El peroné: mal alumno, pero buen profesor. (¿Qué tiene prioridad biológica: la integridad, o la supervivencia?) / Fibula: a bad pupil but a good profesor. (What comes first, integrity or survival?)

La concepción original del mecanostato como un regulador de la rigidez estructural ósea orientado a mantener un determinado 'factor de seguridad' en todos los esqueletos parece no corresponder por igual a cualquier hueso y para cualquier tipo de estímulo. Hemos descubierto que la estructura cortical diafisaria del peroné humano manifiesta un comportamiento ambiguo del sistema, referido al uso del pie. La diáfisis peronea, además de ser insensible al desuso, se rigidiza, como sería de esperar, por entrenamientos en disciplinas deportivas que rotan o revierten el pie (hockey, fútbol, rugby); pero, llamativamente, se flexibiliza en su mitad proximal por entrenamiento en carrera larga, que optimiza el rendimiento del salto que acompaña a cada paso. La referida rigidización robustecería la región peronea de inserción de los músculos que rotan o revierten el pie, favoreciendo la locomoción sobre terrenos irregulares o 'gambeteando', propia de especies predadoras como los leopardos. La 'inesperada' flexibilización proximal, pese a reducir la resistencia a la fractura por flexión lateral (poco frecuente en el hombre), favorecería la absorción elástica de la energía contráctil de la musculatura inserta, optimizando el rendimiento del salto al correr, condición vital para especies presas como las gacelas. La falta de analogía de estas respuestas de la estructura peronea a distintos entrenamientos, incompatible con el mantenimiento de un factor de seguridad, sugiere su vinculación preferencial con la optimización de aptitudes esqueléticas con valor selectivo. Esto ampliaría el espectro regulatorio del mecanostato a propiedades esqueléticas 'vitales', más allá del control de la integridad ósea. Su manifestación en el hombre, ajena a connotaciones selectivas (quizá resultante del mantenimiento de genes ancestrales), permitiría proponer la indicación de ejercicios orientados en direcciones preferenciales a este respecto, especialmente cuando estas coincidieran con las de las fuerzas que podrían fracturar al hueso. (AU)

The original notion of the mechanostat as a regulator of bone structural rigidity oriented to maintain a certain 'safety factor' in all skeletons does not seem to correspond equally to every bone and for any type of stimulus. We have discovered that the diaphyseal cortical structure of the human fibula shows an ambiguous behavior of the system, with reference to the use of the foot. The peroneal shaft, in addition to being insensitive to disuse, becomes stiffened, as might be expected, by training in sport disciplines that involve rotating or reversing the foot (hockey, soccer, rugby); but, remarkably, it becomes more flexible in its proximal half by long-distance running training, which optimizes the performance of the jump that accompanies each step. The stiffening would strengthen the peroneal region of insertion of the muscles that rotate or reverse the foot, favoring locomotion on uneven terrain or 'dribbling', typical of predatory species such as leopards. The 'unexpected' proximal flexibilization, despite reducing the resistance to lateral flexion fracture (rare in human), would favor the elastic absorption of contractile energy from the inserted muscles, optimizing jumping performance when running, a vital condition for prey species such as gazelles. The lack of analogy of these responses of the peroneal structure to different training, incompatible with the maintenance of a safety factor, suggests its preferential link with the optimization of skeletal aptitudes with selective value. This would expand the regulatory spectrum of the mechanostat to 'vital' skeletal properties, beyond the control of bone integrity. Its manifestation in humans, oblivious to selective connotations (perhaps resulting from the maintenance of ancestral genes), would make it possible to propose the indication of exercises oriented in preferential directions, especially when they coincide with the direction of the forces that could fracture the bone. (AU)

Cardiac remodeling indicators in adolescent athletes / Indicadores de remodelagem cardíaca em atletas adolescentes

