COMPARISON OF VISCOELASTIC STRESS RELAXATION RESPONSE BETWEEN FLEXIBLE AND INFLEXIBLE INDIVIDUALS

The aim of this study was to compare the relaxation reaction after viscoelastic stress induced by passive static stretching during 30s between subjects with different flexibility performance. Eighteen male physical education students were randomly assigned to two groups according to flexibility level of knee extension. During the test the individuals should achieve 90% of maximal ROM and maintain the position for 30s while the stress relaxation was measured as relative decrease of torque. The results of this study show significant differences of range of motion (ROM) between the two groups, but no significant difference in stress relaxation. It can be concluded that viscoelastic stress relaxation is similar between subjects with significantly different flexibility performance after 30s passive static stretching

Questão agrária e políticas públicas em Minas Gerais : conflitos sociais e alternativas populares

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The EXECP Project: a neuromechanical examination of hyper-resistance within an exercise intervention for children and young adults with cerebral palsy

CP-oireyhtymä johtuu sikiöaikana tai pian syntymän jälkeen syntyneestä aivojen vauriosta. Spastiselle CP-oireyhtymälle on ominaista liiallinen lihasjäykkyys, rajoitettu nivelten liikelaajuus, lihasheikkous, ongelmat motorisessa koordinaatiossa ja mm. eriytyneiden liikkeiden suorittamisessa. Kaikki nämä oireet haittaavat motorisia toimintoja, mikä osaltaan johtaa fyysisen aktiivisuuden vähenemiseen, täten lisäten monia kardiometabolisia riskitekijöitä. Tämän väitöskirjan tarkoituksena oli kehittää yhdistetty voima-, liikkuvuus- ja kävelyharjoittelua sisältävä interventio (EXECP-interventio), jolla puututaan edellä mainittuihin liikuntakykyä heikentäviin oireisiin. Väitöskirjassa käytettiin monipuolisia neurofysiologisia ja biomekaanisia tutkimusmenetelmiä. Vallalla olevaan venytysrefleksivasteiden arviointimenetelmään, jota kutsutaan venytysrefleksi-kynnykseksi (SRT, stretch reflex threshold), ehdotettiin muutosta. Ehdotetulla muutoksella oli merkittävä vaikutus SRT:n mielekkääseen tulkintaan, ja uutta lähestymistapaa suositellaan tuleviin tutkimuksiin. Tutkittaessa liiallisen lihasjäykkyyden mahdollisia taustatekijöitä, CP-ryhmän ja kontrollihenkilöiden välinen vertailu osoitti merkittäviä eroja lihasjäykkyydessä, nivelmekaniikassa, venytysrefleksivasteissa ja muissa selkäydintason hermostollisissa prosesseissa. Tutkitut muuttujat eivät korreloineet yliherkistyneen venytysrefleksin kanssa. Molempien lihasten venytysrefleksikynnyksellä oli positiivinen korrelaatio mitatun liiallisen lihasjäykkyyden kanssa suurilla venytysnopeuksilla. Tärkeimpänä löydöksenä EXECP-interventio onnistui parantamaan liikuntakykyä (kuuden minuutin kävelytestin tulosta) ja karkeamotorista toimintakykyä. Lisäksi alaraajojen lihasvoima ja nivelten liikelaajuus paranivat EXECP-intervention ansiosta lukuun ottamatta nilkan ojentaja- ja koukistajalihaksia. Kaiken kaikkiaan tulokset osoittivat, että EXECP-interventio oli turvallinen ja tehokas parantamaan liikuntakykyä ilman haittavaikutuksia. Huomattavaa oli, että kolme kuukautta sen jälkeen, kun EXECP-interventio oli päättynyt, suurin osa intervention aiheuttamista parannuksista palautui takaisin interventiota edeltävälle tasolle. Intervention jälkeinen palautuminen viittaa siihen, että harjoittelun tulisi olla elinikäinen valinta henkilöillä, joilla on CP-vamma.Spastic cerebral palsy (CP) is characterized by muscle weakness, limited joint flexibility, motor incoordination and hyper-resistance (i.e., increased resistance to passive muscle stretch). All these symptoms hinder motor function, resulting in reduced physical activity levels, which increases many cardiometabolic risk factors. The purpose of this thesis was to develop a combined strength, flexibility and gait training intervention (EXECP intervention) to address the debilitating symptoms above-mentioned. The EXECP intervention was successful in increasing motor function measured by a gait performance test (six minutes walking test) and the gross motor function measure. Furthermore, muscle strength and joint flexibility improved with the EXECP intervention for most muscles, except the ankle plantarflexors and dorsiflexors. Overall, the results showed that the EXECP intervention was safe and efficient in improving motor function, without any adverse effects. Importantly, three months after the EXECP intervention ceased and the CP participants were re-evaluated, most of the improvements induced by the intervention regressed back to pre-intervention levels. The deadaptation after the intervention suggests that training should be a life-long choice for people with CP. The present study also proposed a correction to a hyperreflexia (i.e., exacerbated stretch reflex responses) assessment method called the stretch reflex threshold (SRT). The proposed correction had a significant effect on the evaluation of the SRT and the new approach is recommended for future studies. Furthermore, this study performed a thorough comparison between individuals with CP and typically developed (TD) controls regarding hyper-resistance, hyperreflexia and joint neuromechanical variables. The comparison between groups showed several significant differences in most studied variables. Ankle joint neuromechanical variables and neurophysiological variables of hyperreflexia were not useful in explaining the neuromechanical variables of hyperreflexia or peak torque during stretch. The SRT of both muscles had a good positive correlation with peak torque at high stretch velocities and was significantly different between CP and TD groups, suggesting it is a useful diagnostic variable

