Application of the "real options theory" method to the production systems used in dairy cattle farming / [Aplicação do método "Teoria das Opções Reais" nos sistemas de produção utilizados na bovinocultura leiteira]

The objective of this study was to analyze applications of real options theory for increasing the productivity of Mantiqueira ecotype dairy cows kept in guinea grass pastures with different sources of bulky supplementation (black oats, fodder cane, or sorghum silage), because the traditional methodologies do not consider the uncertainties related to this activity. Real options theory, an investment evaluation method, fills this gap as its most significant feature is its flexibility to act on uncertain events. Based on the results obtained for two economic indicators, the net present value and internal rate of return, and considering the production items identified in the sensitivity analysis, this study evaluated the expansion flexibility of each system using the real options theory methodology in discrete time as proposed by Copeland and Antikarov (2001). The analysis of the expansion options showed that the values of the production systems increased by 6.73%, 1.21%, and 19.49% for the systems supplemented with sorghum silage, black oats, and fodder cane, respectively. The expanded net present values were R$ 141,642.39, R$ 64,211.08, and R$ 58,013.07 for the systems that adopted bulky supplementation with black oats, fodder cane, and sorghum silage, respectively.(AU)

Objetivou-se analisar a aplicação da Teoria das Opções Reais para expansão da produtividade de vacas leiteiras do ecótipo Mantiqueira, mantidas em pastagem de capim-Mombaça com fornecimento de diferentes fontes de suplementação volumosa (aveia-preta, cana-forrageira ou silagem de sorgo), uma vez que as metodologias tradicionais não consideram as incertezas presentes na atividade. A Teoria de Opções Reais é um método de avaliação de investimento que possui como maior característica a valoração da flexibilidade de agir a eventos incertos, preenchendo, assim, a lacuna deixada pelo método tradicional. A partir dos resultados obtidos pelos indicadores econômicos valor presente líquido e taxa interna de retorno, em conjunto com os itens de produção identificados na análise de sensibilidade, foi possível avaliar o valor da flexibilidade de expansão que cada sistema apresentou. A flexibilidade de expansão foi avaliada utilizando-se a metodologia Teoria das Opções Reais, proposta por Copeland e Antikarov (2001), em tempo discreto. O resultado da análise da opção de expansão apresentou aumento nos valores dos sistemas de produção, na ordem de 6,73%, 1,21% e 19,49%, para os sistemas suplementados com silagem de sorgo, aveia-preta e cana-forrageira, respectivamente. Os resultados obtidos para os valores presentes líquidos expandidos foram de R$ 141.642,39, R$ 64.211,08 e R$ 58.013,07, para os sistemas que adotaram a suplementação volumosa com aveia-preta, cana-forrageira e silagem de sorgo, respectivamente.(AU)

Absolute basophil count is associated with time to recurrence in patients with high-grade T1 bladder cancer receiving bacillus Calmette-Guérin after transurethral resection of the bladder tumor.

BACKGROUND: Basophils, eosinophils and monocytes may be involved in BCG-induced immune responses and be associated with outcomes of bladder cancer patients receiving intravesical BCG. Our objective was to explore the association of baseline counts of basophils, eosinophils and monocytes with outcomes of patients with high-grade T1 bladder cancer receiving a standard course of intravesical BCG. METHODS: We retrospectively reviewed medical records of patients with primary T1 HG/G3 bladder cancer. After re-TURBT, patients were treated with a 6-week course of intravesical BCG induction followed by intravesical BCG every week for 3 weeks given at 3, 6, 12, 18, 24, 30 and 36 months from initiation of therapy The analysis of potential risk factors for recurrence, muscle invasion and cancer-specific and overall survival was performed using univariable Cox regression models. Those factors that presented, at univariate analysis, an association with the event at a liberal p < 0.1, have been selected for the development of a multivariable model. RESULTS: A total of 1045 patients with primary T1 HG/G3 were included. A total of 678 (64.9%) recurrences, 303 (29.0%) progressions and 150 (14.3%) deaths were observed during follow-up. Multivariate analysis showed that logarithmic transformation of basophils count was associated with a 30% increment in the hazard of recurrence per unit increase of logarithmic basophils count (HR 1.30; 95% confidence interval 1.09-1.54; p = 0.0026). Basophil count modeled by quartiles was also significantly associated with time to recurrence [second vs. lower quartile HR 1.42 (1.12-1.79); p = 0.003, third vs. lower quartile HR 1.26 (1.01-1.57); p = 0.041; upper vs. lower quartile HR 1.36 (1.1-1.68); p = 0.005]. The limitations of a retrospective study are applicable. CONCLUSION: Baseline basophil count may predict recurrence in BCG-treated HG/G3 T1 bladder cancer patients. External validation is warranted.

