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Annals of Physical and Rehabilitation... Jan 2021Several studies reported the importance of glenohumeral and scapular muscle activity and scapular kinematics in multidirectional shoulder instability (MDI), yet a... (Review)
Review
BACKGROUND
Several studies reported the importance of glenohumeral and scapular muscle activity and scapular kinematics in multidirectional shoulder instability (MDI), yet a systematic overview is currently lacking.
OBJECTIVE
This systematic review evaluates and summarizes the evidence regarding muscle activity and shoulder kinematics in individuals with MDI compared to healthy controls.
METHOD
The electronic databases PubMed and Web of Science were searched in September 2020 with key words regarding MDI (population), muscle activity, and glenohumeral and scapular movement patterns (outcomes). All studies that compared muscle activity or scapular kinematics between shoulders with MDI and healthy shoulders were eligible for this review, except for case reports and case series. All articles were screened on the title and abstract, and remaining eligible articles were screened on full text. The risk of bias of included articles was assessed by a checklist for case-control data, as advised by the Cochrane collaboration.
RESULTS
After full text screening, 12 articles remained for inclusion and one study was obtained by hand search. According to the guidelines of the Dutch Institute for Healthcare Improvement, most studies were of moderate methodological quality. We found moderate evidence that MDI individuals show increased or prolonged activity of several rotator cuff muscles that control and centre the humeral head. Furthermore, we found evidence of decreased and/or shortened activity of muscles that move or accelerate the arm and shoulder girdle as well as increased and/or lengthened activity of muscles that decelerate the arm and shoulder girdle. The most consistent kinematic finding was that MDI individuals show significantly less upward rotation and more internal rotation of the scapula during elevation of the arm in the scapular plane as compared with controls. Finally, several studies also suggest that the humeral head demonstrates increased translations relative to the glenoid surface.
CONCLUSION
There is moderate evidence for altered muscle activity and altered humeral and scapular kinematics in MDI individuals as compared with controls.
Topics: Biomechanical Phenomena; Humans; Joint Instability; Muscle, Skeletal; Range of Motion, Articular; Scapula; Shoulder; Shoulder Joint
PubMed: 33221471
DOI: 10.1016/j.rehab.2020.10.008 -
Brazilian Journal of Physical Therapy 2019The serratus anterior (SA) is capable of a wide range of actions across the scapulothoracic joint. Furthermore, the lack of control, strength, or activation of this... (Review)
Review
BACKGROUND
The serratus anterior (SA) is capable of a wide range of actions across the scapulothoracic joint. Furthermore, the lack of control, strength, or activation of this important muscle is believed to be associated with several painful conditions involving the shoulder complex. Studies and clinical intuition have therefore identified several exercises that selectively target the activation of the SA.
METHODS
This paper reviews the anatomy, innervation, testing, and complex actions of the SA. In addition, this paper describes the classic signs and symptoms of weakness or reduced activation of the SA. Several exercises are described and illustrated that purportedly target the activation of the SA, with the intention of optimizing muscular control and encouraging pain free shoulder motion.
CONCLUSIONS
This review provides the theoretical background and literature-based evidence that can help explain the SA's complex pathokinesiology, as well as guide the clinician to further develop exercises that likely challenge the muscle. This paper is written along with a companion paper entitled: Kinesiologic considerations for targeting activation of scapulothoracic muscles: part 2: trapezius. Both papers prepare the reader to expand their pallet of exercises that target and challenge these two dominant muscles, with a goal of improving function of the shoulder for several painful conditions caused by their reduced or altered activation pattern.
Topics: Exercise; Humans; Muscle, Skeletal; Shoulder; Superficial Back Muscles
PubMed: 30737019
DOI: 10.1016/j.bjpt.2019.01.008 -
Journal of Shoulder and Elbow Surgery Jan 2020Pathologic activation pattern of muscles can cause shoulder instability. We propose to call this pathology functional shoulder instability (FSI). The purpose of this...
BACKGROUND
Pathologic activation pattern of muscles can cause shoulder instability. We propose to call this pathology functional shoulder instability (FSI). The purpose of this prospective study was to provide an in-detail description of the characteristics of FSI.
METHODS
In the year 2017, a total of 36 consecutive cases of FSI presenting to our outpatient clinic were prospectively collected. Diagnostic investigation included a pathology-specific questionnaire, standardized clinical scores, clinical examination, psychological evaluation, video and dynamic fluoroscopy documentation of the instability mechanism, as well as magnetic resonance imaging (MRI). In a final reviewing process, the material from all collected cases was evaluated and, according to the observed pattern, different subtypes of FSI were determined and compared.
