ArticlePDF Available

Impact of movement training on upper limb motor strategies in persons with shoulder impingement syndrome

Authors:

Abstract and Figures

Movement deficits, such as changes in the magnitude of scapulohumeral and scapulathoracic muscle activations or perturbations in the kinematics of the glenohumeral, sternoclavicular and scapulothoracic joints, have been observed in people with shoulder impingement syndrome. Movement training has been suggested as a mean to contribute to the improvement of the motor performance in persons with musculoskeletal impairments. However, the impact of movement training on the movement deficits of persons with shoulder impingement syndrome is still unknown. The aim of this study was to evaluate the short-term effects of supervised movement training with feedback on the motor strategies of persons with shoulder impingement syndrome. Thirty-three subjects with shoulder impingement were recruited. They were involved in two visits, one day apart. During the first visit, supervised movement training with feedback was performed. The upper limb motor strategies were evaluated before, during, immediately after and 24 hours after movement training. They were characterized during reaching movements in the frontal plane by EMG activity of seven shoulder muscles and total excursion and final position of the wrist, elbow, shoulder, clavicle and trunk. Movement training consisted of reaching movements performed under the supervision of a physiotherapist who gave feedback aimed at restoring shoulder movements. One-way repeated measures ANOVAs were run to analyze the effect of movement training. During, immediately after and 24 hours after movement training with feedback, the EMG activity was significantly decreased compared to the baseline level. For the kinematics, total joint excursion of the trunk and final joint position of the trunk, shoulder and clavicle were significantly improved during and immediately after training compared to baseline. Twenty-four hours after supervised movement training, the kinematics of trunk, shoulder and clavicle were back to the baseline level. Movement training with feedback brought changes in motor strategies and improved temporarily some aspects of the kinematics. However, one training session was not enough to bring permanent improvement in the kinematic patterns. These results demonstrate the potential of movement training in the rehabilitation of movement deficits associated with shoulder impingement syndrome.
Content may be subject to copyright.
BioMed Central
Page 1 of 11
(page number not for citation purposes)
Sports Medicine, Arthroscopy,
Rehabilitation, Therapy & Technology
Open Access
Research
Impact of movement training on upper limb motor strategies in
persons with shoulder impingement syndrome
Jean-Sébastien Roy*1, Hélène Moffet1,2, Bradford J McFadyen1,2 and
Richard Lirette3
Address: 1Centre for Interdisciplinary Research in Rehabilitation and Social Integration, Quebec City, Canada, 2Department of Rehabilitation,
Faculty of Medicine, Laval University, Quebec City, Canada and 3Club Entrain Medical Centre, Quebec City, Canada
Email: Jean-Sébastien Roy* - jean-sebastien.roy.1@ulaval.ca; Hélène Moffet - helene.moffet@rea.ulaval.ca;
Bradford J McFadyen - brad.mcfadyen@rea.ulaval.ca; Richard Lirette - rlirette@mediom.qc.ca
* Corresponding author
Abstract
Background: Movement deficits, such as changes in the magnitude of scapulohumeral and scapulathoracic
muscle activations or perturbations in the kinematics of the glenohumeral, sternoclavicular and
scapulothoracic joints, have been observed in people with shoulder impingement syndrome. Movement
training has been suggested as a mean to contribute to the improvement of the motor performance in
persons with musculoskeletal impairments. However, the impact of movement training on the movement
deficits of persons with shoulder impingement syndrome is still unknown. The aim of this study was to
evaluate the short-term effects of supervised movement training with feedback on the motor strategies of
persons with shoulder impingement syndrome.
Methods: Thirty-three subjects with shoulder impingement were recruited. They were involved in two
visits, one day apart. During the first visit, supervised movement training with feedback was performed.
The upper limb motor strategies were evaluated before, during, immediately after and 24 hours after
movement training. They were characterized during reaching movements in the frontal plane by EMG
activity of seven shoulder muscles and total excursion and final position of the wrist, elbow, shoulder,
clavicle and trunk. Movement training consisted of reaching movements performed under the supervision
of a physiotherapist who gave feedback aimed at restoring shoulder movements. One-way repeated
measures ANOVAs were run to analyze the effect of movement training.
Results: During, immediately after and 24 hours after movement training with feedback, the EMG activity
was significantly decreased compared to the baseline level. For the kinematics, total joint excursion of the
trunk and final joint position of the trunk, shoulder and clavicle were significantly improved during and
immediately after training compared to baseline. Twenty-four hours after supervised movement training,
the kinematics of trunk, shoulder and clavicle were back to the baseline level.
Conclusion: Movement training with feedback brought changes in motor strategies and improved
temporarily some aspects of the kinematics. However, one training session was not enough to bring
permanent improvement in the kinematic patterns. These results demonstrate the potential of movement
training in the rehabilitation of movement deficits associated with shoulder impingement syndrome.
Published: 17 May 2009
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 doi:10.1186/1758-2555-1-8
Received: 15 April 2009
Accepted: 17 May 2009
This article is available from: http://www.smarttjournal.com/content/1/1/8
© 2009 Roy et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 2 of 11
(page number not for citation purposes)
Background
Movement deficits have been observed in persons with
musculoskeletal disorders [1-3]. A cortical reorganization
consecutive to peripheral impairments may explain such
deficits [4-6]. Interestingly, it has been demonstrated that
movement training can induce change in the cortical
organization of healthy subjects [7] and contribute to the
improvement of the motor performance in persons with
peripheral impairments [2,8]. In order to efficiently reha-
bilitate the deficits, movement training should, however,
be based on the best strategies available to favour motor
learning. Factors such as the use of instruction, demon-
stration and extrinsic feedback during movement training
have been proved to promote motor learning [9-11].
Among them, extrinsic feedback is one of the most potent
factors [10]. Extrinsic feedback is given by an external
source and provides error information that can be used in
addition to the person's own intrinsic error signals [9].
According to Fitts & Posner [12], the first phase of learning
is the cognitive stage where one has to solve the problem
and decide what to do. It is during this stage that the use
of extrinsic feedback is thought to be the most effective
since it brings awareness to movement deficits [11].
Shoulder impingement syndrome (SIS) has been
described as a repeated mechanical compression of the
subacromial structures under the coracoacromial arch
during arm elevation [13]. Studies suggest that persons
with SIS may benefit from movement training with extrin-
sic feedback. Indeed, it was shown that they present move-
ment deficits during arm elevation. These deficits range
from changes in the magnitude of scapulohumeral and
scapulathoracic muscle activations [14-16], to perturba-
tions in the kinematics of the scapula (increased or
decreased scapular posterior tilting and lateral rotation)
[14,17,18], clavicle (increased elevation and retraction)
[18,19] and humeral head (superior displacement with
respect of the glenoid) [20] during arm movement. These
deficits most likely contribute to impingement of the sub-
acromial structures and subsequent pain during arm
movement.
The nature and importance of these deficits differ among
persons with SIS [18,19,21]. It has been shown that half
of the persons with SIS used a different motor strategy
compared to a control group during reaching tasks in the
frontal plane [19]. Specifically, these persons used more
trunk rotation and clavicular elevation, and finished
reaching with the trunk more rotated, clavicle more ele-
vated and shoulder in a more anterior plane of elevation.
The explanation for these results is that such movement
strategies may be used to protect the impaired shoulder
following superior displacement of the humeral head dur-
ing arm elevation [19,20]. By using more trunk rotation,
persons with SIS elevate their arm in a manner that pre-
vents them from going into the frontal plane where the
subacromial space is minimal [22]. Furthermore, by ele-
vating their clavicle, they can reach the target even though
the humeral head is superiorly migrated. It suggests that at
least a portion of the persons with SIS present deficits that
could be rehabilitated by movement training. Reduction
of these impairments could be an important factor in
reaching a normal level of shoulder function.
It is still unknown how the motor strategies of persons
with SIS are influenced by movement training. In fact, the
effects of movement training have never been evaluated
for persons with SIS on variables related to motor control,
such as muscular activation or kinematic patterns. The
aim of this study was to evaluate the immediate and short-
term effects of movement training with extrinsic feedback
on the motor strategies of persons with SIS using such var-
iables (muscular activation and kinematic patterns). A
second aim was to determine how subgroups of persons
with SIS who present significant or slight motor deficits
respond to the training. We think that movement training
will help reduce the movement deficits of persons with
shoulder impingement syndrome.
