Muscle coordination during rapid force production by young and older adults

Background. Older adults typically exhibit dramatic reductions in the rate of force development and deficits in the execution of rapid coordinated movements. The purpose of the current study was to investigate the association between the reduced rate of force development exhibited by older adults and the ability to coordinate groups of muscles. Methods. The performance of a visually guided aiming task that required the generation of isometric torque about the elbow joint was compared in 10 young adults (age range, 19 to 29 years) and 10 older adults (age range, 65 to 80 years). Participants were required to exert isometric torque in flexion, extension, pronation, or supination, or in combinations of these directions, to reach a target in minimum time. Surface electromyograms were obtained from the biceps brachii, triceps brachii, brachioradialis, and flexor carpi radialis. Results. Older participants exhibited slower target acquisition times compared with young participants (p < .05), with the extent of the differences between the groups varying markedly between target locations. Conclusions. The impairment in performance, although partially attributable to a general decline in the ability to produce force rapidly, was also affected by the requirements for muscular coordination. At the neuromuscular level, differences between the young and the elderly were expressed most prominently in the bifunctional muscle biceps brachii and in certain temporal aspects of muscular coordination.

Experimental hand pain delays recognition of the contralateral hand: Evidence that acute and chronic pain have opposite effects on information processing?

Recognising the laterality of a pictured hand involves making an initial decision and confirming that choice by mentally moving one's own hand to match the picture. This depends on an intact body schema. Because patients with complex regional pain syndrome type 1 (CRPS1) take longer to recognise a hand's laterality when it corresponds to their affected hand, it has been proposed that nociceptive input disrupts the body schema. However, chronic pain is associated with physiological and psychosocial complexities that may also explain the results. In three studies, we investigated whether the effect is simply due to nociceptive input. Study one evaluated the temporal and perceptual characteristics of acute hand pain elicited by intramuscular injection of hypertonic saline into the thenar eminence. In studies two and three, subjects performed a hand laterality recognition task before, during, and after acute experimental hand pain, and experimental elbow pain, respectively. During hand pain and during elbow pain, when the laterality of the pictured hand corresponded to the painful side, there was no effect on response time (RT). That suggests that nociceptive input alone is not sufficient to disrupt the working body schema. Conversely to patients with CRPS1, when the laterality of the pictured hand corresponded to the non-painful hand, RT increased similar to 380 ms (95% confidence interval 190 ms-590 ms). The results highlight the differences between acute and chronic pain and may reflect a bias in information processing in acute pain toward the affected part.

Resistance training for the older adult: Manipulating training variables to enhance muscle strength

Resistance training has been shown to reliably and substantially enhance muscle function in older adults and these improvements can be accompanied by improved functional performance. Training variables should be manipulated to enhance muscle strength and minimize injury risks in this population.

Do you know where your arm is if you think your head has moved?

Reproduction of a previously presented elbow position is affected by changes in head position. As movement of the head is associated with local biomechanical changes, the aim of the present study was to determine if illusory changes in head position could induce similar effects on the reproduction of elbow position. Galvanic vestibular stimulation (GVS) was applied to healthy subjects in supine lying. The stimulus was applied during the presentation of an elbow position, which the subject then reproduced without stimulation. In the first study, 13 subjects received 1.5 mA stimuli, which caused postural sway in standing, confirming that the firing of vestibular afferents was affected, but no illusory changes in head position were reported. In the second study, 13 subjects received 2.0-3.0 mA GVS. Six out of 13 subjects reported consistent illusory changes in head position, away from the side of the anode. In these subjects, anode right stimulation induced illusory left lateral flexion and elbow joint position error towards extension (p=0.03), while anode left tended to have the opposite effect (p=0.16). The GVS had no effect on error in subjects who did not experience illusory head movement with either 1.5 mA stimulus (p=0.8) or 2.0-3.0 mA stimulus (p=0.7). This study demonstrates that the accuracy of elbow repositioning is affected by illusory changes in head position. These results support the hypothesis that the perceived position of proximal body segments is used in the planning and performance of accurate upper limb movements.

