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An investigation was made on the relationship between music practice and musculoskeletal disorders among piano students, with the main aim of developing health education programmes that would improve the performance and health of the students. The investigation covered three areas (a) Analysis of study organization and main musculoskeletal complaints achieved by a questionnaire distributed to all piano students at the Milan Conservatory. (b) Vocational electromyographic analysis of the effort exerted by the various muscle groups of the trunk, of the shoulder and shoulder blade girdle, and of the arm during performance of a standard set of piano exercises, an unseen passage and a passage of maximum difficulty. This analysis was made on a sample of six subjects. (c) A series of preventive measures was developed on the basis of a critical assessment of the results (38% of the students practised for excessively long periods without breaks; 62% had from 1 to 5 complaints, the most affected sites being the spine and the trapezius muscles). These consisted largely of a health education programme aimed at helping the students to suitably organize practice and rest periods and in instructing them in appropriate exercises for relaxation and stretching of overused muscle groups and strengthening the supporting muscle groups. Changes in lifestyle were also suggested. [ABSTRACT FROM PUBLISHER]

The analysis of lumbar stresses in the sitting posture is performed for situations in which upper limbs are fully or partially supported by a worktable. A method is presented for biomechanical evaluation of moments and compressive forces acting on the lumbar intervertebral disk, based on the use of a force platform, a TV camera and a integrated system for the elaboration of signals. The on-line pictures given by this equipment show the ground reaction vector superimposed on the subject's image and allows a detailed analysis of the intervertebral loads. The results obtained in the subjects under study (six males and five females) are analysed statistically and extrapolation on the basis of body weight is demonstrated to be possible in situations where the arm support forces are not known. The myoelectric activity of the erector spinae muscles was also assessed. The aim of the study was to furnish a tool that can be used in all occupational environments and that will allow evaluation of the lumbar stresses in the sitting posture to be made with a minimum use of complex equipment. An example of the practical application of this concept is presented. [ABSTRACT FROM PUBLISHER]

The authors commence by reviewing the most recent literature on methods for analysing postures and come to the conclusion that two factors are vital for a proper study of working postures. These are the description and the assessment of posture tolerability. The descriptive models most recently put forward in the literature enable the information required for subsequent assessment to be collected and further efforts to improve the descriptive capacity of these would be of slight benefit. The major difficulties in posture analysis arise during assessment. In the first place there is still a need for further basic knowledge to throw light on the natural and clinical development of changes due to unsuitable postures and to isolate the most significant individual or workplace-related factors. In the second place, the most widely used assessment methods (electromyography, study of discal pressures, biomechanical analysis, etc.) are capable of providing useful information on the individual apparatus considered, whereas a posture turns out to be tolerable only when all the apparatuses involved are comprehensively safeguarded. Lastly the above-mentioned assessment methods are not always capable of providing both information on the appearance of short-term postural discomfort and enabling predictions to be made of the appearance of damage in the long term, while both requirements must be met for a working posture to be considered as tolerable. For these reasons the authors are in favour of the combined use of several methods for the assessment of working posture tolerability. Practical examples provide guidelines to the authors' approach and conclusions are given. [ABSTRACT FROM PUBLISHER]

Background: Freezing of gait (FoG) is an episodic failure of gait exposing people with Parkinson's disease (PD) to a high risk of falling. Despite growing evidence of the interconnection between impaired trunk control and FoG, a detailed description of spinal kinematics during walking is still lacking in this population., Research Question: Do spinal alterations impact gait performance in individuals with PD and FoG?, Methods: We analyzed kinematic data of 47 PD participants suffering (PD-FOG, N = 24) or not suffering from FoG (PD-NFOG, N = 23) and 15 healthy controls (HCO) during quiet standing and unperturbed walking. We estimated the main spinal variables (i.e., spinal length, lordosis and kyphosis angles, trunk inclination), the pelvis angles, and the shoulder-pelvis angles during gait and standing. We studied differences across conditions and groups and the relationships between postural and gait parameters using linear regression methods., Results: During standing and walking, both PD groups showed increased trunk inclination and decreased lordosis angle with respect to HCO, as well as a decreased range in variation of kyphosis angle, pelvic obliquity, and shoulder-pelvis angles. Only PD-FOG participants showed reduced range of lordosis angle and spinal length compared to HCO. PD-FOG individuals were also not able to straighten their spine during walking compared to standing. Stride length and velocity were decreased in both patient groups compared to HCO, while swing duration was reduced only in the PD-FOG group. In individuals with FoG, trunk inclination and lordosis angle showed moderate but significant positive correlations with all gait alterations., Significance: Spine alterations impacted gait performance in individuals with PD suffering from FoG. Excessive trunk inclination and poor mastering of the lordosis spinal region may create an unfavourable postural precondition for forward walking. Physical therapy should target combined spinal and stepping alterations in these individuals., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Carbonatites and associated rocks are the main source of rare earth elements (REEs), metals essential to modern technologies. REE mineralization occurs in hydrothermal assemblages within or near carbonatites, suggesting aqueous transport of REE. We conducted experiments from 1200°C and 1.5 GPa to 200°C and 0.2 GPa using light (La) and heavy (Dy) REE, crystallizing fluorapatite intergrown with calcite through dolomite to ankerite. All experiments contained solutions with anions previously thought to mobilize REE (chloride, fluoride, and carbonate), but REEs were extensively soluble only when alkalis were present. Dysprosium was more soluble than lanthanum when alkali complexed. Addition of silica either traps REE in early crystallizing apatite or negates solubility increases by immobilizing alkalis in silicates. Anionic species such as halogens and carbonates are not sufficient for REE mobility. Additional complexing with alkalis is required for substantial REE transport in and around carbonatites as a precursor for economic grade-mineralization., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