Impairment of toll-like receptors 2 and 4 leads to compensatory mechanisms after sciatic nerve axotomy.

BACKGROUND: Peripheral nerve injury results in retrograde cell body-related changes in the spinal motoneurons that will contribute to the regenerative response of their axons. Successful functional recovery also depends on molecular events mediated by innate immune response during Wallerian degeneration in the nerve microenvironment. A previous study in our lab demonstrated that TLR 2 and 4 develop opposite effects on synaptic stability in the spinal cord after peripheral nerve injury. Therefore, we suggested that the better preservation of spinal cord microenvironment would positively influence distal axonal regrowth. In this context, the present work aimed to investigate the influence of TLR2 and TLR4 on regeneration and functional recovery after peripheral nerve injury. METHODS: Eighty-eight mice were anesthetized and subjected to unilateral sciatic nerve crush (C3H/HeJ, n = 22, C3H/HePas, n = 22; C57Bl6/J, n = 22 and TLR2(-/-), n = 22). After the appropriate survival times (3, 7, 14 days, and 5 weeks), all mice were killed and the sciatic nerves and tibialis cranialis muscles were processed for immunohistochemistry and transmission electron microscopy (TEM). Gait analysis, after sciatic nerve crushing, was performed in another set of mice (minimum of n = 8 per group), by using the walking track test (CatWalk system). RESULTS: TLR4 mutant mice presented greater functional recovery as well as an enhanced p75(NTR) and neurofilament protein expression as compared to the wild-type strain. Moreover, the better functional recovery in mutant mice was correlated to a greater number of nerve terminal sprouts. Knockout mice for TLR2 exhibited 30 % greater number of degenerated axons in the distal stump of the sciatic nerve and a decreased p75(NTR) and neurofilament protein expression compared to the wild type. However, the absence of TLR2 receptor did not influence the overall functional recovery. End-point equivalent functional recovery in transgenic mice may be a result of enhanced axonal diameter found at 2 weeks after lesion. CONCLUSIONS: Altogether, the present results indicate that the lack of TLR2 or the absence of functional TLR4 does affect the nerve regeneration process; however, such changes are minimized through different compensatory mechanisms, resulting in similar motor function recovery, as compared to wild-type mice. These findings contribute to the concept that innate immune-related molecules influence peripheral nerve regeneration by concurrently participating in processes taking place both at the CNS and PNS.

Does PSA reduction after antibiotic therapy permits postpone prostate biopsy in asymptomatic men with PSA levels between 4 and 10 ng/mL?

