Identifying candidates for targeted gait rehabilitation: better prediction through biomechanics-informed characterization

BACKGROUND: Walking speed has been used to predict the efficacy of gait training; however, poststroke motor impairments are heterogeneous and different biomechanical strategies may underlie the same walking speed. Identifying which individuals will respond best to a particular gait rehabilitation program using walking speed alone may thus be limited. The objective of this study was to determine if, beyond walking speed, participants' baseline ability to generate propulsive force from their paretic limbs (paretic propulsion) influences the improvements in walking speed resulting from a paretic propulsion-targeting gait intervention. METHODS: Twenty seven participants >6 months poststroke underwent a 12-week locomotor training program designed to target deficits in paretic propulsion through the combination of fast walking with functional electrical stimulation to the paretic ankle musculature (FastFES). The relationship between participants' baseline usual walking speed (UWSbaseline), maximum walking speed (MWSbaseline), and paretic propulsion (propbaseline) versus improvements in usual walking speed (∆UWS) and maximum walking speed (∆MWS) were evaluated in moderated regression models. RESULTS: UWSbaseline and MWSbaseline were, respectively, poor predictors of ΔUWS (R 2  = 0.24) and ΔMWS (R 2  = 0.01). Paretic propulsion × walking speed interactions (UWSbaseline × propbaseline and MWSbaseline × propbaseline) were observed in each regression model (R 2 s = 0.61 and 0.49 for ∆UWS and ∆MWS, respectively), revealing that slower individuals with higher utilization of the paretic limb for forward propulsion responded best to FastFES training and were the most likely to achieve clinically important differences. CONCLUSIONS: Characterizing participants based on both their walking speed and ability to generate paretic propulsion is a markedly better approach to predicting walking recovery following targeted gait rehabilitation than using walking speed alone

The United Kingdom, Republic of Ireland, United States and the conflict in Northern Ireland, August 1971 - September 1974

This thesis offers a new interpretation of the international history of the early period of Northern Ireland’s ‘Troubles’. Such a revision is necessary given the recently released material in the national archives of the United Kingdom, Republic of Ireland and the United States, and in the personal archives of those involved. Furthermore, by adopting a different methodology, made possible by the recent archive material, further new perspectives emerge of the international dimension. Rather than taking a single element of the international history of the Troubles – for example, the ‘Irish dimension’, ‘American dimension’, the Cold War, or European integration – this thesis takes a multidimensional approach analysing the impact of the interactions of each of the international actors. The starting point for this multidimensional analysis is the introduction of internment without trial on 9 August 1971. This was not just a significant event in Northern Ireland, but also had the effect of internationalising the Troubles. Over the months that followed the international dimension developed two distinct spheres of activity – a political sphere and a security sphere. Different combinations of actors interacted in each of these spheres. In addition to the moderate Northern Irish parties, the British and Irish governments participated in the political sphere. The US government eventually ruled itself out of this sphere following the US presidential election in November 1972, but only after it had flirted with intervention. However, interventions by the US Congress’s ‘Irish Caucus’ continued. Meanwhile, in the security sphere, comprehensive Anglo-Irish security cooperation proved impossible to achieve. Instead, Anglo-American and Hiberno-American security cooperation developed – with Dublin eventually exerting as much of an influence on US policy as the UK. However, the US government’s attempts to supress IRA support were seriously restricted by the administration’s unwillingness to pick a fight with the Irish Caucus. The international dimension was an integral component of the peace process that resulted in the establishing of a cross-community power-sharing executive and the Sunningdale Agreement of December 1973. Even when this process was brought to an end by a Protestant backlash in May 1974 the principles developed during this period were confirmed and were to be central to future peace initiatives in Northern Ireland, including the Good Friday Agreement

Better drug therapy for the children of Africa: current impediments to success and potential strategies for improvement

