De acordo com o conceito de cadeia cinética, o controle da posição distal depende da estabilização dos segmentos proximais. Deste modo, a estabilização necessária para o controle e movimento dos membros superiores é proporcionada pelo tronco e pela pelve que servem como meio de transmissão de força e energia. O controle da postura e do movimento é realizado por mecanismos de feedback e feedforward definidos pela teoria do controle motor. O feedforward é descrito pelas atividades antecipatórias corporais a fim de neutralizar os efeitos perturbadores de determinada condição específica. O feedback é representado pelo uso do biofeedback (estímulo verbal, visual, auditivo ou cinestésico) com o objetivo de restaurar a coordenação e o controle muscular, e potencializar os mecanismos de feedforward muscular. Há poucas investigações de tais mecanismos de controle no complexo articular do ombro e estudos prévios demostram a influência de comandos verbais para a orientação escapular sobre os padrões de ativação muscular seletiva do ombro. Objetivo: verificar o efeito da instrução verbal para ativação consciente da musculatura abdominal, sobre a atividade dos músculos periescapulares em pacientes com sintomas da síndrome do impacto no ombro durante exercícios de força. Materiais e Métodos: 30 voluntários com condição dolorosa há pelo menos 4 semanas no ombro, de ambos os sexos ( 11 homens e 19 mulheres) com idade de 35 a 75 anos realizaram exercícios para o complexo sendo que o grupo controle apenas repetiu os exercícios já o outro grupo recebeu treinamento para adicionar a contração abdominal consciente referente a estímulo verbal e tátil durante os mesmos exercícios previamente realizados, assim o sinal eletromiográfico foi captado através do aparelho TrignoTM Wireless System (Delsys Inc. Boston, MA). Resultados: Durante os exercícios a comparação entre grupos com e sem instrução para contração abdominal no momento pré e pós apresentou diferença no modelo linear de efeitos mistos apenas para os músculos Trapézio Transverso durante o Full can (FC) para o lado sintomático (TE:0,92); Trapézio ascendente para o lado 10 sintomático durante (FC) (TE:-0,96) e para o lado assintomático durante External Rotation Kneeling (ERK) (TE:-0,81); já o Serrátil anterior quando exigido no exercício Knee Push (KP) o lado assintomático apresentou diferença entre os grupos (TE:-1,24) assim como no (ERK) com (TE: -2,09) para lado assintomático e no Wall Slide with Towel (WST) com (TE:1,03) também para o lado assintomático; Conclusão / According to the kinetic chain concept, the control of the distal position depends on the stabilization of the proximal segments. Thus, the stabilization necessary for the control and movement of the upper limbs is provided by the trunk and pelvis which serve as a means of transmitting force and energy. The control of posture and movement is performed by feedback and feedforward mechanisms defined by motor control theory. Feedforward is described by anticipatory body activities in order to counteract the disruptive effects of a particular condition. The feedback is represented by the use of biofeedback (verbal, visual, auditory or kinesthetic stimulus) with the objective of restoring coordination and muscular control, and potentiate the mechanisms of muscle feedforward. There are few investigations of such control mechanisms in the shoulder joint complex and previous studies demonstrate the influence of verbal commands on the scapular orientation on selective muscular activation patterns of the shoulder. Objective: To verify the effect of verbal instruction for conscious activation of the abdominal musculature on the activity of the periescapular muscles in patients with symptoms of shoulder impact syndrome during strength exercises. Materials and Methods: 30 volunteers with painful condition for at least 4 weeks on the shoulder, of both sexes (11 men and 19 women) aged 35 to 75 years performed exercises for the complex and the control group only repeated the exercises already the other group received training to add conscious abdominal contraction regarding verbal and tactile stimuli during the same exercises previously performed, so the electromyographic signal was captured through the TrignoTM Wireless System (Delsys Inc. Boston, MA). Results: During the exercises, the comparison between groups with and without instruction for abdominal contraction at the pre and post moments presented a difference in the linear mixed effects model only for Middle trapezoid muscles during Full can (FC) for the symptomatic side (TE: 0.92 ); trapeze lower to the symptomatic side during (FC) (TE: -0.96) and to the asymptomatic side during External Rotation Kneeling (TE: -0.81). The anterior serratus when required in the Knee Push exercise (KP), the asymptomatic side presented a difference between the groups (TE: -1.24) as well as in the (ERK) with (TE: -2.09) for asymptomatic side and Wall Slide with Towel (WST) with (TE: 1.03) also for the asymptomatic side; Conclusion:

