Patellar tendinopathy (PT) is a knee injury resulting in pain localized to the patellar tendon. One main factor that causes PT is repetitive overloading of the tendon. Because of this mechanism, PT is commonly seen in "jumping sports" like basketball. This injury can severely impact a player's performance, and in order for a timely return to preinjury activity levels early diagnosis and treatment is important. The standard for the diagnosis of PT is a clinical examination, including a patient history and a physical assessment. Because PT has similar symptoms to injuries of other knee structures like the bursae, fat pad, and patellofemoral joint, imaging is regularly performed to aid in determining the correct diagnosis. One common imaging modality for the patellar tendon is gray-scale ultrasonography (GS-US). However, the accurate detection of PT in GS-US images is grader dependent and requires a high level of expertise. Machine learning (ML) models, which can accurately and objectively perform image classification tasks, could be used as a reliable automated tool to aid clinicians in assessing PT in GS-US images. ML models, like support vector machines (SVMs) and convolutional neural networks (CNNs), use features learned from labelled images, to predict the class of an unlabelled image. SVMs work by creating an optimal hyperplane between classes of labelled data points, and then classifies an unlabelled datapoint depending on which side of the hyperplane it falls. CNNs work by learning the set of features and recognizing what pattern of features describes each class. The objective of this study was to develop a SVM model and a CNN model to classify GS-US images of the patellar tendon as either normal or diseased (PT present), with an accuracy around 83%, the accuracy that experienced clinicians achieved when diagnosing PT in GS-US images that were already clinically diagnosed as either diseased or normal. We will also compare different test designs for each model to determine which achieved the highest accuracy. GS-US images of the patellar tendon were obtained from male and female Virginia Tech collegiate basketball athletes. Each image was labelled by an experienced clinician as either diseased or normal. These images were split into training and testing sets. The SVM and the CNN models were created using Python. For the SVM model, features were extracted from the training set using speeded up robust features (SURF). These features were then used to train the SVM model by calculating the optimal weights for the hyperplane. For the CNN model, the features were learned by layers within the CNN as were the optimal weights for classification. Both of these models were then used to predict the class of the images within the testing set, and the accuracy, sensitivity and precision of the models were calculated. For each model we looked at different test designs. The balanced designs had the same amount of diseased and normal images. The designs with Long images had only images taken in the longitudinal orientation, unlike Long+Trans, which had both longitudinal and transverse images. The designs with Full images contained the patellar tendon and surrounding tissue, whereas the ROI images removed the surrounding tissue. The best designs for the SVM model were the Unbalanced Long designs for both the Full and ROI images. Both designs had an accuracy of 77.5%. The best design for the CNN model was the Balanced Long+Trans Full design, with an accuracy of 80.3%. Both of the models had more difficulty classifying normal images than diseased images. This may be because the diseased images had a well defined feature pattern, while the normal images did not. Overall, the CNN features and classifier achieved a higher accuracy than the SURF features and SVM classifier. The CNN model is only slightly below 83%, the accuracy of an experienced clinician. These are promising results, and as the data set size increases and the models are fine tuned, the accuracy of the model will only continue to increase. / Master of Science / Patellar tendinopathy (PT) is a common knee injury. This injury is frequently seen in sports like basketball, where athletes are regularly jumping and landing, and ultimately applying a lot of force onto the patellar tendon. This injury can severely impact a player's performance, and in order for a timely return to preinjury activity levels early diagnosis and treatment is important. Currently, diagnosis of PT involves a patient history and a physical assessment, and is commonly supplemented by ultrasound imaging. However, clinicians need to have a high level of expertise in order to accurately assess these images for PT. In order to aid in this assessment, a tool like Machine learning (ML) models could be used. ML is becoming more and more prevalent in our every day lives. These models are everywhere, from the facial recognition tool on your phone to the list of recommended items on your Amazon account. ML models can use features learned from labelled images, to predict the class of an unlabeled image. The objective of this study was to develop ML models to classify ultrasound images of the patellar tendon as either normal or diseased (PT present).

