<p>Aim</p><p>The aim of this study was to evaluate the activity recorded with electromyography (EMG) fine-wire electrodes, in transversus abdominis (TrA) and rectus abdominis (RA) while performing various stabilization exercises, and to investigate how the level of activation was affected by specific instructions</p><p>Method</p><p>Ten physically active women (27.1 ± 5.5year, 1.74 ± 0.05 m, 67.1 ± 8.6 kg) performed six different stabilization exercises (four lying supine with bent knees and hips and two in four point kneeling). They performed two sets of exercises, the first without and the second with specific instructions. The specific instruction was “abdominal hollowing to activate” TrA. The fine-wire electrodes were inserted bilateral into TrA and RA with an injection needle with guidance from an ultrasound. EMG was recorded during the middle second (while the subjects were asked to withhold the final position) and data was normalized to maximal voluntary contraction (MVC) and value at rest.</p><p>Results</p><p>The effects from instructions were significant while looking upon muscle and exercise (p<0,05). All exercises but exercise number 4 (unilateral bridgening) were significant effected by instructions in TrA, but none of the exercises were effected in RA (p>0,05). The mean of the activity in TrA varied without instructions between 2,9% (± 4,4) to 39,5 % (± 20,0) and with instructions 15,2 % (± 14,7) to 45,6 % (± 23,5). In RA the mean of the activity varied without instructions between 0,3% (± 0,8) to 9,8 % (± 27,4) and with instructions between 2.4 % (± 2,9) to 11,3% (± 28,5).</p><p>Conclusion</p><p>It is possible to selectively increase the activity in TrA in the majority of selected stabilization exercises with supine position with bent knees and hips, and in four point kneeling.</p> / <p>Syfte</p><p>Syftet med denna studie var att med intramuskulär elektromyografi utvärdera aktiveringsgraden i transversus abdominis (TrA) och rectus abdominis (RA) vid utförandet av olika stabiliseringsövningar samt att undersöka hur graden av aktivering påverkas av specifika instruktioner.</p><p>Metod: Tio kvinnliga, fysiskt aktiva personer (27.1 ± 5.5 år, 1.74 ± 0.05 m, 67.1 ± 8.6 kg) fick utföra sex olika stabiliseringsövningar (fyra i ryggliggande och två i knäfyrfota) med tre repetitioner på varje övning. Försökspersonen (fp) fick utföra övningarna i två omgångar. Omgång ett utan och omgång två med specifik instruktion, den specifika instruktionen var; ”dra in den nedre delen av magen, den under naveln” (abdominal hollowing) för att aktivera Tr A. Intramuskulära trådelektroder fördes in bilateralt i TrA och RA med hjälp av en injektionsnål under guidning av ultraljud. Elektromyografi (EMG) mättes under den mittersta sekunden av övningen (i kvarhållen slutposition) och normaliserades mot maximal viljemässig kontraktion (MVC) och vilovärde.</p><p>Resultat: Effekten av instruktion var signifikant i betraktandet av muskel och övning (p<0,05). I samtliga övningar utom övning 4 (unilateralt bäckenlyft) påverkade instruktioner signifikant muskelaktiviteten i TrA (p<0,05), men inte i någon av övningarna i RA (p>0,05).</p><p>Medelvärdet av den normaliserade EMG-aktiviteten i TrA varierade i övning 1 till 6 utan instruktioner mellan 2,9 % (± 4,4) och 39,5 % (± 20,0). Med instruktion varierade den procentuella aktiviteten i TrA mellan 15,2 % (± 14,7) och 45,6 % (± 23,5). I RA varierade medelvärdet utan instruktioner mellan 0,3% (± 0,8) till 9.8 % (± 27,4) och med instruktioner 2.4 % (± 2,9) till 11,3% (± 28.5).</p><p>Slutsats; Det går att med hjälp av instruktioner selektivt öka aktiveringsgraden i TrA i majoriteten av valda stabiliseringsövningar i krokligg och knäfyrfota.</p>