Summary Objective: The idea that different sports and physical training type results in different cardiac adaptations has been widely accepted. However, this remodelling process among different sport modalities is still not fully understood. Thus, the current study aims to investigate the heart morphology variation associated with a set of different modalities characterized by distinct models of preparation and different methods and demands of training and completion. Method: The sample comprises 42 basketball players, 73 roller hockey players, 28 judo athletes and 21 swimmers. Anthropometry was assessed by a single and experienced anthropometrist and the same technician performed the echocardiographic exams. Analysis of variance was used to study age, body size and echocardiograph parameters as well as different sport athlete's comparison. Results: Basketball players are taller (F=23.448; p<0.001; ES-r=0.553), heavier (F=6.702; p<0.001; ES-r=0.334) and have a greater body surface area (F=11.896; p<0.001; ES-r=0.427). Basketball and hockey players have larger left auricle diameters compared with judo athletes (F=3.865; p=0.011; ES-r=0.316). Interventricular end-diastolic septal thickness (F=7.287; p<0.001; ES-r=0.347) and left ventricular posterior wall thickness (F=8.038; p<0.001; ES-r=0.362) of the judokas are smaller compared to the mean values of other sports participants. In addition, relative left parietal ventricular wall thickness is lower among swimmers compared with judokas (F=4.127; p=0.008; ES-r=0.268). Conclusion: The major contributors to changes in heart morphology are for the most part associated with sport-specific training and competition and the specific dynamics and adaptive mechanisms imposed by each sport.

Resumo Objetivo: Os efeitos decorrentes da prática de diferentes modalidades desportivas resultam em padrões divergentes de adaptação cardíaca. A presente pesquisa procura estudar a variação da morfologia do coração associada a um conjunto de modalidades desportivas distintas quanto à natureza do esforço e aos modelos de preparação, incluindo metodologias de treino e sistemas de competição. Método: Foram estudados 42 basquetebolistas, 73 hoquistas, 28 judocas e 21 nadadores. A antropometria foi avaliada por um único e experiente antropometrista e os exames ecocardiográficos foram realizados pelo mesmo operador. Recorreu-se à análise da variância para estudar a variação associada a idade, medidas de tamanho corporal e parâmetros ecocardiográficos, bem como para a comparação entre os atletas de diferentes modalidades desportivas. Resultados: Os basquetebolistas são os atletas mais altos (F=23,448; p<0,001; ES-r=0,553), mais pesados (F=6,702; p<0,001; ES-r=0,334), com maior superfície corporal (F=11,896; p<0,001; ES-r=0,427) e, com os hoquistas, apresentam um diâmetro da aurícula esquerda superior ao dos judocas (F=3,865; p=0,011; ES-r=0,316). A espessura telediastólica do septo interventricular (F=7,287; p<0,001; ES-r=0,347) e da parede posterior do ventrículo esquerdo (F=8,038; p<0,001; ES-r=0,362) dos judocas é inferior à dos outros atletas, mesmo quando controlado para o tamanho corporal. Os nadadores apresentam uma espessura parietal relativa do ventrículo esquerdo superior à dos judocas (F=4,127; p=0,008; ES-r=0,268). Conclusão: As diferentes fontes de variação da morfologia cardíaca prendem-se com as dinâmicas do processo de treino, competição e correspondentemente com os mecanismos adaptativos, sobrepondo-se ao processo de formação desportiva a longo prazo.

Seasonal Incidence and Nature of Cricket Injuries among Elite South African Schoolboy Cricketers

Objective. To identify the incidence and nature of injuries sustained by elite South African schoolboy cricketers. Design. Data were collected retrospectively using a questionnaire. Cricketers recalled all injuries from June 2003 to May 2004. Setting. The population consisted of 196 cricketers representing all provincial teams in the 2004 under-19 Coca-Cola Khaya Majola cricket week. Results. Sixty-seven injuries were sustained by 196 cricketers; with an incidence of 34.2during the period under review. Injuries occurred during matches (71.6); throughout the season due to repetitive stresses sustained during matches and practices (14.9); during practice (11.9) and during other forms of training (1.5). Bowling accounted for 50.7of the injuries; fielding 32.8; batting 14.9and the remaining 1.5occurred while warming up or training. The primary mechanism of injury occurred during the delivery stride and follow through of the fast bowler (34.3). Eighty seven per cent of the injuries were first-time injuries while 13were recurrent. Most injuries (40.6) reported were severe and took the cricketers more than 21 days to recover. Cricketers were more prone to injury during December and January. Conclusion. The incidence and nature of injuries have been recorded and potential risk factors for injury have been identified. It is suggested that coaches and cricketers partake in continuous educational processes that focus on all the physical; mental and technical components necessary for success in cricket; with a national database

