Delivery of neurotrophins to the injury site via cellular transplants or viral vectors administration has previously been shown to promote recovery of locomotor behavior in the absence of locomotor training in adult spinalized animals. Viral vectors still pose clinical concerns associated to recombinant genetics and the lack of understanding of how they react with the human immune system. Delivery via graft of autologous fibroblast engineered to produce brain derived neurotrophic factor (BDNF) and Neurotrophin-3 (NT-3) has been shown as a valuable method; however, the need for multiple invasive surgeries, along with the impossibility of delivering a controlled and constant dosage of protein are serious obstacles to obtaining approval by the FDA. The present study was aimed at evaluating the efficacy of BDNF delivered to the lumbar locomotor centers using a clinically translational delivery method at restoring stepping abilities in a large animal model of spinal cord injury. We wanted to evaluate if intrathecal delivery of BDNF to the lumbar spinal cord would promote a locomotor recovery as effective as delivery to the injury site, even at doses low enough not to trigger the side effects observed at high doses. A programmable and implantable mini-pump was used to intrathecally deliver a 50 ng/day dose of BDNF to the lumbar spinal cord for 35 days after spinal thoracic transection. Kinematic evaluation was conducted before, 3 and 5 weeks after injury/pump implant. Ground reaction forces (GRFs) analysis was performed 5 weeks after injury to evaluate the animals’ ability to weight support during locomotion and standing trials. Results showed that treated cats were capable of executing weight-bearing plantar stepping at all velocities tested (0.3-0.8 m/s). Control cats did not recover stepping ability, especially at higher velocities, and dragged their hind paws on the treadmill. We were also interested in measuring the extent of BDNF diffusion within the lumbar area of the spinal cord and the potential damage to the cord caused by catheter insertion. Immunohistological evaluation showed higher BDNF expression in the dorsal root ganglions, with BDNF Immuno-Histo Chemistry (IHC) extending from L3 to L7 in all treated cats. BDNF was also found within multiple cells of the grey matter, although the levels were not significantly higher than background density. Glial fibrillary acidic protein (GFAP) stain was used to measure the immunohistological reaction of the spinal cord to the implanted catheter, and to establish the safety of the delivery method. Gross examination of the spinal cord post-mortem revealed no damage to the cord or the roots with minimal encapsulation of the catheter/pump. Minimal tissue inflammation was revealed by the GFAP stain, underlying the safety of our method. We also wanted to investigate and characterize changes in the locomotor circuitry induced by BDNF delivery. Comparison of multiunit activity in the lumbar area between BDNF treated and non-treated cats allows a better understanding of the mechanism of action of BDNF on the spinal interneurons. This was accomplished by extracellularly recording lumbar interneuronal firing during air-stepping in a 5 weeks post-injury terminal experiment. The cord was exposed at the lumbar level between the L3 and L7 spinal segments. In-vivo recordings of spinal extracellular signals were conducted using two 64 channels microelectrode arrays inserted at the dorsal root entry zone to depths of ~3000µm and ~1500µm. The ability to record simultaneous activity of multiple single neurons made it possible to study the extent to which spiking activity in a given neuron is related to concurrent ensemble spiking activity. A point process generalized linear model (PP-GLM) approach was used to assess the strength of the connections between spike trains. Interneurons activity was assessed in terms of average firing rate, signal-to-noise ratio (SNR), and number of active units per trial. Although BDNF infusion in the lumbar segments did not show significant effect on strengthening synaptic connections, we did find greater multiunit activity in the treated animals, sign of a potential BDNF-induced increase in interneuronal activation, which could be likely involved in recovery of stepping ability after SCI. Together, findings from these aims demonstrated the therapeutic potential of intrathecal lumbar BDNF delivery in spinalized animals. Constant infusion of BDNF to the locomotor centers promotes locomotor recovery similar to training or delivery to the injury site via cellular transplants after complete SCI. Intrathecal delivery by an implantable/programmable pump is a safe and effective method for delivery of a controlled BDNF dosage; it poses minimal risks to the cord and is clinically usable. Lastly, this study confirmed the major involvement of BDNF in increasing the activity of the interneurons in the locomotor circuitry, opening the door to further investigating the mechanism through which neurotrophins induce recovery of locomotion. / Bioengineering