Aim The aim of this study was to evaluate the activity recorded with electromyography (EMG) fine-wire electrodes, in transversus abdominis (TrA) and rectus abdominis (RA) while performing various stabilization exercises, and to investigate how the level of activation was affected by specific instructions Method Ten physically active women (27.1 ± 5.5year, 1.74 ± 0.05 m, 67.1 ± 8.6 kg) performed six different stabilization exercises (four lying supine with bent knees and hips and two in four point kneeling). They performed two sets of exercises, the first without and the second with specific instructions. The specific instruction was “abdominal hollowing to activate” TrA. The fine-wire electrodes were inserted bilateral into TrA and RA with an injection needle with guidance from an ultrasound. EMG was recorded during the middle second (while the subjects were asked to withhold the final position) and data was normalized to maximal voluntary contraction (MVC) and value at rest. Results The effects from instructions were significant while looking upon muscle and exercise (p&lt;0,05). All exercises but exercise number 4 (unilateral bridgening) were significant effected by instructions in TrA, but none of the exercises were effected in RA (p&gt;0,05). The mean of the activity in TrA varied without instructions between 2,9% (± 4,4) to 39,5 % (± 20,0) and with instructions 15,2 % (± 14,7) to 45,6 % (± 23,5). In RA the mean of the activity varied without instructions between 0,3% (± 0,8) to 9,8 % (± 27,4) and with instructions between 2.4 % (± 2,9) to 11,3% (± 28,5). Conclusion It is possible to selectively increase the activity in TrA in the majority of selected stabilization exercises with supine position with bent knees and hips, and in four point kneeling. / Syfte Syftet med denna studie var att med intramuskulär elektromyografi utvärdera aktiveringsgraden i transversus abdominis (TrA) och rectus abdominis (RA) vid utförandet av olika stabiliseringsövningar samt att undersöka hur graden av aktivering påverkas av specifika instruktioner. Metod: Tio kvinnliga, fysiskt aktiva personer (27.1 ± 5.5 år, 1.74 ± 0.05 m, 67.1 ± 8.6 kg) fick utföra sex olika stabiliseringsövningar (fyra i ryggliggande och två i knäfyrfota) med tre repetitioner på varje övning. Försökspersonen (fp) fick utföra övningarna i två omgångar. Omgång ett utan och omgång två med specifik instruktion, den specifika instruktionen var; ”dra in den nedre delen av magen, den under naveln” (abdominal hollowing) för att aktivera Tr A. Intramuskulära trådelektroder fördes in bilateralt i TrA och RA med hjälp av en injektionsnål under guidning av ultraljud. Elektromyografi (EMG) mättes under den mittersta sekunden av övningen (i kvarhållen slutposition) och normaliserades mot maximal viljemässig kontraktion (MVC) och vilovärde. Resultat: Effekten av instruktion var signifikant i betraktandet av muskel och övning (p&lt;0,05). I samtliga övningar utom övning 4 (unilateralt bäckenlyft) påverkade instruktioner signifikant muskelaktiviteten i TrA (p&lt;0,05), men inte i någon av övningarna i RA (p&gt;0,05). Medelvärdet av den normaliserade EMG-aktiviteten i TrA varierade i övning 1 till 6 utan instruktioner mellan 2,9 % (± 4,4) och 39,5 % (± 20,0). Med instruktion varierade den procentuella aktiviteten i TrA mellan 15,2 % (± 14,7) och 45,6 % (± 23,5). I RA varierade medelvärdet utan instruktioner mellan 0,3% (± 0,8) till 9.8 % (± 27,4) och med instruktioner 2.4 % (± 2,9) till 11,3% (± 28.5). Slutsats; Det går att med hjälp av instruktioner selektivt öka aktiveringsgraden i TrA i majoriteten av valda stabiliseringsövningar i krokligg och knäfyrfota.

