Bakgrund: Truppgymnastik är en relativt ung tävlingsgren inom gymnastik med ursprung från de Nordiska länderna. I Sverige är det den mest utövade formen av tävlingsgymnastik med flest rapporterade  skador i nedre extremiteten samt återkommande besvär i ryggen. Tester i syfte att förebygga skador är efterfrågade och få studier har utvärderat tester för idrottande barn och ungdomar. Syftet med studien var att beskriva en grupp unga truppgymnaster utifrån bakgrundsvariabler, och rörelsekontroll med screeningtestet Performance Base Matrix samt att mäta förekomst av muskuloskelettala skador under en period på sju månader.  Metod: Nitton unga truppgymnaster (flickor,7-9 år) genomförde screeningtestet Base Matrix i syfte att bedöma deras rörelsekontroll vid låg respektive/ low threshold och hög belastning/ high threshold. Testerna analyserades visuellt och genom videoupptagning. Resultatet av testerna dokumenterades i ett protokoll som bearbetades on-line samt för beräkning av procentuell förekomst av sämre utförd test i form av svaga länkar. Information om skadeförekomst inhämtades från föräldrar och tränare. Resultat: Alla försökspersoner genomförde screeningtesterna i sin helhet. Försökspersonerna hade en medelpoäng av 15 (max 50), där fler poäng anger fler svaga länkar/ weak links. Vid låg belastning var ländrygg/bäcken i flexion/ Low back/pelvis flexion den mest förekommande svaga länken (58%). Vid hög belastning var anterior rotation i skuldran / shoulder tilt den mest förekommande (63%). Tre skador rapporterades under tidsperioden: två fotledsskador och ett nackbesvär.  Konklusion: Denna studie indikerar att screeningtestet Base Matrix är genomförbart på unga truppgymnaster. Resultaten visar att skuldra framför allt under hög belastning samt ländrygg/bäcken framför allt under låg belastning är områden som uppvisar flest svaga länkar. Detta indikerar att dessa områden vore särskilt att beakta i skadeförebyggande träning av unga truppgymnaster. / Background: Team gym is a relatively new kind of competition in gymnastics with its origin from the Nordic countries. In Sweden it is the most practiced form of competitive gymnastics. Correlations have been found between altered trunk control and injuries in the extremities. Injury prevention testing is performed more frequently and tests requested for improving the training regimen.The purpose of this study was to describe a group of young team gymnasts regarding background variables, test results from Performance Base Matrix screening test and injury incidence during a period of seven months. Method: Nineteen team gymnasts, 7-9 year-old, were screened with the protocol Base Matrix for uncontrolled movement (weak links) under low and high load (threshold). Background data were collected on age, height, weight, dominant side, injuries in the recent year and the practice of other sports. The coaches were asked to register the number of injuries over a period of seven months.Results: The mean age was 8.8 years, BMI 16.1, 89% were right-handed and the average value of the Base Matrix score of 15 out of 50. Two injuries to the ankle and one on the neck reported totally from coaches and parents. Among the most apparent weak links were Low back / pelvis flexion at low load (58% of group) while the shoulder tilt at high load (63% of the group).Conclusion: The result indicates that the Base Matrix screening test is ​​feasible to use in young gymnasts. More studies are needed to confirm the results. The result indicates that the shoulder especially under high load and the lower back especially under low load were the body segments that showed the most weak links. These parts of the body are the most important to take  into consideration in the training of the young team gymnasts.