Everyday ecologically relevant tasks that affect organismal fitness, such as foraging, reproduction, predator avoidance, and escape responses, rely upon successful locomotion. The effectiveness of animal locomotion depends on many underlying factors, such as the morphology of the locomotor limbs, which evolved to fulfill specific locomotor tasks. Besides morphology, the material properties of the limbs also play a crucial role in locomotion. The skeletal structures of locomotor limbs must be able to withstand the repeated stresses that come with locomotion, either on land or underwater, as they use their limbs to generate propulsive forces. The natural environment animals move in is complex and dynamic, as various conditions crucial to locomotor performance can change unexpectedly. Perturbations to locomotor stability can take different forms, such as elevation changes, obstacles, substrate changes, and slipping. To maintain stable locomotor performance in these environments, animals rely on locomotor control mechanisms to counteract destabilizing effects of locomotor perturbations. In this Dissertation, I investigated the biomechanical control mechanisms and morphological adaptations during locomotion in challenging locomotor scenarios. Over the course of three chapters, the goals were to: 1) explore the effects of limb loss on a side-ways running sprint specialist, the Atlantic ghost crab, 2) determine the response and control mechanisms that allow ghost crabs overcome slip perturbations, and 3) to describe the pelvic morphology of bottom-walking Antarctic plunderfish and compare the pelvic morphologies among multiple species of nothenioids that do not bottom-walk. This study demonstrates the robustness of Atlantic ghost crabs to limb loss and slip perturbations. Paired limb removals resulted in a pattern of kinematic adjustments, which reduced locomotor performance by up to 25%, which was dependent on specific limbs being lost. I suggest that these limbs serve more important limb functions that can’t be replaced by the remaining limbs, however the loss of these particular limbs also results in re-patterning of limb relationships, which may reveal a neural component that may be the cause of decreased locomotor performance. Slip perturbations on the other hand were found to not have any significant effects on the locomotor performance of ghost crabs. Kinematics remained constant as ghost crabs traversed the slip surface, suggesting that ghost crabs may rely on feedforward control to overcome slip perturbations, however further studies measuring neural activity are required to confirm our finding. Most importantly though this chapter demonstrates and corroborates the role of momentum and how it allows animals to overcome perturbations. The last chapter investigated the pelvic morphology and material properties of fin rays in bottom walking fish. The Antarctic plunderfish was found to possess high flexural stiffness in its pelvic fin rays, which likely facilitate the bottom walking behavior in this species. Other, non-bottom walking notothenioids did not have fin rays of similar stiffness. Pelvic plate morphology was not different between species, however there were stark differences in mineralization. The bottom-walking fish had higher bone mineral density compared to the other species analyzed in this chapter. I also found mineralization patterns which seem to align with muscle fiber alignment of the major pelvic muscles, suggesting that these regionalized increases in stiffness provide stability while allowing for a lightweight pelvic plate. / Biology

The “risk allocation hypothesis” can predict how prey species will respond to predation risk, balancing vigilance with potentially risky behaviours. In order to maximize fitness, an optimal behavioural repertoire can evolve to respond to predation threat to allow for both survival and future fitness gains. High locomotor activity and time spent engaging in mating behaviours are expected to put Drosophila melanogaster at a greater risk to predation. With direct predator exposure, Drosophila are predicted to reduce activity and mating, which over years of exposure, will be reflected in evolved behavioural traits and evolved changes in the genome. Predation as a selective force shows alterations in flies genomes of experimentally evolved populations. Locomotor activity was found to be reduced in the presence of zebra jumping spiders (Salticus scenicus), presumably due to these spiders as visual hunters, using movement to detect prey. This behaviour is reflected in populations of Drosophila that have been constantly under selection by predators. Flies evolved with spider predators or mantid predators (Tenodera aridifolia sinensis) showed reduced locomotor activity when no predators are present. Interestingly, while alterations are seen for locomotory activity, the presumed risky behaviours of courtship and mating did not show an evolved response. Wild caught populations under threat from spiders, as well as the evolved populations when no predators were present showed no alterations in courtship or copulation behaviour. It appears that although there may be potential risks associated with mating behaviours, the benefits to future fitness when mating outweigh the potential costs from predation risks in Drosophila. / Thesis / Master of Science (MSc) / Predation is a profound selective force, with many anti-predator adaptations seen throughout the diversity of life. Antipredatory behavioural adaptations must balance immediate and future fitness effects, to maximize overall fitness. In Drosophila melanogaster, research into natural ecology and role of predation is generally lacking for behavioural & evolutionary studies. I will discuss research on the influence of predator exposure on Drosophila behaviours, as well as the evolution of Drosophila behaviours and genomes through experimentally evolved populations of Drosophila. While predation risk has resulted in changes in Drosophila locomotory activity, predation has not altered mating behaviours.

