Rotator cuff disease is multi-factored and has been attributed to both intrinsic and extrinsic factors. Extrinsic factors contribute to compression of the rotator cuff tendons. Intrinsic factors that contribute to rotator cuff tendon degradation with tensile/shear overload include alterations in biology, mechanical properties, morphology, and vascularity. Subacromial impingement is related to factors that encroach upon the subacromial space, while internal impingement affects the articular side of the tendons adjacent to glenoid. While the mechanisms of impingement are varied, further research is necessary to improve treatment and patient outcomes. Chapter 2 is a thorough review of literature on the mechanisms of rotator cuff disease. Alterations in scapular kinematics may influence subacromial space and either contribute to the etiology of subacromial impingement with rotator cuff tendon compression or serve as a compensation to alleviate compression. Furthermore alterations in scapular position may directly influence rotator cuff muscle strength. Chapter 3 compares the influence of the scapular assistance test on scapular upward rotation, posterior tilt, subacromial space, and shoulder strength between healthy individuals and subjects with subacromial impingement syndrome. Scapular upward rotation and posterior tilt induced with scapular assistance test appears to influence subacromial space, but not shoulder muscle strength; however, the influence of these scapular rotations do not differ between asymptomatic individuals and those with subacromial impingement. Furthermore scapular posterior tilt appears to have a greater influence on increasing subacromial space and should be emphasized in the treatment of individuals with subacromial impingement. In chapter 4, we examine the influence that obvious scapular dyskinesis and passive scapular correction with the scapular assistance test have on 3D scapular kinematics and subacromial space. Scapular dyskinesis did not alter scapular kinematics or acromiohumeral distance during active elevation in static positions, in the scapular plane, and without a load when compared to those without scapular dyskinesis. This suggests other contributing factors, such as pain, increased load, or fatigue is requisite to alterations in scapular kinematics or AHD. Passive correction with the scapular assistance test increased scapular upward rotation, posterior tilt, and subacromial space in individuals with and without dyskinesis. In patients with obvious dyskinesis, there was a greater increase in scapular upward rotation with passive scapular assistance. This increased scapular upward rotation had a negative relationship with change in the acromiohumeral distance. The scapular dyskinesis test increased acromiohumeral distance and therefore may be helpful identifying individuals where subacromial compression is producing symptoms, regardless of dyskinesis. The results of this research suggest scapular kinematics and subacromial space are altered with the passive maneuver of the scapular assistance test in all individuals, regardless of subacromial impingement syndrome or scapular dyskinesis. Scapular dyskinesis alone may not be detrimental to scapular position and subacromial space when evaluated in static positions of active arm elevation. Other potential factors may be required to alter scapular kinematics to reduce subacromial space including pain, dynamic movement, load or fatigue. Further study is necessary to determine the influence of the combination of these factors in individuals with scapular dyskinesis.

Subacromial impingement accounts for significant burdens on the economy and individual quality of life. The development and progression of this disorder is thought to be related to overuse; however, little is known regarding biomechanical factors such as scapular kinematics, shoulder muscle recruitment and joint proprioception with respect to this disorder. The high degree of variability between individuals on these biomechanical measures limits our ability to make inferences behind the development of shoulder impingement. Here, biomechanical factors associated with impingement are investigated using within-subjects designs in order to reduce this inherent variability. Using modern clinical techniques, this dissertation is applicable towards treatment of shoulder impingement as well as scientific understanding of motor control and function in the presence of pain. This dissertation includes previously published and un-published co-authored material.