Influence of predominant patterns of coordination on the exploitation of interaction torques in a two-joint rhythmic arm movement

In this study we investigate the coordination between rhythmic flexion-extension (FE) and supination-pronation (SP) movements at the elbow joint-complex, while manipulating the intersegmental dynamics by means of a 2-degrees of freedom (df) robot arm. We hypothesized that constraints imposed by the structure of the neuromuscular-skeletal system would (1) result in predominant pattern(s) of coordination in the absence of interaction torques and (2) influence the capabilities of participants to exploit artificially induced interaction torques. Two experiments were conducted in which different conditions of interaction torques were applied on the SP-axis as a function of FE movements. These conditions promoted different patterns of coordination between the 2-df. Control trials conducted in the absence of interaction torques revealed that both the in-phase (supination synchronized with flexion) and the anti-phase (pronation synchronized with flexion) patterns were spontaneously established by participants. The predominance of these patterns of coordination is explained in terms of the mechanical action of bi-articular muscles acting at the elbow joint-complex, and in terms of the reflexes that link the activity of the muscles involved. Results obtained in the different conditions of interaction torques revealed that those neuromuscular-skeletal constraints either impede or favor the exploitation of intersegmental dynamics depending on the context. Interaction torques were indeed found to be exploited to a greater extent in conditions in which the profiles of interaction torques favored one of the two predominant patterns of coordination (i.e., in-phase or anti-phase) as opposed to other patterns of coordination (e.g., 90 degrees or 270 degrees). Those results are discussed in relation to recent studies reporting exploitation of interaction torques in the context of rhythmic movements.

Neuromuscular-skeletal constraints on the acquisition of skill in a discrete torque production task

The organisation of the human neuromuscular-skeletal system allows an extremely wide variety of actions to be performed, often with great dexterity. Adaptations associated with skill acquisition occur at all levels of the neuromuscular-skeletal system although all neural adaptations are inevitably constrained by the organisation of the actuating apparatus (muscles and bones). We quantified the extent to which skill acquisition in an isometric task set is influenced by the mechanical properties of the muscles used to produce the required actions. Initial performance was greatly dependent upon the specific combination of torques required in each variant of the experimental task. Five consecutive days of practice improved the performance to a similar degree across eight actions despite differences in the torques required about the elbow and forearm. The proportional improvement in performance was also similar when the actions were performed at either 20 or 40% of participants' maximum voluntary torque capacity. The skill acquired during practice was successfully extrapolated to variants of the task requiring more torque than that required during practice. We conclude that while the extent to which skill can be acquired in isometric actions is independent of the specific combination of joint torques required for target acquisition, the nature of the kinetic adaptations leading to the performance improvement in isometric actions is influenced by the neural and mechanical properties of the actuating muscles.

Neuromuscular-skeletal origins of predominant patterns of coordination in a rhythmic two-joint arm movement

The authors tested for predominant patterns of coordination in the combination of rhythmic flexion-extension (FE) and supination-pronation (SP) at the elbow-joint complex. Participants (N = 10) spontaneously established in-phase (supination synchronized with flexion) and antiphase (pronation synchronized with flexion) patterns. In addition, the authors used a motorized robot arm to generate involuntary SP movements with different phase relations with respect to voluntary FE. The involuntarily induced in-phase pattern was accentuated and was more consistent than other patterns. That result provides evidence that the predominance of the in-phase pattern originates in the influence of neuro-muscular-skeletal constraints rather than in a preference dictated by perceptual-cognitive factors implicated in voluntary control. Neuromuscular-skeletal constraints involved in the predominance of the in-phase and the antiphase patterns are discussed.

The effects of varying time under tension and volume load on acute neuromuscular responses

The purpose of this study was to examine the effects of different methods of measuring training volume, controlled in different ways, on selected variables that reflect acute neuromuscular responses. Eighteen resistance-trained males performed three fatiguing protocols of dynamic constant external resistance exercise, involving elbow flexors, that manipulated either time-under-tension (TUT) or volume load (VL), defined as the product of training load and repetitions. Protocol A provided a standard for TUT and VL. Protocol B involved the same VL as Protocol A but only 40% concentric TUT; Protocol C was equated to Protocol A for TUT but only involved 50% VL. Fatigue was assessed by changes in maximum voluntary isometric contraction (MVIC), interpolated doublet (ID), muscle twitch characteristics (peak twitch, time to peak twitch, 0.5 relaxation time, and mean rates of force development and twitch relaxation). All protocols produced significant changes (P

