Measuring center of pressure signals to quantify human balance using multivariate multiscale entropy by designing a force platform

Copyright @ 2013 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).To assess the improvement of human body balance, a low cost and portable measuring device of center of pressure (COP), known as center of pressure and complexity monitoring system (CPCMS), has been developed for data logging and analysis. In order to prove that the system can estimate the different magnitude of different sways in comparison with the commercial Advanced Mechanical Technology Incorporation (AMTI) system, four sway tests have been developed (i.e., eyes open, eyes closed, eyes open with water pad, and eyes closed with water pad) to produce different sway displacements. Firstly, static and dynamic tests were conducted to investigate the feasibility of the system. Then, correlation tests of the CPCMS and AMTI systems have been compared with four sway tests. The results are within the acceptable range. Furthermore, multivariate empirical mode decomposition (MEMD) and enhanced multivariate multiscale entropy (MMSE) analysis methods have been used to analyze COP data reported by the CPCMS and compare it with the AMTI system. The improvements of the CPCMS are 35% to 70% (open eyes test) and 60% to 70% (eyes closed test) with and without water pad. The AMTI system has shown an improvement of 40% to 80% (open eyes test) and 65% to 75% (closed eyes test). The results indicate that the CPCMS system can achieve similar results to the commercial product so it can determine the balance.National Science Council (NSC) of Taiwan and the Center for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan (which is sponsored by the NSC)

Age-related differences in adaptation during childhood: The influences of muscular power production and segmental energy flow caused by muscles

Acquisition of skillfulness is not only characterized by a task-appropriate application of muscular forces but also by the ability to adapt performance to changing task demands. Previous research suggests that there is a different developmental schedule for adaptation at the kinematic compared to the neuro-muscular level. The purpose of this study was to determine how age-related differences in neuro-muscular organization affect the mechanical construction of pedaling at different levels of the task. By quantifying the flow of segmental energy caused by muscles, we determined the muscular synergies that construct the movement outcome across movement speeds. Younger children (5-7 years; n = 11), older children (8-10 years; n = 8), and adults (22-31 years; n = 8) rode a stationary ergometer at five discrete cadences (60, 75, 90, 105, and 120 rpm) at 10% of their individually predicted peak power output. Using a forward dynamics simulation, we determined the muscular contributions to crank power, as well as muscular power delivered to the crank directly and indirectly (through energy absorption and transfer) during the downstroke and the upstroke of the crank cycle. We found significant age × cadence interactions for (1) peak muscular power at the hip joint [Wilks' Lambda = 0.441, F(8,42) = 2.65, p = 0.019] indicating that at high movement speeds children produced less peak power at the hip than adults, (2) muscular power delivered to the crank during the downstroke and the upstroke of the crank cycle [Wilks' Lambda = 0.399, F(8,42) = 3.07, p = 0.009] indicating that children delivered a greater proportion of the power to the crank during the upstroke when compared to adults, (3) hip power contribution to limb power [Wilks' Lambda = 0.454, F(8,42) = 2.54, p = 0.023] indicating a cadence-dependence of age-related differences in the muscular synergy between hip extensors and plantarflexors. The results demonstrate that in spite of a successful performance, children construct the task of pedaling differently when compared to adults, especially when they are pushed to their performance limits. The weaker synergy between hip extensors and plantarflexors suggests that a lack of inter-muscular coordination, rather than muscular power production per se, is a factor that limits children's performance ranges

Obesity decreases both whole muscle and fascicle strength in young females but only exacerbates the aging-related whole muscle level asthenia.

Obesity has previously been associated with greater muscle strength. Aging, on the other hand, reduces muscle specific force (the force per unit physiological cross-sectional area [PCSA] of muscle). However, neither the effect of obesity on skeletal muscle specific force nor the combined effects of aging and obesity on this parameter are known. This study aimed to describe the interplay between body mass index (BMI)/adiposity, aging, and skeletal muscle specific force. Ninety-four untrained healthy women categorized by age into young (Y; mean ± SD: 25.5 ± 9.0 years) versus old (O; 64.8 ± 7.2 years) were assessed for body composition, gastrocnemius medialis (GM) muscle volume (V), net maximum voluntary contraction (nMVC), and specific force (SF). The young obese, while demonstrating 71% and 29% (P 40% adiposity. Interestingly, however, obesity appeared advantageous to the aging-related changes in nMVC/V (P < 0.001) and SF (P < 0.001). Unlike previous reports of greater strength in the obese compared with leaner age-matched counterparts, we in fact demonstrate that the young sedentary obese, are substantially weaker, where the volume of skeletal muscle is used to scale the maximal torque output, or forces are quantified at the fascicular level. The seemingly positive impact of obesity on rate of aging, however, is complex and warrants further investigations

Self-perceived performance and satisfaction with performance of daily activities in persons with multiple sclerosis following interdisciplinary rehabilitation.