Methods
Participants
Thirty-three subjects with SIS, diagnosed by an orthopae-
dic surgeon, were recruited (Table 1). They were included
if they had at least one positive finding in each of the fol-
lowing categories [19]: 1) painful arc of movement during
flexion or abduction; 2) positive Neer or Kennedy-
Hawkins impingement signs; and 3) pain on resisted lat-
eral rotation, abduction or Jobe test. The exclusion criteria
were: type III acromion; calcification; shoulder instability;
previous shoulder surgery; and shoulder pain reproduced
during neck movement. A control group composed of 20
subjects with no shoulder pathology was also recruited.
All subjects provided informed consent. This study was
approved by the Ethics Committee of the Quebec Rehabil-
itation Institute.
Study design
Subjects with SIS were involved in two visits, one day
apart. The motor strategies of the upper limb were meas-
ured at each of the four evaluation phases of the study: E1)
before (baseline), E2) during, E3) immediately after, and,
E4) 24 hours after movement training with feedback. At
the first visit, prior to the measurement of the motor strat-
egies, an established self-reported questionnaire, the Dis-
abilities of the Arm, Shoulder and Hand (DASH)
questionnaire, was completed to assess upper limb pain
and functional level [23]. Thereafter, baseline motor strat-
egies were evaluated during reaching movements. This
baseline evaluation (E1) was followed by an education
period on shoulder anatomy and on specific deficits
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 3 of 11
(page number not for citation purposes)
related to impingement using an anatomical model of the
shoulder. Then, motor strategies during reaching were re-
evaluated during (E2) and immediately after (E3) move-
ment training with feedback. The day after, subjects came
back for the second visit where motor strategies during
reaching were re-evaluated (E4). Subjects in the control
group only performed the reaching tasks once during a
visit in order to assess normal motor strategies.
Measurement of motor strategies during reaching
Reaching tasks
The tasks consisted of reaching out and pointing (with
contact) to targets located in two planes of elevation. Sub-
jects were asked to execute reaching at a natural speed, as
if they were performing activities of daily living. In each
plane, 10 trials of reaching movement were performed.
Using the Present Pain Index, pain level was evaluated
after each trial. The symptomatic arm was evaluated for
the SIS group. For the control group, the side was chosen
to have the same proportion of dominant/non-dominant
sides as evaluated in the SIS group. For the trials before,
immediately after and 24 hours after movement training,
a random sequence of trials was established. During
movement training, all trials in a plane of movement were
first carried out before performing the other movement
plane and the first plane of movement executed was bal-
anced between subjects in order to have half the subjects
starting in each plane. In a seated position, reaching tasks
started with the upper limb in a neutral position at the
side of the body and the tip of the second finger in contact
with a pressure switch. One target was located in the fron-
tal plane and positioned at a distance equivalent to the
subject's arm length and at a height equivalent to the posi-
tion of the second finger when the shoulder was at 90° of
abduction. The other target was positioned at the same
length and height as the target in the frontal plane, but
located in front of the contralateral foot, in a sagittal/
oblique plane between flexion and horizontal adduction.
Pressure switches were placed under each target to signal
the end of reaching. Motor strategies were defined by
reaching speed, upper limb kinematic patterns of relative
joint angles and electromyographic (EMG) activity of
seven muscles. Based on previous findings that have
shown only slight deficits for subjects with SIS during
reaching in the sagittal/oblique plane [19], only the fron-
tal plane data are presented here.
Kinematic
Kinematic data were recorded using the Optotrak system
(Northern Digital Inc, 103 Randall Drive, Waterloo,
Ontario, Canada N2V 1C5). Triads of infrared light-emit-
ting diodes were positioned on the hand (dorsal face),
forearm (proximal to the styloid process of the radius),
upper-arm (near the insertion of the deltoid), clavicle (lat-
eral part of the clavicle) and trunk (top of the sternum).
Data were sampled at 100 Hz and digitally low-pass fil-
tered at 8 Hz. Fourteen bony landmarks were digitized
before the acquisition of data in order to recreate the local
coordinate systems which, along with joint rotations,
were defined according to the International Society of Bio-
mechanics recommendations [24]. To compare the four
evaluation phases, two periods (auditory cue to beginning
of the movement; beginning of the movement to end of
the movement) of 100 points each were defined. Each
point represented 1% of each period. Movement ampli-
tudes were plotted for the wrist (hand relative to forearm:
flex/extension; radial/ulnar deviation), elbow (forearm
relative to arm: flex/extension), shoulder (humerus rela-
tive to trunk: plane of elevation; elevation; rotation), S/C
joints (clavicle relative to trunk: retraction/protraction;
elevation/depression) and trunk (trunk relative to global
system: flex/extension; rotation; lateral flexion). Thereaf-
ter, joint position at the end of reaching, as well as total
joint excursion (absolute value of the difference between
maximum and minimum amplitude that occurred during
reaching) were calculated. Maximal hand speed was also
calculated.
Electromyography
Bipolar surface EMG electrodes were used to record the
muscular activity of the upper, middle and lower trape-
zius, serratus anterior, infraspinatus, and anterior and
Table 1: Subjects' characteristics (Mean ± 1 standard deviation or n (%))
SIS subjects
Variables Control group (n = 20) SIS group (n = 33) SISele subgroup
(n = 17)
SISdep subgroup
(n = 10)
Age (y) 46.6 ± 9.9 47.9 ± 8.7 48.4 ± 9.6 45.2 ± 9.2
Gender: Women 13 (65.0%) 22 (66.7%) 12 (70.6%) 6 (60%)
Right hand dominance 17 (85.0%) 28 (84.8%) 15 (88.2%) 8 (80.0%)
Dominant side evaluated 12 (60.0%) 21 (63.6%) 13 (76.5%) 6 (60.0%)
Disease duration
(months)
10.8 ± 9.0 11.7 ± 10.8 9.9 ± 6.7
DASH score
(0–100)
33.3 ± 12.1 35.9 ± 12.5 27.9 ± 8.9
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 4 of 11
(page number not for citation purposes)
middle deltoid. Following skin preparation, Ag/AgCl elec-
trodes (Kendall Medi-Trace 100, Tyco Healthcare Group,
Mansfield, MA 02048) were placed over the muscle belly,
parallel to the direction of the muscle fibres [25]. A refer-
ence electrode was placed over the contralateral
acromion. Verification of the electrode placement and
EMG signal quality was completed by visual monitoring
of EMG signals while subject performed a voluntary con-
traction [25]. Raw EMG signals were amplified for a total
gain of 4000 and transmitted by optical fibre to a mul-
tichannel Neogenix main receiver (NEO 210A, Neogenix
Technologies, 100–3175 Quatre-Bourgeois, Quebec City,
Quebec, Canada G1W 2K7). The EMG signal was band
pass-filtered at 10–500 Hz, converted from analog to dig-
ital (1000 Hz) and stored. Using specially developed soft-
ware, EMG signals were filtered with a digital high-pass
Butterworth filter at a frequency of 10 Hz to minimize the
effect of movement artefacts and full-wave rectified. EMG
activity was normalized to a reference condition and nor-
malized results were expressed as a percent of the refer-
ence condition. The reference condition, recorded before
the experiment, consisted in the mean EMG activity while
the subject maintained his arm at the target position with
a load of 1 kg in his hand for five seconds. Mean normal-
ized EMG activity was calculated for three phases: pre-
movement (beginning of muscle activation to beginning
of movement), acceleration (beginning of movement to
the end of the hand acceleration) and deceleration (begin-
ning of hand deceleration to the end of the movement).
Movement training with extrinsic feedback
Movement training was performed under the supervision
of a physiotherapist who gave feedback aimed at correct-
ing shoulder girdle movement [26]. The results of the tri-
als performed before supervised training were used to
determine the feedback given during supervised training.
