Title: The influence of ACL plastic surgery in relation to the knee joint stability by female handball players and the posibility to influence this topic during training sessions The concept of the problem: One of the most common injuries of lower extremities during a handball game is the tear of the anterior cruciate ligament (ACL) often leading to instability and early offset of degeneration of the knee joint. In order to be able to continue the athletic carier, the patient may require surgery of the cruciate ligament. Usually 6-8 months after the operation, the patient should be able to return to her full extand of the athletic competition. Never-the-less, functional deficit of the operated knee is not uncommon. Often times, patients post ACL surgery experience secondary injuries such as the injury of the oposite knee joint or recurring defects of the prior injured ACL. Objectives: To evaluate the conditions of knee joints by female players (2-5 years) post ACL plastic surgery and to attest the efectivity of the exercise program for improving knee joint stability by those players. Methods: The theoretical part follows up the given issue as a research and theoretical overview of the current findings based on czech and also foreign literature. The practical part is dedicated to the application of...

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The master's thesis "Lower extremity stabilization function assessment using inertial sensors and functional tests in women's american football players" adresses postural control assessment in terms of functional joint stability using inertial sensors. The theoretical part is devoted to matters of functional joint stability, its control and it provides review of assessment options. Also inertial measurement unit function and application for human motion tracking are discussed. The last chapter covers American football considering the research group in the study. The experimental part is in form of study, which uses inertial sensor-based parameters to evaluate functional joint stability that are placed on four body segments and the results are compared with functional test results. We evaluated one-legged stance and single-leg hop test. One-legged stance, bear position and squat were chosen for the functional tests. Obtained data were also discussed in the context of history of injury in the last two years. Results confirm applicability of inertial measurement units for lower extremity stabilization objectification. We proved correlation of thight, shin and instep time to stabilization (TTS) with one-legged stance score and similarly thight and shin TTS with bear position score.

Die Zielsetzung dieser Arbeit besteht darin zu prüfen, ob die Luxationsrate bei Hochrisikopatienten durch den Einsatz von 40-mm- und 44-mm-Köpfen im Vergleich zu Patienten mit maximal 36-mm-Köpfen reduziert werden kann. Hierzu wurden die im Zeitraum von September 2009 bis Mai 2014 hüftendoprothetisch versorgten Patienten mit einem erhöhten Luxationsrisiko erfasst und die Verläufe auf Luxationen überprüft. Zur Risikobewertung diente eine eigens entwickelte Klassifikation. Des Weiteren erfolgte die Analyse der postoperativen Verläufe, der Röntgenbilder und eines Telefoninterviews in den Fällen, in denen Köpfe ≥ 40 mm zum Einsatz kamen. Im Untersuchungszeitraum wurden 288 Hüftendoprotheseneingriffe mit erhöhtem Luxationsrisiko durchgeführt. Bei 278 HTEP-Implantationen erfolgte der Einsatz von Gelenkköpfen ≤ 36 mm. In dieser Gruppe betrug die Luxationsrate 15,1% (n=42). Bei 10 Patienten wurden 40-mm- oder 44-mm-Gelenkköpfe eingesetzt. In diesen Fällen wurde das Luxationsrisiko entsprechend der vorgeschlagenen Klassifikation mit 3A (hoch) bis 4B (sehr hoch) bewertet. Bei einem mittleren Follow up von 22,8 Monaten wurde bei diesen Patienten keine Luxation festgestellt. Die mit 40-mm- sowie 44-mm-Köpfen erzielten Ergebnisse und die aktuelle Literatur sprechen für eine wesentlich höhere Gelenkstabilität und eine deutlich verminderte Luxationsneigung größerer Köpfe. Deren Einsatz ist daher gegenwärtig bei Risiko-patienten gerechtfertigt, sofern dieser in Abhängigkeit vom Pfannenaußendurch-messer konstruktiv möglich ist. In der weiteren Entwicklung der Hüftendoprothetik sollte die Verwendung größerer Köpfe angestrebt werden.

