Le tennis elbow est une pathologie fréquente affectant le membre supérieur. Cette pathologie s'observe également dans un large éventail d'activités manuelles allant de la manipulation d'outils de maçonnerie à la manipulation d'une souris d'ordinateur. Malgré son prévalence élevée, les mécanismes sous-jacents au développement du tennis elbow demeurent paradoxalement largement méconnus et n'offrent pas de consensus scientifique. Toutefois, les outils, les instruments ou les objets manipulés, formant une interface avec la main, sont soupçonnés d'être en partie responsables de l'apparition de cette affection. Cependant, le manque de moyens d'investigation biomécanique sur la main ramène cette assertion au statut d'hypothèse. Dans ce travail de thèse, l'idée que les caractéristiques physiques de la raquette (i.e. taille et forme du manche ; inertie de la raquette) puissent avoir une influence sur le risque d'apparition du tennis elbow a été testée. Pour cela, nous avons mené une démarche structurée en trois étapes. Tout d'abord, une approche expérimentale contrôlée nous a permis de quantifier les efforts exercés au niveau de l'interface main-manche lorsque l'on serre simplement ce dernier. Pour cela, un instrument de mesure des forces a été développé (i.e. ergomètre à 6 poutres couplé à une nappe de pression Tekscan). Cela nous a permis de définir une taille et une forme de manche optimale pour les forces de serrage. Dans un second temps, ce manche optimal (i.e. de section circulaire et de périmètre égal à 17,9% de la longueur de la main) a été testé au cours de frappes de tennis. / Lateral epicondylalgia (LE) have been reported to occur at least once in a range of 40% to 50% of tennis players and in a large number of workers using hand tools. Despite high prevalence, the mechanisms underlying the development of tennis elbow are paradoxically misunderstood and suffer from a lack of scientific consensus. The characteristics of the handled tools (e.g. the grip size and the shape) are believed to be partly responsible for the occurrence of these disorders. However, the available material and technique for investigation and the proceedings studies did not gave evidence for this hypothesis. In this work, the idea that the size and shape of a tennis racket handle can affect the risk of developing tennis elbow was tested in three main steps. First, a controlled experimental approach was performed in order to quantify the forces exerted at the interface hand / handle when squeezing simply a handle. A special force ergometer has been developed to measure the forces at the hand/handle interface. This study enabled us to define an optimal size and shape (i.e. circular perimeter equal to 18% of the length of the hand) to perform a maximal squeezing force. In a second step, the optimal handle was tested during tennis strokes. Our results show that with and without fatigue, the grip force was lower for the optimal handle compared to bigger or smaller handle. Finally, in a last step, a biomechanical model of the hand was used to assess the impact of the tennis racket grip size on the forces applied on muscles affected by tennis elbow during a simulation. Our results suggest that the optimal grip size reduces muscle tensions of hand extensor muscle.

Microcurrent therapy (MCT) involves the application of sub-sensory electric current and can promote tissue repair, possibly by mimicking endogenous electrical cues for healing. It has been used successfully to treat recalcitrant bone fractures and skin ulcers, but its effects on other forms of tissue have received little attention. This study aimed to investigate the potential of MCT to promote healing and alleviate symptoms in a selected soft connective tissue disorder. A systematic review of human studies involving MCT for soft connective tissue damage was conducted. A survey of 93 musculoskeletal physiotherapists was used to help select a common, recalcitrant disorder to treat with microcurrent in a clinical trial. Novel sonographic scales to quantify tendon structural abnormality and tissue healing were developed, and their measurement properties evaluated along with several clinical and patient-rated outcome measures. Two preliminary clinical trials, involving 62 people with the selected disorder – chronic tennis elbow - were conducted, comparing four different types of microcurrent applied daily for 3 weeks. The review found fair quality evidence that certain forms of MCT can relieve symptoms, and low quality evidence that they can promote healing, in several soft connective tissue disorders, including those affecting tendons. Optimal treatment parameters are unknown. In the survey, clinicians identified frozen shoulder, plantar fasciitis and tennis elbow as particularly problematic, and tennis elbow was selected for treatment in the trials. The sonographic scales of hyperaemia had fair-to-good inter-rater and test-retest reliability. Minimum Detectable Change values are calculated for the sonographic scales and for pain-free grip strength measurements. The trials suggest that monophasic microcurrent of peak amplitude 50 µA applied for 35 hours was most effective in symptom alleviation, with a 93% treatment success rate three months after treatment. By final assessment, pain-free grip strength increased by 31% (95%CI:5,57%), pain measured on a multiple-item questionnaire reduced by 27% (95%CI:16,38%) and patient-rated functional disability by 26% (95%CI:14,28%). MCT with a current amplitude of 500 µA was significantly less effective, and varying the waveform appeared less important in determining outcomes. Differences between groups were non-significant on several measurs, though there was a risk of type II error in the tests used. No significant differences between any groups were seen in sonographic assessments, although consistent patterns in bloodflow chage suggested that MCT may modulate hyperaemia levels. Higher baseline hyperaemia was associated with sustained falls in hyperaemia levels after treatment, and with improved clinical outcome. MCT’s analgesic effect does not rely on sensory stimulation, and further investigation of its influence on tendinous blood flow and vascularity, or on the local biochemical milieu, may help elucidate its mechanism of action. On the basis of this investigation, a fully-powered controlled clinical trial is justified. A protocol, combining MCT with an exercise programme, is proposed.