Made available in DSpace on 2014-12-17T15:16:04Z (GMT). No. of bitstreams: 1 AnaCLN.pdf: 1365991 bytes, checksum: a91aa932e949e0fb6e624f6ad5057083 (MD5) Previous issue date: 2009-07-02 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The locomotion is one of the most important capabilities developed by the animals, whose improvement is dependent on several neural centers, including the spinal cord. This activity promotes a lot of spinal modifications that enable it to adapt and improve their connections. This study aimed to observe the morphological changes occurring in the spinal cord after locomotor training in intact rats. For that we used male Wistar rats, which were submitted to locomotor training in wheel activity in protocols 1, 3 and 7 days (30min/day), and the results were compared to a control group not subjected to exercise. Coronal sections of 40 μm of the lumbosacral spinal cord were subjected to immunohistochemical techniques anti-Egr1, anti-NMDA and anti-SP, to characterize the spinal plasticity related to these substances. Egr1-immunoreactive cells were increased in all laminas, essentially in those more intensely activated by locomotion, laminas IV-X levels L4-S3. All observed sections expressed NMDA-immunoreactivity. Analysis of SP in the spinal dorsal horn resulted no significant variations of this neuropeptide related to locomotion. The results suggest that locomotor training provides synaptic plasticity similar to LTP in all laminas of the lumbosacral spinal cord, in different intensities. However, the SP appears do not participate of this process in the spinal dorsal horn. This work will contribute for consolidating and characterization of synaptic plasticity in the spinal cord / A locomo??o ? uma das mais importantes capacidades desenvolvidas pelos animais, cujo aperfei?oamento ? dependente de v?rios centros neurais, incluindo a medula espinal. Esta atividade promove v?rias modifica??es espinais que a possibilita se adaptar e aperfei?oar suas conex?es. Este trabalho teve por objetivo observar as altera??es morfol?gicas ocorridas na medula espinal ap?s o treinamento locomotor de ratos intactos. Para isso foram utilizados ratos Wistar machos, os quais foram submetidos ao treinamento locomotor na roda de atividade em protocolos de 1, 3 e 7 dias (30min/dia), e os resultados foram comparados aos de um grupo controle, n?o submetido ao exerc?cio. Cortes coronais de 40 μm da medula espinal lombossacral foram submetidos a t?cnicas imunohistoquimicas anti-Egr1, anti-NMDA e anti-SP, para caracterizarmos a plasticidade espinal quanto a essas subst?ncias. C?lulas imunorreativas a Egr1 estavam aumentadas em todas as l?minas, intensamente nas regi?es mais ativadas pela locomo??o, l?minas IV-X dos n?veis L4-S3. Todas as sec??es observadas expressaram imunorreatividade a NMDA. A an?lise da SP no corno dorsal espinal resultou em aus?ncia de varia??es significantes deste neuropept?deo relacionadas com a locomo??o. Diante dos resultados, sugerimos que o treinamento locomotor proporciona plasticidade sin?ptica semelhante a LTP em todas as l?minas da medula espinal, em intensidades diferenciadas. No entanto, esse processo parece n?o ter a participa??o da SP no corno dorsal espinal. Este trabalho vem contribuir para a consolida??o e caracteriza??o da plasticidade sin?ptica na medula espinal

No description available.