RESULTS
Based on the pathomechanism, positional FSI (78%) was distinguished from nonpositional FSI (22%). Controllable positional FSI was observed in 6% of all cases and noncontrollable positional FSI in 72%, whereas controllable and noncontrollable nonpositional FSI were each detected in 11% of the cases. The different subtypes of FSI showed significant differences in all clinical scores (Western Ontario Shoulder Instability Index: P = .002, Rowe Score: P = .001, Subjective Shoulder Value: P = .001) and regarding functional impairment (shoulder stability: P < .001, daily activities: P = .001, sports activities: P < .001). Seventy-eight percent had posterior, 17% anterior, and 6% multidirectional instability. Although several patients showed constitutional glenoid shape alterations or soft tissue hyperlaxity, only few patients with acquired minor structural defects were observed.
CONCLUSION
FSI can be classified into 4 subtypes based on pathomechanism and volitional control. Depending on the subtype, patients show different degrees of functional impairment. The majority of patients suffer from unidirectional posterior FSI.
Topics: Adolescent; Adult; Female; Fluoroscopy; Humans; Joint Instability; Magnetic Resonance Imaging; Male; Muscle, Skeletal; Posture; Prospective Studies; Shoulder; Shoulder Joint; Young Adult
PubMed: 31378683
DOI: 10.1016/j.jse.2019.05.025 -
Scientific Reports Dec 2022Glenohumeral internal rotation deficit (GIRD) and weakness in prone external rotation are risk factors for shoulder and elbow injuries in high school baseball pitchers.... (Randomized Controlled Trial)
Randomized Controlled Trial
Shoulder stretching versus shoulder muscle strength training for the prevention of baseball-related arm injuries: a randomized, active-controlled, open-label, non-inferiority study.
Glenohumeral internal rotation deficit (GIRD) and weakness in prone external rotation are risk factors for shoulder and elbow injuries in high school baseball pitchers. While a shoulder-stretching prevention program to improve GIRD decreases the injury rate, the effects of external rotation strength remain unclear. This non-inferiority (NI) study investigates the hypothesis that external rotation strength training is not inferior to sleeper stretching for shoulder and elbow injury prevention in high school baseball pitchers. Participants were randomly allocated to the stretching (n = 62; active control group) and muscle-training (n = 51) groups. Specific exercises were performed each night. Elbow and shoulder injuries were monitored for 150 days. Kaplan-Meier survival curves were generated, and the hazard ratios (HRs) for injury occurrence were calculated using multivariate Cox regression. The log-rank test was used to compare the injury-free time. A one-sided NI test using a fixed NI margin was performed (significance level, P = 0.025). The injury rates were 22.6% (n = 14) in the stretching group and 9.8% (n = 5) in the muscle-training group. The muscle-training group had a lower injury rate (P < 0.001) and a lower risk of injury than the stretching group (HR = 0.489). Therefore, external rotation muscle strength training is not inferior to stretching for preventing baseball-related arm injuries.
Topics: Humans; Shoulder; Resistance Training; Baseball; Elbow Injuries; Range of Motion, Articular; Arm Injuries; Muscle, Skeletal; Risk Factors
PubMed: 36543874
DOI: 10.1038/s41598-022-26682-1 -
Kinesiologic considerations for targeting activation of scapulothoracic muscles - part 2: trapezius.Brazilian Journal of Physical Therapy 2019The trapezius is an extensive muscle subdivided into upper, middle, and lower parts. This muscle is a dominant stabilizer of the scapula, normally operating... (Review)
Review
BACKGROUND
The trapezius is an extensive muscle subdivided into upper, middle, and lower parts. This muscle is a dominant stabilizer of the scapula, normally operating synergistically with other scapular muscles, most notably the serratus anterior. Altered activation, poor control, or reduced strength of the different parts of the trapezius have been linked with abnormal scapular movements, often associated with pain. Several exercises have been designed and studied that specifically target the different parts of the trapezius, with the goal of developing exercises that optimize scapular position and scapulohumeral rhythm that reduce pain and increase function.
METHODS
This paper describes the anatomy, kinesiology, and pathokinesiology of the trapezius as well as exercises that selectively target the activation of the different parts of this complex muscle.
CONCLUSIONS
This review provides the anatomy and kinesiology of the trapezius muscle with the underlying intention of understanding how this muscle contributes to the normal mechanics of the scapula as well as the entire shoulder region. This paper can guide the clinician with planning exercises that specifically target the different parts of the trapezius. It is recommended that this paper be read as a companion to another paper: Kinesiologic considerations for targeting activation of scapulothoracic muscles - part 1: serratus anterior.
