frederick Lanszweert, Dries Notebaert, Arne Roets, Barbara Soetens, Barbara
Rehabilitation of Scapular Muscle Balance: Which Exercises to Prescribe?
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1744
Shoulder pain and dysfunction are common complaints
among individuals seeking care from physical medicine and
rehabilitation specialists.
1,46
Recently, clinicians
25-27,36,42
and investigators
11,29,31,33
have focused increased attention
on the role of the scapula in the pathogenesis of shoulder
pain in general and impingement symptoms in particular.
Scapulothoracic dysfunction, defined as alterations in the
resting position or dynamic motion of the scapula, and
changes in scapular muscle recruitment can affect many
aspects of normal shoulder function.
24
An increasing num-
ber of studies have correlated abnormalities in scapular
position and motion (dyskinesis) with impingement symp-
toms, rotator cuff dysfunction, and instability.
18,29,31,34,48
Various authors have suggested that shoulder abnormali-
ties and abnormal scapular motions may be linked to global
weakness of the scapulothoracic muscles
8,9,15,16,38,43
; others
attribute scapular dyskinesis to scapular muscular imbal-
ance rather than absolute strength deficits.
8-10,29,40
In par-
ticular, excess activation of the upper trapezius (UT),
combined with decreased control of the lower trapezius (LT)
and the serratus anterior (SA), has been proposed as con-
tributing to abnormal scapular motion.
8-11,29,31,37,47
In view of the new insights and research findings on the
role of the scapula in shoulder pathologic abnormality,
Rehabilitation of Scapular Muscle Balance
Which Exercises to Prescribe?
Ann M. Cools,*
PT, PhD, Vincent Dewitte,
PT, Frederick Lanszweert,
PT,
Dries Notebaert,
PT, Arne Roets,
MPSS, Barbara Soetens,
PhD,
Barbara Cagnie,
PT, PhD, and Erik E. Witvrouw,
PT, PhD
From the
Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and
Health Sciences, University Hospital, Ghent, Belgium, and the
Department of Developmental,
Personality and Social Psychology, Faculty of Psychology and Educational Sciences, Ghent
University, Ghent, Belgium
Background: Strengthening exercises for the scapular muscles are used in the treatment of scapulothoracic dysfunction related
to shoulder injury. In view of the intermuscular and intramuscular imbalances often established in these patients, exercises pro-
moting lower trapezius (LT), middle trapezius (MT), and serratus anterior (SA) activation with minimal activity in the upper trapez-
ius (UT) are recommended.
Hypothesis: Of 12 commonly used trapezius strengthening exercises, a selection can be performed for muscle balance reha-
bilitation, based on a low UT/LT, UT/MT, or UT/SA muscle ratio.
Study Design: Controlled laboratory study.
Methods: Electromyographic activity of the 3 trapezius parts and the SA was measured in 45 healthy subjects performing 12
commonly described scapular exercises, using surface electromyography.
Results: For each intramuscular trapezius ratio (UT/LT, UT/MT), 3 exercises were selected for restoration of muscle balance. The
exercises side-lying external rotation, side-lying forward flexion, prone horizontal abduction with external rotation, and prone
extension were found to be the most appropriate for intramuscular trapezius muscle balance rehabilitation. For the UT/SA ratio,
none of the exercises met the criteria for optimal intermuscular balance restoration.
Conclusion: In cases of trapezius muscle imbalance, some exercises are preferable over others because of their low UT/LT and
UT/MT ratios.
Clinical Relevance: In the selection of rehabilitation exercises, the clinician should have a preference for exercises with high acti-
vation of the LT and MT and low activity of the UT.
Keywords: shoulder rehabilitation; scapula; exercise; muscle balance; electromyography
*Address correspondence to Ann Cools, PT, PhD, University Hospital
Ghent, Department of Rehabilitation Sciences and Physiotherapy, De
Pintelaan 185, 6K3, B9000 Ghent, Belgium (e-mail: ann.cools@ugent.be).
No potential conflict of interest declared.
The American Journal of Sports Medicine, Vol. 35, No. 10
DOI: 10.1177/0363546507303560
© 2007 American Orthopaedic Society for Sports Medicine
© 2007 American Orthopaedic Society for Sports Medicine. All rights reserved. Not for commercial use or unauthorized distribution.
by MICHAEL L VOIGHT on October 2, 2007 http://ajs.sagepub.comDownloaded from
Vol. 35, No. 10, 2007 Rehabilitation of Scapular Muscle Balance 1745
current exercise protocols emphasize the importance of
scapular muscle training as an essential component of
shoulder rehabilitation.
3,5,12,20,22,28,35,42,49
Restoration of mus-
cle control and balanced coactivation in particular is a chal-
lenge to the clinician. For patients with an imbalance in the
scapular muscles, selective activation of the weaker muscle
parts with minimal activity in the hyperactive muscles is an
important component in the reduction of the imbalance.
Because a lack of activity in the LT, middle trapezius (MT),
and SA frequently is combined with excessive use of the UT,
the balance ratios UT/LT, UT/MT, and UT/SA are of particu-
lar importance.
10,11,29,47
In addition, integration of shoulder
girdle exercises into a global functional kinetic chain pat-
tern has become a treatment goal in shoulder rehabilitation,
specifically in overhead athletes.
5,14,25
The selection of appropriate exercises in the rehabilita-
tion of scapular muscle performance depends on the actual
strength of the muscles but also on the relative strength of
1 muscle in relation to another. In a study by Ludewig
et al,
30
a selection of exercises was introduced with a low
UT/SA ratio, meaning high activity in the SA with simulta-
neous minimal activation of the UT. However, no other
exercises have been described to optimize the muscle bal-
ance within the trapezius muscle by calculating UT/LT and
UT/MT muscle ratios. In addition, UT/SA ratios have not
been calculated for exercises other than push-up exercises.
Therefore, the purpose of this study was to determine the
UT/LT, UT/MT, and UT/SA muscle ratios for a number of
commonly used shoulder girdle strengthening exercises to
determine which exercises are appropriate to optimize scapu-
lar muscle balance.
MATERIALS AND METHODS
Subjects
Forty-five healthy volunteers (20 men, 25 women),
recruited from the student population, participated in the
study. Their mean age was 20.7 years (±1.7 years), mean
height was 1.73 m (±0.09 m), mean weight was 65.15 kg
(±10.89 kg), and mean body mass index was 21.75 (±2.39).
Exclusion criteria for participation in the study were a history
of cervical spine and shoulder injury or surgery, participation
in overhead sports at a competitive level, and upper limb
strength training for more than 5 hours per week. Inclusion
and exclusion criteria were assessed with a questionnaire.