Master of Science / Department of Psychological Sciences / Mary Cain / Individuals suffering from depression primarily rely on pharmacological interventions to alleviate the incapacitating symptoms of the disorder. In addition to genetic differences underlying the etiology of depression, environmental factors play a key role as well. For example, environmental enrichment results in various neurotransmitter alterations, significantly affecting serotonin. To test the efficacy of novel antidepressant drugs in the preclinical laboratory setting, researchers commonly implement the forced swim test (FST) for rats or mice. However, the effect of environmental enrichment on the expression of depressive-like states in the FST is unclear, and it is unknown whether environmental enrichment or social isolation can alter the efficacy of the commonly prescribed antidepressant drug, fluoxetine. In the present study, locomotor activity and FST performance were measured after 30 days of rearing in enriched (EC), standard (SC), and isolated (IC) conditions. Results showed that regardless of the significant effect of fluoxetine on locomotor activity in EC, SC, and IC rats, fluoxetine failed to increase swimming and decrease immobility in all three environmental conditions, with enriched-fluoxetine rats displaying significantly less swimming behavior in the FST than enriched rats receiving vehicle control injections. These results suggest that differential rearing, specifically environmental enrichment, can alter the efficacy of antidepressants and may suggest that enrichment reverses the effects of fluoxetine.

Introducción: Las caídas en la población mayor son un problema con graves consecuencias personales y elevados costes sociosanitarios. Las alteraciones del equilibrio se consideran riesgo de caídas en esta población. Objetivos: Determinar las pruebas de equilibrio más precisas para predecir el riesgo de sufrir caídas, cuantificar las caídas producidas durante doce meses de seguimiento y describir la incidencia y los factores de riesgo de caídas en personas que viven en residencias de mayores. Metodología: 262 sujetos (edad de 65 a 101, con media de 83,14 años, y 63,75% mujeres), que viven residencias de mayores de Cuenca, participaron en el estudio. Se administraron las pruebas: Escala de Equilibrio de Berg, levantarse y sentarse cinco veces, tiempo de apoyo unipodal, alcance funcional, levantarse y andar cronometrado, POMA de Tinetti, Romberg, y prueba levantarse y andar; y se realizó un seguimiento de las caídas acaecidas durante el siguiente año. Resultados: Las pruebas de Apoyo Unipodal, Levantarse y Andar Cronometrado, Escala de Equilibrio de Berg, Levantarse y Sentarse Cinco Veces y Prueba de Alcance Funcional presentan mayor sensibilidad (0,98, 0,89, 0,86, 0,85 y 0,82 respectivamente) y la escala POMA de Tinetti presenta la mayor especificidad (0,75). 82 personas sufrieron una o más caídas durante el año de seguimiento. Conclusiones: Se recomienda a prueba de Apoyo Unipodal para descartar a las personas sin riesgo de caerse y la escala POMA de Tinetti para detectar a las personas con riesgo de caerse. La probabilidad de caerse es mayor a medida que trascurre el tiempo. Se caen más las mujeres, las personas que tienen estudios primarios o sin estudios, las que precisan ayudas para caminar y las que presentan antecedentes de caídas. / Introduction: Falls in elderly persons are a problem with serious personal consequences and high health care costs. The balance disorder is considered a risk of fall in this population. Objectives: To determine the most accurate balance tests to predict the risk of falls. Monitoring the number of falls in a twelve months period. To evaluate the incidence and other risks of falls for people who live in nursing homes. Methodology: 262 adults (age 65 to 101, with an average of 83.14 years old, and 63.75% females) living in nursing homes in Cuenca, participated in the study. The tests were administered: Berg Balance Scale, Sit to stand Five Times, One-leg Stance Test, Functional Reach Test, Timed up and go, POMA Tinetti, Romberg, and Get Up and Go; and monitoring of falls the following year was made. Results: One-leg Stance Test, Timed Up and Go, Berg Balance Scale, Sit to Stand Five Times and Functional Reach Test have higher sensitivity (0.98, 0.89, 0.86, 0.85 and 0 82 respectively) and Tinetti Scale POMA has the highest specificity (0.75). 82 people suffered one or more falls for the monitoring year. Conclusions: It is recommended to One-leg Stance Test to exclude people without risk of falling and the POMA Scale Tinetti to detect people at risk of falling. The probability of falling is higher as time goes on. The one who fall more are: women, people with primary or non education studies, requiring walking aids and those with a history of falling.