Topics: Dyskinesias; Exercise Therapy; Humans; Muscle, Skeletal; Scapula; Shoulder; Superficial Back Muscles
PubMed: 30797676
DOI: 10.1016/j.bjpt.2019.01.011 -
International Journal of Environmental... Jan 2021The shoulder in CrossFit should have a balance between mobility and stability. Glenohumeral internal rotation deficit and posterior shoulder stiffness are risk factors... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The shoulder in CrossFit should have a balance between mobility and stability. Glenohumeral internal rotation deficit and posterior shoulder stiffness are risk factors for overhead shoulder injury.
OBJECTIVE
To determine the effectiveness of instrument-assisted soft tissue mobilization and horizontal adduction stretch in CrossFit practitioners' shoulders.
METHODS
Twenty-one regular CrossFitters were allocated to experimental (stretching with isometric contraction and instrument-assisted soft tissue mobilization) or control groups (instrument-assisted soft tissue mobilization). Each session lasted 5 min, 2 days a week, over a period of 4 weeks. Shoulder internal rotation and horizontal adduction (digital inclinometer), as well as posterior shoulder stretch perception (Park scale), were evaluated. Shapiro-Wilk test was used to analyze the distribution of the sample. Parametric Student's -test was used to obtain the intragroup differences. The inter- and intra-rater differences were calculated using a repeated measures analysis of variance (ANOVA).
RESULTS
Average age was 30.81 years (SD: 5.35), with an average height of 178 (SD: 7.93) cm and average weight of 82.69 (SD: 10.82) kg. Changes were found in the experimental group following intervention ( < 0.05), and when comparing baseline and follow-up assessments ( < 0.05) in all variables. Significant differences were found in the control group following intervention ( < 0.05), in right horizontal adduction and left internal rotation. When comparing the perception of internal rotation and horizontal adduction in both groups, significant differences were found.
CONCLUSIONS
Instrument-assisted soft tissue mobilization can improve shoulder horizontal adduction and internal rotation. An instrument-assisted soft tissue mobilization technique yields the same results alone as those achieved in combination with post-isometric stretch with shoulder adduction.
Topics: Adult; Humans; Muscle Stretching Exercises; Pilot Projects; Range of Motion, Articular; Rotation; Shoulder; Shoulder Joint
PubMed: 33445505
DOI: 10.3390/ijerph18020575 -
Knee Surgery, Sports Traumatology,... Dec 2021
Topics: Biomechanical Phenomena; Humans; Joint Instability; Musculoskeletal System; Shoulder; Shoulder Joint
PubMed: 34559246
DOI: 10.1007/s00167-021-06743-0 -
Journal of Orthopaedic Surgery and... Jan 2022The shoulder joint is the most commonly injured joint in CrossFit practitioners, because of the high intensity and loads associated with this sport. Despite the large... (Comparative Study)
Comparative Study Observational Study
BACKGROUND
The shoulder joint is the most commonly injured joint in CrossFit practitioners, because of the high intensity and loads associated with this sport. Despite the large number of clinical cases, there is a shortage of studies that investigate influence of biomechanical aspects of upper limbs' injuries on CrossFit practitioners. This study hypothesized that there would be a difference in function, strength, and muscle activation between Crossfit practitioners with and without shoulder pain.
METHODS
We divided 79 Crossfit practitioners into two groups according to whether they reported pain (n = 29) or no pain (n = 50) in the shoulder during Crossfit training. Muscle function, strength, and activation were assessed using the Disability Arm, Shoulder and Hand function questionnaire, Upper Quarter Y Balance Test and Closed Kinetic Chain Upper Extremity Stability Test shoulder tests, isometric muscle strength assessment by manual dynamometry and muscle activation by surface electromyography and pain report.
RESULTS
The function based on questionnaire was associated with pain (p = 0.004). We observed a statistically significant difference between the two groups only in the surface electromyography activity of the lower trapezius, and in the variables of shoulder pain and function (p = 0.038).
CONCLUSION
Crossfit practitioners with shoulder pain occurring during training showed good function and stability of the shoulder joint, but there was a reduction in the activation of stabilizing muscles, especially the lower trapezius. Trial registration Registro Brasileiro de Ensaios Clinico (Brasilian National Registry) with the ID: RBR-2gycyv.
Topics: Adolescent; Adult; Electromyography; Female; Humans; Male; Muscle Strength; Muscle, Skeletal; Musculoskeletal System; Range of Motion, Articular; Shoulder; Shoulder Pain; Superficial Back Muscles
PubMed: 35033136
DOI: 10.1186/s13018-022-02915-x -
Orthopaedic Surgery Aug 2023
Topics: Humans; Shoulder; Elbow; Upper Extremity
PubMed: 37587546
DOI: 10.1111/os.13861 -
Orthopaedic Surgery Oct 2020
Topics: Elbow; Humans; Shoulder
PubMed: 33200573
DOI: 10.1111/os.12813