PURPOSE: We investigated the effect of antibiotics on PSA in asymptomatic patients with mild PSA elevation. MATERIALS AND METHODS: We prospectively evaluated, in a non-randomized design, 106 asymptomatic patients with PSA of 4-10 ng/mL, with a negative digital rectal examination and with no urinary tract infection evidence for 2 years. Patients were divided into two groups: those treated with antibiotics for 3 weeks (G1) and those who were not treated (G2). PSA was taken six weeks after and prostate biopsy was performed in all patients. RESULTS: PCa was diagnosed in 25 of 106 patients (23.6%): 16 (25.0%) in G1 and 9 (21.4%) in G2 (p>0.05). PSA normalization was experienced in 24.5%. In G1, PSA returned to <4 ng/mL in 15 (23.4%) patients compared to 11 (26%) patients in G2. In the patients with a positive biopsy, no significant variation was noted in PSA, fPSA, %fPSA and DPSA after antibiotic treatment. A significantly lower cancer detection rate was noted with decreased PSA, fPSA, and DPSA after antibiotic use. A PSA reduction rate of ≥ 10% occurred in 58.5%, and this was similar in both G1 and G2 groups. The sensibility, specificity and accuracy of PSA reduction of ≥ 10% were 31%, 23% and 25%, respectively. CONCLUSION: Empirical antibiotic therapy in asymptomatic male patients is not related to PSA reduction. The greater than 10% PSA reduction after antibiotic in this population cannot postpone prostate biopsy.

Does PSA reduction after antibiotic therapy permits postpone prostate biopsy in asymptomatic men with PSA levels between 4 and 10ng/mL?

Purpose We investigated the effect of antibiotics on PSA in asymptomatic patients with mild PSA elevation. Materials and Methods We prospectively evaluated, in a non-randomized design, 106 asymptomatic patients with PSA of 4-10ng/mL, with a negative digital rectal examination and with no urinary tract infection evidence for 2 years. Patients were divided into two groups: those treated with antibiotics for 3 weeks (G1) and those who were not treated (G2). PSA was taken six weeks after and prostate biopsy was performed in all patients. Results PCa was diagnosed in 25 of 106 patients (23.6%): 16 (25.0%) in G1 and 9 (21.4%) in G2 (p>0.05). PSA normalization was experienced in 24.5%. In G1, PSA returned to <4ng/mL in 15 (23.4%) patients compared to 11 (26%) patients in G2. In the patients with a positive biopsy, no significant variation was noted in PSA, fPSA, %fPSA and DPSA after antibiotic treatment. A significantly lower cancer detection rate was noted with decreased PSA, fPSA, and DPSA after antibiotic use. A PSA reduction rate of ≥10% occurred in 58.5%, and this was similar in both G1 and G2 groups. The sensibility, specificity and accuracy of PSA reduction of ≥10% were 31%, 23% and 25%, respectively. Conclusion Empirical antibiotic therapy in asymptomatic male patients is not related to PSA reduction. The greater than 10% PSA reduction after antibiotic in this population cannot postpone prostate biopsy. .

Totally laparoscopic repair of primary obstructive megaureter with pyeloplasty, complete excisional tailoring and nonrefluxing ureteral reimplantation.

OBJECTIVE: To describe a new surgical technique of the first case of totally laparoscopic repair of primary obstructive congenital megaureter with pyeloplasty, intracorporeal excisional tailoring of the ureter and nonrefluxing ureteroneocystostomy. METHODS: A 15-year-old male presented with obstructive megaureter. The standard three-port transperitoneal pyeloplasty technique and an additional 5-mm port for dynamic traction were used. Pelvic and ureteral dissection, pyeloplasty, intracorporeal excisional ureteral tailoring and nonrefluxing ureteroneocystostomy were all completed laparoscopically. A double-J stent was used to calibrate the ureter. RESULTS: Operative time was 240 min. No intra and postoperative complications were observed, and there was discharge on postoperative day 2. The patient was pain-free and without urinary tract infection during the 4-month period after surgery. Follow up revealed complete resolution of the ureteral obstruction and adequate pelvic and ureteral caliber. CONCLUSION: Laparoscopic pyeloplasty, intracorporeal excisional tailoring, and non-refluxing reimplantation are safe and effective for the treatment of obstructive congenital megaureter. The totally laparoscopic approach is reproducible and provides low morbidity with inherent cosmetic advantages.

