Electromyography is the study of motor unit action potentials (MUAPs) associated with muscle activity during movement [1]. Muscle fibres are stimulated to contract by action potentials triggering depolarisation and polarisation within individual muscle fibres of the muscle [2,3] creating electromagnetic fields which can be measured by EMG [4]. The recorded EMG signal represents the sum myoelectrical activity for a defined event in the muscle for the pick-up zone (recorded data) of the electrode used [4]. EMG electrodes have a defined pickup zone (Figure 1) which will depend upon the source of the signal and the distance from the source of the current to the electrode [5] as well as the system utilised [6,7]. Features commonly analysed within human and equine EMG research include muscle recruitment, duration of activity and activity levels [8, 9 and 10] (Figure 2). There are two methods of EMG: indwelling EMG, subdivided into fine-wire and concentric or fine needle EMG, where electrodes are inserted into muscles of interest, and surface EMG (sEMG) where electrodes are applied to the extracellular skin surface above muscles of interest [6]. The choice of EMG method and electrode should depend on the research objectives of individual studies [11]. All techniques can fundamentally record the same muscle performance parameters, however indwelling electrodes record signals from >5cm depth, dependent on length of electrode and how deep it is inserted into the muscle, whilst the signals surface systems pick up tend to be limited to ≤5cm depth. Both surface and indwelling techniques have been used in the horse, for example: Takahashi et al. [12]: finewire, Wijnberg et al. [13]: needle EMG, and Robert et al. [14]: surface EMG. sEMG may possess an advantage in locomotor equine research over fine-wire and needle EMG, as sEMG electrodes have the ability to sample more motor units (MU) per electrode, making them better suited providing a representation of total activity within the large muscles of the horse.

مقاله سال 2016

The complexity and uncertainty of twenty-first century business environments diminish the effectiveness of traditional, hierarchical approaches to leadership. To create an adaptive, agile organization, capable of both noticing and responding to emerging trends and customer needs, leaders are increasingly required to act interdependently and share leadership. According to Pearce and Conger, authors of Shared Leadership: Reframing the how’s and whys of leadership, shared leadership is a dynamic, unfolding, interactive social process among individuals, where the objective is to lead one another toward the achievement of collective goals and results in improved performance.

Healthcare organizations are faced with navigating the interconnected forces of the Affordable Care Act, political instability, shifting consumer demands, and all of the resultant evolving financial and regulatory challenges. The reality is that no one can predict what large-scale changes are coming next or their impact. Successful leaders are those who can deal with constant ambiguity, notice important patterns amongst the noise, and look at the world through multiple stakeholder perspectives. Shared leadership offers a way for leaders in the healthcare industry to navigate complexity and deal with uncertainty.

With respect to shared leadership, there remain many questions about how to move from an abstract, conceptual understanding to practically applied actions. The nextstep to advancing the practice of shared leadership is to develop and evaluate tangible models and experiences that enable learning and direct application of the concepts. The work presented here emerged from a test of learning based on one of the most sophisticated, sustainable models of shared leadership in action, namely the shared leadership practices found in herds of horses.