Bakgrund: Excentrisk träning (ECC) har varit det dominerande träningssättet vid patellar tendinopati (PT) under de senaste 15 åren. Det skulle vara av värde för kliniker att veta vilken effekt ECC har på kort sikt efter en träningsperiod. Syfte: Systematiskt granska enskilda artiklar och bedöma tillförlitligheten i det sammanvägda resultatet gällande effekten på funktion och smärta samt förmåga att delta i sport eller fysiska aktiviteter som excentrisk träning har efter en träningsperiod på 12 veckor hos idrottande personer med PT. Design: Systematisk granskning av randomiserade kontrollerade studier. Metod: Sökningar utfördes i PubMed, CINAHL, PEDro och Cochrane library. Sju studier inkluderades och granskades med PEDro Scale. GRADEstud användes för att bedöma tillförlitligheten i resultatet. Resultat: Inkluderade studiers kvalitet varierade mellan acceptabel och hög kvalitet, enligt PEDro Scale. Det var inga skillnader mellan ECC och kontrollbehandlingar. Vid sammanvägningen av studiernas respektive resultat ansågs tillförlitligheten enligt GRADEstud vara måttligt hög (+++) p.g.a. hög samstämmighet, men bristande precision. Slutsats: ECC är inte mer effektivt än andra undersökta kontrollbehandlingar, därav kan denna studie inte säkerställa att förbättringar som sker efter 12 veckor beror på ECC. / Background: Eccentric exercise (ECC) has been the dominant treatment option for patellar tendinopathy (PT) in the last 15 years. It would be of value to clinicians to know about the short-term effect ECC has after a training period. Objective: Systematically review individual articles and assess the certainty in the weighted result regarding the effect on function, pain, and the ability to participate in sport and physical activities that eccentric training has after a 12week period of training on athletes with PT. Design: Systematic review of randomized controlled trials.                                           Method: Searches were conducted in PubMed, CINAHL, PEDro and Cochrane Library. Seven studies were included and reviewed with the PEDro Scale. GRADE-stud was used to assess the certainty in the result.  Results: Included studies quality varied between acceptable and high quality, according to the PEDro Scale. There were no differences between ECC and control treatments. When weighing the respective results of the studies, the certainty was considered moderately high (+++) according to GRADEstud, due to high coherence in all included studies, but a lack of precision. Conclusion: ECC is not more effective than other control therapies studied. Therefore, this study cannot ensure that improvements that occur after 12 weeks are due to ECC.

The principal aim of the present thesis was to prospectively follow (clinical status and ultrasound + Doppler findings) the patellar tendons in the young elite volleyball players at the Swedish National Centre for high school volleyball in Falköping. In an Olympic weightlifter with chronic painful jumper´s knee, the effects of treatment with sclerosing injections followed by early instituted very heavy weightlifting training, was also evaluated. First, in a prevalence study, we demonstrated that the clinical diagnosis patellar tendinopathy-jumper’s knee, together with structural tendon changes and vascularisation in the painful area of the tendon, was demonstrated in 12/114 tendons in Swedish junior elite volleyball players, but not in any tendons of individually matched (age, height and weight) not regularly sports active controls. Structural tendon changes alone was demonstrated among the volleyball players but also among the controls. In a 7 months prospective study of a total of 120 tendons, we demonstrated that the clinical diagnosis patellar tendinopathy-jumper’s knee was associated with neovessels/vascularity in the area with structural tendon changes in 17/19 tendons. Seventy tendons that at start were clinically normal, and had normal ultrasound + Doppler findings, remained clinically normal after 7 months with intensive training and playing volleyball. In a 3-year prospective study it was demonstrated that normal clinical tests and normal ultrasound + Doppler findings at school start, indicated a low risk (8%) for these players to sustain patellar tendinopathy-jumper’s knee during the 3 school years with intensive training and playing. In a case study, involving an Olympic elite weightlifter with chronic painful patellar tendinopathy-jumper’s knee, successful treatment with ultrasound and Doppler-guided injection of the sclerosing agent polidocanol, allowed for pain-free very heavy weight training two weeks after treatment. Further heavy weightlifting training on a daily basis, preparing for European Championships, was done without causing tendon rupture and/or pain. Key words: Jumper’s knee, Patellar tendinopathy, Chronic pain, Ultrasonography, Doppler, Neovascularisation, Volleyball, Weightlifting