A instabilidade articular é responsável pelo desenvolvimento de lesões degenerativas incapacitantes que comprometem o desempenho funcional. Compreender os processos desenvolvidos para estabilização dinâmica articular é um desafio para pesquisadores das mais diversas áreas. O presente estudo propõe o uso da abordagem Biomecânica para reconhecer os mecanismos relacionadas ao processo de estabilização dinâmica articular, por meio de três diferentes condições experimentais. No experimento 1 foi analisada a Força de Reação do Solo (FRS) e a cinemática 3-D no andar, correr e saltar de portadores (n=10) e não portadores de instabilidade crônica (n=10) do tornozelo. No experimento 2 foi analisada a Eletromiografia dos músculos tibial anterior, fibular longo, fibular curto e gastrocnêmio lateral de portadores (n=14) e não portadores de instabilidade crônica (n=14) do tornozelo antes e após um protocolo de indução à fadiga muscular. No experimento 3 (n=20) foi analisado o efeito do exercício de alongamento muscular estático passivo dos músculos fibular longo e fibular curto na simulação da entorse do tornozelo. Nos protocolos de locomoção foram encontrados no lado acometido picos tardios e aumento dos Impulsos da FRS. No início da fase de apoio o tornozelo instável no andar aumentou a dorsiflexão, no correr aumentou a eversão e no saltar diminuiu a inversão e aumentou a dorsiflexão. Tais estratégias representam a tentativa de melhorar a estabilidade dinâmica articular. No entanto, a variação angular da articulação no plano sagital e frontal aumentaram, sugerindo que há mais amplitude de movimento no tornozelo acometido e maior estresse sobre os estabilizadores passivos locais. Em condições de fadiga muscular, após simulação da entorse, indivíduos com articulações saudáveis aumentam a rigidez articular e a intensidade de contração dos eversores do tornozelo, antecipadamente a perturbação, diferente de portadores de instabilidade crônica. A execução do exercício de alongamento dos músculos fibulares longo e curto, seguido da simulação da entorse, gerou o retardo da resposta motora e diminuição da intensidade de ativação. Desta forma, as estratégias desenvolvidas por portadores de instabilidade crônica podem ser relacionadas à causa e/ou consequência do quadro, a fadiga muscular altera o desenvolvimento de estratégias de proteção e o exercício de alongamento pode prejudicar a estabilização dinâmica articular / Joint instability is associated with degenerating injuries that lead to functional incapacitation. Knowing the process involved in joint dynamic stabilization is a challenge to researchers in many fields. This study proposes the use of a biomechanical approach to recognize the mechanisms involved in joint stabilization through three different experimental conditions. The first experiment analyzed the Ground Reaction Force (GRF) and the 3D kinematics in participants with (n=10) and without (n=10) chronic ankle instability during walking, running and jumping. The second experiment analyzed the Electromyography signal of tibialis anterior, peroneus longus, peroneus brevis e gastrocnemius lateralis in participants with (n=14) and without (n=14) chronic ankle instability before and after a muscle fatigue protocol. The third experiment (n=20) analyzed the effect of static passive stretching of peroneus longus and peroneus brevis muscles on the ankle sprain simulation. During the locomotion protocols the injured side showed late peaks and an increase of the GRF impulses. The instable ankle showed an increase of dorsiflexion during the initial phase of gait and an increase of eversion during running. The instable ankle also showed a decrease of inversion and an increase of dorsiflexion during jumping. These strategies represent an attempt to improve the joint dynamic stability. There was an increase in sagittal and frontal angular displacement, suggesting more range of motion as well as more stress in the passive structures that are responsible for stabilization in the injured ankle. During muscular fatigue, after an ankle sprain simulation, subjects with healthy joints increase the joint stiffness and the intensity of the ankle eversion muscles activation, before the intervention, differently from subjects with chronic instability. The peroneus longus and brevis stretching exercise followed by the ankle sprain simulation caused a delay on the motor response and a decrease in the activation intensity. The strategies developed by the subjects with chronic instability can be related to the cause and/or the consequence of the dysfunction. The muscular fatigue changes the development of strategies of protection and the stretching exercise can weaken the dynamic stability of the joint

Background: Joint stability has been experimentally and clinically linked to mechanisms of knee injury and joint degeneration. The only dynamic, and perhaps most important, regulators of knee joint stability are contributions from muscular contractions. In participants with unstable knees, such as anterior cruciate ligament (ACL) injured, a range of neuromuscular adaptations has been observed including quadriceps weakness and increased co-activation of adjacent musculature. This co-activation is seen as a compensation strategy to increase joint stability. In fact, despite increased co-activation, instability persists and it remains unknown whether observed adaptations are the result of injury induced quadriceps weakness or the mechanical instability itself. Furthermore, there exists conflicting evidence on how and which of the neuromuscular adaptations actually improve