The Taylor Spatial Frame (TSF) is a recently introduced form of a circular external orthopaedic fixator for long bone fracture reduction and deformity correction. The TSF is constructed from two circular rings interconnected with six variable-length struts. Its kinematics are based on the Stewart-Gough platform. The TSF is attached to the patient's anatomy using fine wires and half-pins. In this thesis, three aspects of the TSF are analysed. First, the solution to non-trivial forward and inverse kinematics has been addressed. Second, the mechanical properties of the TSF fixator are investigated. Individual component stiffness is assessed separately and then the complete fixator is modelled. Simple stiffuess models of fine wires and half-pins are derived. Considerations for the use of the TSF for the peri-articular fractures are investigated and potential modifications are proposed. The effect of backlash in the frame components on the accuracy of the fixator has been analysed. Finally, in rder to validate the kinematics solution, to provide a training aid for surgeons and to demonstrate the concept of accurately controlled interfragmentary motion, a prototype of an active TSF was designed and built. Computationally efficient algorithms for solving the forward and inverse kinematics have been developed that require little numerical processing overhead and can be implemented on a mobile computing device. It was found that the TSF fixator has similar axial stiffuess to the circular Ilizarov ring fixator, since wires and half-pins are significantly less stiff than the frames. Furthermore, the TSF exhibits more uniform stiffuess for a range of off-axis loads and is significantly stiffer for torsional loads than the Ilizarov fixator. Slack, in the form of a backlash, can lead to severe strains in the unloaded frames and therefore fractures, and hence precautions are recommended. Finally, considerations and prototype for the automated TSF are presented that can be utilised for demonstration purposes and surgeon training.

La déchirure de la coiffe des rotateurs est une des causes les plus fréquentes de douleur et de dysfonctionnement de l'épaule. La réparation chirurgicale est couramment réalisée chez les patients symptomatiques et de nombreux efforts ont été faits pour améliorer les techniques chirurgicales. Cependant, le taux de re-déchirure est encore élevé ce qui affecte les stratégies de réhabilitation post-opératoire. Les recommandations post-chirurgicales doivent trouver un équilibre optimal entre le repos total afin de protéger le tendon réparé et les activités préconisées afin de restaurer l'amplitude articulaire et la force musculaire. Après une réparation de la coiffe, l'épaule est le plus souvent immobilisée grâce à une écharpe ou une orthèse. Cependant, cette immobilisation limite aussi la mobilité du coude et du poignet. Cette période qui peut durer de 4 à 6 semaines où seuls des mouvements passifs peuvent être réalisés. Ensuite, les patients sont incités à réaliser les exercices actifs assistés et des exercices actifs dans toute la mobilité articulaire pour récupérer respectivement l’amplitude complète de mouvement actif et se préparer aux exercices de résistance réalisés dans la phase suivante de la réadaptation. L’analyse électromyographique des muscles de l'épaule a fourni des évidences scientifiques pour la recommandation de beaucoup d'exercices de réadaptation au cours de cette période. Les activités sollicitant les muscles de la coiffe des rotateurs à moins de 20% de leur activation maximale volontaire sont considérés sécuritaires pour les premières phases de la réhabilitation. À partir de ce concept, l'objectif de cette thèse a été d'évaluer des activités musculaires de l'épaule pendant des mouvements et exercices qui peuvent théoriquement être effectués au cours des premières phases de la réhabilitation. Les trois questions principales de cette thèse sont : 1) Est-ce que la mobilisation du coude et du poignet produisent une grande activité des muscles de la coiffe? 2) Est-ce que les exercices de renforcement musculaire du bras, de l’avant-bras et du torse produisent une grande activité dans les muscles de la coiffe? 