Therefore, the type of feedback was established according
to individualized impairments. Three types of feedback
were given: visual, using a mirror; manual, by restricting
shoulder girdle movements or guiding scapular move-
ments; and verbal, with comments related to the motor
performance. Manual and verbal feedbacks were stand-
ardized for each type of altered shoulder kinematics [26].
In each elevation plane, a trial with feedback was followed
by a trial without feedback for a total of 10 trials in each
plane. During the trials with feedback, subjects first exe-
cuted the reaching movement with the unimpaired side in
front of a mirror. Then, still in front of a mirror, they exe-
cuted the same movement with the impaired side. During
movement, subjects received manual feedback if the kine-
matic of the shoulder was altered. Following the move-
ment with feedback, they had to evaluate their own
performance, and finally, they received verbal feedback
related to the motor aspect of the movement that had to
be improved for the next trial (example: elevation of your
shoulder girdle was too important). If the movement was
adequate, the verbal feedback confirmed that the move-
ment was properly executed. No other exercises or train-
ing were performed during this visit.
Statistical analysis
Mean value of the 10 trials during reaching in the frontal
plane was used for the statistical analysis. First, the base-
line motor strategies (total joint excursion, final joint
position and normalized EMG activity) of the SIS group
were compared the ones of the control group using inde-
pendent t-tests. Then, for the SIS group, the effect of
movement training was analysed using one-way (shoul-
der pain, reaching speed and kinematic patterns [total
joint excursion and final joint position]) and two-way
(normalized EMG activity) repeated measures ANOVA.
The factors in the model were the evaluation phase
(before [E1], during [E2], immediately after [E3] and the
day after training with feedback [E4]) and, for the normal-
ized EMG activity, the reaching phases (pre-movement,
acceleration and deceleration). Paired t-tests, with Bonfer-
roni adjustment, were used for multiple pairwise compar-
isons. Multiple pairwise comparisons were only
performed compared to the baseline trials (E1 vs. E2; E1
vs. E3; E1 vs. E4). Data of the control group were not used
for the evaluation of the effects of movement training. All
analyses were conducted with the SPSS software (Version
12; SPSS Inc, 233 S Wacker Dr, 11th Fl, Chicago, Illinois
60606, USA). The alpha level was set at 0.05.
Two SIS subgroups were also defined at baseline accord-
ing to the magnitude of clavicular elevation. A previous
study has shown that this measurement can be used to
subdivide the SIS group in two subgroups with specific
reaching kinematics [19]. Subjects that increased their cla-
vicular elevation during reaching present significant
movement impairments at the trunk, clavicle, and shoul-
der, while the other subjects present slight movement
impairments. The two SIS subgroups were: SIS subjects
having clavicular elevation excursion above (SISele; n =
17) and below (SISdep; n = 10) the 95% confidence inter-
val (CI) of the clavicular elevation excursion of the control
group. Separate analyses were performed for each SIS sub-
group. There were no statistical comparisons between the
subgroups.
Results
The SIS and control groups were similar for age, weight,
height, sex and dominance. No significant differences
were noted between the two SIS subgroups for age, sex,
DASH score and duration of symptoms (Table 1).
Comparison between control and SIS groups and
subgroups at baseline
Analyses of a previous study [19] have shown that the
control group performed reaching using trunk contralat-
eral lateral flexion and ipsilateral rotation, clavicular ele-
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 5 of 11
(page number not for citation purposes)
vation and retraction, with shoulder elevation and lateral
rotation, elbow flexion and wrist extension for the first
50% of movement followed by elbow extension and wrist
flexion. The SIS group used the same pattern; however,
they used significantly larger trunk rotation (mean differ-
ence: 2.6°) and shoulder lateral rotation (9.0°); and fin-
ished reaching with the trunk more rotated (4.7°) and
with the shoulder in a more anterior plane of elevation
(4.1°) (Figures 1 and 2). Compared to the control group,
subjects in SISele subgroup performed reaching with
greater trunk rotation (3.4°), clavicular elevation (6.3°)
and shoulder lateral rotation (11.3°) (Figure 1), as well as
less elbow flexion (13.4°). They also finished reaching
with more trunk rotation (4.5°) and clavicular elevation
(7.1°) and with the shoulder in a more anterior plane of
elevation (6.2°) (Figure 2). For their part, the SISdep
group used less clavicular elevation (3.5°) (Figure 1). Fur-
ther detail of these previous analyses can be found in Roy
et al. (2008) [19].
Effect of movement training on pain, reaching speed and
EMG activity
Compared to their own baseline level, shoulder pain dur-
ing reaching was significantly reduced in the SIS group
and SISele subgroup during (mean difference: 0.3, P =
0.02), immediately after (respectively: 0.6 & 0.5, P <
0.004) and the day after training (respectively: 0.6 & 0.5,
P < 0.004), while it remained unchanged in the SISdep
subgroup. Maximal reaching speeds were significantly
reduced during and following training in the SIS group
and in the two SIS subgroups (Figure 3). For the SIS group
and subgroups, the EMG activity of all the muscles evalu-
ated, except lower trapezius, was significantly decreased in
the pre-movement and acceleration phases during and
following training compared to baseline (5.5 to 100.6%)
(Figure 4). There were no significant differences during
the deceleration phase.
Effect of movement training on the upper limb kinematic
Compared to baseline, subjects with SIS used the same
pattern of movement during training with feedback. How-
ever, excursions of the trunk in lateral flexion (1.2°) and
rotation (1.8°), of the clavicle in protraction/retraction
(2.7°) and of the elbow (8.7°) and wrist (4.5°) in flexion/
extension were significantly decreased, while excursions
of the trunk in flexion/extension (0.6°) and of the shoul-
der in rotation (6.9°) were increased (Figures 1 and 5). In
the SISele subgroup, excursion of the trunk in lateral flex-
ion (1.7°) and rotation (1.7°) and of the clavicle in eleva-
tion/depression (2.8°) and protraction/retraction (3.3°)
were significantly decreased during training compared to
baseline, while excursion of the shoulder in rotation was
increased (6.5°) (Figures 1 and 5). In the SISdep group,
only clavicular protraction/retraction excursion (2.6°)
was significantly decreased during training (Figure 1).
During training, subjects in the SIS group and in the SISele
subgroup also had significantly less trunk rotation (5.6°
and 5.3°) and clavicle elevation (3.4° and 3.2°), with the
shoulder in a more frontal plane of elevation at the end of
reaching (3.5° and 4.3°) (Figure 2).
Immediately following training, excursions of the trunk in
lateral flexion (1.3°) and rotation (1.4°), of the clavicle in
protraction/retraction (2.3°) and of the elbow (5.3°) and
wrist (4.8°) in flexion/extension were still decreased dur-
ing reaching in the SIS group compared to baseline (Fig-
ures 1 and 5). For the subjects in the SISele subgroup,
excursion of the trunk in lateral flexion (1.7°) and rota-
tion (1.3°) and of the clavicle in elevation/depression
(2.4°) and protraction/retraction (2.5°) were also still sig-
nificantly decreased (Figure 1). Again, only clavicular pro-
traction/retraction excursion was significantly decreased
for the SISdep subgroup (2.6°) (Figure 1). The subjects in
the SIS group and in the SISele subgroup also still had sig-
nificantly less trunk rotation (2.8° and 2.7°) and clavicle
elevation (2.5° for both) at the end of reaching immedi-
ately following training (Figure 2).
The day after movement training, clavicular elevation/
depression excursion (4.0°) and clavicular elevation posi-
tion at the end of reaching (2.5°) were significantly
decreased in the SISele subgroup compared to baseline
(Figure 1 and 2). Otherwise, excursion of the trunk in lat-
eral flexion (0.9°), of the clavicle in protraction/retraction
(2.3°) and of the elbow (5.8°) and wrist (5.1°) in flexion/
extension in the SIS group (Figures 1 and 5), and excur-
sion of the clavicle in protraction/retraction (2.3°) (Figure
1) in the SISdep subgroup were still significantly
decreased compared to baseline.
Discussion
This study is the first to look at the effect of movement
training on motor strategies of persons with SIS. Super-
vised training, aimed at improving individualized move-
ment deficits, was shown to have short-term effects on the
upper limb kinematic patterns. For most subjects, these
changes were associated with a decrease of shoulder pain
during reaching.
