Introduction: Loaded barbell squat is one of the most popular exercises among athletes and can be performed in many different ways to achieve different goals. The difference in muscle activation between a free and afixed vertical movement path (using Smith machine) has not been examined to a particularly large extent. Aim: To investigate differences in muscle activation of the gluteal and thigh muscles when performing the loaded barbell squat in a free movement path compared to a fixed vertical movement path in healthy athletes under standardized conditions. Methods: Repeated measures within-subjects design were used. Five squats  per condition was performed with a weight representing 100% of the participants bodyweight at a tempo of four seconds per repetition. Muscle activation was measured with the EMG-shorts MBody3. Both conditions tested on the same day and the participants was randomized to what condition to start with. Results: No difference was observed between the conditions for the mean value of muscle activation the whole squat. Mm. quadriceps and mm. hamstrings showed significantly higher muscle activation at the end of the eccentric and the beginning of the concentric phase of the squat when the squat is performed with the barbell in a free movement path. For m. gluteus maximus no difference was observed, neither in the whole squat nor in any parts of the squat. Conclusion: This study provides preliminary evidence that mm. quadriceps and mm. hamstrings muscle group show lower muscle activation in parts of the squat when performed in a Smith machine. No significant difference was observed considering the whole movement. / Introduktion: Knäböj med skivstång är en av de mest populära övningarna bland idrottare och kan utföras på många olika sätt för att uppnå olika mål. Skillnaden i muskelaktivering mellan fri och fixerad vertikal rörelsebana (med Smithmaskin) har inte undersökts i särskilt stor omfattning. Syfte: Att undersöka skillnader i muskelaktivering av sätes- och lårmuskler vid utförande av knäböj med skivstång i en fri jämfört med en fixerad vertikal rörelsebana hos friska idrottare under standardiserade förhållanden. Metod: Upprepade mätningar inom individer användes. Fem repetitioner knäböj per betingelse utfördes på en vikt som motsvarade 100% av deltagarnas egna kroppsvikt. Varje repetition genomfördes på fyra sekunder. Muskelaktivitet mättes med EMG-byxorna MBody3. Båda betingelserna testades under samma dag och deltagarna randomiserades till vilken förutsättning de skulle börja med. Resultat: Ingen skillnad observerades mellan betingelserna för medelvärdet av muskelaktiveringen under hela knäböjen. Mm. quadriceps och mm. hamstrings hade signifikant högre muskelaktivering i slutet av den excentriska och början av den koncentriska fasen av knäböjen då den utfördes i en fri rörelsebana. Ingen skillnad observerades, varken i hela eller delar av knäböjen, avseende m. gluteus maximus. Slutsats: Denna studie ger preliminära bevis på att muskelgrupperna mm. quadriceps och mm. hamstrings uppvisar lägre muskelaktivering i delar av knäböjen när den utförs i en Smithmaskin. Ingen signifikant skillnad observerades i muskelaktiveringen avseende hela rörelsen.

Women are four to eight times more likely to injure their anterior cruciate ligament (ACL) compared to men. It is most commonly injured through a non-contact mechanism during game time situations. During landings, women display valgus collapse, where a less active gluteus medius muscle (GMed) may be unable to control the internal rotation of the thigh, causing an increase in knee joint abduction angle, augmenting the risk of ACL injury. This study’s purpose was to determine the difference between 12 male and 12 female athletes in muscle activity, specifically the GMed, and the 3D kinematics and kinetics of the lower-limb during drop jump landings from three heights; maximum vertical jump height, tibial length, and a commonly used height of 40cm. Results showed that females had greater hip adduction and knee abduction angles compared to men. The GMed activity showed no significant differences between sexes at each drop jump height.

