There is a big risk that neuroreceptors located in the knee, responsible for our proprioceptive ability, are damaged after an anterior cruciate ligament (ACL) injury occurs. This may cause miscommunication between the neuroreceptors and motoric function in the brain. Due to the brains plasticity, it has been shown that brain activity patterns, presented as blood oxygen dependent level-signal (BOLD-signal), achieved from functional magnetic resonance imaging (fMRI) differs between healthy and injured individuals when performing certain tasks involving knee movement. As there is little consensus on how a proprioceptive test should be performed, a unique test were participants uses blindfold during a knee bending exercise was created at U Motion Lab, Umeå University. A Matlab based general user interface (GUI) was created for evaluation of the proprioceptive test. This GUI is communicating with the third party toolbox SPM12 and performs necessary preprocessing fMRI-image steps for statistical analysis and statistical parametric mapping of the BOLD-signal for both a healthy control- and ACL-injured group. The fMRIimages preprocessed by the GUI were generated by a 3 T GE scanner and the motion data was collected using an eight-camera 3D-motion analysis system. Time events for three different tasks was investigated. These were passive resting, memorizing and proprioceptive events. For both the control (5 participants)- and ACL (2 participants) group the main area of brain activation during the proprioceptive tests occurred in the frontal lobe. For the control group, brain activation was found in the cerebellum anterior lobe which is a possible origin for unconscious proprioception. For the ACL group activation was found in the inferior parietal lobule which involves visuomotor integration. Activation was also found in the inferior frontal gyrus which according to previous studies, may indicate risk-taking/”out of character” decisions. The results of this study indicates that the proprioceptive test seems to be a promising tool for evaluation of proprioceptive ability. However, more subjects need to be included to validate the result of this study.

INTER-SEGMENT COORDINATION VARIABILITY POST ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION SEPTEMBER 2015 DEVIN K. KELLY, B.S., UNIVERSITY OF MASSACHUSETTS AMHERST M.S., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Dr. Joseph Hamill There is an increased risk for ipsilateral graft rupture and contralateral ACL rupture following ACL reconstruction surgery (ACLR) despite return to sport clearance. The reason for this increased risk is not well understood. Previous literature has shown that decreased coordination variability is indicative of an injured system regardless of the absence of pain. PURPOSE: To quantify inter-segment coordination variability during three portions of the stance phase of gait in athletes at three progressive time points post-surgery compared to the contralateral limb (NI) and healthy controls. METHODS: Three-dimensional kinematic and kinetic data were collected for 10 ACLR and 10 healthy athletes matched for age, gender, and activity level. The ACLR group was measured at 4 weeks, 12 weeks, and when cleared to run post-surgery. Kinematic data were used in a modified vector coding technique to determine inter-segment coordination variability of lower extremity couples of interest. Statistical significance was determined using two factor multivariate ANOVAs (limb x visit) for early (1-33%), mid (34-66%), and late (67-100%) stance with alpha level set at .05. Tukey post-hoc tests were performed where appropriate. RESULTS: ACLR athletes have decreased inter-segment coordination variability of the involved lower extremity during the late stance phase of gait compared to both the contralateral limb and healthy controls at 4 weeks post-surgery. By 12 weeks post-surgery there were improvements in joint function as exemplified by inter-segment coordination variability of the ACLR involved limb becoming similar to the healthy control limb. CONCLUSION: Inter-segment coordination variability during late stance in the present study is not an indication for the increased risk for ipsilateral graft rupture and contralateral ACL rupture in ACLR athletes.