Background: Power and work at the ankle joint during gait are usually computed considering the foot as a rigid body [1-6] (Ankle Joint method, AJ). The foot is instead a deformable structure and can absorb and produce work by pronation/supination, foot arch deformation and other intrinsic movements. A different approach, named "the Distal Shank method (DS)" [7-12] considers all these aspects without increasing the complexity of the protocol, and thus it seems promising for clinical applications [12]., Research Questions: a) To characterize the differences in power and work computed using the two mentioned methods for a relatively large number of subjects walking at different velocities, barefoot and with different shoes; b) To assess the practical feasibility of the DS method for clinical applications., Materials and Methods: Eighteen healthy subjects were evaluated while walking barefoot at slow, natural and fast velocity. Shod walking was analysed at natural velocity. Four subjects were also analysed while walking in high-heel shoes. The power at the ankle joint was computed with both the AJ and the DS methods. We then compared the obtained results., Results: The DS method showed a consistent negative peak of power absorption during the load acceptance phase, barely visible with the AJ method. The maximum power production calculated with the DS method was significantly lower. The work at the end of the stride cycle was lower with the DS method, and in most conditions even negative, thus indicating higher energy dissipation., Significance: We confirmed on a large cohort of healthy subjects and in different walking conditions that neglecting foot deformations during gait leads to underestimate power absorption and overestimate power production. The DS method does not require a complex gait analysis protocol, nor additional time for the analysis, and can provide information of clinical interest, related to foot mechanical alterations., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The importance of peripheral visual information during stair climbing and how peripheral visual information is weighted as a function of step number during step climbing is unclear. Previous authors postulated that the knowledge of predictable characteristics of the steps may decrease reliance on foveal vision and transfer the online visual guidance of stair climbing to peripheral vision. Hence the aim of this study was to investigate if and how the occlusion of the lower peripheral visual field influenced stair climbing and if peripheral visual information was weighted differently between steps. Ten young adult male participants ascended a 5-step staircase under 2 visual conditions: full vision (FV) and lower visual occlusion (LO). Kinematic data (100Hz) were collected. The effect of Vision and Step condition on vertical forefoot clearance was examined with a Repeated Measures 2-way ANOVA. Tukey's HSD test was used for post-hoc comparisons. A significant interaction Vision x Step and main effect of Step were found (p<=0.04): vertical forefoot clearance was greater in LO compared to FV condition only on the 1st and the 2nd steps (p<0.013) and on the last step compared to the other steps (p<0.01). These findings suggest that online peripheral visual information is more relevant when negotiating the first two steps, rather than the end of a staircase and that the steps subsequent the first few ones may require different information likely based on proprioception or working memory of the step height., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Mobile phones offer the possibility to monitor and track health parameters. Our aim was to test the feasibility and accuracy of measuring beat-to-beat heart rate using smartphone accelerometers by recording the vibrations generated by the heart during its function and transmitted to the chest wall, i.e. the so-called seismocardiographic signal (SCG)., Methods: 9 healthy male volunteers were studied in supine (SUP) and in standing (ST) posture. A smartphone (iPhone6, Apple) was positioned on the thorax (POS1) to acquire SCG signal. While supine, a second smartphone was positioned on the navel (POS2). The SCG signal was recorded for 3 minutes during spontaneous respiration, synchronous with 3-leads ECG. Using a fully automated algorithm based on amplitude thresholding after rectification, the characteristic peak of the SCG signal (IVC) was detected and used to compute beat-to-beat heart duration, to be compared with the corresponding RR intervals extracted from the ECG., Results: A 100% feasibility of the approach resulted for POS1 in SUP, while 89% in POS2, and 78% for POS1 in ST. In supine, for each smartphones' position, the automated algorithm correctly identified the cardiac beats with >98% accuracy. Linear correlation (r2) with RR was very high (>0.98) in each posture and position, with no bias and narrow limits of agreement., Conclusions: The obtained results proved the feasibility of the proposed approach and the robustness of the applied algorithm in measuring the beat-to-beat heart rate from smartphone-derived SCG, with high accuracy compared to conventional ECG-derived measure.