Before participation, subjects read and signed the informed
consent form. The investigation was approved by the Ethical
Committee of Ghent University.
Instrumentation
Before electrode application, the skin was shaved if neces-
sary and prepared with alcohol to reduce skin impedance
(typically, <10 k). Bipolar surface electrodes (Blue Sensor,
Medicotest, Ballerup, Denmark) were placed with a 2-cm
interelectrode distance over the upper, middle, and lower
portions of the trapezius muscle and the lower portions of
the SA muscle. Electrodes for the UT were placed midway
between the spinous process of the seventh cervical vertebra
and the posterior tip of the acromion process along the line
of the trapezius. The MT electrode was placed midway on a
horizontal line between the root of the spine of the scapula
and the third thoracic spine. The LT electrode was placed
obliquely upward and laterally along a line between the
intersection of the spine of the scapula with the vertebral
border of the scapula and the seventh thoracic spinous
process.
4,8,9,11
The last set of surface electrodes was applied
on the SA parallel to the muscle fibers, below the axilla,
anterior to the latissimus dorsi, and posterior to the pec-
toralis major.
12,28-30
A reference electrode was placed over the
clavicle. In all of the subjects, the dominant arm was tested.
Each set of bipolar recording electrodes from each of 4 mus-
cles was connected to a Noraxon Myosystem 2000 elec-
tromyographic (EMG) receiver (Noraxon USA, Scottsdale,
Ariz). The sampling rate was 1000 Hz. All raw myoelectric
signals were preamplified (overall gain = 1000, common rate
rejection ratio 115 dB, signal to noise ratio <1 µV RMS [root
mean square] baseline noise, filtered to produce a band-
width of 10-1000 Hz).
Testing Procedure
We began by recording the resting level of the electrical
activity of each muscle. Then, verification of EMG signal
quality was completed for each muscle by having the subject
perform maximal isometric contractions in manual muscle
test positions specific to each muscle of interest.
21,23
For the
UT muscle, resistance was applied to abduction of the arm
because Schludt and Harms-Ringdahl
41
found this position
superior to shoulder girdle elevation in activating the UT
muscle. The MT muscle was tested by applying resistance to
horizontal abduction in external glenohumeral rotation.
23
For LT testing, the arm was placed diagonally overhead in
line with the lower fibers of the trapezius. Resistance was
applied against further elevation.
23
Serratus anterior man-
ual muscle testing was performed by resisting humeral ele-
vation at an angle of 135° of forward flexion.
8,23
Subjects
performed three 5-second maximum voluntary isometric
muscle contractions against manual resistance by the princi-
pal investigator (A.C.). A 5-second pause occurred between
muscle contractions.
13,19
A metronome was used to control
duration of contraction. As a normalization reference,
EMG data were collected during maximal voluntary con-
traction (MVC) for each muscle. After signal filtering with
a low-pass filter (single pass, Butterworth, 6-Hz low-pass
filter of the sixth order) and visual inspection for artifacts,
the peak average EMG value over a window of 1 second
was calculated for each trial. Further calculations were
performed with the mean of the repeated trials as a nor-
malization value (100%).
Each subject performed a series of 12 exercises, which
were randomized to avoid systematic influences of fatigue
and learning effects. The exercises were selected based on a
literature review.
2,5-7,12,17,20,22,28,32,35,44,45,49
Numerous studies
have been conducted examining individual muscle activity
during commonly used rehabilitation exercises. In general,
exercises are considered to be relevant for a certain muscle
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by MICHAEL L VOIGHT on October 2, 2007 http://ajs.sagepub.comDownloaded from
1746 Cools et al The American Journal of Sports Medicine
or muscle group if high EMG amplitudes are provoked.
Table 1 summarizes the results of the literature review with
respect to muscle activity of the 3 trapezius parts. On the
basis of the results of these previous investigations, a group
of 12 exercises was selected as relevant for the 3 trapezius
parts. The 12 exercises are described in Table 2. All exer-
cises, with the exception of the exercises performed in
side-lying position, were completed bilaterally. Before data
collection, the exercises were performed without resistance
for familiarization purposes. Each exercise was performed in
3 phases—a concentric, isometric, and eccentric phase, each
during 3 seconds. A metronome was used to control the
duration of the phases. Subjects completed 5 trials of each
exercise. Between trials, a resting period of 3 seconds was
provided. Subjects were allowed to rest for 2 minutes
between exercises. During each exercise, verbal encourage-
ment and, if necessary, performance corrections were given
by the same examiner.
The amount of weight used by the subjects, or resistance
given by the pulley apparatus, was determined based on
gender and body weight (see Appendix A, Tables 1A and 2A,
in the online version of this article at http://ajsm.sagepub
.com/cgi/content/full/35/10/1744/DC1). Subjects were divided
into genders and into 3 subgroups based on their weight for
resistance determination.
Signal Processing and Data Analysis
All raw EMG signals were analog/digital converted (12-bit
resolution) at 1000 Hz. They were digitally fully wave-
rectified and low-pass filtered (single pass, Butterworth,
6-Hz low-pass filter of the sixth order). Results were nor-
malized to the maximum activity measured during the MVC
trials. The EMG data for each muscle and each subject were
averaged for each phase across the 3 intermediate repeti-
tions of the 5 repetitions completed. Periods were defined by
markers based on the 3-second phases of the exercises. One-
second markers were automatically placed on the EMG
signal, based on the metronome sound. The mean amplitude
EMG signal, expressed as a percentage of MVC, was used to
assess the activity of the 3 parts of the trapezius muscle and
the SA muscle in each of the 12 exercises.
Statistical Analysis
A priori power analysis for this study was set at 80%, based
on an α level of .05, resulting in a minimal sample size of 40.
Means and standard deviations were calculated across sub-
jects for the normalized UT, MT, LT, and SA EMG values of
each of the 3 phases of the 12 exercises. Because the specific
topic of interest of this study was to investigate muscle bal-
ance ratios among the scapular muscles during the selected
exercises, the relative activity of the UT with respect to the
MT and LT and to the SA was determined. Intermuscular
and intramuscular ratios were calculated by dividing nor-
malized EMG values of the UT by normalized EMG values
of the LT, MT, and SA, resulting in the ratios UT/LT, UT/MT,
and UT/SA. These values were multiplied by 100 to obtain
relative activity of UT (in %) compared with the other scapu-
lar muscles. Values <100% reflect muscle activity of the MT,
LT, or SA being superior compared with UT, with lower val-
ues suggesting lower relative UT activity. Values >100%
reflect muscle activity of UT exceeding muscle activity of the
other scapular muscles. Means and standard deviations
were calculated for the 3 ratios.