Function of the shoulder complex is highly dependent on the relationship between the scapula and the humerus. Etiologies for the disruption of the glenohumeral relationship include impaired or abnormal scapular function, motion, or position. The lateral scapular slide test (LSST) has been developed as a clinical tool to assess this phenomenon, also known as scapular dyskinesis. The primary purpose of this study was to determine the validity of the LSST by comparing the clinical measurements on the skin surface to the actual anatomical distance between the scapula and the spine as seen on radiographic images. The secondary purpose of this study was to determine the intra-rater and inter-rater reliability of the LSST. Nine subjects (18 shoulders) were assessed with the clinical LSST and radiographic images in three test positions (0��, 45��, and 90�� of glenohumeral abduction). Comparison of the clinical LSST measurements with the radiographs revealed the LSST to be valid (>0.80) in only the 0�� and 45�� test positions with respective Pearson correlation values of 0.91 and 0.98. Excellent (>0.75) intra-rater ICC (2,1) reliability (0.91-0.97) was found for all three test positions. Inter-rater ICC (2,1) reliability values were excellent for the 0�� (0.87) and 45�� (0.83) test positions, and fair to good for the 90�� position (0.71). This study demonstrated that the LSST is an accurate and consistent measure of scapular movement and position for the 0�� and 45�� test positions. Clinicians should exercise caution when interpreting measurements obtained at the 90�� test position because the validity and reliability values did not reach established standards. / Graduation date: 2002

Reproduction de : Thèse d'exercice : Médecine : Nancy 1 : 2005. / Titre provenant de l'écran-titre.

Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. "This dissertation includes unpublished co-authored material"--P. v. Includes bibliographical references (leaves 119-128). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

The human shoulder complex relies on the sensorimotor system to maintain stability. The sensorimotor system includes sensory feedback, control of the central nervous system and motor output. Exercise is considered an important part of shoulder rehabilitation and sports training to help improve control of the sensorimotor system. However, few studies have investigated the effect of exercise on the sensorimotor system. The first study of this dissertation explored the central control of the deltoid and rotator cuff (infraspinatus). Although both the deltoid and infraspinatus contribute to shoulder abduction, the results from this study showed that the modulation of their corticospinal excitability was affected differently by elevation angle. This could be explained by the fact that they play different roles at the shoulder: the deltoid is a prime mover while the infraspinatus is a stabilizer. The second study of this dissertation investigated scapular proprioception, which has not been assessed in previous studies. The findings of this study demonstrated that joint position sense errors of the overall shoulder joint mainly came from the glenohumeral joint. Scapular proprioception may need to be tested separately in addition to overall shoulder proprioception. In the third study, the effect of the exercise on shoulder sensorimotor system was investigated by measuring shoulder kinematics, shoulder joint position sense and cortical excitability before and after a four-week exercise training program. This protocol included strengthening and neuromuscular exercises targeting rotator cuff and scapular muscles. After the training protocol, although strength increased overall, the only observed sensorimotor adaptations were a decrease in upper trapezius activation and a decrease in the corticospinal excitability of the supraspinatus. There were no changes in other key parameters. Exercises focusing on specific muscles, combined with low-intensity closed-chain exercises, were not found to improve shoulder joint position sense or scapular kinematics. Combined with the findings of the decrease in corticospinal excitability of the supraspinatus and no change in muscle activity of the rotator cuff, it appears that while the exercises increased rotator cuff strength, these gains did not transfer to an increase in muscle activation during motion. This dissertation includes previously published co-authored material.