Dynamic training volume: A construct of both time under tension and volume load

The purpose of this study was to investigate the effects of three different weight training protocols, that varied in the way training volume was measured, on acute muscular fatigue. Ten resistance-trained males performed all three protocols which involved dynamic constant resistance exercise of the elbow flexors. Protocol A provided a standard for the time the muscle group was under tension (TUT) and volume load (VL), expressed as the product of the total number of repetitions and the load that was lifted. Protocol B involved 40% of the TUT but the same VL compared to protocol A; protocol C was equated with protocol A for TUT but only involved 50% of the VL. Fatigue was assessed by changes in maximum voluntary isometric force and integrated electromyography (iEMG) between the pre- and post-training protocols. The results of the study showed that, when equated for VL, greater TUT produced greater overall muscular fatigue ( p

Ectopic calcification in the Azores - Clinical and radiological manifestations of Diffuse Idiopathic Skeletal Hypertosis and Chondrocalcinosis families

Objective. Twelve families that were multiply affected with diffuse idiopathic skeletal hyperostosis (DISH) and/or chondrocalcinosis, were identified on the island of Terceira, The Azores, potentially supporting the hypothesis that the 2 disorders share common etiopathogenic factors. The present study was undertaken to investigate this hypothesis. Methods. One hundred three individuals from 12 unrelated families were assessed. Probands were identified from patients attending the Rheumatic Diseases Clinic, Hospital de Santo Espirito, in The Azores. Family members were assessed by rheumatologists and radiologists. Radiographs of all family members were obtained, including radiographs of the dorsolumbar spine, pelvis, knees, elbows, and wrists, and all cases were screened for known features of chondrocalcinosis. Results. Ectopic calcifications were identified in 70 patients. The most frequent symptoms or findings were as follows: axial pain, elbow, knee and metacarpophalangeal (MCP) joint pain, swelling, and/or deformity, and radiographic enthesopathic changes. Elbow and MCP joint periarticular calcifications were observed in 35 and 5 patients, respectively, and chondrocalcinosis was identified in 12 patients. Fifteen patients had sacroiliac disease (ankylosis or sclerosis) on computed tomography scans. Fifty-two patients could be classified as having definite (17%), probable (26%), or possible (31%) DISH. Concomitant DISH and chondrocalcinosis was diagnosed in 12 patients. Pyrophosphate crystals were identified from knee effusions in 13 patients. The pattern of disease transmission was compatible with an autosomal-dominant monogenic disease. The mean age at which symptoms developed was 38 years. Conclusion. These families may represent a familial type of pyrophosphate arthropathy with a phenotype that includes peripheral and axial enthesopathic calcifications. The concurrence of DISH and chondrocalcinosis suggests a shared pathogenic mechanism in the 2 conditions.

Injury risk from popular childhood physical activities: results from an Australian primary school cohort

Background: Children engage in various physical activities that pose different injury risks. However, the lack of adequate data on exposure has meant that these risks have not been quantified or compared in young children aged 5-12 years. Objectives: To measure exposure to popular activities among Australian primary school children and to quantify the associated injury risks. Method: The Childhood Injury Prevention Study prospectively followed up a cohort of randomly selected Australian primary and preschool children aged 5-12 years. Time (min) engaged in various physical activities was measured using a parent-completed 7-day diary. All injuries over 12 months were reported to the study. All data on exposure and injuries were coded using the International classification of external causes of injury. Injury rates per 1000 h of exposure were calculated for the most popular activities. Results: Complete diaries and data on injuries were available for 744 children. Over 12 months, 314 injuries relating to physical activity outside of school were reported. The highest injury risks per exposure time occurred for tackle-style football (2.18/1000 h), wheeled activities (1.72/1000 h) and tennis (1.19/1000 h). Overall, boys were injured more often than girls; however, the differences were non-significant or reversed for some activities including soccer, trampolining and team ball sports. Conclusion: Although the overall injury rate was low in this prospective cohort, the safety of some popular childhood activities can be improved so that the benefits may be enjoyed with fewer negative consequences.