Because all data were normally distributed with equal
variances, parametric tests were used for statistical analy-
sis. The dependent variables of interest were the UT/LT,
UT/MT, and UT/SA ratios. Each of these ratios was ana-
lyzed using a general linear model analysis of variance
with 2 within-subject factors: phase (3 levels) and exercises
(12 levels). In case of significant Mauchly test results for
sphericity, Greenhouse-Geisser correction was performed.
The α level for the analysis of variance was set at .05.
Before further statistical analysis, exercises were catego-
rized in terms of accuracy by performing 1-sample t tests for
each ratio and each phase, with 100%, 80%, and 60% as ref-
erence values. Ratios not significantly lower than 100% sug-
gest that the UT is more active than the LT, MT, and SA
muscle and are considered inadequate for the purpose of our
study. Ratios significantly lower than 100% refer to exercises
relevant to our research question as we wanted to determine
exercises in which the LT, MT, and SA are activated with
minimal activation of the UT muscle. In this group, exercises
were additionally divided into 3 subgroups based on the
ratio: 100% to 80% (moderate), 80% to 60% (good), and <60%
(excellent). For each ratio, the 3 best exercises were used for
further analysis. Classification was based on the following
criteria: exercises in which in each phase, the ratio is smaller
than 60% (category 1); exercises in which in each phase,
the ratio is smaller than 80%, with at least 1 phase having a
ratio between 60% and 80% (category 2); exercises with a
ratio significantly smaller than 100%, with at least 1 phase
between the 60% to 80% limits (category 3); and exercises
with at least 1 of the 3 phases significantly higher than 100%
(category 4). Exercises from category 4 were excluded for fur-
ther analysis and discussion.
TABLE 1
Exercises Commonly Used for Trapezius Training
a
Exercise Movement UT MT LT Reference(s)
Abduction xxx 22,35
Forward flexion xx22,34,35,39
Dynamic hug x 7,12,39
External rotation x 2
Extension xx 7,22,35
Horizontal abduction
(neutral or
external rotation) xxx 7,22,35
Military press x 17,35
Rowing (low or high) xxx 17,20,35
Scaption (neutral or
external rotation) xxx2,12,22,35
Scapular retraction xx 7,22
Shoulder shrug x 12,22
a
UT, upper trapezius; MT, middle trapezius; LT, lower trapezius.
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by MICHAEL L VOIGHT on October 2, 2007 http://ajs.sagepub.comDownloaded from
Vol. 35, No. 10, 2007 Rehabilitation of Scapular Muscle Balance 1747
Across the 3 selected exercises from categories 1 to 3,
multiple pair-wise comparisons were performed for each
phase using paired-sample t tests with Bonferroni correc-
tion. All statistical analyses were performed with SPSS
version 12.0 for Windows (SPSS Science, Chicago, Ill).
RESULTS
The results of the descriptive analysis of the normalized
EMG data for the 12 exercises over the 3 phases are sum-
marized in the online version of this article (see Appendix
A, Table 3A, at http://ajsm.sagepub.com/cgi/content/full/
35/10/1744/DC1). As the major topic of interest of this
study was intermuscular and intramuscular ratios during
shoulder exercises, the mean normalized EMG activity of
each individual muscle across phases was not taken into
account for further statistical analysis and is only stated
for descriptive purposes.
Results of the calculations of the ratios UT/LT, UT/MT,
and UT/SA are summarized in the online version of this
article (see Appendix A, Table 4A, at http://ajsm.sagepub
.com/cgi/content/full/35/10/1744/DC1). The generalized lin-
ear model analysis of variance for repeated measures showed
significant main effects for exercise: F(2.32,102.15) = 28.42,
P < .001; F(1.52,67.07) = 30.86, P < .001; and F(2.79,
122.56) = 37.53, P < .001 for the UT/LT, UT/MT, and UT/SA
ratios, respectively. A significant main effect of phase was also
obtained for all ratios: F(1.59,69.87) = 6.86, P = .004; F(2.88,
138.25) = 16.18, P = .001; and F(1.44,63.24) = 24.54, P = .001
for the UT/LT, UT/MT, and UT/SA ratios, respectively.
Importantly, the data revealed an additional exercise × phase
interaction effect for each ratio: F(2.29,100.76) = 4.71, P = .008
for UT/LT; F(3.85,169.32) = 10.24, P = .001 for UT/MT; and
F(4.17,183.67) = 15.48, P = .001 for UT/SA.
Before post hoc statistical analysis, 1-sample t tests were
performed with 100%, 80%, and 60% as reference values
for all ratios across phases and exercises to classify the
exercises based on their relevance (see Appendix A, Table
5A, at http://ajsm.sagepub.com/cgi/content/full/35/10/1744/
DC1). Based on these criteria, the exercises side-lying for-
ward flexion (Figure 1A), side-lying external rotation
(Figure 1B), and horizontal abduction with external rota-
tion (Figure 1C) were selected as relevant exercises with
low UT/LT ratios. For the UT/MT ratio, side-lying forward
flexion and side-lying external rotation were again
selected as relevant for this ratio, in addition to the prone
extension exercise (Figure 1D). For the UT/SA ratio, no
exercise met the criteria of category 1. Only 1 exercise, high
TABLE 2
Description of the 12 Exercises Performed by the Study Subjects
Exercise Material Description
Prone shoulder Dumbbell Subject prone with the shoulder in neutral position; subject performs shoulder abduction
abduction to 90° with external rotation in a horizontal plane
Forward flexion Dumbbells Subject standing with shoulder in neutral position; subject performs maximal forward
flexion in a sagittal plane
Forward flexion in Dumbbell Subject in side-lying position, shoulder in neutral position; subject performs forward
side-lying position flexion in a horizontal plane to 135°
High row Vertical pulley Subject standing in front of vertical pulley apparatus with the shoulders in
apparatus 135° forward flexion; subject performs an extension with the shoulders until neutral
and V-bar position
Horizontal abduction Dumbbells Subject prone with the shoulders resting in 90° forward flexion; subject performs
horizontal abduction to horizontal position
Horizontal abduction Dumbbells Subject prone with the shoulders resting in 90° forward flexion; subject performs
with external rotation horizontal abduction to horizontal position, with an additional external rotation of the
shoulder at the end of the movement
Low row (1) Pulley apparatus Subject standing in front of pulley apparatus, shoulders in 45° forward flexion and
with 2 handles neutral rotation; subject performs extension with the elbows extended
Low row (2) Pulley apparatus Subject standing in front of pulley apparatus, shoulders in 45° forward flexion and
with 2 handles neutral rotation; subject performs extension with the elbows flexed
Prone extension Dumbbells Subject prone with the shoulders resting in 90° forward flexion; subject performs
extension to neutral position with the shoulder in neutral rotational position
Rowing in sitting Pulley apparatus Subject sitting in front of pulley apparatus with the shoulders in 90° forward flexion;
position with 2 handles subject performs an extension movement with the elbows flexed and in the horizontal
plane
Scaption with external Dumbbells Subject sitting with the arms at the side; subject performs maximal elevation of the arms
rotation in the plane of the scapula (30° anterior of the frontal plane)
Side-lying external Dumbbell Subject side-lying with the shoulder in neutral position and the elbow flexed 90°; subject
rotation performs external rotation of the shoulder (with towel between trunk and elbow to
avoid compensatory movements)
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by MICHAEL L VOIGHT on October 2, 2007 http://ajs.sagepub.comDownloaded from
1748 Cools et al The American Journal of Sports Medicine
row (Figure 2), reached the criterion of category 2. The exer-
cises forward flexion (Figure 3) and scaption with external
rotation (Figure 4) were further selected within the 3 best
exercises—however, with moderate accuracy (category 3).