Orientador: José Corrêa de Lacerda Neto / Banca: Thiago Luiz de Salles Gomes / Banca: Claudia Acosta Duarte / Banca: Flora Helena de Freitas D'Angelis / Banca: Antonio de Queiroz Neto / Resumo: Objetivou-se avaliar o efeito da suplementação com diferentes concentrações de óleo de soja e do treinamento de resistência nas adaptações do músculo glúteo médio de 20 eqüinos da raça Puro Sangue Árabe. Os animais foram distribuídos em cinco grupos, cada grupo foi composto por quatro cavalos. O grupo controle não recebeu óleo e os demais foram suplementados com 6, 12, 18 e 24% de óleo. Os animais foram submetidos a sete semanas consecutivas de exercício em esteira rolante e trilha. Analisou-se a influência do treinamento e da suplementação com óleo sobre o peso e escore corporal, concentração de glicogênio muscular e características das fibras do músculo glúteo médio. Os resultados demonstraram que as diferentes concentrações de óleo na dieta não influenciaram as variáveis estudadas. Houve redução significativa do peso corpóreo após o treinamento, no entanto o escore corporal permaneceu constante. O músculo glúteo médio expressou três tipos de fibras puras: I, IIA, IIX. O treinamento não induziu hipertrofia das fibras do músculo glúteo médio. O treinamento ocasionou aumento na proporção e na área relativa das fibras tipo IIA em detrimento das fibras IIX, melhorando a capacidade oxidativa muscular. Tanto as dietas com óleo como o treinamento não aumentaram as concentrações de glicogênio muscular. / Abstract: The aim of this study was evaluate the effects of supplementation with different concentrations of soy oil and endurance training on gluteus medius muscle adaptations in twenty Arabian horses. The horses were randomized in five groups (four horses each group). The control group did not receive the oil and the other groups were supplemented with 6%, 12%, 18% and 24% of soy oil. The animals were submitted to seven weeks of exercise on treadmill and track. The influence of training and oil supplementation on body weight, corporal score, muscular glycogen stores and characteristics of the gluteus medius muscular fibers were analyzed. The results showed that the supplementation of soy oil in diet was not significantly effective on the studied parameters. There was a significant reduction of the body weight after the end of training; however the corporal score showed no changes. The gluteus medius muscle expressed three types of pure fibers: I, IIA and IIX. The training induced a increase in the proportion and relative area of the type IIA fibers in detriment of type IIX fibers, improving the oxidative capacity muscular. No hypertrophy of the muscular fibers was observed. There were no significant changes in the values of the total glycogen after the training period. / Doutor

Women are four to eight times more likely to injure their anterior cruciate ligament (ACL) compared to men. It is most commonly injured through a non-contact mechanism during game time situations. During landings, women display valgus collapse, where a less active gluteus medius muscle (GMed) may be unable to control the internal rotation of the thigh, causing an increase in knee joint abduction angle, augmenting the risk of ACL injury. This study’s purpose was to determine the difference between 12 male and 12 female athletes in muscle activity, specifically the GMed, and the 3D kinematics and kinetics of the lower-limb during drop jump landings from three heights; maximum vertical jump height, tibial length, and a commonly used height of 40cm. Results showed that females had greater hip adduction and knee abduction angles compared to men. The GMed activity showed no significant differences between sexes at each drop jump height.

PURPOSE: To examine gluteus medius strength and endurance in relation to lower limb stability, targeting and agility. METHODS: 57 participants performed isometric and dynamic gluteus medius strength and endurance tests of both lower limbs. Lower limb dominance was determined using the Waterloo Footedness Questionnaire-Revised (WFQ-R). Strength and endurance of gluteus medius were compared to single-leg performance of a stork stand, a lateral foot targeting task and a hopping test of agility. RESULTS: Body mass normalized isometric gluteus medius strength was found to be weakly and inversely correlated to agility score for both dominant limbs (r=-0.262, p=0.026) and non-dominant limbs (r=-0.335, p=0.006) with a lower agility score indicating better agility performance. For non-dominant limbs only, body mass normalized isometric gluteus medius strength correlated negatively to targeting speed (r=-0.229, p=0.045) and isometric gluteus medius endurance measured as percentage drop in strength over time correlated weakly and positively to the amount of body sway demonstrated during a single-leg stork stand task (r=0.253, p=0.030). CONCLUSION: Gluteus medius strength may be weakly related to improved agility performance while gluteus medius endurance may weakly relate to improved single-leg static balance performance. It is likely that other factors such as neuromuscular training have a much larger influence on stability, targeting ability and agility than the strength and endurance of the hip abductors alone.