Changes observed in the upper limb kinematics during
and following training led to some improvements. As
observed during the baseline trials, the SIS group used
more trunk rotation and finished reaching with the trunk
more rotated and the shoulder in a more anterior plane of
elevation when compared to healthy subjects. During and
immediately following training, all these impairments
observed in persons with SIS were reduced. However,
these kinematic improvements returned to the baseline
level the day after training. According to Doyon and
Benali [27], the first steps of learning are characterized by
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 6 of 11
(page number not for citation purposes)
Mean total joint excursionFigure 1
Mean total joint excursion. Total joint excursion (mean and standard deviation) before (E1; baseline), during (E2), immedi-
ately after (E3) and the day after (E4) movement training with feedback are shown for the SIS group and subgroups (SISele; SIS-
dep). The grey band represents the 95% confidence interval (95%CI) of the control group. * Significant difference at baseline
between the group/subgroups with SIS and the control group Significant difference in the group/subgroups with SIS compared
to their baseline trials (E1).
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 7 of 11
(page number not for citation purposes)
Mean joint position at the end of reachingFigure 2
Mean joint position at the end of reaching. Joint position at the end of reaching (mean and standard deviation) before (E1;
baseline), during (E2), immediately after (E3) and the day after (E4) movement training with feedback are shown for the SIS
group and subgroups (SISele; SISdep). The grey band represents the 95% confidence interval (95%CI) of the control group. *
Significant difference at baseline between the group/subgroups with SIS and the control group Significant difference in the
group/subgroups with SIS compared to their baseline trials (E1).
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 8 of 11
(page number not for citation purposes)
improvement in performance occurring within a single
session. Still, the skills are not consolidated and multiple
training sessions are needed before their consolidation.
Present results support this view with short-term positive
changes, but minimal retention 24 hours after. One ses-
sion, therefore, was not enough to bring permanent
changes in motor strategies.
For some joints, movement training led to decreased
excursions which increased baseline differences with the
control group. These changes could be seen as unfavoura-
ble. However, it has been shown that early in motor learn-
ing, when persons have to choose how to efficiently
manage the various degrees of freedom, control is simpli-
fied through the freezing of some degrees of freedom [28].
Such a strategy could be temporarily adopted to facilitate
performance by allowing the opportunity to control a few
necessary degrees of freedom [28]. As seen in the results
(see Figure 5), persons with SIS mostly restricted the
movements of the more distal joints with training. By
restricting the excursion of the elbow and wrist joints, they
could put more emphasis on providing the proper strategy
at the shoulder joint to avoid impingement. This adapta-
tion could be seen as an early step in motor learning [28].
EMG activity was decreased during and following train-
ing. The baseline differences with the control group were
increased for most of the muscles and the standard devia-
tions were larger than the ones of the control group. Pre-
viously, it has been shown that the standard deviation is
similar between persons with and without SIS [19].
Present findings show that the variability in the muscular
performance of the persons with SIS was more important
during and following training. According to the learning
phases of Fitts & Posner [12], the subjects were involved
in the first phase of learning, the cognitive stage. They had
to solve the problem first and find out what had to be
done to improve shoulder control. This phase required
considerable cognitive activity in order to determine the
appropriate strategies. Therefore, performances were
inconsistent, leading to large within and between subject
variability. Such cognitive activities most likely also led to
the reduction of reaching speed observed during and fol-
lowing training. This reduction of speed makes it difficult
to compare the EMG activity with baseline since lower
speed is associated with lower EMG activity [19].
The training session was designed to optimize motor
learning. Studies have looked at different ways to enhance
training by looking at the best motor learning strategies
[9-11,29]. One conclusion of these studies is that subjects
have to be actively involved in solving the motor problem
during training [9]. The training session was planned
around that principle. As a result, to improve the intrinsic
error-detection capabilities of the subjects [9]: a) pre-
training education with an anatomical model of the
shoulder was given [11], and, b) a mirror was used to
observe the kinematics of the unimpaired and impaired
shoulders in order to give a visual comparison to the sub-
ject of the movements that had to be improved. Moreover,
to allow active engagement in information processing
activities [9,11,29]: a) external feedbacks was given in
only half of the trials, and b) subjects had to judge their
own performance before the verbal feedback from the
physiotherapist. Furthermore, it has been shown that the
learning effects are greater when feedback is not given on
each trial and when the subjects have to evaluate their per-
formance first [30].
The separate analyses of the two SIS subgroups proved
that not all persons with SIS respond the same way to
training. Subjects in the SISele subgroup were the ones
who seem to have benefited the most from training. With
training, they significantly changed their trunk, clavicle
and shoulder kinematics leading to a reduction of the
baseline differences with the control group. Furthermore,
shoulder pain during reaching was significantly reduced.
This suggests that, for persons with significant kinematic
deficits, rehabilitation of their motor control deficits is an
important step for improving their shoulder pain. Indeed,
the reduced clavicular elevation could be a sign that they
are able to reach without superiorly migrating their
humeral head. Thus, these persons most likely reduced
the impingement of the subacromial structures leading to
the observed decrease of pain. Moreover, by reducing their
trunk movement and by moving more into the frontal
plane, they demonstrated that they do not prevent their
Maximal hand speed (in m/s) during reachingFigure 3
Maximal hand speed (in m/s) during reaching. The
maximal hand reaching speed (mean and standard deviation)
observed before (baseline), during, immediately after and the
day after training with feedback is shown. The grey band rep-
resents the 95% confidence interval (95%CI) of the control
group. * Significant difference in the group/subgroups with
SIS compared to their baseline trials (E1).
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 9 of 11
(page number not for citation purposes)
Mean difference with baseline EMG activityFigure 4
Mean difference with baseline EMG activity. The differences (mean and standard deviation) between the EMG activity at
baseline and during, immediately after and the day after movement training are shown (0 = no difference with the baseline
value) for the SIS group. The differences (mean and standard deviation) at baseline between the EMG activity of the control
group and of the SIS group are also plotted (grey band). * Significant difference in the group with SIS compared to their baseline
trials.
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 10 of 11
(page number not for citation purposes)
shoulder from moving in a plane where the subacromial
space is minimal [22].
In the SISdep subgroup, only clavicular pro/retraction was
changed with training, increasing baseline differences
with the control group. Furthermore, pain level remained
unchanged. It could be argued that training was more rel-
evant for the SISele group. Training was design to correct
the specific movement deficits observed in patients with
SIS and persons with SIS who use greater clavicular eleva-
tion during reaching present the most altered kinematic
patterns. Thus, persons presenting mild kinematic deficits
may benefit better of other types of rehabilitation, such as
strengthening or stretching exercises. However, the small
number of subjects in the SISdep subgroup could have
contributed to the lack of differences.
Some limitations of this investigation are worthy of note.
Only the short-term effect of movement training with
feedback was evaluated in this study. Further researches
will have to look at its long-term effects. Scapular move-
ment was not evaluated. However, no valid and reliable
method was available in our laboratory to characterize
scapular dynamic changes. Training with feedback is only
one aspect of the rehabilitation program. Evaluation of
physical factors, such as muscle strength, endurance and
range of motion that could interfere with the ability of
persons with SIS to perform arm movement also need to
be addressed. Furthermore, it is still unknown, as in other
musculoskeletal conditions [31], if the motor control def-
icits precede or follow the onset of pain and through
which cortical or subcortical mechanisms these deficits
take place. Only future neurophysiologically based stud-
ies will help to better understand the neural mechanisms
underlying motor control deficits observed in persons
with SIS.
Conclusion
Movement training with feedback led to short-term
changes during arm movements with respect to shoulder
pain and upper limb kinematic patterns. Persons with SIS
who presented the greater kinematic deficits at baseline
were the ones who demonstrated the most significant
changes in pain and kinematics following movement
training. Thus, rehabilitation strategies should be based
on initial kinematic deficits. Our results support the need
to evaluate this approach during a long-term training pro-
gram.