For the 3 best exercises, post hoc t tests with Bonferroni
correction were performed across the phases to see
whether some phases were more accurate than others in
terms of adequate muscle ratios.
Figure 1. Exercises to restore intramuscular trapezius muscle balance. A, forward flexion in side-lying position; B, side-lying
external rotation; C, horizontal abduction with external rotation; and D, prone extension. The results of this study suggest that
the exercises A, B, and C are optimal for restoration of UT/LT muscle imbalances, and A, B, and D are optimal for restoration of
UT/MT muscle imbalances. UT, upper trapezius; LT, lower trapezius; MT, middle trapezius.
Figure 2. High row exercise.
Figure 3. Forward flexion in standing position.
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by MICHAEL L VOIGHT on October 2, 2007 http://ajs.sagepub.comDownloaded from
Vol. 35, No. 10, 2007 Rehabilitation of Scapular Muscle Balance 1749
DISCUSSION
The purpose of this investigation was to identify scapular
muscle strengthening exercises in which the LT, MT, and
SA muscles are optimally activated with minimal partici-
pation of the UT. Our results support the hypothesis that,
out of a number of commonly used rehabilitation exercises,
exercises with optimal muscle balance ratios may be
selected based on EMG analysis.
Three exercises were selected as exercises with a low
UT/LT ratio: side-lying external rotation, side-lying for-
ward flexion, and prone horizontal abduction with exter-
nal rotation. Previous investigations have shown that the
side-lying external rotation exercise enhances activity in
the supraspinatus, infraspinatus, teres minor, and poste-
rior deltoid.
44
Ballantyne et al
2
also demonstrated high
levels of EMG activity in the LT muscle when the shoul-
der was externally rotated with the patient in a prone
position. Performing the exercise in a side-lying position
possibly minimizes UT activity by eliminating gravity
and thus minimizing the postural role of that muscle.
Probably for the same reason, side-lying forward flexion
gives minimal UT activity. In both these exercises, the
isometric phase revealed the lowest UT/LT ratio. This
emphasizes the importance of controlled contraction
throughout the required range of motion, with a “hold”
phase at maximal external rotation or 135° of forward
flexion. Moreover, our results suggest that patients with
UT/LT imbalances should not perform forward flexion
movements in the standing position because of excessive
activity in the UT.
The horizontal abduction with external rotation exercise
frequently is promoted for optimal shoulder rehabilita-
tion.
35,44
Townsend et al
44
as well as Moseley et al
35
included
this exercise in their selection for glenohumeral and scapu-
lothoracic muscle strengthening programs. Our results
confirm the clinical relevance of this exercise and empha-
size the additional advantage of optimal muscle balance
restoration capacity. In addition, our results show that the
additional external rotation performed during the isomet-
ric phase is essential for selection into the top 3 of all exer-
cises. Overall across phases, the horizontal abduction with
external rotation exercise reveals lower UT/LT ratios than
the horizontal abduction exercise.
Surprisingly, no rowing exercise was selected based on
low UT/LT ratio. However, clinical papers often suggest this
exercise for LT strength training.
5,6,26,35,38,39
Our results
show not only that throughout these exercises, mean EMG
activity of the LT is rather low, but also that the ratios are
not in favor of the LT. Further investigation on different
exercise modalities, for example, prone versus standing
position and integration of other parts of the kinetic chain
into the exercise, are needed to evaluate the therapeutic
value of this exercise in the restoration of scapular muscle
balance.
Our analysis of exercises with optimal UT/MT ratios
resulted in 3 exercises, of which 2 were already selected
based on low UT/LT ratio. Indeed, it seems that both exer-
cises, side-lying external rotation and side-lying forward
flexion, optimally recruit the MT with minimal activity in
the UT. As a previous study showed that overhead athletes
with impingement symptoms show decreased activity in
the LT as well as in the MT with excessive activation of the
upper part,
10
these exercises may be used for restoration of
both muscle imbalances.
A third exercise, selected on the basis of low UT/MT ratio,
was prone extension. Moseley et al
35
found the MT to be
highly activated during the prone extension movement.
Our results confirm the accuracy of this movement for
training this muscle part, with minimal UT activation.
Notable is the finding that performing an extension move-
ment in standing position, such as during the high and low
row exercises, does not result in optimal UT/MT ratios. As
in the UT/LT exercises, body position apparently influences
individual muscle activity and hence intramuscular activ-
ity ratios.
No exercise met the criteria for selection in optimizing
UT/SA ratio. This means that of the exercises performed in
this investigation, none can be qualified for SA training with
inhibition of the UT. This finding is probably the result of
the criteria we used to select our exercises. Indeed, during
our literature research, the main topic of interest was find-
ing commonly prescribed exercises for trapezius training,
rather than SA. None of the exercises selected in our inves-
tigation were previously promoted specifically to enhance
SA strength. Intermuscular balance ratios between SA and
UT were already examined by Ludewig et al.
30
Our exercises
have overall higher ratios than the exercises selected in the
Ludewig
30
study. Indeed, the push-up exercise, examined in
that study with a variety of modalities, is considered to be
an optimal exercise in SA training. Ludewig et al
30
reported
generally low UT/SA ratios (<30%) for all phases throughout
all push-up modalities, with the exception of the eccentric
nonplus phase. Our UT/SA ratios vary from 50.51% in the
isometric phase of the high row exercise to 467.60% during
the isometric phase of the horizontal abduction with exter-
nal rotation exercise. Based on our results, optimal UT/SA
exercises cannot be identified.
