Differential postural effects of plantar-flexor muscles fatigue under normal, altered and improved vestibular and neck somatosensory conditions

The aim of the present study was to assess the effects of plantar-flexor muscles fatigue on postural control during quiet standing under normal, altered and improved vestibular and neck somatosensory conditions. To address this objective, young male university students were asked to stand upright as still as possible with their eyes closed in two conditions of No Fatigue and Fatigue of the plantar-flexor muscles. In Experiment 1 (n=15), the postural task was executed in two Neutral head and Head tilted backward postures, recognized to degrade vestibular and neck somatosensory information. In Experiment 2 (n=15), the postural task was executed in two conditions of No tactile and Tactile stimulation of the neck provided by the application of strips of adhesive bandage to the skin over and around the neck. Centre of foot pressure displacements were recorded using a force platform. Results showed that (1) the Fatigue condition yielded increased CoP displacements relative to the No Fatigue condition (Experiment 1 and Experiment 2), (2) this destabilizing effect was more accentuated in the Head tilted backward posture than Neutral head posture (Experiment 1) and (3) this destabilizing effect was less accentuated in the condition of Tactile stimulation than that of No tactile stimulation of the neck (Experiment 2). In the context of the multisensory control of balance, these results suggest an increased reliance on vestibular and neck somatosensory information for controlling posture during quiet standing in condition of altered ankle neuromuscular function

Getting the right balance: insole design alters the static balance of people with diabetes and neuropathy

BACKGROUND: Over 1 in 3 older people with diabetes sustain a fall each year. Postural instability has been identified as independent risk factor for falls within people with Diabetic Peripheral Neuropathy (DPN). People with DPN, at increased risk of falls, are routinely required to wear offloading insoles, yet the impact of these insoles on postural stability and postural control is unknown. The aim of this study was to evaluate the effect of a standard offloading insole and its constituent parts on the balance in people with DPN. METHODS: A random sample of 50 patients with DPN were observed standing for 3 × 30 s, and stepping in response to a light, under five conditions presented in a random order; as defined by a computer program; 1) no insole, 2) standard diabetic: a standard offloading insole made from EVA/poron®, and three other insoles with one design component systematically altered 3) flat: diabetic offloading insole with arch fill removed, 4) low resilient memory: diabetic offloading insole with the cover substituted with low resilience memory V9, 5) textured: diabetic offloading insole with a textured PVC surface added (Algeos Ltd). After each condition participants self-rated perceived steadiness. RESULTS: Insole design effected static balance and balance perception, but not stepping reaction time in people with DPN. The diabetic and memory shaped insoles (with arch fill) significantly increased centre of pressure velocity (14 %, P = 0.006), (13 %, P = 0.001), and path length (14 %, P = 0.006), (13 %, P = 001), when compared to the no insole condition. The textured shaped and flat soft insole had no effect on static balance when compared to the no insole condition (P > 0.05). CONCLUSION: Insoles have an effect on static balance but not stepping reaction time. This effect is independent of neuropathy severity. The addition of a textured cover seems to counter the negative effect of an arch fill, even in participants with severe sensation loss. Static balance is unaffected by material softness or resilience. Current best practice of providing offloading insoles, with arch fill, to increase contact area and reduce peak pressure could be making people more unstable. Whilst flat, soft insoles maybe the preferable design option for those with poor balance. There is a need to develop an offloading insole that can reduce diabetic foot ulcer risk, without compromising balance

Non-linear stimulus-response behavior of the human stance control system is predicted by optimization of a system with sensory and motor noise

We developed a theory of human stance control that predicted (1) how subjects re-weight their utilization of proprioceptive and graviceptive orientation information in experiments where eyes closed stance was perturbed by surface-tilt stimuli with different amplitudes, (2) the experimentally observed increase in body sway variability (i.e. the “remnant” body sway that could not be attributed to the stimulus) with increasing surface-tilt amplitude, (3) neural controller feedback gains that determine the amount of corrective torque generated in relation to sensory cues signaling body orientation, and (4) the magnitude and structure of spontaneous body sway. Responses to surface-tilt perturbations with different amplitudes were interpreted using a feedback control model to determine control parameters and changes in these parameters with stimulus amplitude. Different combinations of internal sensory and/or motor noise sources were added to the model to identify the properties of noise sources that were able to account for the experimental remnant sway characteristics. Various behavioral criteria were investigated to determine if optimization of these criteria could predict the identified model parameters and amplitude-dependent parameter changes. Robust findings were that remnant sway characteristics were best predicted by models that included both sensory and motor noise, the graviceptive noise magnitude was about ten times larger than the proprioceptive noise, and noise sources with signal-dependent properties provided better explanations of remnant sway. Overall results indicate that humans dynamically weight sensory system contributions to stance control and tune their corrective responses to minimize the energetic effects of sensory noise and external stimuli

Socotherm group

Vicenza (Italy), 3 December 2008. Zeno Soave, the founder of Socotherm Group, a large supplier of pipe coating and insulation services both for the oil & gas industry and the deep water sector, and Cristiano Battelli, the Group Chief Restructuring Officer, were considering how to fix the company’s financial and organizational problems. The financial crisis that broke out in 2007 and some errors in past investments, caused a lack of liquidity that affected the group operations. In fact, the consolidated operating income was expected to be considerably negative in 2008. In addition, a major instalment of a huge amount of debt borrowed by the holding company was coming due. Therefore, the two men were considering how to reorganize the company in order to immediately prevent a potential crisis, that would be caused by an almost certain loan covenant breach. This case is particularly useful in corporate finance and restructuring courses. It offers the opportunity to analyze the operational and financial soundness of a distressed global company, to practice the concepts of unused debt capacity, and to consider different restructuring strategy from a going-concern perspectiv

Eccellenza imprenditoriale: il valore dell’internazionalizzazione per le imprese italiane

L’internazionalizzazione è quel processo attraverso cui le imprese non solo dispiegano le loro vendite su più mercati esteri ma dagli stessi mercati o da altri attingono anche per il loro approvvigionamento di materie prime, di componenti, di tecnologie, di impianti, di attrezzature, di risorse finanziarie, di forza lavoro. L’obiettivo di tale ricerca è quello di studiare il grado di internazionalizzazione delle imprese italiane e lombarde, analizzando l’apertura dell’Italia all’estero e indagando sulla dinamica economico – finanziaria e sulle prospettive di sviluppo internazionale delle imprese italiane, nonché sulle problematiche legate allo svolgimento di transazioni internazionali

L’impresa veneta: finanza,internazionalizzazione e crescita,

La ricerca esamina e approfondisce i conti economici e le situazioni patrimoniali riferiti al 2004 di circa 10.000 piccole e medie aziende, quindi inserite nelle fasce tra 2 e 10 milioni di euro di giro d’affari e tra 10 e 50 milioni. A questa analisi è stata affiancata nello stesso tempo un’indagine empirica, svolta attraverso interviste a un centinaio di giovani imprenditori attivi nel Veneto. L’obiettivo di fondo è interrogarci sulla consistenza del tessuto imprenditoriale e sul suo possibile sviluppo futuro, con particolare attenzione alle dimensioni delle aziende e alla capacità del sistema di integrarsi e di affrontare la competizione internazionale sia valorizzando gli asset storici che proponendo nuovi modelli in grado di far crescere le nostre imprese