A commentary is presented on the urgent need for a comprehensive effort to improve the practice of pediatric therapeutics in Africa. A call for action is addressed to a variety of practitioners internationally, many of whom possess skills that could be fruitfully applied to the improvement of health outcomes for African children. Successful engagement with the many challenges requires the complementary effort of researchers in basic and clinical pharmacology and toxicology, nurses, pharmacists, physicians, clinical pharmacologists, clinical pharmacists, and political leaders and civil servants. While a comprehensive or systematic review of the relevant literature has not been attempted, the authors have highlighted promising initiatives driven by international agencies and academic networks. Two African perspectives are presented to reinforce the prospect of child health gains that can be achieved through consistent pursuit of optimal therapy for conditions such as respiratory infection, diarrhea, malaria, and HIV/AIDS. There is an imperative for development of north-south and south-south partnerships that will amplify current research efforts and mobilize existing knowledge concerning pediatric drugs. The overall goal is a multidisciplinary commitment to making essential medicines available at the right time, the right place, and in the right formulation for African children from infancy to adolescence

Mechanisms to increase propulsive force for individuals poststroke

Background: Propulsive force generation is critical to walking speed. Trialing limb angle and ankle moment are major contributors to increases in propulsive force during gait. For able-bodied individuals, trailing limb angle contributes twice as much as ankle moment to increases in propulsive force during speed modulation. The aim of this study was to quantify the relative contribution of ankle moment and trailing limb angle to increases in propulsive force for individuals poststroke. Methods: A biomechanical-based model previously developed for able-bodied individuals was evaluated and enhanced for individuals poststroke. Gait analysis was performed as subjects (N = 24) with chronic poststroke hemiparesis walked at their self-selected and fast walking speeds on a treadmill. Results: Both trailing limb angle and ankle moment increased during speed modulation. In the paretic limb, the contribution from trailing limb angle versus ankle moment to increases in propulsive force is 74% and 17%. In the non-paretic limb, the contribution from trailing limb angle versus ankle moment to increases in propulsive force is 67% and 22%. Conclusions: Individuals poststroke increase propulsive force mainly by changing trailing limb angle in both the paretic and non-paretic limbs. This strategy may contribute to the inefficiency in poststroke walking patterns. Future work is needed to examine whether these characteristics can be modified via intervention

Changes in Predicted Muscle Coordination with Subject-Specific Muscle Parameters for Individuals after Stroke

Muscle weakness is commonly seen in individuals after stroke, characterized by lower forces during a maximal volitional contraction. Accurate quantification of muscle weakness is paramount when evaluating individual performance and response to after stroke rehabilitation. The objective of this study was to examine the effect of subject-specific muscle force and activation deficits on predicted muscle coordination when using musculoskeletal models for individuals after stroke. Maximum force generating ability and central activation ratio of the paretic plantar flexors, dorsiflexors, and quadriceps muscle groups were obtained using burst superimposition for four individuals after stroke with a range of walking speeds. Two models were created per subject: one with generic and one with subject-specific activation and maximum isometric force parameters. The inclusion of subject-specific muscle data resulted in changes in the model-predicted muscle forces and activations which agree with previously reported compensation patterns and match more closely the timing of electromyography for the plantar flexor and hamstring muscles. This was the first study to create musculoskeletal simulations of individuals after stroke with subject-specific muscle force and activation data. The results of this study suggest that subject-specific muscle force and activation data enhance the ability of musculoskeletal simulations to accurately predict muscle coordination in individuals after stroke

Gaelic and identity:A response to Iain MacKinnon

This article responds to the recent special issue of Scottish Affairs on ‘Gàidhealtachd Futures’ and in particular the article by Iain MacKinnon proposing that ancestry, ethnicity and indigeneity should become the principal elements in contemporary Gaelic identity. The editors of the special issue do not give an analytically meaningful presentation of the term Gàidhealtachd and MacKinnon fails to give a complete or balanced account of previous research on the question of Gaelic identity. There is considerable uncertainty about how the term Gael is understood today; many Gaelic speakers are reluctant to accept this label for themselves. MacKinnon's arguments concerning the role of ancestry in defining Gaelic identity are highly problematic in both analytical and political terms. His proposals concerning ethnicity and indigeneity are unsustainable, particularly in light of relevant legal standards, and amount to a strategic, ethical and legal dead end for the Gaelic revitalisation movement