3) Au cours d'élévations actives du bras, est-ce que le plan d'élévation affecte l'activité de la coiffe des rotateurs? Dans notre première étude, nous avons évalué 15 muscles de l'épaule chez 14 sujets sains par électromyographie de surface et intramusculaire. Nos résultats ont montré qu’avec une orthèse d’épaule, les mouvements du coude et du poignet et même quelques exercices de renforcement impliquant ces deux articulations, activent de manière sécuritaire les muscles de ii la coiffe. Nous avons également introduit des tâches de la vie quotidienne qui peuvent être effectuées en toute sécurité pendant la période d'immobilisation. Ces résultats peuvent aider à modifier la conception d'orthèses de l’épaule. Dans notre deuxième étude, nous avons montré que l'adduction du bras réalisée contre une mousse à faible densité, positionnée pour remplacer le triangle d’une orthèse, produit des activations des muscles de la coiffe sécuritaires. Dans notre troisième étude, nous avons évalué l'électromyographie des muscles de l’épaule pendant les tâches d'élévation du bras chez 8 patients symptomatiques avec la déchirure de coiffe des rotateurs. Nous avons constaté que l'activité du supra-épineux était significativement plus élevée pendant l’abduction que pendant la scaption et la flexion. Ce résultat suggère une séquence de plan d’élévation active pendant la rééducation. Les résultats présentés dans cette thèse, suggèrent quelques modifications dans les protocoles de réadaptation de l’épaule pendant les 12 premières semaines après la réparation de la coiffe. Ces suggestions fournissent également des évidences scientifiques pour la production d'orthèses plus dynamiques et fonctionnelles à l’articulation de l’épaule. / Rotator cuff tear is one of the most common causes of shoulder pain and dysfunction. The operative repair has been widely performed for symptomatic patients and many efforts have been done to improve the surgical techniques. However, the re-tear rate is still high and this affects post-repair rehabilitation strategies. Post-surgical care should balance between the restriction imposed to protect the repaired tendon and the activities prescribed to restore range of motion and muscle strength. Frequently, early after rotator cuff repair, shoulder is immobilized in a sling or abduction orthosis, but this immobilization includes elbow and wrist joints as well. In this period that may last 4-6 weeks, only passive range of motion exercises are performed. After removing the immobilizer, patients are encouraged to do active assisted and active range of motion exercises respectively to regain the full active range of motion and be prepared for the resistance exercises in the following phase of rehabilitation. Electromyography of shoulder muscles has provided scientific basis for many of rehabilitation exercises during this period. Anecdotally, the activities of less than 20% of the maximal voluntary contraction of rotator cuff muscles are considered safe for the first phases of rehabilitation after rotator cuff repair. Using this concept, the aim of this dissertation is to evaluate the activity of shoulder musculature during some movements and exercises that can theoretically be performed during the early phases of rehabilitation. Three main questions of this thesis are: 1) Do elbow and wrist mobilizations highly activate rotator cuff muscles? 2) Do some resistance exercises of arm, forearm and chest muscles produce high activity in rotator cuff muscles? 3) During active arm elevation, does the plane of elevation affect rotator cuff activity? In our first study, we evaluated 15 shoulder muscles in 14 healthy subjects with both surface and indwelling EMG. Our results showed that while wearing a shoulder orthosis, elbow and wrist movements and even some resistance training involving these two joints, would minimally activate the rotator cuff muscles and can be considered safe. We also introduced some daily living tasks that can be performed safely during immobilization period. These findings may help to modify the design of current shoulder orthoses. In the second study, we also showed that resisted arm adduction against a low-density foam that replaced the hard wedge of orthosis would not highly activate the cuff muscles. In our final study, we evaluated the EMG of shoulder musculature during arm elevation tasks in 8 symptomatic patients with rotator cuff tears. We found that supraspinatus activity during arm elevation is significantly higher in abduction plane than in scaption and flexion planes in patients with rotator cuff tears. This suggested a plane sequences for active range of motion exercises during rehabilitation. The findings that are presented in this dissertation, suggest some modifications in the rehabilitation protocols during the first 12 weeks after rotator cuff repair. These suggestions also provide a scientific basis for producing more dynamic and functional shoulder orthoses.