In general, the EMG values of the active muscles are
lower in our investigation, compared with those in the
Moseley
35
study examining EMG activity during a variety
of commonly used shoulder rehabilitation exercises.
Figure 4. Scaption with external rotation.
© 2007 American Orthopaedic Society for Sports Medicine. All rights reserved. Not for commercial use or unauthorized distribution.
by MICHAEL L VOIGHT on October 2, 2007 http://ajs.sagepub.comDownloaded from
1750 Cools et al The American Journal of Sports Medicine
Differences in methods and determination of testing
weight may account for these differences. Therefore, as the
purpose of our study was to evaluate balance ratios rather
than individual normalized muscle activity, our EMG data
for each individual muscle were not taken into account for
further statistical analysis and should be compared with
other studies with caution.
Some limitations of our investigation should be noted. The
use of surface electromyography during dynamic movements
has been a topic of discussion in literature regarding skin
displacement, movement artifacts, influences of contraction
modalities on the EMG signals, and normalization meth-
ods.
13,19
In general, systematic control of all interfering fac-
tors during the test is recommended to obtain reliable EMG
data in a noninvasive manner. On the basis of these recom-
mendations, our investigation was executed with maximal
standardization and accuracy. In addition, we did not obtain
synchronized kinematic data during the exercises to stan-
dardize the procedure, like in some other studies.
2,20,28,30
Although numerous investigations have been performed
without simultaneous kinematic movement analysis,
12,35,44
we have to acknowledge this limitation. For further discus-
sion on the technical issues of the use of surface electromyo-
graphy during dynamic movements, see Appendix B in the
online version of this article at http://ajsm.sagepub.com/cgi/
content/full/35/10/1744/DC1).
From a clinical point of view, the major limitation of this
study can be found in the outcome itself. Indeed, all the exer-
cises selected for a low UT/LT or UT/MT ratio are performed
in a lying position, prone or side-lying. However, recent lit-
erature emphasizes the importance of functional exercises,
resembling daily or sport-specific arm function, and integra-
tion of the shoulder rehabilitation exercise into a functional
kinetic chain.
5,14,25
These treatment goals are very difficult
to accomplish with the patient lying prone or on his or her
side. Diagonal patterns, combined with trunk and lower
limb stabilization, as promoted by a number of authors,
14,25
are not possible in our exercise modalities. Therefore, we
propose our exercises to be performed in the early stages of
rehabilitation and before more functional kinetic chain exer-
cises, in which functional muscle recruitment patterns can
be trained with normalized intermuscular and intramuscu-
lar balance ratios.
Our data were obtained from a group of young, healthy
subjects with no history of shoulder impairment. It should
be noted that extrapolation of our results to patients with
shoulder injury or other age categories should be per-
formed with caution. On the basis of our results, we cannot
conclude that patients suffering from shoulder pain or
local muscle imbalances will show similar muscle balance
ratios performing the exercises we propose. Our study may
be considered as a first step in the investigation of reha-
bilitation exercises for the restoration of trapezius muscle
balance, where the use of noninjured subjects must be rec-
ognized as a clinical limitation.
On the basis of our research question and our results, we
believe further examinations should be performed.
Bilateral versus unilateral movements should be com-
pared, as well as the influence on unilateral versus bilat-
eral stance during the exercises in standing positions, and
the influence of lumbar and thoracic spine position. In
addition, it may be interesting to obtain data from other
muscles beyond the SA and the trapezius that can con-
tribute to scapular movement and control, which were not
considered in this study.
CONCLUSION
We investigated the activation of the 3 trapezius muscle
parts and the SA muscle during 12 commonly used shoulder
girdle rehabilitation exercises and calculated intermuscular
and intramuscular balance ratios. This is the first study cal-
culating balance ratios of trapezius activity during these
exercises. Based on our results, we suggest the use of side-
lying external rotation, side-lying forward flexion, prone hor-
izontal abduction with external rotation, and prone
extension exercises to promote LT and MT activity with min-
imal activation of the UT part. These results may help the
clinician in the treatment of scapular muscle imbalances.
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... Several studies [19][20][21][22][23][24][25][26] have suggested that scapular stabilization exercises (SSE), defined as exercises aimed at strengthening scapular muscles and optimizing neuromuscular control, should be included in rehabilitation programs for RCRSP [24,27]. In fact, SSE incorporated into a rehabilitation program have been shown to be more effective than stretching or strengthening exercises alone for improving muscle strength, increasing shoulder proprioception, and decreasing scapular dyskinesis [20,28,29]. ...
... Significant changes in static scapular positioning and in scapulothoracic mobility have also been reported after an SSE program [20]. While multiple SSE are currently proposed for the rehabilitation of RCRSP [19][20][21][22][23]25], no consensus has been established regarding the most commonly recommended exercises for the management of RCRSP [24,26]. ...
... Participant panel of physiotherapists recognized the relevance of these muscles as evidenced by the number of exercises targeting scapular protraction (3/13) or wall slide (3/13) in the inventory. Interestingly, the SSE included in the proposed inventory differ in some aspects from those proposed in recent studies [19,21,24,33]. For example, Kibler et al. proposed three closed-chain scapular exercises to stimulate depression, retraction, and protraction of the scapula [24]. ...
Article
Full-text available
Background: Scapular stabilization exercises (SSE) are often included in the treatment of individuals with rotator cuff-related shoulder pain (RCRSP) to decrease pain and improve function. These SSE typically aim to strengthen the scapular muscles and optimize dynamic neuromuscular control of the scapula, which may improve overall shoulder stability and movement quality. No consensus of the recommended SSE for the management of RCRSP is available. Hence, this study aimed to consult physiotherapists to co-create an inventory of recommended SSE based on the exercise's relevance and frequency of prescriptions for the rehabilitation of individuals with RCRSP. Methods: A group of 16 physiotherapists with experience in treating shoulder pain participated in a sequential consultation incorporating two distinct rounds of consultation focusing on SSE (modified Delphi design). In round 1, physiotherapists identified and demonstrated up to 10 SSE that they commonly recommend or use among individuals with RCRSP. The description and performance of all SSE were audio and video recorded. All SSE suggested by more than one participant in round 1 advanced to round 2. In round 2, physiotherapists rated these SSE on a 4-point Likert scale according to their perceived relevance and frequency of prescription for this population. Results: In round 1, out of the 25 SSE recommended by participants, 19 SSE (76.0%) were recommended by more than one physiotherapist and advanced to round 2. In round 2, 13 SSE were consensually classified (agreement ≥75%) as being relevant for the rehabilitation of individuals with RCRSP. SSE targeting the recruitment of the serratus anterior and lower trapezius muscles were considered the most relevant for the management of RCRSP, whereas SSE targeting neuromuscular scapular control were the most prescribed SSE for the management of RCRSP. Conclusions: An inventory composed of 13 SSE was co-created by physiotherapists based on their relevance and frequency of prescription for the rehabilitation of individuals with RCRSP. When designing an exercise program, physiotherapists can use this SSE inventory to inform their exercise selection, in combination with their current knowledge on shoulder rehabilitation, as well as patients’ preferences.