and/or reduce knee joint stability. Purpose: The overall aim of this thesis is therefore to elucidate the role of injury and muscle weakness on muscular contributions to knee joint stability by addressing two main objectives: (1) to further our understanding of individual muscle contribution to internal knee joint moments; and (2) to investigate neuromuscular adaptations, and their effects on knee joint moments, caused by either ACL injury and experimental voluntary quadriceps inhibition (induced by pain). Methods: The relationship between individual muscle activation and internal net joint moments was quantified using partial least squares regression models. To limit the biomechanical contributions to force production, surface electromyography (EMG) and kinetic data was elicited during a weight-bearing isometric force matching task. A cross-sectional study design determined differences in individual EMG-moment relationships between ACL deficient and healthy controls (CON) groups. A crossover placebo controlled study design determined these differences in healthy participants with and without induced quadriceps muscle pain. Injections of hypertonic saline (5.8%) to the vastus medialis induced muscle pain. Isotonic saline (0.9%) acted as control. Effect of muscle pain on muscle synergies recruited for the force matching task, lunging and squatting tasks was also evaluated. Synergies were extracted using a concatenated non-negative matrix factorization framework. Results/Discussion: In CON, significant relationships of the rectus femoris and tensor fascia latae to knee extension and hip flexion; hamstrings to hip extension and knee flexion; and gastrocnemius and hamstrings to knee rotation were identified. Vastii activation was independent of moment generation, suggesting mono-articular vastii activate to produce compressive forces, essentially bracing the knee, so that bi-articular muscles crossing the hip can generate moments for the purpose of sagittal plane movement. Hip ab/adductor muscles modulate frontal plane moments, while hamstrings and gastrocnemius support the knee against externally applied rotational moments. Compared to CON, ACL had 1) stronger relationships between rectus femoris and knee extension, semitendinosus and knee flexion, and gastrocnemius and knee flexion moments; and 2) weaker relationships between biceps femoris and knee flexion, gastrocnemius and external knee rotation, and gluteus medius and hip abduction moments. Since the knee injury mechanism, is associated with shallow knee flexion angles, valgus alignment and rotation, adaptations after ACL injury are suggested to improve sagittal plane stability, but reduce frontal and rotational plane stability. During muscle pain, EMG-moment relationships of 1) semitendinosus and knee flexor moments were stronger compared to no pain, while 2) rectus femoris and tensor fascia latae to knee extension moments and 3) semitendinosus and lateral gastrocnemius to knee internal rotation moments were reduced. Results support the theory that adaptations to quadriceps pain reduces knee extensor demand to protect the joint and prevent further pain; however, changes in non-painful muscles reduce rotational plane stability. Individual muscle synergies were identified for each moment type: flexion and extension moments were respectively accompanied by dominant hamstring and quadriceps muscle synergies while co-activation was observed in muscle synergies associated with abduction and rotational moments. Effect of muscle pain was not evident on muscle synergies recruited for the force matching task. This may be due to low loading demands and/or a subject-specific redistribution of muscle activation. Similarly, muscle pain did not affect synergy composition in lunging and squatting tasks. Rather, activation of the extensor dominant muscle synergy and knee joint dynamics were reduced, supporting the notion that adaptive response to pain is to reduce the load and risk of further pain and/or injury. Conclusion: This thesis evaluated the interrelationship between muscle activation and internal joint moments and the effect of ACL injury and muscle pain on this relationship. Findings indicate muscle activation is not always dependent on its anatomical orientation as previous works suggest, but rather on its role in maintaining knee joint stability especially in the frontal and transverse loading planes. In tasks that are dominated by sagittal plane loads, hamstring and quadriceps will differentially activate. However, when the knee is required to resist externally applied rotational and abduction loads, strategies of global co-activation were identified. Contributions from muscles crossing the knee for supporting against knee adduction loads were not apparent. Alternatively hip abductors were deemed more important regulators of knee abduction loads. Both muscle pain and ACL groups demonstrated changes in muscle activation that reduced rotational stability. Since frontal plane EMG-moment changes were not present during muscle pain, reduced relationships between hip muscles and abduction moments may be chronic adaptions by ACL that facilitate instability. Findings provide valuable insight into the roles muscles play in maintaining knee joint stability. Rehabilitative/ preventative exercise interventions should focus on neuromuscular training during tasks that elicit rotational and frontal loads (i.e. side cuts, pivoting maneuvers) as well as maintaining hamstring balance, hip abductor and plantarflexor muscle strength in populations with knee pathologies and quadriceps muscle weakness.