ABSTRACT Background: Most cases of lumbar disc herniation are asymptomatic. When symptomatic, LDH may cause a significant physical and mental distress. Initially, most patients are treated conservative but sometimes operations may be required. Aim: The aim of this study was to provide a review of the scientific basis of physiotherapy, including behavioural therapy, as a treatment to lumbar disc herniation regarding pain, function and the size of disc herniation in people suffering from lumbar disc herniation. Method: Four databases were used in the searches of literature. Assessment of the validity of the studies was done with the PEDro-scale and valuation of evidence rate was made according to guidelines made by the Swedish Council on Health Technology Assessment (SBU). Result: Nine RCT-studies were included with a total of 713 participants. The scientific basis is moderate to support a pain reduction and limited regarding improvement of physical function when it comes to physical exercises, including MDT. There is also a limited scientific basis supporting a reduction of pain from manipulation. Laser, on the other hand, showed a limited scientific basis to have no effect on pain. Traction and acupuncture had an insufficient scientific basis. Overall there were an insufficient scientific basis on the size of disc herniation.There was no study found examining the efficacy on behavioural therapy. Conclusion: The scientific basis is moderate to support a pain reduction when it comes to physical exercises, including MDT. There were few studies of high evidential rate and the scientific basis is difficult to determine due to heterogeneous studies. Additional science is required to determine which physiotherapy methods are the most effective for patients with lumbar disc herniation. / SAMMANFATTNING Bakgrund: Många gånger ger ett diskbråck inga besvär men symtomgivande diskbråck kan vara väldigt fysiskt och psykiskt påfrestande för patienten. Initialt behandlas de flesta konservativt. Syfte: Syftet med denna litteraturöversikt är att granska det vetenskapliga underlaget för olika sjukgymnastiska behandlingars effektivitet, inkluderande beteendemedicinska åtgärder, på smärta, funktion och diskbråcksstorlek vid ländryggsdiskbråck. Metod: Fyra databaser användes för litteratursökningar. Bedömning av studiernas validitet gjordes med PEDro-skalan och bevisvärdet bedömdes enligt riktlinjer från SBU. Resultat: Nio RCT-studier inkluderades med totalt 713 deltagare. Det vetenskapliga underlaget (VU) för att träning/ MDT, är effektivt gällande smärtreduktion visade sig vara måttligt, och begränsat gällande funktionsförbättring. Även manipulation hade begränsat VU, då det gäller smärtreduktion. Laser visade sig ha ett begränsat VU för att inte ha någon effekt på smärta. Traktion och akupunktur visade sig ha ett otillräckligt VU. Övergående fanns det ett otillräckligt VU gällande effekten på diskbråcksstorlek. Ingen studie identifierades med beteendemedicinska åtgärder vid ländryggsdiskbråck. Slutsats: Det VU visade sig måttligt för att träning/MDT är effektivt gällande smärtreduktion. Antalet studier av hög kvalitet är begränsat och VU är svårvärderat då studierna är heterogena. Ytterligare forskning behövs för att kunna avgöra vilka behandlingsmetoder som är effektiva vid ländryggsdiskbråck.

Background: Prolonged sitting in an automobile seat may alter the passive tissue stiffness of the lumbar spine differentially in males and females. Gender specific ergonomic interventions may be indicated for the automobile seat design. Purpose: To compare time-varying passive lumbar spine stiffness in response to a two hour simulated driving trial with time-varying lumbar spine and pelvic postures during sitting in an automobile seat. A secondary purpose was to investigate gender differences in lumbar spine stiffness, seat/occupant pressure profile, discomfort rating and posture. Methods: Twenty (10 males, 10 females) subjects with no recent history of back pain were recruited from a university population. Participants completed a simulated driving task for two hours. Passive lumbar range of motion was measured on a customized frictionless jig before, halfway through and at the end of the two-hour driving trial. Changes in the passive moment-angle curves were quantified using the transition zone slopes, breakpoints and maximum lumbar flexion angles. Lumbar spine and pelvic postures were monitored continuously during the simulated driving trial with average and maximum lumbar flexion angles as well as pelvic tilt angles being calculated. Results: Both men and women initially demonstrated an increase in transitional zone stiffness after 1 hour of sitting. After 2 hours of sitting, transitional zone stiffness was found to increase in males and decrease in females. During sitting, women were found to sit with significantly greater lumbar flexion than males and to significantly change the amount of lumbar flexion over the 2 hour period of simulated driving. Conclusions: Postural differences during simulated driving were demonstrated between genders in this study. In order to prevent injury to the passive elements of the spine during prolonged driving, gender specific ergonomic interventions, such as improved lumbar support, are indicated for the automobile seat.