Swimmers depend on accessory breathing muscles for adequate ventilation. Pectoralis minor is an accessory breathing muscle. The daily repetition of gleno-humeral flexion and medial rotation results in adaptive shortening of Pectoralis, a common phenomenon in competitive swimmers. If Pectoralis minor is shortened the scapula is in an anteriorly tipped position. This anteriorly tipped position will affect scapula kinematics as well as the strength of Pectoralis minor to function as an accessory breathing muscle. One of the risk factors contributing to shoulder dysfunction in competitive swimmers is an altered scapular position. The study aimed to determine if lateral costal breathing dissociation exercises in conjunction with scapular retraining exercises had an effect on the position of the scapula in competitive swimmers. A comparative parallel group longitudinal design was used in this study. During a six week supervised intervention period the intervention group (n=28) and control group (n=30) did retraining of the scapula stabilisers and stretching of Pectoralis minor. The intervention group did breathing dissociation exercises to facilitate lateral costal breathing. No specific breathing exercises were facilitated within the control group. Pectoralis minor length and thoracic expansion had been measured. The function of the scapula stabilisers was evaluated. The resting as well as dynamic scapula positions were evaluated. Evaluations were done at baseline, six weeks and five months post intervention. Treatment groups were compared with respect to change from baseline to six weeks and baseline to five months in PMI, FVC and thoracic expansion utilizing analysis of covariance (ANCOVA) with covariates baseline reading. The intervention group showed an increase in the Pectoralis minor Index (PMI) of 0.5 (left & right) and the control group reflected an increase of 0.5 (left) and 0.7 (right). The intervention group reflected continuous improvement in PMI and the control group showed deterioration. In addition to the PMI upper thoracic, expansion decreased and lower thoracic expansion increased in the intervention group. The control group showed a decrease in upper and lower thoracic expansion. Groups were compared with respect to change from baseline to six weeks and five months respectively for categorical parameters, muscle function and scapula position (resting and dynamic) using Fisher’s exact test. After six weeks the intervention group showed significantly (p<0.04) less winging of the distal third of the scapula on the left side when compared to the control group. After five months the scapula showed significantly less tipping (p<0.02) during gleno-humeral flexion, on the left side. The McNemar test for symmetry had been applied to determine if any within group changes occurred. Within the intervention group ten of the thirteen markers used to determine the resting position of the scapula, reflected significant improvement compared to the six markers in the control group. Only the intervention group reflected remarkable improvement in function of the lower fibres of Trapezius muscle. Serratus anterior and middle fibres of Trapezius muscles showed significance within group improvement in function for both groups. The scapula showed significantly less dysrhythmia within the intervention group on the left and right sides (p< 0.0209) when compared to the control group. After five months the resting scapula position reflected deterioration for both groups. Dysrhythmia and winging of the scapula deteriorated from six weeks to five months for both groups. The muscle function of the lower fibres of Trapezius showed significance within group changes for both groups from six weeks to five months. The ability to contract Serratus anterior and the middle fibres of Trapezius agonistically was maintained from six weeks to five months. However the eccentric control and ability to contract the muscle without fatigue within the Serratus anterior and middle fibres of Trapezius showed deterioration from six weeks to five months for both groups. Conclusion: The increase in PMI and increase in lower thoracic expansion for the intervention group could favour swimmers to breathe more effectively. An increase in Pectoralis minor length resulted in a more posteriorly tipped scapula. This better positioned scapula promotes optimum function of the lower fibres of Trapezius. Contracting from a stable scapula, Pectoralis minor can fulfil its function as an accessory breathing muscle more effectively. / Thesis (PhD)--University of Pretoria, 2015. / tm2015 / Physiotherapy / PhD / Unrestricted

Rotator cuff deficiency with glenohumeral arthritis presents a unique challenge to the orthopaedic surgeon. Under these conditions, total shoulder replacement has yielded poor results as a result of eccentric loading of the glenoid leading to loosening and early failure. Multiple procedures have been recommended to resolve this problem including total shoulder arthroplasty, shoulder arthrodesis, and hemiarthroplasty. Hemiarthroplasty, the current standard of care for this condition, offers only limited goals for functional improvement and only a modest improvement in pain. Recently, there has been renewed interest in reverse shoulder arthroplasty. The main concept behind the reverse shoulder implant is the stabilization of the joint by replacing the head of the arm with a socket and placing a ball on the shoulder side. This "reverse" configuration creates a fixed fulcrum through which the deltoid can act more efficiently at raising the arm and thus increasing range of motion and returning the patient to a more normal level of function. This dissertation attempts to fill in some of the gaps in reverse basic science with six published studies. The important results found in these studies were: Implantation of the glenosphere with an inferior tilt reduces the incidence of mechanical failure of the baseplate. A positive linear correlation is present between abduction range of motion (ROM) and center of rotation offset (CORO). When comparing several factors affecting ROM and scapular impingement, CORO had the largest effect on ROM, followed by glenosphere position. Neck-shaft angle had the largest effect on inferior scapular impingement, followed by glenosphere position. Stability is determined primarily by increasing joint compressive forces and, to a lesser extent, by increasing humerosocket depth. There are three distinct classes of arc of motion relative to the articular constraint: I - arc of motion decreased with increased constraint, II - arc of motion with a complex relationship to constraint, and III - arc of motion increased with increased constraint. The information presented in this dissertation may be useful to the orthopaedic surgeon when deciding on an appropriate reverse implant and improving surgical technique, as well as aiding engineers in improving reverse implant design.