The present research quantified the shoulder rhythm for arm postures that represent the right-handed reachable workspace and compared 3 methods of scapular tracking: acromion marker cluster (AMC), stylus and scapular locator. The shoulder rhythm models can be incorporated into existing and future shoulder biomechanical models to determine shoulder geometry when simulating postures experienced in workplaces and thus have ergonomic implications for correctly identifying risk factors. The results of this research also provide guidance for future studies involving scapular tracking. Fourteen male and 14 female participants performed static arm postures spread over 5 elevation angles: 0, 45, 90, 135, 180 degrees, three elevation planes: 0, 45, 90 degrees to the frontal plane and, three axial rotations: maximum internal, neutral, and maximum external rotation. Kinematic data was recorded using a Vicon MX20+ motion-tracking system. Bone rotations were calculated using Euler angles and continuous prediction models were generated to estimate scapular and clavicular orientations based primarily on thoracohumeral relative orientations. Methods of scapular tracking were compared using repeated measures analysis of variance. Participant characteristics did not influence any of the scapular or the clavicular angles (p>.05). Axial rotation did not influence scapular retraction/protraction and elevation plane did not influence clavicular elevation (p>.05). Elevation angle was the largest contributor to lateral rotation and posterior tilt of the scapula and all clavicular angles. Plane of elevation was the largest contributor to scapular protraction. Using the stylus as the gold standard, the locator and the AMC underestimated lateral rotation, with a maximum difference of 11 degrees and 9 degrees between the locator and the stylus and AMC and the stylus measurements, respectively. The AMC and the locator overestimated posterior tilt at overhead postures and underestimated it at low elevation angles. The maximum difference between the AMC- and the locator- and the stylus-measured tilt was 10 degrees. The scapular locator consistently overestimated protraction by approximately 5 degrees. The AMC underestimated protraction in the frontal plane at low elevation angle but overestimated it at all other postures and the overestimation increased with plane of elevation, internal rotation and elevation angle. Overall, it is recommended to use AMC rather than the scapular locator to measure scapular position.

The present research quantified the shoulder rhythm for arm postures that represent the right-handed reachable workspace and compared 3 methods of scapular tracking: acromion marker cluster (AMC), stylus and scapular locator. The shoulder rhythm models can be incorporated into existing and future shoulder biomechanical models to determine shoulder geometry when simulating postures experienced in workplaces and thus have ergonomic implications for correctly identifying risk factors. The results of this research also provide guidance for future studies involving scapular tracking. Fourteen male and 14 female participants performed static arm postures spread over 5 elevation angles: 0, 45, 90, 135, 180 degrees, three elevation planes: 0, 45, 90 degrees to the frontal plane and, three axial rotations: maximum internal, neutral, and maximum external rotation. Kinematic data was recorded using a Vicon MX20+ motion-tracking system. Bone rotations were calculated using Euler angles and continuous prediction models were generated to estimate scapular and clavicular orientations based primarily on thoracohumeral relative orientations. Methods of scapular tracking were compared using repeated measures analysis of variance. Participant characteristics did not influence any of the scapular or the clavicular angles (p>.05). Axial rotation did not influence scapular retraction/protraction and elevation plane did not influence clavicular elevation (p>.05). Elevation angle was the largest contributor to lateral rotation and posterior tilt of the scapula and all clavicular angles. Plane of elevation was the largest contributor to scapular protraction. Using the stylus as the gold standard, the locator and the AMC underestimated lateral rotation, with a maximum difference of 11 degrees and 9 degrees between the locator and the stylus and AMC and the stylus measurements, respectively. The AMC and the locator overestimated posterior tilt at overhead postures and underestimated it at low elevation angles. The maximum difference between the AMC- and the locator- and the stylus-measured tilt was 10 degrees. The scapular locator consistently overestimated protraction by approximately 5 degrees. The AMC underestimated protraction in the frontal plane at low elevation angle but overestimated it at all other postures and the overestimation increased with plane of elevation, internal rotation and elevation angle. Overall, it is recommended to use AMC rather than the scapular locator to measure scapular position.