Bakgrund: Knäkontroll är ett svenskt skadeförebyggande träningsprogram som visat sig ha god effekt för prevention mot främre korsbandsskador vilket är en vanlig knäskada inom fotboll både på herr- och damsidan. Idag finns det studier som utforskat tränares syn och erfarenheter av Knäkontroll och generell skadeförebyggande träning, i nuläget finns det dock en kunskapslucka om vad fotbollsspelare själva har för upplevelser och erfarenheter av att genomföra träningsprogrammet Knäkontroll.  Syfte: Att undersöka fotbollsspelande unga vuxnas upplevelser och erfarenheter av att genomföra SISU:s skadeförebyggande träningsprogram Knäkontroll. Syftet var dessutom att få kännedom om hindrande och underlättande faktorer för genomförande av programmet för att möjliggöra utveckling. Metod: Kvalitativ design i form av en semistrukturerad intervjustudie med fem deltagare från ett bekvämlighetsurval. Databearbetningen genomfördes med kvalitativ innehållsanalys.   Resultat: Fem kategorier presenterades; Hur programmet används av lagen, Vikten av kunskap, Programmets positiva påverkan på kroppen, Spelarnas roll och ansvar och Klubbarnas möjligheter och ansvar. Varje kategori bestod av två till fem subkategorier där några av de mest prominenta var; Timing på när Knäkontroll utförs, Tidsaspekten och Utbildning är essentiellt.  Slutsats: Deltagarnas upplevelser av att utföra Knäkontroll var både positiva och negativa. Deltagarna beskrev även flertalet hindrande och underlättande faktorer för att programmet skulle utföras. I linje med tidigare forskning lyftes det upp att implementering av Knäkontroll i uppvärmningen, kunskap, utbildning och tydliga instruktioner sågs som de viktigaste faktorerna för att underlätta användning av programmet. / Background: Knee control is a Swedish injury prevention training program that has been shown to have good effects on preventing anterior cruciate ligament injuries which is a common Knee injury in both men's and women's football. Today there are studies which have explored football coaches´ views and experiences of Knee control, however there is a knowledge gap on views and experiences of the program from the football players themselves.   Objective: To explore football playing young adults' experiences of utilizing Knee control from SISU to get information about facilitating factors and barriers for implementation of the program for further development. Method: A qualitative method in the form of semi-structured interviews with five participants from a convenience sample. Data processing consisted of qualitative content analysis.  Results: Five categories were presented; How the programme is used by the teams, The importance of knowledge, The programme’s positive impact on the body, The role and responsibilities of the players and The club’s opportunities and responsibilities. Every category consisted of two to five subcategories where some of the most prominent were; Timing on when Knee Control is performed, The time aspect and Education is essential. Conclusion: The participants' experiences of performing Knee control was both positive and negative. The participants also highlighted the most hindering and facilitating factors for the program to be carried out. In line with previous research, it was highlighted that implementation of Knee control in the warm-up, knowledge, education and instructions was seen as the most important factors in facilitating use of the program.

Knee osteoarthritis affects approximately 25 million adults. In severe cases, total knee arthroplasty (TKA) is the most common solution. TKA is effective at addressing pain and reducing continued degeneration of articular cartilage. However, effective physical therapy (PT) following TKA is vital for a full functional recovery. Despite the importance of PT, half of patients never achieve a full functional recovery. Decreases in proprioceptive feedback, severe atrophy, and pain inhibition all likely contribute to the variability in effectiveness. Surface electromyography-based biofeedback (sEMGBF) may allow clinicians to address some of these barriers by supplementing proprioceptive feedback and targeting small muscle contractions before eventually increasing the contraction requirement. Using a between group design, we compare the effectiveness of sEMGBF (7) to neuromuscular stimulation (NMES) (6), and a control group (6) in recovery following TKA. Effectiveness was evaluated across 4 metrics (quadriceps strength, range of motion, functional improvement, and quality of life) in a pre-test/post-test fashion. At the statistical level this study suggest that sEMGBF leads to greater improvements in quadriceps strength relative to the NMES and control group. Additionally, visual analysis suggests that sEMGBF may also lead to greater improvements in range of motion, and functional improvement relative to the NMES and control group. The results for quality of life are mixed. Overall, the study provides initial clinical support for the utility of sEMGBF following TKA.