Despite the restricted morphology and distribution of sloths today, fossils sloths show a wide variety of forms and behaviors and used to range from South America to Alaska. These extinct forms have in the past simply been lumped together as "ground sloths", separated from modern "tree sloths". However there are intermediate forms that have been posited to be semi-arboreal. In other groups such as primates the shape of the shoulder blade has been shown to vary significantly between groups with different arboreal behaviors. This study used geometric morphometrics to examine the scapulae of modern and extinct sloths to show that these three locomotor groups can in fact be distinguished by their shoulder blade shape. Juveniles of giant ground sloths also have significantly different shoulder blade shapes than the much larger adults, however they do not overlap with the smaller intermediate sloths, so may have been just as terrestrial as their parents despite their much smaller size. Finally, ontogenetic trajectories of several sloth genera do not show evidence of having different slopes. They start and end in different areas of morhospace but are all on parallel paths. This argues against the hypothesis of convergence in modern tree sloths, which despite both having an unusual suspensory lifestyle are not closely related. Rather they are both retaining an ancestral growth trajectory that all sloths have possessed.

Le degré de rétention de l’arboricolisme dans le répertoire locomoteur des hominines fossiles du Pliocène est toujours matière à débat, les études ayant principalement porté sur la courbure des phalanges et la proportion des membres. Vu la récente découverte de DIK-1-1 (A. afarensis) et de la scapula qui lui est associée, l’étude de cet os d’un point de vue fonctionnel est intéressante, puisqu’il est directement impliqué dans la locomotion de presque tous les hominoïdes. Le but de cette étude est de tenter d’établir un lien entre l’orientation supéro-inférieure (SI) et antéro-postérieure (AP) de la cavité glénoïde de la scapula et les comportements locomoteurs chez les grands singes et l’humain moderne. Des analyses comparatives sur les adultes ont été réalisées pour 1) voir s’il existe des différences dans la morphologie étudiée entre les espèces et 2) voir si ces différences peuvent être expliquées par la taille corporelle. Des analyses ontogéniques ont aussi été réalisées pour voir si un accroissement de la taille corporelle pendant le développement et les changements locomoteurs qui y sont associés correspondent à un changement d’orientation de la cavité glénoïde. Les résultats montrent que les humains ont une cavité glénoïde qui est orientée moins supérieurement que les grands singes, mais que Pongo, bien qu’étant le plus arboricole, n’a pas l’orientation la plus supérieure. Les « knuckle-walkers » (Pan et Gorilla) se distinguent des autres hominoïdes avec une orientation de la surface glénoïde relative à l’épine plus inférieure. La taille corporelle ne semble pas influencer la morphologie étudiée, sauf parfois chez le gorille. Seuls l’humain et les mâles Pongo montrent un changement ontogénique dans l’orientation de la cavité glénoïde relativement à l’épine. Sur la base de ces résultats, l’orientation de la cavité glénoïde semble refléter partiellement la fonction du membre supérieur dans la locomotion, mais des recherches plus poussées sont nécessaires. Mots-Clés : Scapula, cavité glénoïde, grands singes, humains, locomotion, arboricolisme. / The degree to which Pliocene fossil hominins have retained some form of arborealism in their locomotor repertoire is still matter of debate, in part because studies linking upper limb morphology to locomotor behaviors in primates mostly focused on phalangeal curvature and limb proportions. Given the recent discovery of DIK-1-1 (A. afarensis) and its associated scapula, investigation of this bone from a functional perspective seemed of interest since it is directly involved in almost every hominoid’s locomotion. The purpose of this study is to try to establish a link between the superoinferior and anteroposterior orientation of the glenoid cavity of the scapula and locomotor behaviors in living great apes and modern humans. Comparative analyses were performed on adult individuals to 1) establish if there were differences across species and 2) verify that those differences, if any, could be linked to overall body size. Ontogenetic analyses were also performed at the intraspecific level to see if a change in body size during development, which is often associated with changes in locomotor behaviors, is related to a change in the orientation of the glenoid cavity. These results show that humans have a more inferiorly oriented glenoid cavity than great apes, but Pongo, even if it is the most arboreal species, does not have the most superiorly oriented glenoid cavity. Knuckle-walkers (Pan and Gorilla) differ from other hominoids, exhibiting a more inferiorly oriented glenoid cavity relative to the spine. Body size does not seem to influence the orientation of the articulation, with a few exceptions for gorillas. Only humans and male Pongo show a significant ontogenetic change in the orientation of the glenoid cavity relative to the spine. On the basis of these results, the orientation of the glenoid cavity seems to reflect only in part the use of the upper limb in locomotion, however, it will need to be investigated further.