A relação entre dor no ombro e a discinese escapular (DE) é ainda incerta. Diferenças entre participantes com e sem DE têm sido demonstradas na literatura, com enfoque na quantidade de movimento escapular em graus específicos de elevação do úmero. No entanto, essa abordagem não considera a forma das séries temporais que representam os movimentos escapulares. A Análise de Componentes Principais (ACP) pode aprofundar o atual conhecimento dos padrões \"anormais\" da escápula por considerar a colinearidade e a variabilidade presentes nas séries temporais cinemáticas. Este estudo objetivou avaliar a cinemática escapular em pacientes com dor no ombro e participantes assintomáticos com e sem DE usando a ACP. Dados foram coletados em 98 participantes separados em quatro grupos: Dor+DE (n=24), Dor (n=25), Sem Dor+DE (n=24), e Sem dor (n=25). Os dados cinemáticos foram capturados por um sistema de captura de movimento eletromagnético durante as fases de elevação e abaixamento do braço. ACP e análise de variância foram utilizadas para comparar os grupos. O grupo Sem Dor+DE apresentou progressivo aumento da inclinação anterior ao longo da fase de elevação do braço comparado aos grupos sem DE, Dor (tamanho de efeito = 0.79) e Sem Dor (tamanho de efeito = 0.80). Durante a fase de abaixamento do braço, o grupo Dor+DE apresentou progressivo aumento da inclinação anterior ao longo da fase comparado ao grupo Sem Dor+DE (tamanho de efeito = 0.68). Assim, a ACP demonstrou diferenças no padrão da inclinação anterior da escápula relacionada a presença de DE e dor. A presença de DE revelou um padrão com progressivo aumento da inclinação anterior da escápula ao longo da fase de elevação. No entanto, durante a fase de abaixamento, participantes assintomáticos com DE modificaram seu padrão de movimento, diferente do grupo sintomático, reforçando a sugerida associação entre modificações no movimento escapular e sintomas no ombro. / The relationship between shoulder pain and scapular dyskinesis (SDK) is still unclear. Differences between participants with and without SDK have been demonstrated, focusing on the amount of scapular motion at specific degrees of humeral elevation. However, this approach does not consider the shape of the scapular motion temporal series. Principal Component Analysis (PCA) may advance current understanding of \'abnormal\' movement patterns by considering the collinearity and the variability present in the kinematic temporal series. This study aimed to evaluate the scapular kinematics in patients with shoulder pain and in asymptomatic participants with and without SDK using PCA. Data were collected in 98 participants separated in four groups: Pain+SDK (n=24), Pain (n=25), No Pain+SDK (n=24), and No Pain (n=25). Scapulothoracic kinematic data were measured with an electromagnetic tracking device during arm elevation and lowering phases. PCA and analysis of variance were used to compare the groups. The No Pain+SDK group had a progressive increasing in anterior tilt over the elevation phase compared to the Pain (effect size=0.79) and No Pain (effect size=0.80) groups. During the arm-lowering, the Pain+SDK group had a progressive increasing in anterior tilt over this phase in comparison to the No Pain+SDK group (effect size=0.68). Therefore, PCA demonstrated differences in the scapular anterior tilt related to SDK and shoulder pain. The presence of SDK revealed a scapular pattern with progressive increasing in anterior tilt over the elevation phase. However, during the arm-lowering phase, asymptomatic participants with SDK changed their motion pattern, unlike the symptomatic group, reinforcing the suggested association between scapular modifications and shoulder symptoms.