A IMPORTÂNCIA DAS TICS E DA EDUCAÇÃO COMO PROCESSO COMUNICACIONAL DIALÓGICO NO ENSINO SUPERIOR: Um Estudo da Universidade Estadual de Mato Grosso do Sul

Esta tese teve por objetivo saber como o corpo docente da Universidade Estadual de Mato Grosso do Sul (UEMS) percebe, entende e reage ante a incorporação e utilização das Tecnologias de Informação e Comunicação (TICs) nos cursos de graduação dessa Instituição, considerando os novos processos comunicacionais dialógicos que elas podem proporcionar na sociedade atual. Metodologicamente, a tese é composta por pesquisa bibliográfica, buscando fundamentar as áreas da Educação e Comunicação, assim como a Educomunicação; pesquisa documental para contextualização do lócus da pesquisa e de uma pesquisa exploratória a partir da aplicação de um questionário online a 165 docentes da UEMS, que responderam voluntariamente. Verificou-se que os professores utilizam as TICs cotidianamente nas atividades pessoais e, em menor escala, nos ambientes profissionais. Os desafios estão em se formar melhor esse docente e oferecer capacitação continuada para que utilizem de forma mais eficaz as TICs nas salas de aula. Destaca-se ainda que os avanços em tecnologia e os novos ecossistemas comunicacionais construíram novas e outras realidades, tornando a aprendizagem um fator não linear, exigindo-se revisão nos projetos pedagógicos na educação superior para que estes viabilizem diálogos propositivos entre a comunicação e a educação. A infraestrutura institucional para as TICs é outro entrave apontado, tanto na aquisição como na manutenção desses aparatos tecnológicos pela Universidade. Ao final, propõe-se realizar estudos e pesquisas que possam discutir alterações nos regimes contratuais de trabalho dos docentes, uma vez que, para atuar com as TICs de maneira apropriada, exige-se mais tempo e dedicação do docente.

Editorial

Full text: There are phrases in daily use today which were not so common a decade or so back, such as ‘ageing population’ or ‘climate changes’ or ‘emerging markets’ or even ‘social networking’. How do these things affect our lives is certainly interesting but for us as eye care practitioners how these changes affect our clinical work may be also relevant and sometimes more interesting. A recent advertisement for recruitment to the Royal Marine Corps of the British Army ended with a comment ‘find us on Facebook!’ The BCLA, IACLE and other organisations as well as many manufacturers have their own Facebook groups. In 2011 Chandni Thakkar was awarded the BCLA summer studentship and her project was based around increasing the contact lens business of a small independent optometric practice where contact lens sales were minimal. The practice typically recruited one new wearer per month. Chandni was able to increase the number of new patient fits with various strategies (her work was presented as poster at the 2012 BCLA conference in Birmingham). One of her strategies was to start a Facebook group and 655 joined the special group she started in just over a month. Interestingly she found that the largest single factor in convincing patients to trial contact lenses was recommendation by the eye care practitioner at the end of the examination, but nonetheless it is interesting that so many people used the social networking site to find out more information regarding contact lenses in her study. Moreover, we already see the use, by some practitioners, of smart phone ‘apps’ or electronic diaries or text messages when coordinating patient check-ups. Climate change has affected the way we think and act; we now leave out special recycle bins and we hope that the items that are recyclable are actually recycled and do not just join our other refuse somewhere down the track! How environmentally friendly are contact lenses? This was discussed by various speakers at this year's BCLA conference in Birmingham. Daily disposable lenses surely produce more contact lens waste but do not involve solutions in plastic bottles like monthly lenses. It is certainly something that manufacturers are taking seriously and of course there are environmental benefits but the cynic in each of us sees the marketing potential too. The way the ageing population is certainly something that will impact all healthcare providers. In the case of eye care with people living longer they will need refractive corrections for longer. Furthermore, since presbyopes are not resigning themselves to only gentle hobbies like knitting and gardening, but instead want to continue playing tennis or skiing or whatever, their visual demands are becoming more complex. This is certainly an area that contact lens manufacturers are focussing on (pun not intended!). Again the BCLA conference in Birmingham saw the launch of various new products by different companies to help us deal with our presbyopic contact lens wearers. It is great to have such choice and now with fitting methods becoming easier too we have no excuse not to try them out with our clients. Finally to emerging markets – well there was not a specific session at the BCLA conference in May discussing this but this most certainly would have been discussed by professional services managers and marketing directors of most of the contact lens companies. ‘How will we conquer China?’ ‘How can we increase our market share in Russia?’ Or ‘How should we spend our marketing budget in India?’ These topics as well as others would certainly have cropped up in backroom discussions. Certainly groups like IACLE (International Association of CL Educators) have increasing numbers of members and activities in developing markets to ensure that educators educate, to that practitioners can practice successfully and in turn patients can become successful contact lenses wearers. Companies also wish to increase their market share in these developing markets and from the point of view of CLAE we are certainly seeing more papers being submitted from these parts of the world. The traditional centres of knowledge are being challenged, I suppose as they have been throughout history, and this can only be a good thing for the pursuit of science. The BCLA conference in Birmingham welcomed more international visitors than ever, and from more countries, and long may that continue. Similarly, CLAE looks forward to a wider audience in years to come and a wider network of authors too.