The effect of galvanic vestibular stimulation on postural response of Down syndrome individuals on the seesaw.

In order to better understand the role of the vestibular system in postural adjustments on unstable surfaces, we analyzed the effects of galvanic vestibular stimulation (GVS) on the pattern of muscle activity and joint displacements (ankle knee and hip) of eight intellectually normal participants (control group--CG) and eight control group individuals with Down syndrome (DS) while balancing on seesaws of different heights. The CG individuals adopted a pattern of muscle activation characterized by alternation between ankle agonist and antagonist muscles. The individuals with DS adopted a pattern of muscle co-contraction. The GVS affected neither the ability of CG individuals to maintain balance nor their pattern of muscle contraction. On the other hand, the individuals with DS showed greater sensitivity to GVS while balancing on a seesaw and were not able to select the appropriate motor strategy to efficiently balance and compensate the effects of GVS. These increased vestibular sensitivities observed in individuals with DS can reflect deficits in the proprioceptive system.

[Transumbilical single-incision laparoscopic ureterolithotomy]. / Ureterolitotomía laparoscópica con incisión única transumbilical.

INTRODUCTION: laparoendoscopic single-site surgery (LESS) using transumbilical access and conventional laparoscopic instruments is a very attractive alternative to perform ureterolithotomy for ureteral stone with failed endourological management. MATERIAL AND METHOD: a 29-year-old woman presented with chronic right lumbar pain and a 1.2 cm impacted calculus localized at transition of abdominal to pelvic ureter. Semi-rigid ureteroscopy had failed to fragment the stone and shockwave lithotripsy was not available. Double-J ureteral catheter had been inserted preoperatively. We performed a transumbilical single-incision laparoscopic ureterolithotomy. Three conventional trocars were inserted in a single semi-circular umbilical incision. Right colon was detached and the ureter was identified. Calculus was extracted and the ureteral incision was closed with intracorporal sutures. RESULTS: ureterolithotomy was successfully completed, with all the operative steps performed transumbically. Operative time was 180 minutes. No single-port device or articulating and bent instruments were utilized. Estimated blood loss was less than 50 mL. No intraoperative, access-related and postoperative complications took place. The duration of hospitalization was 24 hours and scarless appearance was observed on postoperative day 15. CONCLUSION: transumbilical single-incision laparoscopic ureterolithotomy is feasible and safe. This approach offers an inherent cosmetic advantage and few postoperative discomfort. Additional experience and continued investigation are warranted.

Assessment of postural adjustments in persons with intellectual disability during balance on the seesaw.

BACKGROUND: The purpose of this study was to investigate the kinematic and electromyography strategy used by individuals with intellectual disability to keep equilibrium during anterior-posterior balance on seesaws with different degrees of instability. METHOD: Six individuals with Down syndrome (DS) and six control group individuals (CG) balanced on three seesaws. The movement of the hip, knee and ankle joints and electromyography activities of selected leg and trunk muscles were recorded. RESULTS: Both groups maintained their balance mainly at the ankle joint. Contrary to the CG, the individuals with DS adopted a pattern of co-contraction and were not able to modulate the magnitude of postural response with the seesaw's degree of instability. CONCLUSIONS: These unusual strategies used by individuals with DS, such as their inability to discriminate different levels of mechanical demands in terms of the seesaw's instability, can reflect deficits in the proprioceptive system. The integration at cerebellum level could be a good candidate.

Principles for learning horizontal-planar arm movements with reversal.