Abbreviations
ANOVA: Analysis of variance; DASH: Disabilities of the
arm, shoulder, and hand; E1: Baseline evaluation; E2:
Evaluation during movement training; E3: Evaluation
immediately after movement training; E4: Evaluation 24
hours after movement training; SIS: Shoulder impinge-
ment syndrome; EMG: Electromyographic
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
JSR: participated in the design of the study, carried out the
acquisition, the analysis and the interpretation of data
and drafted the manuscript.
HM: participated in the design of the study, the analysis
and the interpretation of data and drafted the manuscript.
BJM: participated in the design of the study, carried out
the acquisition, the interpretation of data and drafted the
manuscript.
RL: participated in the development of the study question,
enrolled subjects, and participated in the revision of the
manuscript.
All authors read and approved the final manuscript.
Acknowledgements
The authors wish to thank Guy St. Vincent for his help in the development
of the experimental procedure and in the acquisition of data. This study was
supported by a grant from the Ordre de la physiothérapie du Québec. The
funding source was not involved in the study's design, conduct and report-
ing. JSR was supported by scholarships from the Institut de recherche en
Interjoint coordination between elbow and wrist flexion/extensionFigure 5
Interjoint coordination between elbow and wrist flex-
ion/extension. The interjoint coordination between elbow
and wrist flexion/extension observed before (baseline), dur-
ing, immediately after and the day after movement training
are shown for the SIS group. * Significant difference in the
group with SIS compared to elbow and wrist excursions at
baseline.
Publish with BioMed Central and every
scientist can read your work free of charge
"BioMed Central will be the most significant development for
disseminating the results of biomedical research in our lifetime."
Sir Paul Nurse, Cancer Research UK
Your research papers will be:
available free of charge to the entire biomedical community
peer reviewed and published immediately upon acceptance
cited in PubMed and archived on PubMed Central
yours — you keep the copyright
Submit your manuscript here:
http://www.biomedcentral.com/info/publishing_adv.asp
BioMedcentral
Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2009, 1:8 http://www.smarttjournal.com/content/1/1/8
Page 11 of 11
(page number not for citation purposes)
santé et sécurité du travail and the Fonds de recherche en Santé du
Québec.
References
1. Myers JB, Wassinger CA, Lephart SM: Sensorimotor contribution
to shoulder stability: effect of injury and rehabilitation. Man
Ther 2006, 11:197-201.
2. Cowan SM, Bennell KL, Hodges PW, Crossley KM, McConnell J:
Simultaneous feedforward recruitment of the vasti in
untrained postural tasks can be restored by physical therapy.
J Orthop Res 2003, 21:553-558.
3. Hodges PW: Changes in motor planning of feedforward pos-
tural responses of the trunk muscles in low back pain. Exp
Brain Res 2001, 141:261-266.
4. On AY, Uludag B, Taskiran E, Ertekin C: Differential corticomotor
control of a muscle adjacent to a painful joint. Neurorehabil
Neural Repair 2004, 18:127-133.
5. Flor H: Cortical reorganisation and chronic pain: implications
for rehabilitation. J Rehabil Med 2003:66-72.
6. van Vliet PM, Heneghan NR: Motor control and the manage-
ment of musculoskeletal dysfunction. Man Ther 2006,
11:208-213.
7. Tyc F, Boyadjian A, Devanne H: Motor cortex plasticity induced
by extensive training revealed by transcranial magnetic
stimulation in human. Eur J Neurosci 2005, 21:259-266.
8. Tsao H, Hodges PW: Immediate changes in feedforward pos-
tural adjustments following voluntary motor training. Exp
Brain Res 2007, 181:537-546.
9. Winstein CJ, Campbell-Stewart J: Conditions of tasks practice for
individuals with neurologic impairments. In Textbook of Neural
Repair and Rehabilitation. Medical Neurorehabilitation Volume II. Edited
by: Selzer M, Clarke S, Cohen L, Duncan P, Gage F. New York: Cam-
bridge University Press; 2006:89-102.
10. Salmoni AW, Schmidt RA, Walter CB: Knowledge of results and
motor learning: a review and critical reappraisal. Psychol Bull
1984, 95:355-386.
11. Schmidt RA, Lee TD: Motor Control and Learning: a behavioral emphasis
Champaign, Ill: Human Kinetics; 2005.
12. Fitts PM, Posner MI: Human Performance Belmont, CA: Brooks/Cole;
1967.
13. Matsen FA, Arntz CT: Subacromial impingement. In The Shoulder
Edited by: Rockwood, Matsen. Philaldelphia: WA Saunders Co;
1990:623-646.
14. Ludewig PM, Cook TM: Alterations in shoulder kinematics and
associated muscle activity in people with symptoms of shoul-
der impingement. Phys Ther 2000, 80:276-291.
15. Wadsworth DJ, Bullock-Saxton JE: Recruitment patterns of the
scapular rotator muscles in freestyle swimmers with subac-
romial impingement. Int J Sports Med 1997, 18:618-624.
16. Reddy AS, Mohr KJ, Pink MM, Jobe FW: Electromyographic anal-
ysis of the deltoid and rotator cuff muscles in persons with
subacromial impingement. J Shoulder Elbow Surg 2000, 9:519-523.
17. Borstad JD, Ludewig PM: Comparison of scapular kinematics
between elevation and lowering of the arm in the scapular
plane. Clin Biomech (Bristol, Avon) 2002, 17:650-659.
18. McClure PW, Michener LA, Karduna AR: Shoulder function and 3-
dimensional scapular kinematics in people with and without
shoulder impingement syndrome. Phys Ther 2006,
86:1075-1090.
19. Roy JS, Moffet H, McFadyen BJ: Upper limb motor strategies in
persons with and without shoulder impingement syndrome
across different speeds of movement. Clin Biomech (Bristol, Avon)
2008, 23:1227-1236.
20. Deutsch A, Altchek DW, Schwartz E, Otis JC, Warren RF: Radio-
logic measurement of superior displacement of the humeral
head in the impingement syndrome. J Shoulder Elbow Surg 1996,
5:186-193.
21. Graichen H, Stammberger T, Bonel H, Wiedemann E, Englmeier KH,
Reiser M, Eckstein F: Three-dimensional analysis of shoulder
girdle and supraspinatus motion patterns in patients with
impingement syndrome. J Orthop Res 2001, 19:1192-1198.
22. Moff et H, He be rt LJ, Dufour M, Tardif J: Variation in sub-acromial
distance measured by magnetic resonance imaging during
shoulder flexion and abduction movements. Can J Rehabil
1998, 11:265-267.
23. Hudak PL, Amadio PC, Bombardier C: Development of an upper
extremity outcome measure: the DASH (disabilities of the
arm, shoulder and hand). The Upper Extremity Collabora-
tive Group (UECG). Am J Ind Med 1996, 29:602-608.
24. Wu G, van der Helm FC, Veeger HE, Makhsous M, van Roy P, Anglin
C, Nagels J, Karduna AR, McQuade K, Wang X, Werner FW, Buch-
holz B: ISB recommendation on definitions of joint coordi-
nate systems of various joints for the reporting of human
joint motion–Part II: shoulder, elbow, wrist and hand. J Bio-
mech 2005, 38:981-992.
25. Delagi EF, Perotto A, Iazzetti J, Morrison D: Anatomic Guide For the
Electromyographer Spingfield, Ill: Charles C. Thomas; 1980.
26. Roy JS, Moffet H, Hébert LJ, Lirette R: Effect of motor control and
strengthening exercises on shoulder function in persons with
impingement syndrome: A single-subject study design. Man
Ther 2008, 14:180-188.
27. Doyon J, Benali H: Reorganization and plasticity in the adult
brain during learning of motor skills. Curr Opin Neurobiol 2005,
15:161-167.
28. Hodges NJ, Hayes S, Horn RR, Williams AM: Changes in coordina-
tion, control and outcome as a result of extended practice
on a novel motor skill. Ergonomics 2005, 48:1672-1685.
29. Shumway-Cook A, Woollacott MH: Motor Control: Theory and Practical
Applications Philadelphia, Pa: Lippincott Williams & Wilkins; 2000.
30. Winstein CJ: Knowledge of results and motor learning–impli-
cations for physical therapy. Phys Ther 1991, 71:140-149.