M.Tech. / The term „myofascial‟ is derived from the word „myo‟ meaning muscle and „fascia‟ meaning connective tissue. Myofascial pain syndrome is a regional pain syndrome characterized by the presence of myofascial trigger points (Mense and Simons, 2001). The most crucial component of myofascial pain is muscle shortening from contracture (or „spasm‟). In fact, myofascial pain does not exist without muscle shortening. Prolonged shortening not only causes pain in the muscle but also physically pulls on tendons, thereby straining them and distressing the bone and joints they insert into and act upon (Gunn, 2002). Trigger points are most often discussed in the setting of myofascial pain syndromes, in which widespread or regional muscular pain is associated with hyperalgesia, psychological disturbance and significant restriction of daily activities (Huguenin, 2004).

A dissertation presented in partial compliance with the requirements of the Master's Degree in Technology: Chiropractic, Durban Institute of Technology, 2003. / In recent years, sacroiliac syndrome has been widely accepted by many different health professions as one of the major contributors to low back pain. Manipulation to effect the relief of the condition has thus far proven to be one of the most effective methods. Comparatively little research has however been done on the different forms of physical therapy that can be used in conjunction with a manipulation so as to maximise its affect / M

Women are four to eight times more likely to injure their anterior cruciate ligament (ACL) compared to men. It is most commonly injured through a non-contact mechanism during game time situations. During landings, women display valgus collapse, where a less active gluteus medius muscle (GMed) may be unable to control the internal rotation of the thigh, causing an increase in knee joint abduction angle, augmenting the risk of ACL injury. This study’s purpose was to determine the difference between 12 male and 12 female athletes in muscle activity, specifically the GMed, and the 3D kinematics and kinetics of the lower-limb during drop jump landings from three heights; maximum vertical jump height, tibial length, and a commonly used height of 40cm. Results showed that females had greater hip adduction and knee abduction angles compared to men. The GMed activity showed no significant differences between sexes at each drop jump height.

Introduktion: Ländryggssmärta är en av de vanligaste åkommorna och är en anledning till att individer söker kontakt med vården. Forskning visar att personer med ländryggssmärta har en annorlunda EMG-amplitud (muskelaktivering) samt rekryteringsordning jämfört med personer utan ländryggssmärta. Syfte: Syftet med denna studie var att jämföra EMG-amplitud samt rekryteringsordning av rygg- och höftextensorer hos personer med eller utan ländryggssmärta vid utförande av övningen hip thrust. Metod: Sex stycken deltagare varav tre stycken med ländryggssmärta och tre stycken utan ländryggssmärta deltog i studien. Deltagarna utförde övningen hip thrust samtidigt som man mätte EMG från gluteus maximus, erector spinae och semidentinousus. Insamling av data gjordes med Noraxon, utfallsvariabler som jämfördes mellan grupperna var EMG-amplitud och rekryteringsordning. Resultat: De med ländryggssmärta hade en annorlunda rekryteringsordning med större variation jämfört med personer utan ländryggssmärta. Det var även en variation i EMG-amplituden mellan grupperna där deltagare med ländryggssmärta hade en högre aktivering av semitendinosus jämfört med kontrollgruppen vid utförande av övningen hip thrust. Konklusion: Personer med ländryggssmärta har en avvikande EMG-amplitud samt rekryteringsordning av rygg-och höft-extensorer jämfört med personer utan ländryggssmärta vid utförande av en hip thrust. Resultatet av denna studie kan endast påvisa att det finns en skillnad av EMG-amplitud samt rekryteringsordning mellan personer med ländryggssmärta jämfört med utan. En slutsats kan ej göras om ländryggssmärtan är den bakomliggande orsaken till detta. Vidare forskning inom området behöver göras med metodologiska förändringar för att förstärka resultatet av studien.

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