Sammanfattning Syfte och frågeställningar: Syftet med studien var att utvärdera förändringar över tid vid excentrisk träning av quadriceps i en ny dosering i kombination med träning av höft- och bålmuskulatur under 12 veckor vid patellar tendinopti med avseende på a) smärta, b) skattning av symtom, funktion och förmåga att delta i idrott, c) funktionellt hopptest samt c) vävnadsförändringar i patellarsenan. Metod: Studien var en pilotstudie utan kontrollgrupp. Tolv personer som kliniskt diagnostiserats med patellar tendinopati samt hade ultraljudsverifierad tendinos i patellarsenan deltog frivilligt i studien (2 kvinnor och 10 män; medelålder 29,2 år, besvärsduration > tre månader). För att utvärdera träningsinterventionen användes visuell analog skala (VAS) för smärta i vila och under aktivitet, frågeformuläret Victorian Institute of Sport Assessment score (VISA-P) för skattning av symtom, funktion och förmåga att delta i idrott, funktionellt hopptest, one-leg hop for distance (OLH). Undersökning av patellarsenan gjordes med ultraljud och färgdoppler. Utvärdering genomfördes före och efter tolv veckors träningsintervention. Träningsprogrammet innehöll excentrisk träning av quadriceps (bromsande knäböjning på ett ben) stående på en kil inklusive stretch av quadriceps i kombination med träning av höft- och bålmuskulaturen som utfördes tre gånger i veckan under 12 veckor. Signifikansnivå p < 0.05 användes i studien och en tendens inkluderades mellan 0.05 < p < 0.1 Resultat: Efter träningsperioden sågs en signifikant minskning av smärta i vila (VAS från 64 till 11,5) och under aktivitet (från 80 till 21 på VAS skalan) samt en ökad funktion och förmåga att delta i idrott sågs på VISA-P (från 44 till 71,5). En signifikant förbättrings sågs också på funktionellt hopptest på ett ben med en ökad hopplängd (från 103 till 132 cm) efter träningsinterventionen. Ingen signifikant skillnad kunde ses gällande vävnadsförändringar i patellarsenan. Det fanns däremot en tendens (p=.083) till förbättring av senstrukturen i patellarsenan efter träningsinterventionen. Slutsats: Efter tolv veckors intervention sågs en signifikant förbättring med avseende på smärta och funktion vid patellar tendinopati. Dessa resultat bör följas upp för att utvärdera långsiktiga förändringar av träningsinterventionen. Resultaten från denna pilotstudie kan ligga till grund för en kommande randomiserad kontrollerad interventionsstudie. / Abstract Aim: The aim of this study was to evaluate changes over time during eccentric quadriceps training with a previously unstudied exercise dosage in combination with hip and core exercises for a period of 12 weeks in patients with patellar tendinopathy. The outcome measures were: pain, self-evaluated symptoms, functions and ability to participate in sport, functional jumptest and patellar tendon tissue changes. Method: This was an uncontrolled pilot study. Twelve patients diagnosed with patellar tendinopathy using clinical testing and ultrasound imaging participated in the study voluntarily (2 female and 10 men, mean age 29.2 years, duration of symptoms > 3 months). To evaluate the intervention a visual analogue scale (VAS) was used to measure pain at rest and during activity. The Victorian Institute of Sport Assessment score (VISA-P) was used to evaluate self-assessed symptoms, function and ability to participate in sport. One-leg hop test for distance (OLH) was used as a functional test. Changes in the patellar tendon were examined using ultrasound imaging and colour doppler. Measurements took place at baseline and at 12 weeks. The exercise program contained eccentric quadriceps training (drop-squat on one leg) standing on a decline board, quadriceps stretching in combination with hip and core exercises performed 3 times per week for twelve weeks. P-value was set at < 0.05 and a tendency was included between 0.05 < p < 0.1 Results: At 12 weeks a significant reduction of pain was observed at rest (from 64 to 11.5) and during activity (from 80 to 21) as well as improved VISA-P scores (from 44 to 71.5). A significant improvement was observed on the functional hop test (from 103 to 132 cm). No significant changes in the patellar tendon were observed with ultrasound imaging. Although there was a tendency towards structural improvement of the patellar tendon (p=.083) after 12 weeks of intervention. Conclusion: After twelve weeks of intervention a significant improvement was observed with respect to pain and function. It would be of interest to examine long-term changes of this combined training program. These results may be used as a foundation for a future randomised controlled intervention study.