A instabilidade articular é responsável pelo desenvolvimento de lesões degenerativas incapacitantes que comprometem o desempenho funcional. Compreender os processos desenvolvidos para estabilização dinâmica articular é um desafio para pesquisadores das mais diversas áreas. O presente estudo propõe o uso da abordagem Biomecânica para reconhecer os mecanismos relacionadas ao processo de estabilização dinâmica articular, por meio de três diferentes condições experimentais. No experimento 1 foi analisada a Força de Reação do Solo (FRS) e a cinemática 3-D no andar, correr e saltar de portadores (n=10) e não portadores de instabilidade crônica (n=10) do tornozelo. No experimento 2 foi analisada a Eletromiografia dos músculos tibial anterior, fibular longo, fibular curto e gastrocnêmio lateral de portadores (n=14) e não portadores de instabilidade crônica (n=14) do tornozelo antes e após um protocolo de indução à fadiga muscular. No experimento 3 (n=20) foi analisado o efeito do exercício de alongamento muscular estático passivo dos músculos fibular longo e fibular curto na simulação da entorse do tornozelo. Nos protocolos de locomoção foram encontrados no lado acometido picos tardios e aumento dos Impulsos da FRS. No início da fase de apoio o tornozelo instável no andar aumentou a dorsiflexão, no correr aumentou a eversão e no saltar diminuiu a inversão e aumentou a dorsiflexão. Tais estratégias representam a tentativa de melhorar a estabilidade dinâmica articular. No entanto, a variação angular da articulação no plano sagital e frontal aumentaram, sugerindo que há mais amplitude de movimento no tornozelo acometido e maior estresse sobre os estabilizadores passivos locais. Em condições de fadiga muscular, após simulação da entorse, indivíduos com articulações saudáveis aumentam a rigidez articular e a intensidade de contração dos eversores do tornozelo, antecipadamente a perturbação, diferente de portadores de instabilidade crônica. A execução do exercício de alongamento dos músculos fibulares longo e curto, seguido da simulação da entorse, gerou o retardo da resposta motora e diminuição da intensidade de ativação. Desta forma, as estratégias desenvolvidas por portadores de instabilidade crônica podem ser relacionadas à causa e/ou consequência do quadro, a fadiga muscular altera o desenvolvimento de estratégias de proteção e o exercício de alongamento pode prejudicar a estabilização dinâmica articular / Joint instability is associated with degenerating injuries that lead to functional incapacitation. Knowing the process involved in joint dynamic stabilization is a challenge to researchers in many fields. This study proposes the use of a biomechanical approach to recognize the mechanisms involved in joint stabilization through three different experimental conditions. The first experiment analyzed the Ground Reaction Force (GRF) and the 3D kinematics in participants with (n=10) and without (n=10) chronic ankle instability during walking, running and jumping. The second experiment analyzed the Electromyography signal of tibialis anterior, peroneus longus, peroneus brevis e gastrocnemius lateralis in participants with (n=14) and without (n=14) chronic ankle instability before and after a muscle fatigue protocol. The third experiment (n=20) analyzed the effect of static passive stretching of peroneus longus and peroneus brevis muscles on the ankle sprain simulation. During the locomotion protocols the injured side showed late peaks and an increase of the GRF impulses. The instable ankle showed an increase of dorsiflexion during the initial phase of gait and