... Scapular muscle imbalance is a frequently reported alteration in individuals with shoulder pain, overhead athletes, and physically active and healthy populations (Ludewig & Cook, 2000;Cools et al., 2007Cools et al., , 2014De Mey et al., 2013;Kinsella & Pizzari, 2017). A correct muscle balance between the scapular muscles (e.g., upper trapezius [UT], lower trapezius [LT], and serratus anterior [SA]) is important for normal shoulder function (Ludewig & Cook, 2000;Cools et al., 2007). ...
... Scapular muscle imbalance is a frequently reported alteration in individuals with shoulder pain, overhead athletes, and physically active and healthy populations (Ludewig & Cook, 2000;Cools et al., 2007Cools et al., , 2014De Mey et al., 2013;Kinsella & Pizzari, 2017). A correct muscle balance between the scapular muscles (e.g., upper trapezius [UT], lower trapezius [LT], and serratus anterior [SA]) is important for normal shoulder function (Ludewig & Cook, 2000;Cools et al., 2007). For instance, a decrease in the activation of the SA or LT, and the consequent overactivation of the UT, generates an alteration of the position and scapular movement, i.e., dyskinesia, characterized by excessive upward rotation and anterior scapular tilt during arm elevation which can lead to subacromial impingement or glenohumeral instability (Ludewig & Cook, 2000;Kibler et al., 2013;Kinsella & Pizzari, 2017;Huang, Ou & Lin, 2019). ...
... It is widely recognized that scapular dyskinesis rehabilitation programs focused on decreasing UT activation and increasing SA and LT activation in early stages of the rehabilitation process contribute to restoring normal scapular position and movement (Cools et al., 2007;Youdas et al., 2020b;Berckmans et al., 2021). Several closed kinetic chain exercises have been reported as efficient to increase SA and LT myoelectrical activity, such as "push-up" (Calatayud et al., 2014a;Santos et al., 2018), "push-up plus" (scapular protraction posture in the end of the ascending phase of a push-up) Batbayar et al., 2015;Gioftsos et al., 2016;Hwang et al., 2017), "scapular protraction" (scapular protraction and retraction with elbows extended) (Andersen et al., 2012;De Mey et al., 2014), and "plank" (prone position, with the trunk and leg fully extended, the shoulders flexed at 90° and elbows in extension) (Pontillo et al., 2007;Tucker et al., 2010;Ashnagar et al., 2016;Oliver et al., 2018). ...
Article
Background: Multiple investigations have compared the electromyographic (EMG) activity of the scapular muscles between stable and unstable support surfaces during the execution of closed kinetic chain exercises. However, these comparative analyses have grouped different unstable surfaces (wobble board, BOSU, therapeutic ball, and suspension equipment) into a single data pool, without considering the possible differences in neuromuscular demand induced by each unstable support surface. This study aimed to analyze the individual effect of different unstable support surfaces compared to a stable support surface on scapular muscles EMG activity during the execution of closed kinetic chain exercises. Methodology: A literature search was conducted of the Pubmed Central, ScienceDirect and SPORTDiscus databases. Studies which investigated scapular muscles EMG during push-ups and compared at least two support surfaces were included. The risk of bias of included articles was assessed using a standardized quality assessment form for descriptive, observational and EMG studies, and the certainty of the evidence was measured with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. A random-effects model was used to calculate effect sizes (ES, Hedge’s g). Results: Thirty studies were selected in the systematic review. Of these, twenty-three low-to-high quality studies (498 participants) were included in the meta-analysis. The main analyzes revealed, in decreasing order, greater UT EMG activity during push-ups performed on suspension equipment (ES = 2.92; p = 0.004), therapeutic ball (ES = 1.03; p < 0.001) and wobble board (ES = 0.33; p = 0.003); without effect on the BOSU ball. In addition, no effect was observed for SA on any unstable device. The certainty of the evidence ranged from low to very low due to the inclusion of descriptive studies, as well as high imprecision, inconsistency, and risk of publication bias. Conclusion: These findings could be applied in scapular muscles strengthening in healthy individuals. The use of suspension equipment achieves higher UT activation levels. Conversely, the use of any type of unstable devices to increase the activation levels of the SA in shoulder musculoskeletal dysfunctions is not recommended. These conclusions should be interpreted with caution as the available evidence showed a low to very low certainty of evidence, downgraded mostly by inconsistency and imprecision. PROSPERO registration number: CRD42021240500. The authors received no funding for this work.
... 7 Electromyography (EMG) is a frequently used method to investigate scapular muscle activity during therapeutic exercises and could aid in suggesting recommendations for appropriate exercise selection. [16][17][18][19][20][21] Several studies have examined scapular muscle activity during elevation exercises while standing. 8,[22][23][24] But, performing shoulder elevation exercises from a prone position could be of interest for several reasons. ...
... However, similar populations have been tested in previous EMG research, suggesting appropriate shoulder rehabilitation exercises. 16,20,22,35,38,40 Third, this study evaluated four scapular muscles important for scapular control, which are often the scapular muscles of interest to examine with surface EMG. Other muscles such as the pectoralis minor, rhomboids, or levator scapulae might also have significant value in scapular control during rehabilitation exercises. ...
Article
Background Scapular rehabilitation exercises should target appropriate muscles. Recently, adding external rotation resistance to scapular exercises has gained interest. Moreover, clinical experts advise kinetic chain integration into shoulder rehabilitation exercises. Objective To investigate scapular muscle activity during kinetic chain variations of a prone elevation exercise. Methods Activity of the upper (UT), middle (MT), and lower (LT) trapezius and serratus anterior (SA) muscles was determined with surface electromyography (EMG) in 31 asymptomatic participants during six prone elevation exercise variations. Variation was created by adding external rotation resistance, adding trunk extension, or changing exercise position (prone on a Swiss ball with knees or feet supported, or prone on a physiotable). All data were normalized as a percentage of maximal voluntary isometric contraction (% MVIC). For each muscle, a Friedman's ANOVA was conducted to analyse statistical differences in EMG signal intensity between exercises. Results The LT was moderately (42 - 48% MVIC) and MT highly (63 - 66% MVIC) activated during all exercise variations. No significant differences between exercises for these muscles could be detected. Adding external rotation to a prone elevation exercise decreased UT activity while adding trunk extension increased UT activity. Altering exercise position had no influence on scapular muscle activity except increased UT activity when lying prone on a physiotable with trunk extension. Conclusion Prone elevation exercises are appropriate for facilitating LT and MT activity. Adding external rotation inhibits UT activity while UT facilitation could be achieved when adding trunk extension.