PURPOSE: This study tested the hypothesis that muscle and interaction torques can be altered independently in order to improve in specific kinematics performance observed following practice. We also tested the hypothesis that a simple set of rules of EMG-control and kinetic-control models could explain the EMG and kinetic changes due to practice of movements with reversal. SCOPE: Kinematics of the upper arm with reversal, performed over three distances, was reconstructed using motion analysis. The muscle and interaction torques were calculated using inverse-dynamics. EMG activities of the major arm muscles were also recorded. The results demonstrate that improved performance is facilitated by an increase in muscle torque (and therefore acceleration) at the proximal joint (shoulder) and by an increase in the interaction torque at the distal joint (elbow). No changes were observed in the amount of muscle activity underlying these kinetic modifications, except for a decrease in the shoulder antagonist latency. CONCLUSION: The results confirm Bernstein's idea that the central nervous system takes advantage of the passive-interactive properties of the moving system. Also the modulation of the EMG patterns should be explained taking in account the reactive forces and the dual functions (maintenance of posture and generation of movement) of the muscles.

Controle de movimentos voluntários no membro superior não plégico de portadores de paralisia cerebral hemiplégica espástica / Control of voluntary movements in the non-affected upper limb of spastic hemiplegic cerebral palsy patients

OBJETIVO: Analisar os movimentos de flexão do ombro e do cotovelo do hemicorpo não plégico de portadores de paralisia cerebral (PC) hemiplégica espástica e do hemicorpo mais utilizado de indivíduos sem comprometimento motor e/ou neurológico (normais). MÉTODOS: Seis portadores de PC (18,2 ± 3,7 anos) e seis indivíduos normais (18,5 ± 3,3 anos) participaram deste estudo. Marcadores ativos foram afixados nos centros articulares do ombro, cotovelo e punho para aquisição de dados cinemáticos e eletrodos de superfície foram afixados nos ventres musculares do deltóide anterior, deltóide posterior, bíceps braquial e tríceps braquial para aquisição da atividade eletromiográfica (EMG) muscular. Os participantes tiveram que flexionar o ombro na tarefa de flexão do ombro e o cotovelo na tarefa de flexão do cotovelo o mais rápido possível em direção a um alvo que estava posicionado em três distâncias angulares diferentes (25º, 50º e 75º). RESULTADOS: Todos os participantes realizaram as duas tarefas motoras e os dois grupos movimentaram predominantemente o ombro para realizar a tarefa de flexão de ombro. Porém, para realizar a tarefa de flexão de cotovelo, os portadores de PC movimentaram o cotovelo e o ombro, enquanto que os indivíduos normais movimentaram predominantemente o cotovelo. CONCLUSÃO: Diferentemente dos indivíduos normais, os portadores de PC hemiplégica espástica não controlaram os movimentos mais distais da mesma forma que os movimentos proximais. Portanto, o hemicorpo não plégico não deve ser considerado normal e, mais importante, ao se propor um programa de intervenção para os portadores de PC, os dois hemicorpos devem ser considerados.

OBJECTIVE: To analyze shoulder and elbow flexion movements in the non-affected side of the body in spastic hemiplegic cerebral palsy (CP) patients and in the side of the body used more often in normal individuals (without motor and/or neurological impairment). METHOD: Six CP patients (18.2 ± 3.7 years old) and six normal individuals (18.5 ± 3.3 years old) participated in this study. Active markers were affixed to the shoulder, elbow and wrist joint centers in order to acquire kinematic data, and surface electrodes were affixed to the muscle belly of the anterior deltoid, posterior deltoid, biceps brachii, and triceps brachii in order to acquire muscle electromyographic data. All participants were asked to flex their shoulder joint in a shoulder flexion task and their elbow joint in an elbow flexion task, as fast as possible, towards a target that was positioned at three different angular distances (25º, 50º and 75º). RESULTS: All participants accomplished both motor tasks and both groups predominantly moved the shoulder to perform the shoulder flexion task. However, to perform the elbow flexion task, the CP patients moved their elbow and shoulder, while the normal individuals predominantly moved the elbow. CONCLUSION: Differing from normal individuals, spastic hemiplegic CP patients did not control distal movements in the same way as done for proximal movements. Therefore, the non-affected side of the body should not be considered normal and, most importantly, both the affected and non-affected sides of the body must be taken in account in any intervention program.