Bakgrund: Patellar tendinopati (PT) är framförallt en vanlig diagnos bland aktiva inom idrotter där hopprörelser ofta förekommer. Diagnosen innebär ofta överbelastning av knäskålsenan, vilket leder till smärta och nedsatt funktionsförmåga. Fysioterapeutisk behandling syftar till att minska smärtan och återställa funktionsförmågan. Infrapatellara remmar (IPR) har använts sedan många år för symptomlindring vid idrottsaktiviteter men det saknas forskning som har sammanställt effekter av användning, vilket föranleder behovet av en systematisk litteraturöversikt. Syftet var att genom en systematisk litteraturstudie beskriva hur IPR används och utvärderas i studier vid PT, rapporterade effekter samt studiekvalitet och preliminär evidensstyrka. Metod: Artikelsökning genomfördes i databaserna PubMed och PEDro. Fem studier analyserades utifrån litteraturstudiens syfte och frågeställningar samt kvalitetsgranskades enligt SBU:s granskningsmallar. Resultat: Av studierna undersökte tre IPR:s effekt på smärtintensitet, två proprioception och två indirekt uppmätt senbelastning. Endast kortsiktiga utfall mättes och när dessa var statistiskt signifikanta var kliniska relevansen ofta oklar. Sammantagen preliminär evidensstyrka bedömdes som måttligt stark. Slutsatser: Studierna visade på varierande effekt av att använda IPR avseende förbättring av proprioception, smärtintensitet och indirekt uppmätt senbelastning. Fler högkvalitativa randomiserade studier behövs och framtida forskning bör undersöka långsiktiga effekter vid användning av IPR. / Background: Patellar tendinopathy (PT) is common in jumping athletes. It’s mostly related to excessive loading of the patellar tendon, which leads to pain and decreased functional capacity. Physiotherapy treatment aims to reduce pain and restore functional capacity. Infrapatellar straps (IPS) have been utilized for many years to alleviate symptoms during sports activities but there is a lack of research that has compiled reports on effects of usage, which leads to the need of a systematic review. Objective: To describe use and evaluation of IPS in studies on patients with PT and describe reported effects, study quality and preliminary strength of evidence. Method: The PubMed and PEDro databases were searched for articles. Five studies were analyzed considering the review’s objective. Study quality was assessed according to SBU’s checklists. Results: Among the studies three investigated the effect of IPS on pain intensity, two on proprioception and two on indirectly measured tendon load. Short-term outcomes were investigated and the clinical relevance was often unclear when outcomes were statistically significant. Total preliminary strength of evidence was assessed as moderate. Conclusion: Variable effects are shown from IPS usage regarding pain intensity, proprioception and indirectly measured tendon load. More high-quality randomized trials and investigations of long-term effects are needed.

BakgrundPatellatendinopati (PT) är förekommande hos personer som tränar rekreativt och bland elitidrottare men förekomsten bland inaktiva är okänd. Forskningen på PT har huvudsakligen varit fokuserad på de fysiska begränsningarna av tillståndet med viss framgång på utfall som smärta och funktion genom olika träningsprotokoll. Men PT tenderar att bli långvarigt och långt ifrån alla blir bra. Internationellt vetenskapligt konsensus inom tendinopati menar att det saknas kunskap om tillstånden ur ett bredare biopsykosocialt hänseende. Hittills har såvitt studieförfattarna vet, inga studier utforskat vilka erfarenheter personer med PT har av att leva med och rehabilitera besväret.SyfteAtt utforska erfarenheterna av att leva med och rehabilitera PT hos personer som rekreativt tränar/idrottar.MetodDetta är en deskriptiv intervjustudie med semi-strukturerade intervjuer där en kvalitativ induktiv ansats användes. En tematisk analys utfördes med en semantisk och induktiv inriktning. Totalt rekryterades tio deltagare.ResultatFem huvudteman identifierades ur datan: (1) Hot mot identiteten, (2) Att inte kunna leva sitt liv fullt ut, (3) En ogynnsam relation till smärta, (4) Att känna makt över sin situation återgav kontroll (5) Avgörande för rehab var att se helheten och inte bara ett knä.SlutsatsPT visar sig kunna vara ett tillstånd som innehåller ett större lidande utöver de uppenbara fysiska begränsningarna. Bland personerna som deltog framkom flertalet negativa kognitiva och emotionella erfarenheter och maladaptiva beteenden i relation till smärtan. Resultaten kan argumenteras ha en viktig klinisk innebörd. Omhändertagandet av PT bör ske personcentrerat med ett förhållningssätt förankrat i att smärta har en biopsykosocial inverkan. Av metodologiska skäl ska överförbarheten till en bredare population dock tolkas med viss försiktighet. / BackgroundPatellar tendinopathy (PT) is common within an active population, especially elite athletes, but less is known about the presence among sedentary people. Previous research has focused on the physical impairments with modest effect on outcomes like pain and function through different training protocols. Nonetheless, PT tends to be persistent and many fail to recover. Current international consensus highlights the lack of knowledge of tendinopathy through a biopsychosocial perspective. No studies have explored people with PT and their experiences with living and rehabilitating the condition.PurposeTo explore the experiences of living with and rehabilitating PT among people who exercise or do sports recreationally.MethodA descriptive interview study with semi-structured online interviews was performed. A total of 10 participants participated. A thematic analysis was performed with a semantic and inductive procedure.ResultsFive main-themes were identified from the data: (1) Threatened identity, (2) Not being able to live your life to the fullest, (3) A adverse relationship with pain, (4) To feel in charge over ones situation brought back control (5) To be seen as a whole and not just a knee was crucial to rehab.ConclusionPT has a larger impact beyond the physical impairments. Negative cognitions and emotions coupled with maladaptive behaviours in relation to the pain emerged to a considerable degree. These results could have an important clinical message, that the management of PT would benefit from being person-centred where the biopsychosocial impact of pain is acknowledged. Caution should be taken in regards to this study's transferability to a wider population due to methodological aspects.