Objetivos. Se valoró la disposición sagital de la columna vertebral en gimnastas especialistas en la modalidad de trampolín. Material y métodos. Se realizó un estudio transversal, en el que participaron 91 gimnastas de trampolín (47 mujeres y 44 varones) con una edad media de 15,57+4,69 años, y de 7+4,14 años de entrenamiento. La valoración se realizó en tres posiciones: bipedestación relajada, sedentación relajada y flexión máxima del tronco. En todas las posiciones se diferenció la curva dorsal y la lumbar. Para la cuantificación de los grados se utilizó un inclinómetro ISOMED Unilevel-95. Resultados. En bipedestación la cifosis dorsal media fue 44,25°+7,99°, la lordosis lumbar fue de 35,19°+10,11°. En máxima flexión del tronco desde la sedentación test dedos planta los grados de la curvatura dorsal y lumbar fueron de 58,02°+15,18° y 27,56°+8,16°. En sedentación relajada los grados de la curvatura dorsal y lumbar fueron de 50,16°+10,17° y 17,75°+9,74° respectivamente. Conclusiones. Los valores medios del plano sagital de los gimnastas especialistas en trampolín muestran en bipedestación valores de hipercifosis para la curva dorsal, con una lordosis lumbar normal. En la flexión máxima del tronco se observan valores normales para la cifosis dorsal y valores hipercifóticos para la curva lumbar. En sedentación se observan valores hipercifóticos tanto en la curva dorsal como en la lumbar. Los gimnastas presentan tendencia a una mayor cifosis dorsal en bipedestación y en flexión de tronco. Las gimnastas presentan tendencia a una mayor lordosis en bipedestación y menor cifosis lumbar en flexión y sedentación. / The sagittal plane of the spine was measured in trampoline gymnasts. Material and methods. In this cross-sectional study, 91 club-level trampoline gymnasts (47 females and 44 males) participated. They had a mean age of 15,57+4,69 years and had participated in this sport for 7+4,14 years. The sagittal plane was measured in three positions: standing, seated, and maximal trunk flexion. In all positions the thoracic and lumbar curvature angular values were measured using an ISOMED Unilevel-95 inclinometer. Results. Average standing thoracic kyphosis was 44,25°+7,99°, and average standing lumbar lordosis was 35,19°+10,11°. In seated forward flexion, the measurements for the thoracic and lumbar spines were 57.94º+15º and 27.72º+7.51º. In slumped sitting, the measurements for the thoracic and lumbar spines were 50,16°+10,17° y 17,75°+9,74°, respectively. Conclusions. The average values of the sagittal plane in these trampoline gymnasts demonstrate hyperkyphosis for the thoracic curvature and normal lordosis for the lumbar curvature when standing. For maximal trunk flexion normal values were found in the thoracic curvature and hyperkyphotic values were found in the lumbar curvature. For seated positions hyperkyphotic values were found in the thoracic and lumbar curvatures. Male gymnasts tend to have more dorsal kyphosis in standing and maximal trunk flexion. The female gymnasts tend to have greater lordosis in standing and lesser lumbar kyphosis in trunk flexion and in seated position.

INTRODUCCIÓN. Un alto volumen de entrenamiento, en posiciones concretas y específicas al deporte, con acciones articulares repetitivas, podría generar adaptaciones en el sistema músculo-esquelético. En este sentido, varios estudios han valorado el morfotipo raquídeo en deportistas de diferentes disciplinas deportivas, encontrando adaptaciones específicas del morfotipo raquídeo al deporte practicado. No obstante, la influencia de la práctica del tenis no ha sido suficientemente analizada. Además, solo algún estudio ha analizado qué influencia tienen los entrenamientos realizados o la competición. OBJETIVO. Determinar la disposición sagital del raquis torácico, lumbar e inclinación pélvica de tenistas adolescentes en posiciones habituales (bipedestación y sedentación) y en posturas de máxima flexión y extensión del tronco, así como su extensibilidad isquiosural, antes y después de un entrenamiento. MUESTRA. Participaron en el estudio 40 tenistas varones entre 14 y 18 años (media de edad: 16,35 ± 1,82). Los criterios de inclusión de los tenistas fueron: seguir un entrenamiento sistematizado, al menos, durante cuatro años, no haber sido operado de la columna vertebral o de la musculatura isquiosural, ni tener algún tipo de lesión o alteración raquídea estructurada diagnosticada en el momento de la valoración que impidiera la realización de las mediciones. PROCEDIMIENTOS. Se valoró la disposición sagital del raquis y pelvis en las posiciones de bipedestación, bipedestación en autocorrección, máxima