Estrategias eletromiograficas e cineticas para o controle motor dos movimentos / Electromyographic and kinetic strategies to control movements

O presente trabalho e uma revisao de literatura sobre as estrategias eletromiograficas e cineticas usadas pelo sistema nervoso central para controlar movimentos voluntarios. Essas estrategias foram identificadas durante a execucao dos movimentos simples e complexos, com e sem reversao em direcao. Objetivo: a proposta desse artigo e discutir o conjunto de regras usadas para modular os padroes de atividade muscular e a forca gerada nas articulacoes (torque muscular). Primeiramente abordamos as estrategias eletromiograficas usadas para controlar movimentos envolvendo uma ou duas articulacoes. Discutimos as estrategias cineticas, em termos de geracao e modulacao do torque muscular para realizar movimentos simples e complexos. A sinergia linear entre atividade muscular e torque muscular ea correlacao entre torque muscular gerado em articulacoes ligadas em cadeia tambem sera discutida. Alem disso, abordamos o papel das forcas de interacao para o controle dos movimentos. Conclusao: a pratica da fisioterapia requer um arcabouco teorico baseado no conhecimento tecnico-cientifico para guia-la. Nesse sentido, as teorias de controle motor sao ferramentas importantes. tais conhecimentos seriam utilizados para entender as adaptacoes e modificacoes que ocorrem nos mecanismos de controle motor devido a uma disfuncao ou doenca

Coupling between muscle activities and muscle torques during horizontal-planar arm movements with direction reversal.

In this study we investigated the hypothesis that the simple set of rules used to explain the modulation of muscle activities during single-joint movements could also be applied for reversal movements of the shoulder and elbow joints. The muscle torques of both joints were characterized by a triphasic impulse. The first impulse of each joint accelerated the limb to the target and was generated by an initial burst of the muscles activated first (primary mover). The second impulse decelerated the limb to the target, reversed movement direction and accelerated the limb back to the initial position, and was generated by an initial burst of the muscles activated second (secondary movers). A third impulse, in each joint, decelerated the limb to the initial position due to the generation of a second burst of the primary movers. The first burst of the primary mover decreased abruptly, and the latency between the activation of the primary and secondary movers varied in proportion with target distances for the elbow, but not for the shoulder muscles. All impulses and bursts increased with target distances and were well coupled. Therefore, as predicted, the bursts of muscle activities were modulated to generate the appropriate level of muscle torque.

Postural strategy to keep balance on the seesaw.

This work investigates the kinematic and electromyography (EMG) strategy used by the central nervous system (CNS) to keep equilibrium during anterior-posterior balance on seesaws with different degrees of instability. The movement of hip, knee, and ankle were reconstructed using a 3D motion-analysis system and the EMG activities of selected ankle, knee, and hip muscles were recorded. Balance was kept mainly at the ankle joint. The EMG patterns of the gastrocnemius and anterior tibialis alternated between agonist and antagonist bursts. The agonist burst started before the end of the lengthening phase and was prolonged until the end of the shortening phase. The EMG activities of the muscles crossing the knee and hip joints were characterized by a pattern of generalized co-activation. The movements at these two joints were very small, suggesting a neural or biomechanical constraint underlying the operations of the equilibrium control. Our results also indicate that the strategy to keep balance on the seesaw is qualitatively the same for the different levels of mechanical demands in terms of the seesaw's instability.