... 7,8 Exercise therapy may include proprioceptive training, strengthening, and stretching exercises aiming at the rotator cuff and periscapular muscles. [8][9][10] Telerehabilitation is a way of delivering physical therapy through digital technologies and communication. 11 It may decrease long waiting lists and facilitate access when barriers can hinder in-person care, such as elevated costs related to long-term treatments and traveling distances, including time spent commuting to clinical care and feasibility of transportation from remote areas to service provider. ...
Article
Objective To systematically review the effects of physical therapy given by telerehabilitation on pain and disability in individuals with shoulder pain. Data sources PubMed, Embase, CINAHL, LILACS, Cochrane, Web of Science, SCOPUS, SciELO and Ibecs were searched in January/2022. Methods This systematic review followed PRISMA guidelines. Randomized controlled trials investigating the effects of physical therapy given by telerehabilitation on pain and disability in patients with shoulder pain were included. The quality and level of the evidence were assessed with the Cochrane Risk of Bias tool and GRADE, respectively. The effect sizes of the main outcomes were also calculated. Results Six randomized controlled trials were included with a total sample of 368 patients with shoulder pain. Four and two randomized controlled trials were assessed as low and high risk of bias, respectively. Three randomized controlled trials assessed shoulder post-operative care, two assessed chronic shoulder pain, and one assessed frozen shoulder. Very low to low evidence suggests that there is no difference between telerehabilitation and in-person physical therapy or home-based exercises programs to improve pain and disability in patients with shoulder pain. Low evidence suggests that telerehabilitation is superior to advice only to improve shoulder pain (effect size: 2.42; 95% Confidence Interval: 1.72, 3.06) and disability (effect size: 1.61; 95% Confidence Interval: 1.01, 2.18). Conclusions Although telerehabilitation may be a promising tool to treat patients with shoulder pain and disability, the very low to low quality of evidence does not support a definite recommendation of its use in this population.
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Parsonage–Turner Syndrome or neuralgic amyotrophy is a peripheral neuropathy typically characterized by an abrupt onset of pain, followed by progressive neurological deficits (e.g. weakness, atrophy, occasionally sensory abnormalities) that involve the upper limb, mainly the shoulder, encompassing an extensive spectrum of clinical manifestations, somehow difficult to recognize. This case report describes the proper management of a 35-year-old, bank employee and sports amateur who reported subtle and progressive upper limb disorder with previous history of neck pain. SARS-CoV-2 pandemic era made patient's access to the healthcare system more complicated. Nevertheless, proper management of knowledge, relevant aspects of telerehabilitation-based consultation for musculoskeletal pain, advanced skills, tools and technologies led the physiotherapist to suspect an atypical presentation of Parsonage–Turner Syndrome. Further, neurologist consultation and electromyography suggested signs of denervation in the serratus anterior and supraspinatus muscle. Therefore, an appropriate physiotherapist's screening for referral is conducted to correct diagnosis and thorough treatment.
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The rapid aging phenomenon in Korea affects the increase in medical expenses such as musculoskeletal and cerebrovascular diseases. This phenomenon requires establishing a rehabilitation exercise service system aimed at continuously promoting the health of the disabled and the elderly in accordance with the Act on the Guarantee of Health Rights and Medical Accessibility for the Disabled. Therefore, through the cooperation of three government agencies, the Ministry of Retaliation, the Ministry of Science and Technology, and the Ministry of Culture, Sports and Tourism, the currently unconnected dual rehabilitation system between the hospital and the local community is to be established as one systematic and unified rehabilitation system. To be specific, the role of the Ministry of Culture, Sports, and Tourism is to build a big data platform for exercise rehabilitation using big data to develop and disseminate systematic and organizational infrastructure for exercise rehabilitation and life sports. The main purpose of this study was to develop an intelligent AI-based exercise rehabilitation program and content for the Life-cycle rehabilitation exercise program service in hospitals and communities.
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Impairments in muscle activation have been linked to increased risk of developing shoulder pathologies such as subacromial impingement syndrome (SIS) and associated rotator cuff injuries. Individuals with SIS have demonstrated increased upper trapezius (UT) muscle activation and reduced serratus anterior (SA) and lower trapezius (LT) muscle activation, which can be collectively represented as ratios (UT/SA and UT/LT). Targeted exercise is an important component of shoulder rehabilitation programs to re-establish optimal muscle activation and ratios. Electromyography (EMG) biofeedback during exercise has been shown to reduce UT activation and favorably alter scapular muscle activation ratios, however, a literature gap exists regarding the efficacy of other types of biofeedback. Therefore, we compared the effects of three types of biofeedback (visual EMG, auditory, verbal cues) on UT/SA and UT/LT ratios during a seated resisted scaption exercise in fifteen subjects without shoulder pain. Baseline muscle activation was recorded and compared to real-time muscle activation during each randomized biofeedback trial. All biofeedback types showed improvements in the UT/SA and UT/LT ratios, with visual EMG demonstrating a significant change in UT/LT ratio (p < 0.05). These results suggest that biofeedback could be utilized as a component of rehabilitation programs to prevent or treat shoulder pain.
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Background Deficits in movement and muscle activation of scapulohumeral joint are related to Subacromial Pain Syndrome. Electromyography biofeedback during exercise may enhance muscle activation and coordination, and consequently improve pain and shoulder function. Methods This study compared the effects of an exercise protocol with and without using electromyographic biofeedback on pain, function and movement of the shoulder complex in subjects with Subacromial Pain Syndrome. A total of 24 patients with subacromial pain (mean age = 46.2 + 8.1;18 women) were randomized to either therapeutic exercise or exercise plus biofeedback to the trapezius and serratus muscles. Pain and shoulder function were evaluated as the primary outcome and range of motion, muscle strength, electromyographic activity and scapulohumeral kinematics as secondary outcomes. The subjects underwent eight weeks of intervention and comparisons were made between groups in baseline, at 4 weeks, 8 weeks, and at 4 weeks post intervention. Findings There were differences between groups for pain [mean difference = 1.5 (CI 0.3, 3.2) p = 0.01] at 8 weeks in the Exercise group and scapular upward rotation at 60° of arm elevation [mean difference = 13.9 (CI 0.9, 9.3), p = 0.006] in the Biofeedback group. There was no difference for the other variables of scapular kinematics as well as for shoulder function (DASH), muscle strength, range of motion and electromyographic variables. Interpretation The addition of Biofeedback to the exercise protocol increased upward rotation of the scapula. However, the volunteers who performed only the Exercises had a better response in reducing pain.