31. Hodges PW, Moseley GL, Gabrielsson A, Gandevia SC: Experimen-
tal muscle pain changes feedforward postural responses of
the trunk muscles. Exp Brain Res 2003, 151:262-271.
... The axillary hand guides the lateral rotation and elevation of the scapula as the arm is raised. The PT must ensure that elbow extension is proportional to shoulder flexion (Roy et al., 2009). ...
... The part of ROM loss observed between the end of the first session and the beginning of the second one demonstrates the interest of repeating the sessions to memorize the new perceptual-motor control (Roy et al., 2009). ...
... The hand into the axillary web provides error information that can be used in association with the patient's own intrinsic error signals (mobilization number 12). This extrinsic feedback is particularly important during the first phase of learning (Roy et al., 2009) since it brings awareness to wrong movement. ...
Article
Download final version : https://authors.elsevier.com/a/1itlM4rR6weiql
... The shoulder, the most mobile joint of the body, relies on its finetuning stabilizing muscles for its stability, especially in elevated arm positions. The shoulder is therefore particularly at risk of injury in the presence of altered movements [1,4,5]. In fact, movement alterations at the shoulder and scapula are regularly observed in injured populations [2,[4][5][6][7]. ...
... The shoulder is therefore particularly at risk of injury in the presence of altered movements [1,4,5]. In fact, movement alterations at the shoulder and scapula are regularly observed in injured populations [2,[4][5][6][7]. ...
... while experiencing fatigue in the ipsilateral upper limb [8]. Increased sternoclavicular elevation has been observed in populations with shoulder pain and is thought to be a kinematic adaptation to protect the subacromial structure [2,[5][6][7]. The central mechanisms contributing to the feeling of fatigue in the dominant arm could have also affected the contralateral arm movement planning, leading to similar protective kinematic adaptation in that (non-dominant) arm [1,2,4,5,8]. ...
Article
Full-text available
Background Altered movement patterns have been proposed as an etiological factor for the development of musculoskeletal pain. Fatigue influences upper limb kinematics and movement performance which could extend to the contralateral limb and potentially increasing risk of injury. The aim of this study was to investigate the impact of fatigue at the dominant arm on the contralateral upper limb movement. Methods Forty participants were randomly assigned to one of two groups: Control or Fatigue Group. All participants completed a reaching task at the baseline and post-experimental phase, during which they reached four targets with their non-dominant arm in a virtual reality environment. Following the baseline phase, the Fatigue Group completed a shoulder fatigue protocol with their dominant arm only, while the Control Group took a 10-minute break. Thereafter, the reaching task was repeated. Upper limb and trunk kinematics (joint angles and excursions), spatiotemporal (speed and accuracy) and surface electromyographic (sEMG) activity (sEMG signal mean epoch amplitude and median frequency of the EMG power spectrum) were collected. Two-way repeated-measures ANOVA were performed to determine the effects of Time, Group and of the interaction between these factors. Results There was a significant Time x Group interaction for sternoclavicular elevation range of motion (p = 0.040), movement speed (p = 0.043) and accuracy (p = 0.033). The Fatigue group showed higher contralateral sternoclavicular elevation and increased movement error while experiencing fatigue in the dominant arm. Moreover, the Control group increased their speed during the Post-experimental phase compared to baseline (p = 0.043), while the Fatigue group did not show any speed improvement. There was no EMG sign of fatigue in any of the muscles evaluated. Conclusion This study showed that fatigue at the dominant shoulder impacts movement at the contralateral upper limb. Such changes may be a risk factor for the development of shoulder pain in both the fatigued and non-fatigued limbs.
... Intervention using scapular correction has been reported in earlier studies using EMG activity of scapular muscles and/or scapular kinematics as outcome. (De Mey et al., 2013;Roy et al., 2009;Jones et al., 2018;Staker et al., 2019). Staker et al. found an increase of LT and SA in an external rotation shoulder exercise, after an intervention, resulting in a decrease of UT/LT muscle ratio with 11.2% (Staker et al., 2019). ...
... The two post-tests showed a lower EMG activity for all muscles except for LT, compared to pre-test. The second test showed additionally improvement of kinematics, but this improvement was back to baseline measurement at the 24 h test (Roy et al., 2009). Contrary to the two studies on shoulder pain patients we studied overhead athletes with shoulder pain in late rehabilitation and we do not know if an intervention could have a different impact if introduced earlier in rehabilitation. ...
... Contrary to our study, Roy et al. did not use thoraco-humeral or abdominal muscles activity as outcome but measured motor strategies during reaching movements. They found that shoulder pain patients used significantly larger trunk rotation and shoulder external rotation than healthy controls (Roy et al., 2009). We on the other hand did not measure motor strategies but found significant higher muscle activity for both PM and OEC muscles in the shoulder pain-group compared to healthy controls during the exercise. ...
Article
Objectives To investigate if there is a difference in muscle activity for overhead athletes before and after an intervention with correction of both core and scapula compared to no intervention and is there a difference between overhead athletes with or without shoulder pain. Design Controlled laboratory EMG study including intervention. Setting University EMG laboratory. Participants Sixty overhead athletes, 30 with shoulder pain and 30 healthy controls were included performing plyometric rotational shoulder exercise. Main outcomes Half of the participants received an intervention the other half were controls with no intervention. EMG muscle activity from 10 scapular, thoraco-humeral and trunk muscles were measured. Results There were no significant differences in muscle activation levels between the groups with or without intervention. For the shoulder pain group, there were significant lower activity in Upper Trapezius when repeating the exercise. The shoulder pain group had significant higher activity in Pectoralis Major compared to the Healthy Control group. Conclusions Most differences were found between the pre- and post-test. Repetition of the exercise seems to be more important than verbal and tactile instructions. Comparing the shoulder pain group with the healthy controls confirms previous findings that, pain patients recruit muscles differently from healthy persons.
... Similarly, a research study that appeared in the Journal of Manipulative and Physiological Therapy discovered that physiotherapy therapies improved both pain and function in people suffering from neck discomfort according to Miller et al. (2010).Another research study presented in the Journal of Shoulder and Elbow Surgery from Roy et al. (2009) discovered that physiotherapy therapies increased function and decreased pain in people suffering from shoulder pain. ...
Article
Full-text available
For patients with musculoskeletal diseases, physiotherapy is a safe and efficient treatment option that can help them manage their symptoms and enhance their health. In primary care, physiotherapists aid in the diagnosis, cure, and manage of a broad spectrum of acute and chronic disorders, as well as promote physical exercise, mobility, and function. Physiotherapists in basic medical teams maximize patients’ mobility in accordance with their lifelong needs. This brief study emphasizes the significance of musculoskeletal disorders treatable with physiotherapy. Physiotherapy interventions, when delivered remotely through e-Health platforms, have gained prominence as accessible and effective tools for managing musculoskeletal conditions. These interventions provide patients with valuable resources for self-management, while greatly used to improve everyones quality of life. At the same time, helping to moderate the challenges that this load can create on healthcare systems. The use of telehealth in physiotherapy offers opportunities for personalized care, continuous monitoring, and the implementation of evidence-based interventions. The relevancy of this approach is mainly noticed when put in the context of the COVID-19 pandemic, where the need for remote healthcare delivery has become paramount. Telehealth allows patients to receive timely care and support while adhering to social distancing guidelines. The concept of adherence to eHealth technology in physiotherapy is crucial for ensuring the success of remote interventions. Understanding when and how patients engage with eHealth platforms can guide the development of more effective interventions. It is essential to explore factors that influence patient adherence to technology-driven physiotherapy interventions to optimize their benefits. As healthcare systems worldwide face increasing demands, the implementation of remote physiotherapeutic e-Health interventions can help alleviate the burden by offering scalable and cost-effective solutions. These interventions have the potential to reach a broader patient population and improve access to care for individuals with musculoskeletal disorders. The evaluation of the effectiveness of these remote interventions is essential to provide evidence-based guidance for their integration into clinical practice. By conducting systematic reviews and meta-analyses, researchers can contribute valuable insights into the outcomes and impact of telehealth-based physiotherapy on pain management and overall patient well-being.