an increase of eversion during running. The instable ankle also showed a decrease of inversion and an increase of dorsiflexion during jumping. These strategies represent an attempt to improve the joint dynamic stability. There was an increase in sagittal and frontal angular displacement, suggesting more range of motion as well as more stress in the passive structures that are responsible for stabilization in the injured ankle. During muscular fatigue, after an ankle sprain simulation, subjects with healthy joints increase the joint stiffness and the intensity of the ankle eversion muscles activation, before the intervention, differently from subjects with chronic instability. The peroneus longus and brevis stretching exercise followed by the ankle sprain simulation caused a delay on the motor response and a decrease in the activation intensity. The strategies developed by the subjects with chronic instability can be related to the cause and/or the consequence of the dysfunction. The muscular fatigue changes the development of strategies of protection and the stretching exercise can weaken the dynamic stability of the joint

Die Zielsetzung dieser Arbeit besteht darin zu prüfen, ob die Luxationsrate bei Hochrisikopatienten durch den Einsatz von 40-mm- und 44-mm-Köpfen im Vergleich zu Patienten mit maximal 36-mm-Köpfen reduziert werden kann. Hierzu wurden die im Zeitraum von September 2009 bis Mai 2014 hüftendoprothetisch versorgten Patienten mit einem erhöhten Luxationsrisiko erfasst und die Verläufe auf Luxationen überprüft. Zur Risikobewertung diente eine eigens entwickelte Klassifikation. Des Weiteren erfolgte die Analyse der postoperativen Verläufe, der Röntgenbilder und eines Telefoninterviews in den Fällen, in denen Köpfe ≥ 40 mm zum Einsatz kamen. Im Untersuchungszeitraum wurden 288 Hüftendoprotheseneingriffe mit erhöhtem Luxationsrisiko durchgeführt. Bei 278 HTEP-Implantationen erfolgte der Einsatz von Gelenkköpfen ≤ 36 mm. In dieser Gruppe betrug die Luxationsrate 15,1% (n=42). Bei 10 Patienten wurden 40-mm- oder 44-mm-Gelenkköpfe eingesetzt. In diesen Fällen wurde das Luxationsrisiko entsprechend der vorgeschlagenen Klassifikation mit 3A (hoch) bis 4B (sehr hoch) bewertet. Bei einem mittleren Follow up von 22,8 Monaten wurde bei diesen Patienten keine Luxation festgestellt. Die mit 40-mm- sowie 44-mm-Köpfen erzielten Ergebnisse und die aktuelle Literatur sprechen für eine wesentlich höhere Gelenkstabilität und eine deutlich verminderte Luxationsneigung größerer Köpfe. Deren Einsatz ist daher gegenwärtig bei Risiko-patienten gerechtfertigt, sofern dieser in Abhängigkeit vom Pfannenaußendurch-messer konstruktiv möglich ist. In der weiteren Entwicklung der Hüftendoprothetik sollte die Verwendung größerer Köpfe angestrebt werden.:Inhaltsverzeichnis Bibliographische Beschreibung Abkürzungsverzeichnis 1. Einleitung 1.1 Bedeutung der Hüftendoprothetik 1.2 Hüftendoprothesenluxation 1.2.1 Definition und Häufigkeit 1.2.2 Ursachen 1.2.3 Einteilung und Klassifikation 1.2.4 Risikofaktoren 1.2.5 Beurteilung des Luxationsrisikos bei hüftendoprothetischen Eingriffen 1.2.6 Ursachen des luxations-mindernden Effektes großer Köpfe 1.2.7 Vorgehen nach Luxation 1.2.7.1 Diagnostik 1.2.7.2 Therapie 1.3 Zielsetzung der Arbeit 2. Publikation 3. Zusammenfassung 4. Literaturverzeichnis 5. Tabellenverzeichnis 6. Abbildungsverzeichnis 7. Erklärung über die eigenständige Abfassung der Arbeit 8. Lebenslauf und wissenschaftlicher Werdegang 9. Danksagung 10. Anlagen Anlage 1 - Dokumentationsbogen Patienten mit Großköpfen Anlage 2 - Telefoninterviewbogen zu 40/44mm Köpfen