ABSTRAKT INTRODUKTION: Huvudvärk av spänningstyp (HST) är den vanligaste huvudvärksformen som diagnostiseras och representerar 90 % av fallen som söker sjukvård med huvudvärk och nästan nio av tio kvinnor drabbas av denna typ av huvudvärk någon gång i livet. Skapulär dyskinesi (SD) som beskriver positionsskillnad mellan skulderbladen kan orsakas av olika faktorer och är ett tillstånd som kan vara osymptomatiskt eller symptomatiskt. Den vanligaste orsaken är på grund av svaghet av de viktigaste skulderstabilisatorerna och sambandet mellan HST och SD är att i båda tillstånd ingår träning av styrka och uthållighet av nack- och skulderbladsmuskulatur.   SYFTE: Syftet med arbetet är att undersöka förekomsten av skapulär dyskinesi hos fysisk aktiva kvinnor med huvudvärk av spänningstyp.   METOD: För arbetet rekryterades fysisk aktiva kvinnor med huvudvärk från olika sportföreningar och kvinnor som sökte sig till öppenvården på Aleris Rehab Tullinge. Det användes en enkät som innehöll två delar. Första delen bestod av två frågor från enkäten Neck Disability Index (NDI) som skulle besvaras och andra delen av enkäten fylldes i av undersökaren efter en manuell isometrisk muskeltest av skuldrorna för att diagnostisera SD. Totalt undersöktes 25 kvinnor med huvudvärk. Resultatet sammanställdes i diagram för bättre analys.   RESULTAT: Av 25 fysiska aktiva kvinnor som drabbades av huvudvärk visade 23 kvinnor någon form av SD, vilket motsvarar 92 %. Vilken typ av SD var inte av intresse eftersom syftet var enbart att undersöka förekomsten av SD hos kvinnor med HST.   KONKLUSSION: Fler studier rekommenderas mellan huvudvärk och skapulär dyskinesi eftersom eventuella fynd kan hjälpa fysioterapeuter att ändra eller justera deras träningssätt för att undvika och förebygga HST och SD för bättre prestation av idrottaren. / ABSTRACT INTRODUCTION: Tension type headache (TTH) is the most common type of headache diagnosed and represents 90 % of cases seeking headache healthcare and nearly nine out of ten women suffer from this type of headache sometime in life. Scapular dyskinesia (SD) that describes the position difference between the shoulder blades can be caused by various factors and is a condition that may be symptomatic or symptomatic. The most common reason is the weakness of the main shoulder stabilizers, and the connection between TTH and SD is that in both states it includes training of strength and endurance of the neck and shoulder blades muscles.   OBJECTIVE: The purpose of the work is to investigate the occurrence of scapular dyskinesia in physically active women with tension type headache.   METHOD: For the study, physically active women were recruited with headaches from various sports associations and women who sought outpatient care at Aleris Rehab Tullinge. A survey was used that contained two parts. The first part consisted of two questions from the Neck Disability Index (NDI) questionnaire that were to be answered and the second part of the survey was filled in by the investigator following a manual isometric muscle test of the shoulders to diagnose SD. A total of 25 women with headache were examined. The result was compiled in charts for better analysis.   RESULTS: Of 25 physical active women affected by headache, 23 women showed some form of SD, which represents 92 %. What kind of SD was not of interest because the purpose was to investigate the presence of SD in women with TTH.   CONCLUSION: More studies are recommended between headache and scapular dyskinesia because any findings may help physiotherapists to change or adjust their training methods to avoid and prevent TTH and SD for better athletes performance.

