Upper limb joint coordination preserves hand kinematics after a traumatic brachial plexus injury.

Background: Traumatic brachial plexus injury (TBPI) causes a sensorimotor deficit in upper limb (UL) movements. Objective: Our aim was to investigate the arm-forearm coordination of both the injured and uninjured UL of TBPI subjects. Methods: TBPI participants (n = 13) and controls (n = 10) matched in age, gender, and anthropometric characteristics were recruited. Kinematics from the shoulder, elbow, wrist, and index finger markers were collected, while upstanding participants transported a cup to their mouth and returned the UL to a starting position. The UL coordination was measured through the relative phase (RP) between arm and forearm phase angles and analyzed as a function of the hand kinematics. Results: For all participants, the hand transport had a shorter time to peak velocity (p < 0.01) compared to the return. Also, for the control and the uninjured TBPI UL, the RP showed a coordination pattern that favored forearm movements in the peak velocity of the transport phase (p < 0.001). TBPI participants' injured UL showed a longer movement duration in comparison to controls (p < 0.05), but no differences in peak velocity, time to peak velocity, and trajectory length, indicating preserved hand kinematics. The RP of the injured UL revealed altered coordination in favor of arm movements compared to controls and the uninjured UL (p < 0.001). Finally, TBPI participants' uninjured UL showed altered control of arm and forearm phase angles during the deceleration of hand movements compared to controls (p < 0.05). Conclusion: These results suggest that UL coordination is reorganized after a TBPI so as to preserve hand kinematics.

Kinematic Changes in the Uninjured Limb After a Traumatic Brachial Plexus Injury.

Background: Traumatic brachial plexus injury (TBPI) typically causes sensory, motor and autonomic deficits of the affected upper limb. Recent studies have suggested that a unilateral TBPI can also affect the cortical representations associated to the uninjured limb. Objective: To investigate the kinematic features of the uninjured upper limb in participants with TBPI. Methods: Eleven participants with unilateral TBPI and twelve healthy controls matched in gender, age and anthropometric characteristics were recruited. Kinematic parameters collected from the index finger marker were measured while participants performed a free-endpoint whole-body reaching task and a cup-to-mouth task with the uninjured upper limb in a standing position. Results: For the whole-body reaching task, lower time to peak velocity (p = 0.01), lower peak of velocity (p = 0.003), greater movement duration (p = 0.04) and shorter trajectory length (p = 0.01) were observed in the TBPI group compared to the control group. For the cup-to-mouth task, only a lower time to peak velocity was found for the TBPI group compared to the control group (p = 0.02). Interestingly, no differences between groups were observed for the finger endpoint height parameter in either of the tasks. Taken together, these results suggest that TBPI leads to a higher cost for motor planning when it comes to movements of the uninjured limb as compared to healthy participants. This cost is even higher in a task with a greater postural balance challenge. Conclusion: This study expands the current knowledge on bilateral sensorimotor alterations after unilateral TBPI and should guide rehabilitation after a peripheral injury.

Citation distribution profile in Brazilian journals of general medicine.

CONTEXT AND OBJECTIVE: Impact factors are currently the bibliometric index most used for evaluating scientific journals. However, the way in which they are used, for instance concerning the study or journal types analyzed, can markedly interfere with estimate reliability. This study aimed to analyze the citation distribution pattern in three Brazilian journals of general medicine. DESIGN AND SETTING: This was a descriptive study based on numbers of citations of scientific studies published by three Brazilian journals of general medicine. METHODS: The journals analyzed were São Paulo Medical Journal, Clinics and Revista da Associação Médica Brasileira. This survey used data available from the Institute for Scientific Information (ISI) platform, from which the total number of papers published in each journal in 2007-2008 and the number of citations of these papers in 2009 were obtained. From these data, the citation distribution was derived and journal impact factors (average number of citations) were estimated. These factors were then compared with those directly available from the ISI Journal of Citation Reports (JCR). RESULTS: Respectively, 134, 203 and 192 papers were published by these journals during the period analyzed. The observed citation distributions were highly skewed, such that many papers had few citations and a small percentage had many citations. It was not possible to identify any specific pattern for the most cited papers or to exactly reproduce the JCR impact factors. CONCLUSION: Use of measures like "impact factors", which characterize citations through averages, does not adequately represent the citation distribution in the journals analyzed.

Citation distribution profile in Brazilian journals of general medicine / Perfil de distribuição de citações em jornais brasileiros de medicina geral

CONTEXT AND OBJECTIVE: Impact factors are currently the bibliometric index most used for evaluating scientific journals. However, the way in which they are used, for instance concerning the study or journal types analyzed, can markedly interfere with estimate reliability. This study aimed to analyze the citation distribution pattern in three Brazilian journals of general medicine. DESIGN AND SETTING: This was a descriptive study based on numbers of citations of scientific studies published by three Brazilian journals of general medicine. METHODS: The journals analyzed were São Paulo Medical Journal, Clinics and Revista da Associação Médica Brasileira. This survey used data available from the Institute for Scientific Information (ISI) platform, from which the total number of papers published in each journal in 2007-2008 and the number of citations of these papers in 2009 were obtained. From these data, the citation distribution was derived and journal impact factors (average number of citations) were estimated. These factors were then compared with those directly available from the ISI Journal of Citation Reports (JCR). RESULTS: Respectively, 134, 203 and 192 papers were published by these journals during the period analyzed. The observed citation distributions were highly skewed, such that many papers had few citations and a small percentage had many citations. It was not possible to identify any specific pattern for the most cited papers or to exactly reproduce the JCR impact factors. CONCLUSION: Use of measures like "impact factors", which characterize citations through averages, does not adequately represent the citation distribution in the journals analyzed.

CONTEXTO E OBJETIVO: O fator de impacto é atualmente o índice bibliométrico mais utilizado para a avaliação de revistas científicas. No entanto, as condições de seu uso, por exemplo, em relação ao tipo de estudos ou revistas analisadas, podem interferir significativamente com a confiabilidade de suas estimativas. Este trabalho teve como objetivo estudar o padrão de distribuição de citações em três periódicos brasileiros de medicina geral. TIPO DE ESTUDO E LOCAL: Trata-se de um estudo descritivo, baseado nos números de citações de trabalhos científicos publicados por três revistas brasileiras de Medicina Geral. MÉTODOS: As revistas analisadas foram São Paulo Medical Journal, Clinics e Revista da Associação Médica Brasileira. A pesquisa utilizou-se de dados disponibilizados pela plataforma do Institute for Scientific Information (ISI), da qual foram obtidos o total de publicações de cada revista no período de 2007-2008 e o número de citações a esses trabalhos em 2009. A distribuição de citações e os fatores de impacto (média do número de citações) para cada revista foram estimados a partir desses dados, e os fatores de impacto assim obtidos foram comparados aos fornecidos diretamente pelo ISI Journal of Citation Reports (JCR). RESULTADOS: No período, foram publicados respectivamente 134, 203 e 192 artigos pelas revistas analisadas. Observou-se que a distribuição das citações a esses artigos é altamente enviesada, com um grande número de trabalhos pouco citados e um pequeno percentual com muitas citações. Não foi possível identificar um padrão específico para os trabalhos mais citados ou reproduzir exatamente os fatores de impacto JCR. CONCLUSÃO: O uso de medidas como "fatores de impacto" que caracterizam citações por meio de médias não representa adequadamente a distribuição de citações nas revistas analisadas.