The European Patterns of "Homo Academicus“ and The Chances of Its Evolution In Current Hungarian Higher Education

In the recent four or five years, there have been abrupt and radical changes in the governance of Hungarian higher education. It can then be interesting to assess the state of “homo academicus“ as it looks currently in Hungary. The notion of “homo academicus“ is obvious: it concerns participants in the system of a country’s higher education. The paper as follows still comes back to the definition of “homo academicus“ by referring first to it as occupation, or rather as a profession that can be interpreted in terms of sociology. Secondly, some historic patterns can also be mobilised, based on the assumption that university is a very European institutions that is even rooted in the tradition of the Middle Ages. The elbow-room of seeking for identity and the role to be filled by academics are limited by the effective system of the governance of higher education. It is a key to the chances of academics of meeting the historically corroborated professional standards that they exercise academic freedom. As it cannot be done individually, but in cooperation (through a collegial system), academic freedom is always combined with collective action. The field where this freedom can be exercised can be specified through university autonomy, the lack of which makes a serious barrier to the full development of a character of “homo academicus“. This is now the case in Hungary, the paper suggests. The paper seeks to gain deeper understanding of the character of academics, their vocation and professional roles, and the governance of higher education, serving as the environment for academic activity, by creating a conceptual framework. The paper is established on the results of sociological research and the experience of legal management, although it remains to be of theoretical nature. It criticises the current Hungarian situation of the governance of higher education, arguing for the reconstruction of university autonomy and financial stability. It also emphasises the importance of predictable regulations.

Latin America and the Caribbean in 2011 and Beyond: A conversation among Latin America and Caribbean Specialists.