In developing a method of quantifying stability in the lumbar spine Cholewicki and McGill (1996) have also broached the notion of sufficient stability, where too much stiffness (and stability) would hinder motion. Thus people highly skilled at maintaining stability may use different and optimal strategies, where <i>sufficient</i> stability is maintained. The purpose of this work was to explore the contributors to <i>sufficient</i> stability, how they coordinate and relate to injury mechanisms. This work represents a cascade of investigations where. 1) To explore the balance of various sources of stiffness and their effect on the critical load and post-buckling behaviour, simulations were undertaken where the buckled configuration of the spine was predicted and its stability in this new configuration was assessed. 2) The various sources of stiffness contributing to stability in the lumbar spine have been in some cases found to be deficient. The question of how these deficiencies place individuals at risk of instability, if at all, remains unresolved. A challenged breathing task was used to determine if there was a difference in stabilizing potential between healthy individuals and low back pain sufferers. Given that differences in stabilizing potential are apparent, several tasks which included a predetermined motor strategy, such as 3)pressurizing the abdomen and 4) abdominal hollowing vs. muscle bracing, were evaluated to determine if individuals can utilize motor strategies to augment stability. The stabilizing potential of abdominal pressure (IAP) and its interaction with muscle activation was evaluated. Some individuals are more skilled at stabilizing their lumbar spine than others. Some consciously controlled motor strategies are better stabilizers than others. These strategies highlight the relative contributions of various components (posture, passive tissue, muscle activation, and load) in that no single muscle dominates stability and IAP appears to augment stability beyond muscle activation alone. The margin of safety is considerable and depends on the task at hand, but it is possible to speculate on which tissues are at greatest risk of injury.

Background: Prolonged sitting in an automobile seat may alter the passive tissue stiffness of the lumbar spine differentially in males and females. Gender specific ergonomic interventions may be indicated for the automobile seat design. Purpose: To compare time-varying passive lumbar spine stiffness in response to a two hour simulated driving trial with time-varying lumbar spine and pelvic postures during sitting in an automobile seat. A secondary purpose was to investigate gender differences in lumbar spine stiffness, seat/occupant pressure profile, discomfort rating and posture. Methods: Twenty (10 males, 10 females) subjects with no recent history of back pain were recruited from a university population. Participants completed a simulated driving task for two hours. Passive lumbar range of motion was measured on a customized frictionless jig before, halfway through and at the end of the two-hour driving trial. Changes in the passive moment-angle curves were quantified using the transition zone slopes, breakpoints and maximum lumbar flexion angles. Lumbar spine and pelvic postures were monitored continuously during the simulated driving trial with average and maximum lumbar flexion angles as well as pelvic tilt angles being calculated. Results: Both men and women initially demonstrated an increase in transitional zone stiffness after 1 hour of sitting. After 2 hours of sitting, transitional zone stiffness was found to increase in males and decrease in females. During sitting, women were found to sit with significantly greater lumbar flexion than males and to significantly change the amount of lumbar flexion over the 2 hour period of simulated driving. Conclusions: Postural differences during simulated driving were demonstrated between genders in this study. In order to prevent injury to the passive elements of the spine during prolonged driving, gender specific ergonomic interventions, such as improved lumbar support, are indicated for the automobile seat.

No description available.

This dissertation has two major parts; Analytical and Experimental. The analytical section contains a study using Finite Element Analysis of dynamic instrumentation to demonstrate stress reduction in adjacent level discs. The experimental section contains biomechanical testing of facet fusion allograft technique and finally a comparison between In Vivo and In Vitro intradiscal pressures to determine forces acting on Lumbar spine segment L4-L5. A comprehensive study of available data, technology and literature was done. Conventional fusion instrumentation is believed to accelerate the degeneration of adjacent discs due to the increased stresses caused by motion discontinuity. A three dimensional finite element model of the lumbar spine was obtained which simulated flexion and extension. Reduced stiffness and increased axial motion of dynamic posterior lumbar fusion instrumentation designs results in a ~10% cumulative stress reduction for each flexion cycle. The cumulative effect of this reduced amplitude and distribution of peak stresses in the adjacent disc may partially alleviate the problem of adjacent level disc degeneration. Traditionally a pedicle screw system has been used for fixation of the lumbar spine and this involves major surgery and recovery time. Facet fixation is a technique that has been used for stabilization of the lumbar spine. The cadaver segments were tested in axial rotation, combined flexion/extension and lateral bending. Implantation of the allograft dowel resulted in a significant increase in stiffness compared to control. Facet fusion allograft provides an effective minimally invasive method of treating debilitating pain caused by deteriorated facet joints by permanently fusing them. An In Vitro biomechanical study was conducted to determine the intradiscal pressure during spinal loading. The intradiscal pressures in flexion/extension, lateral bending and axial rotation was compared to In Vivo published data. There is no data that explains the actual forces acting on the spine during flexion, extension, lateral bending or axial rotation. The functional spinal units were tested in combined axial compression and flexion/extension, combined axial compression and lateral bending and combined axial compression and axial rotation using a nondestructive testing method. Overall, this study found a good correlation between In Vivo and In Vitro data. This can essentially be used to make physiological relation from experimental and analytical evaluations of the lumbar spine. It is important to know how much load needs to be controlled by an implant.

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published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

No description available.