A relação entre dor no ombro e a discinese escapular (DE) é ainda incerta. Diferenças entre participantes com e sem DE têm sido demonstradas na literatura, com enfoque na quantidade de movimento escapular em graus específicos de elevação do úmero. No entanto, essa abordagem não considera a forma das séries temporais que representam os movimentos escapulares. A Análise de Componentes Principais (ACP) pode aprofundar o atual conhecimento dos padrões \"anormais\" da escápula por considerar a colinearidade e a variabilidade presentes nas séries temporais cinemáticas. Este estudo objetivou avaliar a cinemática escapular em pacientes com dor no ombro e participantes assintomáticos com e sem DE usando a ACP. Dados foram coletados em 98 participantes separados em quatro grupos: Dor+DE (n=24), Dor (n=25), Sem Dor+DE (n=24), e Sem dor (n=25). Os dados cinemáticos foram capturados por um sistema de captura de movimento eletromagnético durante as fases de elevação e abaixamento do braço. ACP e análise de variância foram utilizadas para comparar os grupos. O grupo Sem Dor+DE apresentou progressivo aumento da inclinação anterior ao longo da fase de elevação do braço comparado aos grupos sem DE, Dor (tamanho de efeito = 0.79) e Sem Dor (tamanho de efeito = 0.80). Durante a fase de abaixamento do braço, o grupo Dor+DE apresentou progressivo aumento da inclinação anterior ao longo da fase comparado ao grupo Sem Dor+DE (tamanho de efeito = 0.68). Assim, a ACP demonstrou diferenças no padrão da inclinação anterior da escápula relacionada a presença de DE e dor. A presença de DE revelou um padrão com progressivo aumento da inclinação anterior da escápula ao longo da fase de elevação. No entanto, durante a fase de abaixamento, participantes assintomáticos com DE modificaram seu padrão de movimento, diferente do grupo sintomático, reforçando a sugerida associação entre modificações no movimento escapular e sintomas no ombro. / The relationship between shoulder pain and scapular dyskinesis (SDK) is still unclear. Differences between participants with and without SDK have been demonstrated, focusing on the amount of scapular motion at specific degrees of humeral elevation. However, this approach does not consider the shape of the scapular motion temporal series. Principal Component Analysis (PCA) may advance current understanding of \'abnormal\' movement patterns by considering the collinearity and the variability present in the kinematic temporal series. This study aimed to evaluate the scapular kinematics in patients with shoulder pain and in asymptomatic participants with and without SDK using PCA. Data were collected in 98 participants separated in four groups: Pain+SDK (n=24), Pain (n=25), No Pain+SDK (n=24), and No Pain (n=25). Scapulothoracic kinematic data were measured with an electromagnetic tracking device during arm elevation and lowering phases. PCA and analysis of variance were used to compare the groups. The No Pain+SDK group had a progressive increasing in anterior tilt over the elevation phase compared to the Pain (effect size=0.79) and No Pain (effect size=0.80) groups. During the arm-lowering, the Pain+SDK group had a progressive increasing in anterior tilt over this phase in comparison to the No Pain+SDK group (effect size=0.68). Therefore, PCA demonstrated differences in the scapular anterior tilt related to SDK and shoulder pain. The presence of SDK revealed a scapular pattern with progressive increasing in anterior tilt over the elevation phase. However, during the arm-lowering phase, asymptomatic participants with SDK changed their motion pattern, unlike the symptomatic group, reinforcing the suggested association between scapular modifications and shoulder symptoms.

No description available.

Context: Scapular motion evaluation is a necessary component of the upper extremity exam. Several methods exist, but most lack good reliability or diagnostic accuracy. The yes/no scapular dyskinesis test has the best of both measures but is untested on inexperienced clinicians. Objective: The purpose of this study was to evaluate the reliability and diagnostic accuracy of the yes/no scapular dyskinesis test when used by graduate assistant athletic trainers. Participants: The participants were college-aged students with no prior history of upper extremity fracture or nerve injury. Data Collection and Results: Participants were evaluated for scapular dyskinesis by a physician and 10 graduate assistant athletic trainers. Ratings were for normal or dyskinetic and then determination of side. Reliability was calculated using Gwet’s AC1 statistic and diagnostic accuracy from standard 2x2 contingency tables. Results: Reliability was moderate (AC1 = 0.48, p < 0.0025, 95% CI [0.147, 0.812]) when side was not accounted for and moderate (AC1 = 0.43, p < 0.0001, 95% CI [0.242, 0.632]) when side-per-side decisions were made. Sensitivity and negative predictive values were low to moderate (34.4%-66.2%, 8.9%-74.1% ). Specificity and positive predictive values were moderate to high (50%-85.2%, 51.5%-95.2%). Accuracy was moderate (65.2%-69.4%) and positive and negative likelihood ratios were low (1.325-2.333, 0.675-0.769). Conclusions: The reliability in this study was on par with previously published studies. Measures of diagnostic accuracy met or exceeded previous results. Clinically, to avoid false negative results and enhance the use of positive results, it appears necessary to combine methods and begin the evaluation with a gross assessment of whether or not dyskinesis is present and if it is to then evaluate which side is dyskinetic.

No description available.