Bloqueio do plexo braquial, por via infraclavicular vertical, em paciente com doença pulmonar obstrutiva crônica: relato de caso / Infraclavicular vertical brachial plexus blockade in patients with chronic obstructive pulmonary disease: case report

JUSTIFICATIVA E OBJETIVOS: Os pacientes com doença pulmonar obstrutiva crônica (DPOC) têm risco aumentado de complicações pós-operatórias, sobretudo quando submetidos à anestesia geral. O bloqueio do plexo braquial representa uma alternativa para estes pacientes em intervenções cirúrgicas de membros superiores. O objetivo deste relato foi apresentar um caso de bloqueio do plexo braquial, por via infraclavicular vertical em paciente com DPOC com fratura de cotovelo. RELATO DO CASO: Paciente do sexo feminino, 67 anos, 52 kg, estado físico ASA III, com indicação de osteossíntese de cotovelo, portadora de bronquiectasias desde nove anos de idade após uma pneumonia. Apresentava tosse produtiva habitualmente, e fora submetida à avaliação de seu pneumologista que a liberou para o procedimento. Após instalação de monitorização com pressão arterial não-invasiva, ECG e oxímetro de pulso, foi realizado bloqueio do plexo braquial por via infraclavicular vertical com 30 mL de ropivacaína a 0,5 por cento. A intervenção cirúrgica foi realizada sem intercorrências. A paciente recebeu alta hospitalar no dia seguinte ao procedimento cirúrgico. CONCLUSÕES: O bloqueio do plexo braquial por via infraclavicular vertical é uma técnica alternativa para portadores de DPOC e fratura de cotovelo, por sua menor morbidade quando comparado com a anestesia geral e com a via supraclavicular.

BACKGROUND AND OBJECTIVES: Patients with Chronic Obstructive Pulmonary Disease (COPD) have a higher risk of postoperative complications, especially when undergoing general anesthesia. Brachial plexus blockade is an alternative for these patients when they undergo upper limb surgeries. The objective of this report is to present a case of infraclavicular brachial plexus blockade in patients with COPD and a fractured elbow. CASE REPORT: A female patient, 67 years old, 52 kg, physical status ASA III, with post-pneumonia bronchiectasis since nine years of age and an indication of osteosynthesis of the elbow. She presented productive cough regularly; after evaluation, her pneumologist cleared her for the surgery. The patient was monitored with non-invasive blood pressure. ECG, and pulse oximeter. Infraclavicular brachial plexus blockade with 0.5 percent ropivacaine 30 mL was performed, without intercurrences. The patient was discharged from the hospital the following day. CONCLUSIONS: Infraclavicular brachial plexus blockade is an alternative for patients with COPD and fracture of the elbow, due to its lower morbidity when compared to general anesthetic.

JUSTIFICATIVA Y OBJETIVOS: Los pacientes con enfermedad pulmonar obstructiva crónica (DPOC) presentan riesgo mayor de complicaciones postoperatorias especialmente cuando se les someten a la anestesia general. El bloqueo del plexo braquial representa una alternativa para esos pacientes en intervenciones quirúrgicas de miembros superiores. El objetivo de este relato fue el de presentar un caso de bloqueo del plexo braquial, por vía infraclavicular vertical en paciente con DPOC con fractura de codo. RELATO DEL CASO: Paciente del sexo femenino, 67 años, 52 kg, estado físico ASA III, con indicación de osteosíntesis de codo, portadora de bronquiectasias desde los nueve años de edad después de una pneumonía. Presentaba una tos productiva habitualmente, y fue sometida a la evaluación de su neumólogo que la liberó para el procedimiento. Después de la instalación de monitorización con presión arterial no invasiva, ECG y oxímetro de pulso, se realizó un bloqueo del plexo braquial por vía infraclavicular vertical con 30 mL de ropivacaína a 0,5 por ciento. La intervención quirúrgica fue realizada sin incidencias. La paciente recibió alta hospitalaria al día siguiente del procedimiento quirúrgico. CONCLUSIONES: El bloqueo del plexo braquial por vía infraclavicular vertical es una alternativa técnica para portadores de DPOC y fractura de codo, por su menor morbidez cuando se le compara a la anestesia general y a su vía supraclavicular.