No description available.

Magister Artium (Sport, Recreation and Exercise Science) - MA(SRES) / Hamstrings muscle injury is the most frequent soccer-related injury in amateur and professional soccer players. Despite various interventions, the risk of hamstrings re-injury remains high. Several scientific studies examined the potential risk factors and their contribution to the occurrence of hamstrings injuries in male soccer players. The aim of the study was to investigate the relationship between selected physical characteristics, such as time-to-peak torque, hip abduction peak torque, hamstrings-to-quadriceps strength ratio, and hamstrings flexibility and the occurrence of hamstrings injuries in amateur male soccer players. A prospective, quantitative cross-sectional study design was utilized in this study. A total of 89 amateur male soccer players aged 18-35 years were recruited from the Cape Town Football District to perform functional assessments before injury occurred, which included anthropometric measurements, an evaluation of lower extremity isokinetic muscle strength (both knee and hip) and hamstrings flexibility tests. Instruments used to measure the anthropometric data were a calibrated Seca balance beam scale and stadiometer, a skinfold caliper, a sliding caliper, an anthropometer (All Harpenden, UK) and a metal tape measure. The Biodex Pro System 4 isokinetic dynamometer was used to measure lower extremity isokinetic muscle strength and a goniometer to measure hamstrings flexibility. Descriptive statistics included means and standard deviations, and inferential statistics included Pearson product-moment correlation to determine the relationship between selected physical characteristics and the occurrence of hamstrings injuries. Multivariate logistic regression via the forward stepwise method was utilised to predict potential physical characteristics (risk factors) for hamstrings injury in amateur male soccer players. Statistical significance was a p value of below 0.05. The prevalence of hamstrings injury was 4.3 %, with the multivariate logistic regression analysis indicating that time-to-peak torque was a significant predictor of the occurrence of hamstrings injury (OR = 1; p = 0.027). In conclusion, time-to-peak torque was a significant predictor of the occurrence of hamstrings injury. The players with hamstrings injuries produced a significantly slower time-to-peak torque, which has relevance for soccer players and coaches in addressing this common injury at all levels of competition.

Sammanfattning Bakgrund: Stretching har använts i många år inom sport och rehabilitering med målet att minska risken för muskelskador, bland annat skador i kombination med kort hamstrings. Flera olika stretchingmetoder används för att uppnå ökad rörlighet. Tre av dessa är; 1) Statisk stretching, 2) Dynamisk stretching, 3) Proprioceptiv neuromuskulär facilitering (PNF). Syfte: Syftet med den här litteraturstudien var att jämföra och undersöka tre olika stretchingmetoder (statisk, dynamisk och PNF stretching) för att se vilken som är mest effektiv för att öka rörligheten i hamstringsmuskulaturen. Metod: Sökning av artiklar gjordes i databaserna Pubmed, Sport Discus, samt Science Direct. Sökorden som användes var static stretching, dynamic stretching, pnf, flexibility samt range of motion. Totalt inkluderades till slut 26 artiklar i den här litteraturöversikten som dels överensstämde med inklusionskriterierna och som dessutom var tillgängliga gratis och i fulltext. Resultat: De flesta studierna var gjorda på unga vuxna mellan 16 och 35 år. Alla studier utom två visade på en statistisk signifikant ökning av rörligheten i hamstrings. Ferber et al. som studerade olika PNF-tekniker, uppvisade bäst resultat med en ökad hamstring rörlighet på 15,66 ± 0,95°. Den PNF-teknik som gav detta resultat var PNF- Agonist Contract-Relax. Slutsats: Baserat på de resultat som gavs i studierna verkar statisk stretching och PNF fungera lika bra, men, studierna som gjorts på PNF är för få för att verkligen kunna fastställa att denna teknik är lika bra som statisk stretching. Mycket få studier har gjorts på dynamisk stretching (färre än PNF) vilket innebär att det är svårt att bedöma exakt vilken effekt dynamisk stretching har på hamstrings rörlighet.