RÉSUMÉ Le degré de rétention de l’arboricolisme dans le répertoire locomoteur des hominines fossiles du Pliocène est toujours matière à débat, les études ayant principalement porté sur la courbure des phalanges et la proportion des membres. Vu la récente découverte de DIK-1-1 (A. afarensis) et de la scapula qui lui est associée, l’étude de cet os d’un point de vue fonctionnel est intéressante, puisqu’il est directement impliqué dans la locomotion de presque tous les hominoïdes. Le but de cette étude est de tenter d’établir un lien entre l’orientation supéro-inférieure (SI) et antéro-postérieure (AP) de la cavité glénoïde de la scapula et les comportements locomoteurs chez les grands singes et l’humain moderne. Des analyses comparatives sur les adultes ont été réalisées pour 1) voir s’il existe des différences dans la morphologie étudiée entre les espèces et 2) voir si ces différences peuvent être expliquées par la taille corporelle. Des analyses ontogéniques ont aussi été réalisées pour voir si un accroissement de la taille corporelle pendant le développement et les changements locomoteurs qui y sont associés correspondent à un changement d’orientation de la cavité glénoïde. Les résultats montrent que les humains ont une cavité glénoïde qui est orientée moins supérieurement que les grands singes, mais que Pongo, bien qu’étant le plus arboricole, n’a pas l’orientation la plus supérieure. Les « knuckle-walkers » (Pan et Gorilla) se distinguent des autres hominoïdes avec une orientation de la surface glénoïde relative à l’épine plus inférieure. La taille corporelle ne semble pas influencer la morphologie étudiée, sauf parfois chez le gorille. Seuls l’humain et les mâles Pongo montrent un changement ontogénique dans l’orientation de la cavité glénoïde relativement à l’épine. Sur la base de ces résultats, l’orientation de la cavité glénoïde semble refléter partiellement la fonction du membre supérieur dans la locomotion, mais des recherches plus poussées sont nécessaires. Mots-Clés : Scapula, cavité glénoïde, grands singes, humains, locomotion, arboricolisme. / ABSTRACT The degree to which Pliocene fossil hominins have retained some form of arborealism in their locomotor repertoire is still matter of debate, in part because studies linking upper limb morphology to locomotor behaviors in primates mostly focused on phalangeal curvature and limb proportions. Given the recent discovery of DIK-1-1 (A. afarensis) and its associated scapula, investigation of this bone from a functional perspective seemed of interest since it is directly involved in almost every hominoid’s locomotion. The purpose of this study is to try to establish a link between the superoinferior and anteroposterior orientation of the glenoid cavity of the scapula and locomotor behaviors in living great apes and modern humans. Comparative analyses were performed on adult individuals to 1) establish if there were differences across species and 2) verify that those differences, if any, could be linked to overall body size. Ontogenetic analyses were also performed at the intraspecific level to see if a change in body size during development, which is often associated with changes in locomotor behaviors, is related to a change in the orientation of the glenoid cavity. These results show that humans have a more inferiorly oriented glenoid cavity than great apes, but Pongo, even if it is the most arboreal species, does not have the most superiorly oriented glenoid cavity. Knuckle-walkers (Pan and Gorilla) differ from other hominoids, exhibiting a more inferiorly oriented glenoid cavity relative to the spine. Body size does not seem to influence the orientation of the articulation, with a few exceptions for gorillas. Only humans and male Pongo show a significant ontogenetic change in the orientation of the glenoid cavity relative to the spine. On the basis of these results, the orientation of the glenoid cavity seems to reflect only in part the use of the upper limb in locomotion, however, it will need to be investigated further. Keywords : Scapula, glenoid cavity, great apes, humans, locomotion, arboreality.