For the first time in more than fifty years, the domestic and external conflicts in Latin America and the Caribbean (LAC) are not primarily ideological in nature. Democracy continues to thrive and its promise still inspires hope. In contrast, the illegal production, consumption, and trading of drugs – and its links to criminal gangs and organizations – represent major challenges to the region, undermining several States’ already weak capacity to govern. While LAC macroeconomic stability has remained resilient, illegal economies fill the region, often offering what some States have not historically been able to provide – elements of human security, opportunities for social mobility, and basic survival. Areas controlled by drug trafficking organizations (DTOs) are now found in Central America, Mexico, and the favelas of Rio de Janeiro and São Paulo, reflecting their competition for land routes and production areas. Cartels such as La Familia, Los Zetas, and Primeiro Comando da Capital (PCC-Brazil), among others, operate like trade and financial enterprises that manage millions of dollars and resources, demonstrating significant business skills in adapting to changing circumstances. They are also merciless in their application of violence to preserve their lucrative enterprises. The El Salvador-Guatemala-Honduras triangle in Central America is now the most violent region in the world, surpassing regions in Africa that have been torn by civil strife for years. In Brazil’s favelas and Guatemala’s Petén region, the military is leaving the barracks again; not to rule, however, but to supplement and even replace the law enforcement capacity of weak and discredited police forces. This will challenge the military to apply lessons learned during the course of their experience in government, or from the civil wars that plagued the region for nearly 50 years during the Cold War. Will they be able to conduct themselves according to the professional ethics that have been inculcated over the past 20 years without incurring violations of human rights? Belief in their potential to do good is high according to many polls as the Armed Forces still enjoy a favorable perception in most societies, despite frequent involvement in corruption. Calling them to fight DTOs, however, may bring them too close to the illegal activities they are being asked to resist, or even rekindle the view that only a “strong hand” can resolve national troubles. The challenge of governance is occurring as contrasts within the region are becoming sharper. There is an increasing gap between nations positioned to surpass their “developing nation” status and those that are practically imploding as the judicial, political and enforcement institutions fall further into the quagmire of illicit activities. Several South American nations are advancing their political and economic development. Brazil in particular has realized macro-economic stability, made impressive gains in poverty reduction, and is on track to potentially become a significant oil producer. It is also an increasingly influential power, much closer to the heralded “emerging power” category that it aspired to for most of the 20th century. In contrast, several Central American States have become so structurally deficient, and have garnered such limited legitimacy, that their countries have devolved into patches of State controlled and non-State-controlled territory, becoming increasingly vulnerable to DTO entrenchment. In the Caribbean, the drug and human trafficking business also thrives. Small and larger countries are experiencing the growing impact of illicit economies and accompanying crime and violence. Among these, Guyana and Suriname face greater uncertainty, as they juggle both their internal affairs and their relations with Brazil and Venezuela. Cuba also faces new challenges as it continues focusing on internal rather than external affairs and attempts to ensure a stable leadership succession while simultaneously trying to reform its economy. Loosening the regime’s tight grip on the economy while continuing to curtail citizen’s civil rights will test the leadership’s ability to manage change and prevent a potential socio-economic crisis from turning into an existential threat. Cuba’s past ideological zest is now in the hands of Venezuela’s President Hugo Chavez, who continues his attempts to bring the region together under Venezuelan leadership ideologically based on a “Bolivarian” anti-U.S. banner, without much success. The environment and natural disasters will merit more attention in the coming years. Natural events will produce increasing scales of destruction as the States in the region fail to maintain and expand existing infrastructure to withstand such calamities and respond to their effects. Prospects for earthquakes, tsunamis, and hurricanes are high, particularly in the Caribbean. In addition, there are growing rates of deforestation in nearly every country, along with a potential increase in cross-sector competition for resources. The losers might be small farmers, due to their inability to produce quantities commensurate to larger conglomerates. Regulations that could mitigate these types of situations are lacking or openly violated with near impunity. Indigenous and other vulnerable populations, including African descendants, in several Andean countries, are particularly affected by the increasing extraction of natural resources taking place amongst their terrain. This has led to protests against extraction activities that negatively affect their livelihoods, and in the process, these historically underprivileged groups have transitioned from agenda-based organization to one that is bringing its claims and grievances to the national political agenda, becoming more politically engaged. Symptomatic of these social issues is the region’s chronically poor quality of education that has consistently failed to reduce inequality and prepare new generations for jobs in the competitive global economy, particularly the more vulnerable populations. Simultaneously, the educational deficit is also exacerbated by the erosion of access to information and freedom of the press. The international panorama is also in flux. New security entities are challenging the old establishment. The Union of South American Nations, The South American Defense Council, the socialist Bolivarian Alliance, and other entities seem to be defying the Organization of American States and its own defense mechanisms, and excluding the U.S. And the U.S.’s attention to areas in conflict, namely Iraq, Afghanistan, and Pakistan – rather than to the more stable Latin America and Caribbean – has left ample room for other actors to elbow in. China is now the top trading partner for Brazil. Russian and Iran are also finding new partnerships in the region, yet their links appear more politically inclined than those of China. Finally, the aforementioned increasing commercial ties by LAC States with China have accelerated a return to the preponderance of commodities as sources of income for their economies. The increased extraction of raw material for export will produce greater concern over the environmental impact that is created by the exploitation of natural resources. These expanded trade opportunities may prove counterproductive economically for countries in the region, particularly for Brazil and Chile, two countries whose economic policies have long sought diversification from dependence on commodities to the development of service and technology based industries.