Proximal forearm fractures account for over 10% of all upper limb fractures. There is limited epidemiological data available and much of the literature focuses on the more complex fracture patterns, with the role of non-operative management for the isolated proximal forearm fracture still to be defined. Prospective short and long-term patient reported outcome data for simple isolated fractures of the radial head and olecranon would help define the indications for the non-operative management of these injuries. This thesis aims to test the hypothesis that non-operative management provides a comparable outcome to operative intervention for defined fractures of the proximal forearm. A large prospective database of 6872 fractures collected over a one-year period was used to define the epidemiology of proximal forearm fractures. A separate large prospective study carried out over an eighteen-month period using a pre-defined management protocol for all isolated radial head and neck fractures was analysed to determine the short and long-term outcome. Additional retrospective databases were collected and analysed to determine the short and long-term outcome for the non-operative and operative management of olecranon fractures, as well as the operative management of complex radial head fractures. Finally, two prospective randomised controlled trials (PRCTs) of isolated displaced fractures of the olecranon were carried out to compare 1) tension band wire (TBW) versus plate fixation in younger patients (< 75 years) and 2) operative versus non-operative management in elderly patients (≥75 years). The primary outcome measure for these studies was the upper limb specific patient reported Disabilities of the Arm, Shoulder and Hand (DASH) score. Secondary outcome measures included surgeon reported outcome scores, complication rates and cost. The incidence of proximal forearm fractures was 68 per 100,000. Radial head fractures fit a type D distribution curve (unimodal young man, bimodal woman) and radial neck type A (unimodal young man, unimodal older woman). Proximal ulna and olecranon fractures were both a type F (unimodal older man, unimodal older woman), with an increasing incidence after the 6th decade. Over 90% of proximal radial fractures were isolated stable fractures. Prospective analysis of 201 isolated proximal radius fractures found that the patient and surgeon reported outcome following primary non-operative management for Mason type 1 and type 2 (n=185) fractures was excellent in the short and long-term, with < 2% of patients undergoing secondary surgical intervention. At a mean of 10 years post injury (n=100), the mean DASH score was 5.8 and 92% of patients were satisfied. Factors associated with a poorer short and long-term patient reported outcome included increasing fracture displacement (≥5mm) and socio-economic deprivation. Retrospective analysis of 105 acute unstable complex radial head fractures found that the mean short-term functional outcome was good (mean Broberg and Morrey Score 80) following radial head replacement. In the long-term (mean 7 years), 28% of patients required removal or revision of the prosthesis, with younger patients and silastic implants independent risk factors (both p < 0.05). Retrospective analysis of 36 operatively managed isolated displaced olecranon fractures found satisfactory short and long-term outcomes, with the symptomatic metalwork removal rate 47% and the mean DASH 2.5 at a mean of seven years post injury. In the PRCT of plate (n=34) versus TBW (n=33) fixation, comparable functional and patient reported outcomes (DASH 8.5 vs 13.5; p=0.252) were found at one year following injury. Complication rates were significantly higher in the TBW group (63.3% vs 37.5%; p=0.042), predominantly due to a significantly higher rate of symptomatic metalwork removal (50.0% vs 21.9%; p=0.021), resulting in equivocal costs for both techniques (p=0.131). In older lower-demand patients, short and long-term retrospective analysis found very satisfactory outcomes following non-operative management of isolated displaced fractures of the olecranon, with patient satisfaction 91% and no patients requiring surgery for a symptomatic non-union. The preliminary results of the PRCT of non-operative (n=8) versus operative (n=11) management demonstrated comparable functional and patient reported outcomes at all points over the one-year following injury (all p≥0.05), with a higher rate of complications (81.8% vs 14.3%; p=0.013) and cost (p=0.01) following surgical intervention. The association found between fragility and the epidemiology of proximal forearm fractures highlighted the importance of considering non-operative management for these injuries. These findings support non-operative management for isolated stable radial head and neck fractures. For more complex injuries when radial head replacement is indicated, there is a high rate of removal or revision, with younger patients most at risk. In younger active patients with an isolated displaced fracture of the olecranon, TBW and plate fixation provide comparable short-term results, with TBW fixation as cost effective despite an increased rate of metalwork removal. In older lower demand patients, this data provides strong evidence for the non-operative management of isolated displaced olecranon fractures.