extensión en bipedestación, sedentación relajada, máxima flexión de tronco en sedentación, decúbito prono, así como la extensibilidad isquiosural mediante los test de distancia dedos-suelo, test de distancia dedos-planta y test de elevación de pierna recta activo y pasivo. Se realizó una primera medición antes de un entrenamiento estándar, y justo al finalizar el mismo. Para determinar la disposición angular del raquis y el ángulo de inclinación de la pelvis se utilizó un Spinal Mouse®. Para obtener dichos valores, una vez que el deportista adoptaba la posición a medir, se desplazaba el Spinal Mouse® por las apófisis espinosas desde T1 hasta S1. El entrenamiento específico de tenis que se realizó tuvo una duración total de 2 horas, con la siguiente estructura: 1) Calentamiento general, con una duración total de 10 minutos. 2) Calentamiento específico, con una duración de 10 minutos. 3) Trabajo específico de técnica en el que se realizaban correcciones de todos los gestos técnicos (30 minutos). 4) Trabajo de táctica: situaciones de juego reales controladas (30 minutos). 5) Situaciones reales de juego: se realizaron partidos y minicompeticiones entre los jugadores (40 minutos). CONCLUSIONES. 1) En la bipedestación, la gran mayoría de los tenistas presentan valores angulares normales tanto en la curva torácica como en la curva lumbar. En la sedentación relajada, casi la mitad de los tenistas presentan valores de normalidad tanto en la curva torácica como en la lumbar, siendo más frecuentes valores de hipercifosis torácica leve e inversiones moderadas en la zona lumbar. En la flexión máxima del tronco, los tenistas evidencian una gran movilidad de la zona lumbar en el plano sagital, mostrando una cifosis funcional tanto en la zona torácica como en la lumbar, ya que en bipedestación la mayoría de los tenistas presentan curvas normales. 2) Un entrenamiento tipo de tenis genera ligeros cambios en la disposición sagital del raquis y en la extensibilidad isquiosural. La fatiga podría ser la causa de la disminución de los casos de normalidad y el aumento de las hipercifosis en el raquis torácico y un aumento de casos de rectificación lumbar. Estos cambios no están asociados a cambios significativos en la inclinación pélvica. Las modificaciones en los valores angulares después del entrenamiento en la postura de autocorrección evidencian un menor control postural, el cual reduce la capacidad del tenista de modular su disposición sagital del raquis, probablemente debido a la fatiga muscular. El entrenamiento no parece tener una influencia significativa en la sedentación. Aunque, el entrenamiento provoca una limitación en la flexión pélvica asociada a un aumento de la cifosis torácica. En cuanto al efecto del entrenamiento en la extensibilidad de la musculatura isquiosural, se produce una mejora de la misma en todos los test utilizados para su valoración. 3) Dos tercios de los tenistas presentan valores considerados normales en la extensibilidad isquiosural. Al valorar la extensibilidad con test lineales, se observa un aumento de casos de cortedad isquiosural que evidencia una alteración del ritmo lumbo-pélvico. Por este motivo, test lineales no son adecuados para valorar la extensibilidad isquiosural en tenistas adolescentes. / INTRODUCTION A high volume of training in specific postures and repetitive movements could generate specific adaptations. For this reason, several studies have assessed the spinal curvatures in different sport disciplines, finding specific morphological spine adaptations depending on the sport practiced. However, the influence of tennis practice has not been sufficiently analyzed. Furthermore, few studies have examined the acute influence of training or competition. OBJECTIVE To determine the sagittal thoracic and lumbar curvatures as well as pelvic tilt of tennis players in several positions (standing, sitting and during trunk flexion and extension). Furthermore, the hamstring extensibility was evaluated with angular and linear tests. All measures were taken before and after a tennis training session. METHODS Forty adolescent tennis players from 14 to 18 years old (mean age: 16.35 ± 1.82 years) participated in this study. The inclusion criteria were: having played tennis for at least four years. The exclusion criteria were: a history of spinal and hamstring surgery, a medically diagnosed spinal disorder or having hamstring or spinal pain at the moment of the assessment. PROCEDURES Sagittal spinal curvatures and pelvic tilt were assessed in standing position, standing in self-correction, maximum trunk extension in standing, slumped sitting, maximum trunk flexion in seated position and prone lying. Hamstring extensibility was measured by the sit-and-reach test, toe-touch test and straight leg raise test (passive and active). The measurement was performed before (pre-test) and after a training session (post-test). Spinal Mouse® was used to determine the angular values of the spinal curvatures and pelvic inclination. The specific tennis session lasted for two hours and had the following structure: 1) General warm up, with a total duration of 10 minutes. 