Master of Philosophy (MPhil) / Background: Physical deconditioning is often associated with chronic pain and is believed to be a result of gradual movement inhibition and reduction of physical activities. It is common for chronic pain sufferers to present with limited muscle extensibility and poor tolerance to physical movement. Exercises are therefore prescribed to assist in regaining muscle extensibility, strength, fitness and endurance. Of particular interest is stretch, a type of exercise aimed at increasing muscle extensibility. Stretch is commonly prescribed as part of physical rehabilitation in pain management programs, yet little is known of its effectiveness in the chronic pain population. Aim: The aim of this randomised controlled trial was to investigate the effects of a three-week stretch program on muscle extensibility and stretch tolerance in patients with chronic musculoskeletal pain. Methods: Thirty adults with pain persisting for at least three months and limited hamstring muscle extensibility were recruited from patients enrolled in a multidisciplinary pain management program at a Sydney Hospital. A within-subject design was used, with one leg of each participant randomly allocated to an experimental (stretch) condition and the other to a control (no stretch) condition. The hamstring muscles of the experimental leg were stretched for one minute a day over a three-week period, whilst the hamstring muscles of the control leg were not stretched during this time. This intervention was embedded within a pain management program and supervised by physiotherapists. Primary outcome measures were muscle extensibility and stretch tolerance, reflected by passive hip flexion angles produced with standardised and non-standardised torques, respectively. Initial measures were taken prior to the first stretch on day one and final measures were taken one to two days after the last stretch. A blinded assessor was used for all testing. Results: After three weeks of intervention, stretch did not increase muscle extensibility (mean between-group difference in hip flexion was 1 degree; 95% CI -2 to 4 degrees) but did improve stretch tolerance (mean between-group difference in hip flexion was 8 degrees; 95% CI 5 to 10 degrees). Conclusion: Three weeks of stretch increases tolerance to the discomfort associated with stretch but does not change muscle extensibility in patients with chronic musculoskeletal pain. This study provides support for the ongoing incorporation of stretch in pain management programs, where stretch may be conceptualised as a graded exposure to movement and assisting in the restoration of normal activity and function.

Master of Philosophy (MPhil) / Background: Physical deconditioning is often associated with chronic pain and is believed to be a result of gradual movement inhibition and reduction of physical activities. It is common for chronic pain sufferers to present with limited muscle extensibility and poor tolerance to physical movement. Exercises are therefore prescribed to assist in regaining muscle extensibility, strength, fitness and endurance. Of particular interest is stretch, a type of exercise aimed at increasing muscle extensibility. Stretch is commonly prescribed as part of physical rehabilitation in pain management programs, yet little is known of its effectiveness in the chronic pain population. Aim: The aim of this randomised controlled trial was to investigate the effects of a three-week stretch program on muscle extensibility and stretch tolerance in patients with chronic musculoskeletal pain. Methods: Thirty adults with pain persisting for at least three months and limited hamstring muscle extensibility were recruited from patients enrolled in a multidisciplinary pain management program at a Sydney Hospital. A within-subject design was used, with one leg of each participant randomly allocated to an experimental (stretch) condition and the other to a control (no stretch) condition. The hamstring muscles of the experimental leg were stretched for one minute a day over a three-week period, whilst the hamstring muscles of the control leg were not stretched during this time. This intervention was embedded within a pain management program and supervised by physiotherapists. Primary outcome measures were muscle extensibility and stretch tolerance, reflected by passive hip flexion angles produced with standardised and non-standardised torques, respectively. Initial measures were taken prior to the first stretch on day one and final measures were taken one to two days after the last stretch. A blinded assessor was used for all testing. Results: After three weeks of intervention, stretch did not increase muscle extensibility (mean between-group difference in hip flexion was 1 degree; 95% CI -2 to 4 degrees) but did improve stretch tolerance (mean between-group difference in hip flexion was 8 degrees; 95% CI 5 to 10 degrees). Conclusion: Three weeks of stretch increases tolerance to the discomfort associated with stretch but does not change muscle extensibility in patients with chronic musculoskeletal pain. This study provides support for the ongoing incorporation of stretch in pain management programs, where stretch may be conceptualised as a graded exposure to movement and assisting in the restoration of normal activity and function.

No description available.

Introduction: Mental imagery (MI) has been shown to influence flexibility when used with treatments such as stretching. Currently, little evidence supports the efficacy of MI as an independent tool to increase flexibility. Therefore, the purpose of this investigation was to test if a guided mental imagery protocol could positively influence subject physical measures, including myofascial length, muscle tone and range of motion measures. Methods: Individuals with no history of lower limb injuries that would affect hamstring flexibility underwent initial measures, random assignment to a mental imagery or control group, and post-intervention measures. The imagery group followed a guided visualization of a hamstring stretch, and the control group remained still for the same amount of time. Independent T-Test, Dependent T-Test, and one-way ANOVA were used to analyze between-group differences, within-group differences, and group by time interaction, respectively. Results: 30 individuals enrolled in the study. No significant differences between groups at baseline were found for baseline demographics and ROM measures. No significant group by time differences were found between the two groups for any of the recorded measures. A posthoc power analysis showed a small effect size on the ANOVA test for knee extension. Discussion: Our evidence shows an acute MI-only protocol may not positively influence ROM measures. Future work should use familiarization periods, assess if imagery increases perceptions of flexibility, and utilize different musculature and stretches to see if visualization has a uniform influence globally.