Atualmente são utilizados diversos equipamentos e implementos para treinamento de força. Os flexores do cotovelo apresentam enorme variedade de exercícios, cada qual apresentando diferentes características de torque externo. Na maioria dos casos, a escolha dessa característica aparenta não seguir nenhum critério pré-estabelecido para sua determinação, sendo que a variação desse torque externo é fator causador de grande influência na adaptação do músculo ao treinamento imposto. Com isso, a escolha de um exercício demanda conhecimento dos objetivos de treino, além do conhecimento das características musculares, no que diz respeito à possibilidade de produção de força e torque musculares. Esse estudo objetivou verificar o comportamento do torque muscular de flexão do cotovelo de indivíduos ativos e sedentários, comparando-os com a característica de torque externo de quatro exercícios usuais de flexão do cotovelo (Rosca Direta, Rosca Scott, Rosca Banco Inclinado e Rosca Polia). Além disso, visou-se comparar a capacidade de produção de torque entre as três posições da articulação rádio-ulnar. Assim, foi avaliado o torque concêntrico máximo de flexão do cotovelo, numa velocidade de 45º/s, num dinamômetro isocinético. A amostra contou com 20 universitários jovens e saudáveis, divididos nos dois grupos. As relações torque-ângulo encontradas para o grupo de ativos não apresentaram pico de torque e, sim, um platô que se prolonga por grande parte da relação. As relações torqueângulo encontradas para o grupo de sedentários apresentam um pico definido, ocorrendo, em média, entre 32º e 43º de flexão do cotovelo, porém com grande variabilidade. Não foram encontradas diferenças estatisticamente significativas entre as posições da articulação rádioulnar com relação à: ângulo de pico, taxa de acréscimo, taxa de decréscimo, torque final (sedentários) e torque absoluto. Apenas o grupo de ativos apresentou diferenças significativas entre as posições com relação ao torque final. Não foram encontradas diferenças estatisticamente significativas entre os grupos com relação à: taxa de acréscimo e torque final. Houve diferenças significativas entre os grupos com relação à taxa de decréscimo, em todas as posições da articulação rádio-ulnar. Nenhum dos exercícios avaliados parece apresentar uma característica de torque externo condizente com quaisquer relações torque-ângulo encontradas nesse estudo. Assim, foi sugerida uma polia assimétrica, com raio variando de acordo com as taxas de variação média de torque encontradas na amostra, produzindo, assim, um torque externo que acompanha as características de produção de torque muscular. Nesse estudo, foi possível concluir que existe grande variabilidade com relação às variáveis inerentes às características de produção máxima de torque flexor do cotovelo. Assim, é possível que se faça inferências com relação à adaptação funcional obtida com o treinamento, o qual levaria a musculatura a apresentar um pico de torque mais bem definido e próximo aos 90º de flexão do cotovelo. Por outro lado, o sedentarismo faria com que o ângulo de maior produção de torque muscular se aproxime da extensão do cotovelo, numa característica de produção de força condizente com o trecho ascendente da relação forçacomprimento, atuando num ciclo alongamento-encurtamento. / Nowadays there are many types of equipment used to strength training. Especially the elbow flexors present great variety of exercises, each one with different resistance moment characteristics. In the majority of the cases, this characteristic of resistance moment does not seem to follow any criterion for its determination and its variation is a causing factor of great influence in the muscle adaptation to the imposed training. Thus, the exercise choice demands to know the objectives of the training and muscle characteristics, in respect to the possibility of muscle force and moment production. This aim of this study was to verify the elbow flexor muscle moment profile of actives and sedentary subjects, comparing it with resistance moment characteristics of four usual exercises of elbow flexion (Barbell Biceps Curl, Scott Biceps Curl, Lying Dumbbell Curl and Standing Cable Curl). Moreover, it was aimed to compare the moment production capacity between three forearm positions. Thus, it was measured maximal concentric elbow flexion moment, at 45º/s, on an isokinetic dynamometer. The sample was composed by 20 young and healthy students, divided in two groups. The moment-angle relationship founded in the active group did not show a moment peak, but a plateau that prolongs for great part of the relationship. The moment-angle relationship founded in the sedentary group showed a defined peak, occurring, on average, between 32º and 43º of elbow flexion, however with great variability. It was not founded statistic differences between forearm positions in relation to: moment peak angle, moment increase rate, moment decrease rate, final moment (sedentary) and absolute moment. Only the active group shown statistic differences between positions in relation to final moment. It was not founded statistic differences between groups in relation to: moment increase rate and final moment. There was statistic difference between groups in relation to moment decrease rate, in all forearm positions. None of the evaluated exercises seems to show an external moment characteristic suitable with any moment-angle relationship founded on this study. Thus, it was suggested an asymmetrical pulley, whose radius variation fit well with increase and decrease rates founded at this sample, producing, in this way, an external moment suitable with the capacity of muscle moment production. In this study, it was possible to conclude that occur great variability in respect to the variables inherent to the characteristics of maximal elbow moment flexion production. Thus, it was possible to infer in relation to functional adaptation gotten with the training, which would lead the muscle to present a most defined moment peak and closer to 90º of elbow flexion. Nevertheless, the sedentary would lead the moment peak angle closer to elbow extension, which force production characteristic would be suitable with the ascending limb of force-length relationship, undergoing a stretch-shortening cycle.