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Background: Diagnoses and treatments based on movement system impairment syndromes were developed to guide physical therapy treatment. Objectives: This masterclass aims to describe the concepts on that are the basis of the syndromes and treatment and to provide the current research on movement system impairment syndromes. Results: The conceptual basis of the movement system impairment syndromes is that sustained alignment in a non-ideal position and repeated movements in a specific direction are thought to be associated with several musculoskeletal conditions. Classification into movement system impairment syndromes and treatment has been described for all body regions. The classification involves interpreting data from standardized tests of alignments and movements. Treatment is based on correcting the impaired alignment and movement patterns as well as correcting the tissue adaptations associated with the impaired alignment and movement patterns. The reliability and validity of movement system impairment syndromes have been partially tested. Although several case reports involving treatment using the movement system impairment syndromes concept have been published, efficacy of treatment based on movement system impairment syndromes has not been tested in randomized controlled trials, except in people with chronic low back pain.
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This lecture explores the various uses of surface electromyography in the field of biomechanics. Three groups of applications are considered: those involving the activation timing of muscles, the force/EMG signal relationship, and the use of the EMG signal as a fatigue index. Technical considerations for recording the EMG signal with maximal fidelity are reviewed, and a compendium of all known factors that affect the information contained in the EMG signal is presented. Questions are posed to guide the practitioner in the proper use of surface electromyography. Sixteen recommendations are made regarding the proper detection, analysis, and interpretation of the EMG signal and measured force. Sixteen outstanding problems that present the greatest challenges to the advancement of surface electromyography are put forward for consideration. Finally, a plea is made for arriving at an international agreement on procedures commonly used in electromyography and biomechanics.
Article
The methods used in the preparation of the schedule of the muscles form part of those used for clinical diagnosis and constitute the essential element in the application of specific treatment adapted for the management of muscular and neuro muscular affections. This work comprises a detailed account of the methods of the schedule and the functional consequences of muscular deficiencies and retractions.
Article
The purpose of this section is to present the general guidelines for rehabilitating an injured tennis player. The focus is on treating the most common injury pattern of overhead athletes, i.e., rotator cuff pathology with secondary bursitis and finally microtraumatic instability. The pathologic cascade starts with an overload of the dynamic stabilizers, and if not recognized and not treated appropriately, the affected tissues will decompensate in this stage and result in chronic tendinitis. In case of a misinterpretation of the athlete's symptoms and a therapeutic mismanagement, the dynamic overload increases successively and ends up in a static overload of the capsuloligamenteous restraints. A static overload in terms of a capsular elongation has to be suspected if competent and specific physical therapy does not succeed in alleviating the athlete's symptoms. The rehabilitation program concerns a three-phase approach. It begins with the acute phase, followed by an intermediate phase, and finally the return to sports phase. Weight-bearing exercises are an integral part of the rehabilitation program. Specific criteria are discussed to determine when the athlete can return to unrestricted playing.
Article
The exact role and the function of the scapula are misunderstood in many clinical situations. This lack of awareness often translates into incomplete evaluation and diagnosis of shoulder problems. In addition, scapular rehabilitation is often ignored. Recent research, however, has demonstrated a pivotal role for the scapula in shoulder function, shoulder injury, and shoulder rehabilitation. This knowledge will help the physician to provide more comprehensive care for the athlete. This "Current Concepts" review will address the anatomy of the scapula, the roles that the scapula plays in overhead throwing and serving activities, the normal biomechanics of the scapula, abnormal biomechanics and physiology of the scapula, how the scapula may function in injuries that occur around the shoulder, and treatment and rehabilitation of scapular problems.
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Muscle activity (measured by electromyography) and applied load were measured during seven shoulder rehabilitation exercises done with an elastic resistance device. Nineteen men with no shoulder abnormalities performed seven exercises: external and internal rotation, forward punch, shoulder shrug, and seated rowing with a narrow, middle, and wide grip. Qualitative video (60 Hz) was synchronized with the electromyography data from eight muscles (2000 Hz). Fine-wire intramuscular electrodes were inserted into the supraspinatus and subscapularis muscles, and surface electrodes were placed over the anterior deltoid, infraspinatus, pectoralis major, latissimus dorsi, serratus anterior, and trapezius muscles. Ten trials per subject were analyzed for average and peak amplitude, and the results were expressed as a percentage of maximum voluntary contractions. The peak loads for all exercises ranged from 21 to 54 N. The muscle activity patterns suggest that these shoulder rehabilitation exercises incorporating elastic resistance, controlled movements, and low initial loading effectively target the rotator cuff and supporting musculature and are appropriate for postinjury and postoperative patients.
Article
Background and Purpose. Treatment of patients with impingement symptoms commonly includes exercises intended to restore “normal” movement patterns. Evidence that indicates the existence of abnormal patterns in people with shoulder pain is limited. The purpose of this investigation was to analyze glenohumeral and scapulothoracic kinematics and associated scapulothoracic muscle activity in a group of subjects with symptoms of shoulder impingement relative to a group of subjects without symptoms of shoulder impingement matched for occupational exposure to overhead work. Subjects. Fifty-two subjects were recruited from a population of construction workers with routine exposure to overhead work. Methods. Surface electromyographic data were collected from the upper and lower parts of the trapezius muscle and from the serratus anterior muscle. Electromagnetic sensors simultaneously tracked 3-dimensional motion of the trunk, scapula, and humerus during humeral elevation in the scapular plane in 3 hand-held load conditions: (1) no load, (2) 2.3-kg load, and (3) 4.6-kg load. An analysis of variance model was used to test for group and load effects for 3 phases of motion (31°–60°, 61°–90°, and 91°–120°). Results. Relative to the group without impingement, the group with impingement showed decreased scapular upward rotation at the end of the first of the 3 phases of interest, increased anterior tipping at the end of the third phase of interest, and increased scapular medial rotation under the load conditions. At the same time, upper and lower trapezius muscle electromyographic activity increased in the group with impingement as compared with the group without impingement in the final 2 phases, although the upper trapezius muscle changes were apparent only during the 4.6-kg load condition. The serratus anterior muscle demonstrated decreased activity in the group with impingement across all loads and phases. Conclusion and Discussion. Scapular tipping (rotation about a medial to lateral axis) and serratus anterior muscle function are important to consider in the rehabilitation of patients with symptoms of shoulder impingement related to occupational exposure to overhead work.