Grau de subestimação histopatológica por core biopsy de lesões não palpáveis da mama Underestimation of malignancy of core needle biopsy for nonpalpable breast lesions

OBJETIVO: Determinar o grau de subestimação de core biopsy, guiada por imagem, de lesões impalpáveis da mama subsequentemente submetidas à exérese cirúrgica. MÉTODOS: Foram revisados retrospectivamente 352 casos com biópsias de fragmento que foram submetidos à cirurgia entre fevereiro de 2000 e dezembro de 2005, cujo laudo histopatológico estava registrado no sistema interno de informação. Os resultados foram comparados com os da cirurgia e a taxa de subestimação foi calculada dividindo-se o número de carcinoma in situ e/ou invasivo à cirurgia pelo número de lesões de alto risco ou carcinoma in situ que foram submetidas à cirurgia. O grau de concordância entre os resultados foi obtido pelo percentual de concordância e pelo coeficiente kappa de Cohen. A associação das variáveis estudadas com a subestimação do diagnóstico foi verificada pelos testes do c2 exato de Fisher, ANOVA e Mann-Whitney U. O risco de subestimação foi medido por meio do risco relativo acompanhado dos respectivos intervalos com 95% de confiança (IC95%). RESULTADOS: Core biopsy foi inconclusiva em 15,6%. O laudo histopatológico foi benigno em 26,4%, sugestivo de lesão de alto risco em 12,8% e maligno em 45,2%. A concordância entre a core biopsy e a cirurgia foi de 82,1% (kappa=0,75). A taxa de falso negativo foi de 5,4% e a lesão foi completamente removida em 3,4%. A taxa de subestimação foi de 9,1% e esteve associada com BI-RADS® categoria 5 (p=0,01), microcalcificações (p < 0,001) e estereotaxia (p= 0,002). Todos os casos subestimados apresentavam diâmetro menor que 20 mm e em todos foram retirados pelo menos cinco fragmentos. A taxa de subestimação para lesões de alto risco foi de 31,1%, 41,2%, para hiperplasia ductal atípica, 31,2% para lesões papilíferas, 16,7% para tumor filóides e 41,9% para carcinoma ductal in situ. CONCLUSÕES: Core biopsy guiada por imagem é um procedimento confiável, contudo permanece a recomendação de ressecção cirúrgica de lesões de alto risco detectadas à biópsia de fragmento já que não foi possível estabelecer características clínicas, imaginológicas, do procedimento e patológicas que pudessem predizer subestimação e evitar a cirurgia. Amostras representativas da lesão são mais importantes que o número de fragmentos.<br>PURPOSE: To determine the rate of underestimation of an image-guided core biopsy of nonpalpable breast lesions, with validation by histologic examination after surgical excision. METHODS: We retrospectively reviewed 352 biopsies from patients who were submitted to surgery from February 2000 to December 2005, and whose histopathologic findings were recorded in the database system. Results were compared to surgical findings and underestimation rate was determined by dividing the number of lesions that proved to be carcinomas at surgical excision by the total number of lesions evaluated with excisional biopsy. Clinical, imaging, core biopsy and pathologic features were analyzed to identify factors that affect the rate of underestimation. The degree of agreement between the results was obtained by the percentage of agreement and Cohen's kappa coefficient. The association of variables with the underestimation of the diagnosis was determined by the chi-square, Fisher exact, ANOVA and Mann-Whitney U tests. The risk of underestimation was measured by the relative risk (RR) together with the respective 95% confidence intervals (95%CI). RESULTS: Inconclusive core biopsy findings occurred in 15.6% of cases. The histopathological result was benign in 26.4%, a high-risk lesion in 12.8% and malignant in 45.2%. There was agreement between core biopsy and surgery in 82.1% of cases (kappa=0.75). The false-negative rate was 5.4% and the lesion was completely removed in 3.4% of cases. The underestimation rate was 9.1% and was associated with BI-RADS® category 5 (p=0,01), microcalcifications (p CONCLUSIONS: The core breast biopsy under image guidance is a reliable procedure but the recommendation of surgical excision of high-risk lesions detected in the core biopsy remains since it was not possible to assess clinical, imaging, core biopsy and pathologic features that could predict underestimation and avoid excision. Representative samples are much more important than number of fragments

The road to 21 seconds : a case report of a 2016 Olympic swimming sprinter

This study aimed to describe training characteristics as well as physical, technical and morphological changes of an elite Olympic swimming sprinter throughout his road to 21 s in the 50 m freestyle. Over a ∼2.5-year period, the following assessments were obtained: external training load, competitive performance, instantaneous swimming speed, tethered force, dry-land maximal dynamic strength in bench press, pull-up and back squat and body composition. From 2014 to 2016, the athlete dropped 3.3% of his initial best time by reducing total swimming time (i.e. the total time minus 15-m start time – from 17.07 s to 16.21 s) and improving the stroke length (from 1.83 m to 2.00 m). Dry-land strength (bench press: 27.3%, pull-up: 9.1% and back squat: 37.5%) and tethered force (impulse: 30.5%) increased. Competitive performance was associated to average (r = −0.82, p = 0.001) and peak speeds (r = −0.71; p = 0.009) and to lean body mass (r = −0.55; p = 0.03), which increased in the first year and remained stable thereafter. External training load presented a polarized pattern in all training seasons. This swimmer reached the sub-22 s mark by reducing total swimming time, which was effected by a longer stroke length. He also considerably improved his dry-land strength and tethered force levels likely due to a combination of neural and morphological adaptations14339340