Tennis elbow (TE) is a relatively common painful condition affecting the upper extremity. The aetiology is not known, but TE is most often seen in middle aged individuals using repetitive and forceful gripping at work or recreational activities, and is referred to overuse injuries. The pathogenesis is not known, but there are so-called degenerative changes in the wrist- and finger-extensor muscle origin (common extensor origin - CEO). The pain mechanisms involved have not been scientifically clarified. The studies in the present thesis aimed to 1) evaluate the structure and blood flow using ultrasound (US) and colour Doppler (CD) examinations of the CEO in patients with TE, and in pain-free elbows, 2) evaluate the clinical effects of US- and CD-guided intratendinous injection treatment with the sclerosing substance polidocanol, 3) evaluate the long term (2 years) effects of injection treatment on the tendon structure and blood flow, and 4) investigate if there is a local production of sympathetic and parasympathetic signal substances in non-neural cells in the CEO. Structural tendon changes and high blood flow was found in the CEO in patients with TE, but not in pain-free controls. Remaining structural changes and additional bone spur formation at the lateral epicondyle, but not high blood flow, were seen 2 years after successful injection treatment. In a randomised double-blind study, US- and CD-guided intratendinous injection treatment with sclerosing polidocanol or the local anaesthetic lidocaine combined with epinephrine, targeting the region with high blood flow, was found to reduce pain and increase grip strength in patients with TE. There were no differences in the outcome between the two treatment groups. A local production of catecholamines, but not acetylcholine, was found in fibroblasts in the CEO, in patients with TE. This thesis presents results showing US and CD examinations to be useful methods to diagnose TE, and to evaluate structure and blood flow in the CEO after treatment. US- and CD-guided injection treatment targeting high blood flow in the region with structural changes can reduce pain symptoms in patients with TE. The localised high blood flow, and local production of catecholamines in the tendon cells in the CEO, might be involved in the pain mechanisms.

Habilitation-Thesis--Cologne. / Includes bibliographical references (p. 45-48) and index.

The present study quantifies electromyographic variables in one and two degree of freedom elbow movements involving flexion/extension and pronation/supination, in order to understand the associated central commands. Agonist burst magnitude varied with motion in a second degree of freedom for some muscles but not for others. In movements for which a biarticular muscle acted as agonist in two degrees of freedom, agonist burst magnitudes were approximately the sum of the magnitudes in the component movements. Agonist burst magnitude varied with motion in a second degree of freedom for some, but not all, monoarticular muscles. When biarticular muscles acted as agonist in one degree of freedom and antagonist in the other, the muscle often displayed both components simultaneously. The additivity of EMG burst magnitudes in two degree of freedom movements and the presence of both agonist and antagonist bursts in a muscle suggest that central commands associated with motion in individual degrees of freedom are superimposed in producing two degree of freedom movements.

Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: Thomas W. Kaminski, Dept. of Health, Nutrition, & Exercise Sciences. Includes bibliographical references.

Habilitation-Thesis--Cologne. / Includes bibliographical references (p. 45-48) and index.

No description available.