Lesão e reconstrução do LCA: uma revisão biomecânica e do controle motor / Lesion and reconstruction of ACL: biomechanical and motor control review

Neste artigo e apresntada uma revisao de literatura sobre as principais modificacoes e adaptacoes biomecanicas e dos mecanismos de controle motor decorrentes de lesao no ligamento cruzado anterior (LCA) e/ou de sua reconstrucao cirurgica. Inicialmente, sao descritas a funcao mecanica do LCA e sua anatomia. Em seguida, e disutido como essa funcionalidade e modificada do ponto de vista dos fatores neuromusculares na presenca de lesao e/ou reconstrucao do LCA. Sao enfatizadas as modificacoes proprioceptivas nas respostas reflexas e na ordem de recrutamento e a quantidade e o padrao de atividade da musculatura do membro inferior. Essas mudancas nos padroes eletromiograficos sao debatidas com base nas modificacoes biomecanicas causadas pela lesao do LCA. Em especial e mostrado como as mudancas nos padroes eletromiograficos podem explicar as alteracoes observadas nos movimentos rotacionais e translacionais do joelho nessa populacao. Finalmente, e discutido o efeito dessas mudancas na cinematica dos movimentos nos padroes dos torques musculares na articulacao do joelho

Instabilidade funcional do tornozelo: controle motor e aplicacao fisioterapeutica / Functional instability of the Ankle: motor control and physical therapy application

A instabilidade funcional do tornozelo e um problema cronico muito frequente, principalmente entre atletas. Esse problema e sempre abordado na pratica fisioterapeutica, porem pouco se sabe de concreto acerca de sua verdadeira etiologia. Por essa razao, os tratamentos fisioterapeuticos atualmente oferecidos sao pouco padronizados e pouco fundamentados cientificamente. Neste artigo e feita uma revisao da literatura sobre a instabilidade funcional do tornozelo, ressaltando os aspectos mais relevantes para atualizacao do fisioterapeuta que trata essa lesao. Juntamente com esta revisao foram mostrados alguns dados de um estudo de movimentos voluntarios realizados em laboratorio. Primeiro lugar, foi descrito um tornozelo normal em seus aspectos anatomicos e funcionais. Em seguida relatou-se a incidencia do entorse e sua relacao com a instabilidade funcional. Depois, discorreu-se sobre os mecanismos de lesao, assim como as modificacoes e adaptacoes das estruturas envolvidas no entorse. Na sequencia foram escritos os possiveis mecanismos defesa e protecao do organismo para evitar lesoes em inversao do tornozelo. Tambem discutimos como as mudancas nesses mecanismos podem predispor o individuo ao entorse, enfocando particularmente as respostas reflexas mono e polissinapticas (reacoes pre-programadas) na musculatura dessa articulacao. Alem das respostas reflexas, tambem foi abordado o papel do controle dos movimentos voluntarios do tornozelo na instabilidade funcional. Finalmente, elegeu-se um sistema de avaliacao fisioterapeutica e classificacao do entorse, tambem fazendo consideracoes em relacao as condutas adotadas para o tratmento da instabilidade funcional do tornozelo

Effect of age and gender in the control of elbow flexion movements.

In previous studies of rapid elbow movements in young healthy men, characteristic task-dependent changes in the patterns of muscle activation when movement speed or distance was varied have been reported. In the present study, the authors investigated whether age or gender is associated with changes in the patterns of muscle activity previously reported in young men. Arm movements of 10 healthy older and 10 healthy younger participants (5 men and 5 women in each group) were studied. Surface electromyograms (EMGs) from agonist (biceps) and antagonist (triceps) muscles, kinematic and kinetic parameters, as well as anthropometric and strength measures were recorded. All 4 groups of participants showed similar task- (distance or speed) dependent changes in biphasic EMG activity. Similar modulation of the initial rate of rise of the EMG, integrated agonist and antagonist EMG activity, as well as their relative timing were observed in all 4 groups. Those results suggest that older individuals of both genders retain the control strategies for elbow movements used by young individuals. Despite the qualitative similarities in the patterns of muscle activation, the men moved more quickly than the women, and younger participants moved more quickly than older participants. Those performance differences could not be explained in terms of differences in body size and strength alone.

Horizontal-plane arm movements with direction reversals performed by normal individuals and individuals with down syndrome.