... The pain was mostly described as deep in the deltoid area of the shoulder, which is close to the pain experienced by patients Sole et al., 2014. However, subacromial pain is usually reproduced by movement when peri-articular and muscle-tendinous structures are loaded Lewis et al., 2015;Roy et al., 2009. The experimentally induced pain did not reproduce this effect, as participants most frequently reported the pain to be constant, regardless of position or movement, until it subsided. ...
Article
Full-text available
Background: People with chronic shoulder pain have been shown to present with motor adaptations during arm movements. These adaptations may create abnormal physical stress on shoulder tendons and muscles. However, how and why these adaptations develop from the acute stage of pain is still not well-understood. Objective: To investigate motor adaptations following acute experimental shoulder pain during upper limb reaching. Methods: Forty participants were assigned to the Control or Pain group. They completed a task consisting of reaching targets in a virtual reality environment at three time points: (1) baseline (both groups pain-free), (2) experimental phase (Pain group experiencing acute shoulder pain induced by injecting hypertonic saline into subacromial space), and (3) Post experimental phase (both groups pain-free). Electromyographic (EMG) activity, kinematics, and performance data were collected. Results: The Pain group showed altered movement planning and execution as shown by a significant increased delay to reach muscles EMG peak and a loss of accuracy, compared to controls that have decreased their mean delay to reach muscles peak and improved their movement speed through the phases. The Pain group also showed protective kinematic adaptations using less shoulder elevation and elbow flexion, which persisted when they no longer felt the experimental pain. Conclusion: Acute experimental pain altered movement planning and execution, which affected task performance. Kinematic data also suggest that such adaptations may persist over time, which could explain those observed in chronic pain populations.
... 27 Recently, the hypothesis has been raised that reorganization in the brain could explain part of the deficits associated with RC tendinopathy. 21,22,26,29 If some of the deficits experienced by patients with RC tendinopathy stem from neural changes, the clinical approach should be broadened to incorporate interventions, such as sensorimotor training aimed at the reversal of neural changes. Human motor control has been shown to exhibit a feedforward and future-oriented approach. ...
Article
Full-text available
Background Previous research investigating rotator cuff (RC) tendinopathy has usually focused on pathoanatomy. The pathologic response to anticipatory postural adjustments (APAs) has not yet been investigated. Purpose/Hypothesis To explore changes in APAs as detected by pre-emptive activation of shoulder muscles during ball catching. It was hypothesized that anticipatory muscle activation (AMA) would be present in the unaffected shoulder but delayed or absent in the affected shoulder in patients with RC tendinopathy. Study Design Controlled laboratory study. Methods This study included 21 RC tendinopathy patients with a mean age of 49.5 years. Patients were required to grab a ball embedded with an electromyography sensor when it dropped on their hand, and surface electromyography signals were recorded from the infraspinatus, upper trapezius, anterior deltoid, and biceps. The trials utilized 2 balls, weighing 200 g and 500 g. Each ball was used in 2 trials, 1 involving a number count preceding the ball drop (predictable) and the other involving a sudden drop (unpredictable). The onsets of AMA between the affected and unaffected limbs were compared. Results Regardless of the experimental condition, significantly delayed AMA onsets were identified in all investigated muscles of the affected side compared with those of the unaffected side, except for the biceps muscle in the 500-g predictable trial. For the infraspinatus, the mean onset time in the 200-g predictable trial was –141.0 ± 60.2 ms on the affected side and –211.9 ± 67.1 ms on the unaffected side ( P < .001); in the 200-g unpredictable trial this value was –139.5 ± 54.9 ms on the affected side and –199.5 ± 56.2 ms on the unaffected side ( P < .001). Conclusion Delayed AMA was observed in the affected shoulder compared with the unaffected shoulder in patients with RC tendinopathy, not only in the RC muscle but also in the periscapular and upper arm muscles. This may indicate that central hypoexcitability is partly responsible. Clinical Relevance The basis for RC tendinopathy treatment should not be limited to the tendon pathoanatomy. Delayed AMA around the shoulder joint could provide insight into potential mechanisms related to the central nervous system.
... With a planning-control model underpinning the assessment and management of motor control/function, two principles guided the management of abnormal neuromuscular activity and motion in this study: (1) Treatment strategies to re-educate neuromuscular activity and control incorporating criteria for a preferred pattern of muscle activation prior to and during the execution of a motor command; (2) optimization of internal feedback mechanisms, so a deviation or perturbation of predicted movement can be effectively detected and corrected in real-time. Roy et al. [59,60] showed that conscious movement training with feedback causes immediate effects on motor strategies and can restore the force-couple activation in the scapular muscles, especially the stabilizers, consistent with the improvement in LT and SA activity in both groups of this study. ...
Article
Full-text available
Current clinical practice lacks consistent evidence in the management of scapular dyskinesis. This study aims to determine the short- and long-term effects of a scapular-focused exercise protocol facilitated by real-time electromyographic biofeedback (EMGBF) on pain and function, in individuals with rotator cuff related pain syndrome (RCS) and anterior shoulder instability (ASI). One-hundred and eighty-three patients were divided into two groups (n = 117 RCS and n = 66 ASI) and guided through a structured exercise protocol, focusing on scapular dynamic control. Values of pain and function (shoulder pain and disability index (SPADI) questionnaire, complemented by the numeric pain rating scale (NPRS) and disabilities of the arm, shoulder, and hand (DASH) questionnaire) were assessed at the initial, 4-week, and 2-year follow-up and compared within and between. There were significant differences in pain and function improvement between the initial and 4-week assessments. There were no differences in the values of DASH 1st part and SPADI between the 4-week and 2-year follow-up. There were no differences between groups at the baseline and long-term, except for DASH 1st part and SPADI (p < 0.05). Only 29 patients (15.8%) had a recurrence episode at follow-up. These results provide valuable information on the positive results of the protocol in the short- and long-term.
... This is consistent with the results of the present study, in which movement control exercise caused significant changes in the position and function of the scapula. In addition, Roy et al. [35] reported results similar to our study findings, as they observed that movement control exercises improved movement disorders affecting the scapulothoracic and scapulohumeral areas. The PNF muscle control exercise used in this study differed from the other two exercises in that it involved manual contact by a physiotherapist. ...
Article
Full-text available
Background and Objectives; Proprioceptive neuromuscular facilitation (PNF) are effective in improving and maintaining Range of motion(ROM), increasing muscular strength and power, and increasing athletic performance, especially after exercise. The scapula patterns defined in PNF are activated within the upper extremity patterns and scapula motions together. Proper function of the upper extremities requires both motion and stability of the scapula. The purpose of this study was to compare the effects of scapula stabilization exercise training involving muscle strengthening, muscle balance, and movement control exercises on office workers with scapula dysfunction. Materials and Methods: A total of 42 office workers with scapula dyskinesis were recruited and randomly divided into three groups: muscle strengthening exercise group (n = 14), muscle balance exercise group (n = 14), and movement control exercise group (n = 14). The participants underwent 18 sessions (25 min/session, 3 days a week for 6 weeks) of training involving the three types of exercises. Results: The measurement outcomes included the scapula index, measured using a digital Vernier caliper; scapula function, evaluated using the Disability of the Arm, Shoulder, and Hand (DASH) outcome questionnaire (pain and performing, work ability, and sports and art activities); and scapulohumeral movements (scapula upward rotation at humeral abduction angles of 0°, 45°, 90°, 135°, and 180°), evaluated using inclinometers. After the exercise intervention, the scapula index (p = 0.002), DASH pain and performing score (p = 0.000), DASH work ability score (p = 0.000), DASH sports and art activity score (p = 0.027), and scapulohumeral movements (scapula upward rotation at 0° (p = 0.013) and 45° (p = 0.043) humeral abduction) showed significantly greater improvements in the movement control group than in the muscle strengthening and muscle balance groups. Conclusions: Thus, proprioceptive neuromuscular facilitation can be used as a rehabilitation intervention for scapula position and movement, pain reduction, and functional improvement in office workers with scapula dyskinesis.