Bakgrund: Inom forskningen studeras styrkeförhållandet i lårets muskler och anges ofta som flexor/extensor kvot (F/E-kvot). Ett sätt att mäta denna kvot är att använda isokinetiska styrketest.  Forskningen är inte överens om ett optimalt styrkeförhållande i denna muskulatur eller om för stor styrkeskillnad kan ge upphov till skada. Om en optimal kvot kan fastställas är det intressant i ett förebyggande och rehabiliterande syfte.  Syfte: Att beskriva och jämföra F/E-kvoten hos en grupp manliga fotbollsspelare med en grupp fysiskt aktiva män mellan 16 och 25 år. Metod: Mätning av maximal isokinetisk styrka i knäledens flexor och extensormuskler genomfördes med Genesis Single. Resultat: Studien fann en F/E-kvot hos fotbollsspelarna på 78,2 % på höger ben och 77 % på vänster ben. Jämförelsegruppen hade en F/E-kvot på 73,7 % på höger ben och76,4 % på vänster ben. Utifrån detta kunde man inte finna någon signifikant skillnad mellan de båda grupperna Slutsats: Studien fann ingen signifikant skillnad i F/E-kvot i höger respektive vänster ben mellan en grupp fotbollsspelare och jämförelsegrupp. Vidare forskning om reliabilitet och validitet med Genesis Single som mätinstrument bör utföras innan fler studier utförs med maskinen. / Background: The kneeflexor and kneextensor muscle strength ratio (F/E ratio) is a widely researched area where isokinetic tests are often used. There seems to be little consensus regarding the optimal ratio and also whether a low ratio increase the risk of injury. It would be interesting from a preventive and rehabilitative stand point if an optimal ratio could be decided upon.  Objectives: To compare the F/E ratio between a group of 16-25 year old soccer players and a group of physically active males. Methods: Isokinetic maximal strength in kneeflexors and kneextensors were measured with Genesis Single. Results: The ratio of the soccer players was 78,2 % in the right leg and 77 % in the left. The comparison group was found to have a ratio of 73,7 % in the right leg and 76,4 % in the left leg. There were no significant differences between the two groups. Conclusions: No significant differences could be determined between the two groups. Genesis Single needs to be further investigated with regards to its reliability and validity.

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.

Purpose The purpose of this study was to describe the evidence-based research recommendations on injury prevention methods against hamstring injuries among Swedish men's elite team in football. The research-based recommendations was then to be compared with the way Swedish elite football teams work to prevent hamstrings injuries. Method First a literature search of PubMed and SPORTDiscuss was made to find the most evidence-based training methods to hamstring injuries. Then an Internet questionnaire regarding injury prevention training methods against hamstring injuries was sent to all Swedish elite football teams. The answers off the questionnaire was then compared with the research that had the most evidence based training methods to hamstring injuries. Results Research shows that the method with the most evidence is eccentric strength training. Flexibility, static stretch and core stability training is research methods that can be used to prevent hamstrings injuries but these methods lack a large validated research basis. 8 of 32 (25 %) teams answered the questionnaire. All teams indicated that they were working with injury prevention methods but the methods varied from the eccentric strength training to periodization and flexibility training. 2 of 8 teams indicated that they worked with eccentric strength training that is recommended by science as the most evidence-based training method. Conclusion The study shows that the teams partly work after what the research recommends as the most evidence-based training methods against hamstring injuries. However, the study lacks validity and further research is needed before definitive conclusions can be drawn. / Syfte Syftet med denna studie är att beskriva vilka evidensbaserade forskningsrekommendationer som finns kring skadeförebyggande träningsmetoder mot hamstringsskador hos svenska herrelitlag i fotboll. De forskningsbaserade rekommendationerna ska sedan jämföras med arbetssättet hos herrelitlagen i svensk fotboll. Metod Först gjordes en litteratursökning på databaserna PubMed och SPORTDiscuss för att hitta de mest evidensbaserade träningsmetoderna mot hamstringsskador. Sedan skickades en webbenkät angående skadeförebyggande träningsmetoder mot hamstringsskador ut till alla svenska herrelitfotbollslag. Svaren på enkäten speglades sedan mot vad forskningen rekommenderade som de mest effektiva träningsmetoderna mot hamstringsskador. Resultat Forskning visar att den metoden med mest evidens är excentrisk styrketräning. Rörelse/stretch samt bålstabilitetsträning är enligt forskningen metoder som kan användas för att förebygga hamstringsskador men dessa metoder saknar ett stort validerat forskningsunderlag. 8 av 32 (25%) föreningar besvarade enkäten. Alla föreningar angav att de arbetade med skadeförebyggande åtgärder men metoderna varierade från excentrisk styrketräning till periodisering och rörlighetsträning. 2 av 8 föreningar angav att de arbetade med excentrisk styrketräning som forskningen rekommenderar som den mest evidensbaserade träningsmetoden. Slutsats Studien visar att föreningarna delvis arbetar efter vad forskningen rekommenderar som evidensbaserade träningsmetoder mot hamstringsskador. Dock saknar studien validitet och ytterligare forskning behövs för att slutgiltiga slutsatser ska kunna dras.