We examined the systematic variation in shoulder and elbow torque, as well as movement kinematics, for horizontal-plane arm movements with direction reversals performed by normal individuals and individuals with Down syndrome. Eight neurologically normal individuals and eight individuals with Down syndrome performed horizontal, planar reversal movements to four different target locations. The four locations of the targets were chosen such that there is a systematic increase in elbow interaction torque for each of the four different target locations. This systematic increase in interaction torque has previously been shown to lead to progressively larger movement reversal errors, and trajectories that do not show a sharp reversal of direction, for movements to and from the target in patients who have proprioceptive abnormalities. We computed joint torques at the elbow and shoulder and found a high correlation between elbow and shoulder torque for the neurologically normal subjects. The ratio of joint torques varied systematically with target location. These findings extend previously reported findings of a linear synergy between shoulder and elbow joints for a variety of point-to-point movements. There was also a correlation between elbow and shoulder torque in individuals with Down syndrome, but the magnitude of the correlation was less. The ratio of joint torques changed systematically with target direction in individuals with Down syndrome but was slightly different from the ratio observed for neurologically normal individuals. The difference in the ratio was caused by the generation of proportionately more elbow torque than shoulder torque. The fingertip path of individuals with Down syndrome showed a sharp reversal in moving toward and then away from the target. In this respect, they were similar to neurologically normal individuals but dissimilar to individuals with proprioceptive deficits. Finally, we observed that individuals with Down syndrome spend proportionately more time in the vicinity of the target than normal individuals. Collectively these results show that there is a systematic relationship between joint torques at the elbow and shoulder. This relationship is present for reversal movements and is also present in individuals with Down syndrome.

Effects of direction and curvature on variable error pattern of reaching movements.

A number of studies have analyzed various indices of the final position variability in order to provide insight into different levels of neuromotor processing during reaching movements. Yet the possible effects of movement kinematics on variability have often been neglected. The present study was designed to test the effects of movement direction and curvature on the pattern of movement variable errors. Subjects performed series of reaching movements over the same distance and into the same target. However, due either to changes in starting position or to applied obstacles, the movements were performed in different directions or along the trajectories of different curvatures. The pattern of movement variable errors was assessed by means of the principal component analysis applied on the 2-D scatter of movement final positions. The orientation of these ellipses demonstrated changes associated with changes in both movement direction and curvature. However, neither movement direction nor movement curvature affected movement variable errors assessed by area of the ellipses. Therefore it was concluded that the end-point variability depends partly, but not exclusively, on movement kinematics.

Multidimensional assessment of motor function in a child with cerebral palsy following intrathecal administration of baclofen.

This case report describes an 11-year-old boy with spastic diplegia whose reflex status, range of motion (ROM), strength, and motor performance were measured before and after implantation of an indwelling system for delivery of intrathecally administered baclofen. Before baclofen use, the subject experienced clonus that interfered with walking, needed assistance with transfers, and was unable to independently put on underwear and socks. Measures of spasticity, kinematics and electromyographic activity during voluntary movements, ROM, Gross Motor Function Measure (GMFM) scores, and self-reports of change were obtained at baseline, before and after bolus baclofen injection, during a double-blind placebo-controlled clinical trial of baclofen administration via an indwelling pump, and after 1 and 2 years of baclofen therapy. Spasticity, Babinski reflexes, clonus, strength, and coactivation of antagonist muscles during voluntary movement were decreased shortly after baclofen administration began. Hip and ankle ROM increased, upper-extremity movement speed increased, independence in dressing and transfers improved, and orthoses were discarded. After 1 and 2 years, GMFM scores were 7.8% and 6.4% above baseline, respectively; the subject won a fitness award. After 2 years, ROM was worse than at baseline and concerns regarding hip subluxation arose. Single-joint movement control and independence improved and spasticity decreased during baclofen administration.