Article
Full-text available
Introduction: Lifetime prevalence of shoulder pain is 70%, and approximately 50% of people with shoulder pain will experience pain for more than a year. Rotator cuff-related shoulder pain (RCRSP) is the most common shoulder condition and the main non-surgical intervention is exercise therapy. For approximately 30% of people with RCRSP, this approach does not lead to a significant reduction in symptoms. This may be due to an inappropriate dosage or choice of exercises. The aim of this investigation is to compare the short, mid and long-term effects, in terms of symptoms, functional limitations, kinesiophobia and pain catastrophising, of three different shoulder rehabilitation approaches (education, strengthening, motor control) in adults with RCRSP. Methods and analysis: In this single-blind (assessor), parallel-group, randomised clinical trial, 123 adults presenting with RCRSP will take part in a 12-week rehabilitation programme. They will be randomly assigned to one of three groups (education only, strengthening approach or motor control-focused approach). Abbreviated version of the Disabilities of the Arm, Shoulder and Hand Questionnaire, the primary outcome, Western Ontario Rotator Cuff Index and Brief Pain Inventory will evaluate symptoms and functional limitations, while Tampa Scale of Kinesiophobia and Pain Catastrophizing Scale will evaluate pain-related fear and catastrophising at baseline and at 3, 6, 12 and 24 weeks. Ultrasonographic acromiohumeral distances and tendon thickness will be assessed at baseline and 12 weeks. Intervention groups will be compared on outcomes with intention-to-treat analyses using two-way repeated measures analysis of variance if the data are normally distributed or non-parametric analysis of longitudinal data if they are not. Ethics and dissemination: Ethics approval was obtained from the Sectorial Rehabilitation and Social Integration Research Ethics Committee of the Centre Intégré Universitaire de Santé et de Services Sociaux de la Capitale Nationale (CIUSSS-CN). Results will be disseminated through international publications in peer-reviewed journals, in addition to international conference presentations. Trial registration number: NCT03892603; pre-results.
Article
Background: Clinician-led training through tactile and verbal guidance to improve muscle activity and joint motion are a common but understudied focus of therapeutic interventions for shoulder pain. The purpose of this study was to determine if clinician guidance changes scapulothoracic muscle activity and kinematics compared to unguided shoulder exercises. Methods: Eleven participants with shoulder pain were studied. Electromyographic (EMG) sensors were placed on the serratus anterior and upper and lower trapezii. Scapulothoracic and sternoclavicular kinematics were collected using electromagnetic sensors. Five common resisted shoulder exercises were performed with the following guidance: unguided, combined (verbal and tactile cues), and verbal guidance only. One-way repeated measures ANOVAs determined the effect of guidance versus unguided conditions for each exercise. Results: Nine of ten combinations of exercise and guidance techniques demonstrated a significant effect of guidance for either muscle activity or joint kinematics. The guidance condition with the most frequent significant improvements across all variables was the combined condition. The exercises with the most frequent significant improvements across all variables were the external rotation exercises. Variables improved most frequently were: upper:lower trapezius EMG ratio (up to 11%), sternoclavicular elevation (up to 6°) and scapulothoracic internal rotation positioning (up to 8°), and sternoclavicular retraction displacement (up to 5°). Conclusion: Shoulder muscle activity and kinematics during exercises can be modified by tactile and verbal guidance. Most improvements in muscle activity occurred with verbal guidance during external rotation exercises. Most improvements in joint positioning and movement occurred with combined guidance during external rotation exercises.
Article
Full-text available
This paper describes the development of an evaluative outcome measure for patients with upper extremity musculoskeletal conditions. The goal is to produce a brief, self-administered measure of symptoms and functional status, with a focus on physical function, to be used by clinicians in daily practice and as a research tool. This is a joint initiative of the American Academy of Orthopedic Surgeons (AAOS), the Council of Musculoskeletal Specialty Societies (COMSS), and the Institute for Work and Health (Toronto, Ontario).Our approach is consistent with previously described strategies for scale development. In Stage 1, Item Generation, a group of methodologists and clinical experts reviewed 13 outcome measurement scales currently in use and generated a list of 821 items. In Stage 2a, Initial Item Reduction, these 821 items were reduced to 78 items using various strategies including removal of items which were generic, repetitive, not reflective of disability, or not relevant to the upper extremity or to one of the targeted concepts of symptoms and functional status. Items not highly endorsed in a survey of content experts were also eliminated. Stage 2b, Further Item Reduction, will be based on results of field testing in which patients complete the 78-item questionnaire. This field testing, which is currently underway in 20 centers in the United States, Canada, and Australia, will generate the final format and content of the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Future work includes plants for validity and reliability testing. © 1996 Wiley-Liss, Inc.
Chapter
In two freestanding but linked volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. This volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation for the work of clinical neurorehabilitation professionals .
Article
Examines some critical definitional and experimental-design problems that underlie the principles of knowledge of results (KR) and learning, the KR literature, and how newer principles of KR lead to notions of how KR works in human motor-learning situations. KR is defined as augmented feedback, where the KR is additional to those sources of feedback that are naturally received when a response is made. Transfer tests, usually under no-KR conditions, are essential for unraveling the temporary effects of KR manipulations from their relatively permanent learning effects. When this is considered, the literature reveals findings that produce reasonable agreement, although there are a number of inconsistencies in studies examining the same variables. When learning vs performance effects of KR are separated, a number of contradictions occur; new principles that emerge include the notion that KR acts as guidance, that it is motivating or energizing, and that it has a role in the formation of associations. It is suggested that KR may guide an S to the proper target behavior, with other processes (e.g., simple repetition) being the critical determinants of learning. (4 p ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).
Article
The purpose of this study was to compare subjects with subacromial impingement and subjects with normal shoulders with respect to muscle activity. Fifteen subjects in each group were studied by means of fine-wire electromyography. The middle deltoid and rotator cuff muscles were evaluated during isotonic scaption from 30 to 120 degrees. Overall, the impingement group demonstrated decreased mean muscle activity in comparison with the group of normal subjects. The magnitude of diminished activity was statistically significantly different (P
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.
Article
Activities requiring repetitive arm movements, including high velocity actions, have been identified as a risk factor for shoulder impingement. However, the effect of speed on upper limb motor strategies has yet to be evaluated for individuals with shoulder impingement. The aims of this study were to characterize upper limb motor strategies in individuals with and without shoulder impingement during reaching at natural speed and to evaluate their adaptation to higher speeds of movement. Twenty healthy individuals and 33 individuals with shoulder impingement took part in one evaluation session. They performed reaching at natural and fast speeds, toward targets located at 90 degrees of arm elevation in two different planes. Reaching speed, upper limb kinematics and shoulder muscular activity were used to characterize motor strategies. Individuals with shoulder impingement present altered motor strategies during reaching tasks. However, changes with speed were comparable in both groups, showing similar adaptation to speed. Larger intergroup differences were found when individuals with shoulder impingement were separated into groups presenting higher or lower than normal clavicular elevation. In the frontal plane, increased clavicular elevation for individuals with impingement was associated with more trunk rotation, less elbow flexion and upper trapezius electromyographic activity during reaching, and a more anterior plane of shoulder elevation at the end of reaching as compared to the healthy individuals. The present results demonstrate that not all individuals with shoulder impingement present the same abnormal motor strategy. Therefore, characterizing motor strategies before implementing rehabilitation intervention is essential.
Article
Relevant to this special series on movement science, a brief overview of research in the field of motor learning is provided. A distinction between learning and performance is emphasized with respect to experimental design and the evaluation of laboratory and clinical intervention techniques. Intrinsic and extrinsic feedback are defined. Basic principles of motor learning pertaining to the use of augmented feedback or knowledge of results (KR) are reviewed. Particular emphasis is placed on recent research regarding the effects of selected KR variations (KR relative frequency, bandwidth KR, and KR delay) on motor performance and learning in healthy young adults. Results are discussed in terms of short-lasting temporary performance effects and relatively long-lasting learning effects. Theoretical and practical implications from this research are discussed. It is suggested that it is appropriate to use the principles obtained through laboratory experimentation as guidelines rather than as exact recommendations when applying basic research findings to clinical practice.