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Made available in DSpace on 2016-06-02T20:18:24Z (GMT). No. of bitstreams: 1 6564.pdf: 1314773 bytes, checksum: df3f916c4bcf4793146140f5b5882b3e (MD5) Previous issue date: 2015-02-24 / Financiadora de Estudos e Projetos / The incidence of anterior cruciate ligament (ACL) injury in female athletes is higher compared to men in the same sports activity. Subjects who have undergone ACL reconstruction show biomechanical changes that may predispose to a second injury. In addition, the muscular fatigue can increase the ACL injury risk. However, few studies have evaluated the effects of muscular fatigue in the kinematics and muscle activation in patients with ACL reconstruction, and no studies had compared the effects between men and women who undergoing reconstruction. Thus, the aim of this thesis was to evaluate the effects of muscular fatigue on the trunk, pelvis and lower limb kinematics, as well as the lower limb muscle activation during single-leg landing between two distinct groups of subjects, healthy recreational athletes and patients who have undergone ACL reconstruction. We also aim to compare the differences of the effects of fatigue between healthy men and women, and between men and women with ACL reconstruction. This thesis is divided into three studies, in which were performed kinematic analysis of the trunk, pelvis, hip and knee and electromyography of the gluteus maximus, gluteus medius, vastus lateralis and biceps femoris, during a singleleg landing, before and after a fatigue protocol. The first study compared healthy female and male recreational athletes; the second study compared recreational athletes with ACL reconstruction to a healthy control group, and the third study compared men and women with ACL reconstruction. The first study showed that fatigue caused changes in knee kinematics that could predispose healthy women to ACL injury. The second study found that fatigue can alter the kinematics and muscle activation, but these changes were not different between healthy subjects and patients who have undergoing ACL reconstruction. Finally, the third study showed that fatigue leads to kinematic changes that may predispose women who underwent ACL reconstruction to a second injury. / As mulheres atletas possuem maior propensão à lesão do ligamento cruzado anterior (LCA) quando comparadas os homens, praticando uma mesma atividade esportiva. Indivíduos submetidos à reconstrução do LCA possuem alterações biomecânicas que podem predispor à uma segunda lesão. Além disso, a fadiga muscular é um fator que pode aumentar as chances de lesão do LCA. Porém, poucos estudos avaliaram os efeitos da fadiga muscular na cinemática e na magnitude de ativação muscular de indivíduos submetidos à reconstrução do LCA, bem como não há estudos comparando os seus efeitos entre homens e mulheres submetidos à reconstrução. Dessa forma, o objetivo desta tese foi avaliar os efeitos da fadiga muscular na cinemática do tronco, pelve e membro inferior, assim como na magnitude de ativação de músculos do membro inferior durante a aterrissagem de um salto unipodal em dois grupos distintos de indivíduos, atletas recreacionais sadios e submetidos à reconstrução do LCA. Além disso, também foi objetivo comparar as diferenças dos efeitos da fadiga entre homens e mulheres sadios, bem como entre homens e mulheres submetidos à reconstrução do LCA. Esta tese está dividida em 3 estudos nos quais foram realizadas análise cinemática do tronco, pelve, quadril e joelho e análise eletromiográfica dos músculos glúteo máximo, glúteo médio, vasto lateral e bíceps femoral, durante a aterrissagem de um salto unipodal, antes e após a indução de fadiga muscular . O primeiro estudo comparou homens e mulheres atletas recreacionais sadios; o segundo estudo comparou atletas recreacionais com reconstrução do LCA com um grupo controle sadio, enquanto o terceiro estudo comparou homens e mulheres com reconstrução do LCA. O estudo 1 mostrou que a fadiga levou a alterações na cinemática do joelho que podem predispor as mulheres sadias à lesão do LCA. No estudo 2 foi encontrado que a fadiga alterou a cinemática e a magnitude de ativação muscular, mas que essas alterações não foram diferentes entre indivíduos sadios e indivíduos submetidos à reconstrução do LCA. Finalmente, o estudo 3 mostrou que a fadiga resultou em alterações cinemáticas que podem predispor as mulheres submetidas à reconstrução do LCA à segunda lesão.

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Physical activity is an essential component of a healthy life, e.g. to prevent obesity, cardiovascular disease and premature death, of which sports can be an important part. Unfortunately, sports activities increase the risk of both overuse and acute injuries. Severe acute injuries may also lead to a permanent medical impairment (PMI), which may influence the ability to be physically active throughout life. However, sports injuries may be prevented, but a profound understanding of the injuries and how to prevent them is needed. This doctoral thesis examine acute sports injuries reported by licensed athletes of all ages and level of sports nationwide in Sweden, by using national insurance data. Approximately 80% of all the Sports Federations (SF) had their mandatory accident insurance in the insurance company Folksam, and since there is no national sports injury surveillance system in Sweden, this is a unique database, able to be used in epidemiological studies on acute injuries occurring in organized sports in Sweden. The main aim of this thesis was to identify high-risk sports for acute injuries, the most common and the most severe injuries, especially in large sports with numerous licensed athletes, many injuries and injuries resulting in PMI. Based on the results, there will be recommendations regarding sports and body locations where injury prevention efforts should be focused to gain the greatest prevention effect at a national level in Sweden. Another aim was to evaluate the effectiveness of a neuromuscular knee control training program (KCP) that has been implemented nationwide to reduce knee and cruciate ligament injuries, among football players in Sweden. After evaluating the validity and reliability of the information within the database based on international guidelines, acute injury data were examined and the results presented in four papers. These results showed that there is a need of injury prevention especially in motorcycle sports, team ball sports, and ice hockey. Particularly, knee injuries need to be prevented since they were both the most common injuries and leading to PMI. The severe head- and upper limb injuries also need attention. Sixty-nine percent of the PMI injured athletes, were younger than 25 years. The injury prevention training program, KCP can be considered partially implemented nationwide, since 21 out of 24 district SFs provided KCP educations. The incidence of knee and cruciate ligament injuries has decreased among football players in Sweden. A concerning aspect is that there is no national official policy regarding sports injury and injury prevention in Sweden, nor an official authority that has the explicit responsibility for these issues.