2) Specific warm up, lasting for 10 minutes. 3) Specific technical training in which technical corrections to all technical skills were made (30 minutes). 4) Tactical training in controlled real game situations (30 minutes). 5) Real game situations: matches and modified competitions (40 minutes). CONCLUSION 1) In standing position, most of the players have normal angular values in the thoracic and lumbar curvatures. In relaxed sitting, almost half of the tennis players have normal values in the thoracic and lumbar curves, being more frequent values of mild thoracic kyphosis and moderate lumbar kyphosis. In the position of maximum trunk flexion, the players show a great mobility of the lumbar spine in the sagittal plane, showing a functional kyphosis in both thoracic and lumbar spinal curvatures, as in standing position most of the tennis players presented normal curves. 2) Standard tennis training generates slight changes in the sagittal plane of the spine and hamstring extensibility. Fatigue could be the cause of the decline in cases of normal values and increased hyperkyphotic positions in the thoracic spine and more cases of lumbar hypolordosis. These changes are not associated with significant changes in the pelvic tilt. The changes in the angular values after training in self-corrected posture show less postural control, which reduces the ability of the tennis player to modulate their sagittal spinal curvatures, probably due to muscle fatigue. Training does not seem to have a significant influence the seated positions. However, training causes a limitation of the pelvic bending movement associated with increased thoracic kyphosis. As for the effect of training on the extensibility of the hamstring muscles, a improvement of it occurs in all tests used for its assessment. 3) Two thirds of the players have normal values on the hamstring muscle extensibility. In assessing the hamstring extensibility with lineal test, an increase in cases of hamstring shortness is observed,which shows an alteration in lumbopelvic rhythm. For this reason, lineal tests are not suitable to assess hamstring extensibility in adolescent tennis players.

Algunos estudios biomecánicos han sugerido la implicación de los cambios artrósicos de la columna como factor de riesgo local de la fractura vertebral (FV). Se realizaron dos estudios de casos-controles (varones [N=507] y mujeres [N=441, apareadas 1:2 según la edad]). La espondiloartrosis y la FV fueron evaluadas sobre imágenes radiológicas, y se analizaron asimismo variables antropométricas, clínicas y densitométricas. Se obtuvieron modelos validados de regresión múltiple. La osteofitosis, la disminución del espacio intervertebral (DEI) y la FV mostraron una distribución bifásica, con picos de frecuencia coincidentes en la zona torácica media. La osteofitosis (odds ratio[OR]=1,84, IC95% 1,05-3,17, en los varones, y OR=2,21, IC95% 1,25-3,93 en las mujeres) y la DEI torácicas (OR=2,52, IC95% 1,43-4,46 en los varones, y OR=1,80, IC95% 1,03-3,16 en las mujeres) se asociaron de forma independiente a un mayor riesgo de FV, tras ajustar por la edad, la densidad mineral ósea y el resto de variables analizadas. / Several biomechanical studies have pointed out the implication of the osteoarthritic changes of the spine as a local risk factor of vertebral fracture (VF). Two studies of cases-controls were conducted (males [N=507] and women [N=441, paired 1:2 according to age]). Osteoarthritis and VF were evaluated on radiological images. Other anthropometric, clinical and densitometric variables were analyzed. We obtained two validated models of multiple regression. The osteophytosis, the disc space narrowing (DSN) and the VF showed a biphasic distribution, with coincident peaks of frequency in the middle-thoracic zone. In the thoracic spine, both osteophytosis (odds ratio [OR] =1,84, CI 95% 1,05-3,17 in men and OR=2,21, CI 95% 1,25-3,93 in women) and DSN (OR=2,52, CI 95% 1,43-4,46 in men and OR=1,80, CI 95% 1,03-3,16 in women) showed an independent relationship to the risk of VF, after adjusting by age, bone mineral density and the other variables.