Abstract Purpose: To assess self-perceived performance and satisfaction with performance of daily activities in persons with multiple sclerosis (MS) on admission to and at discharge from interdisciplinary rehabilitation. Method: A retrospective study with a pre-post design. Twenty-seven women and 16 men with MS (mean age 51 years; median EDSS 6.5) participated in an individualised, goal-oriented, interdisciplinary, rehabilitation programme (average length 4 weeks). The Canadian Occupational Performance Measure (COPM) was used on admission to rehabilitation and at discharge. Results: On admission, the persons prioritised 216 activities that they perceived difficult to perform (mean number 3, range 2-8). Of these, 136 (63%) were in the COPM area of self-care, 52 (24%) in productivity and 28 (13%) in leisure. The lowest mean ratings of performance were found in the subgroups active recreation, community management and socialisation, and for satisfaction in the subgroup socialisation. For about 60% of the 216 prioritised activities, ratings of COPM performance as well as satisfaction were higher at discharge than on admission. For 18 (42%) and 24 (56%) persons, respectively, the mean change scores of performance and of satisfaction were equal to or greater than 2.0 at discharge, indicating a clinically significant change. Conclusions: Persons with MS can experience problems with all types of daily activities upon admission to rehabilitation, but also perceive improvements in their performance and satisfaction with performance in these activities at discharge from rehabilitation. Using patient-reported outcome measures, such as the COPM, may contribute to a broader understanding of the benefits of interdisciplinary rehabilitation in persons with MS. Implications for Rehabilitation Persons with MS can perceive problems with all types of daily activities which have to be considered during interdisciplinary rehabilitation. Following interdisciplinary rehabilitation, persons with MS can perceive improvements in their performance and satisfaction with performance in all types of daily activities. Patient-reported outcome measures can contribute to a broader understanding of the benefits of interdisciplinary rehabilitation in persons with MS

Sport, sex and age increase risk of illness at the Rio 2016 Summer Paralympic Games: a prospective cohort study of 51 198 athlete days

OBJECTIVETo describe the epidemiology of illness at the Rio 2016 Summer Paralympic Games. METHODS A total of 3657 athletes from 78 countries, representing 83.5% of all athletes at the Games, were monitored on the web-based injury and illness surveillance system (WEB-IISS) over 51 198 athlete days during the Rio 2016 Summer Paralympic Games. Illness data were obtained daily from teams with their own medical support through the WEB-IISS electronic data capturing systems. RESULTSThe total number of illnesses was 511, with an illness incidence rate (IR) of 10.0 per 1000 athlete days (12.4%). The highest IRs were reported for wheelchair fencing (14.9), para swimming (12.6) and wheelchair basketball (12.5) (p<0.05). Female athletes and older athletes (35–75 years) were also at higher risk of illness (both p<0.01). Illnesses in the respiratory, skin and subcutaneous and digestive systems were the most common (IRs of 3.3, 1.8 and 1.3, respectively). CONCLUSION (1) The rate of illness was lower than that reported for the London 2012 Summer Paralympic Games; (2) the sports with the highest risk were wheelchair fencing, para swimming and wheelchair basketball; (3) female and older athletes (35–75 years) were at increased risk of illness; and (4) the respiratory system, skin and subcutaneous system and digestive system were most affected by illness. These results allow for comparison at future Games

Engagement in occupations in persons with Multiple Sclerosis

The overall aim of this thesis was to increase our knowledge of engagement in occupations in persons with Multiple Sclerosis (MS) in order to develop client-centred occupational therapy and rehabilitation. In study I, observations of the performance of self-care and household occupations were pursued in 44 participants, and study II identified self-perceived problems in performance of occupations in 47 participants. In studies III and IV, in-depth interviews with ten participants revealed experiences related to engagement in occupations and to the process of adaptation of engagement in occupations. The results showed that persons with MS can perceive problems related to all areas of occupations, and at different hierarchical levels. They can be dissatisfied with performance in occupations, especially related to self-care and household occupations and observational assessments confirm that performance in these occupations is impacted on. Furthermore, they can be independent in self-care but dependent in household occupations, and can have problems in their performance regardless of their age, disease severity, or their living arrangements. They can experience that they need to struggle continuously to manage occupations, and that this changes them as a person and make them live their lives differently than they had anticipated. In addition, they experience their adaptation of engagement in occupations as an ongoing, non-linear process, involving both themselves and their family, and they consider who would benefit the most, before they choose their adaptation of engagement in occupations. In summary, this thesis has shown that engagement in occupations in persons with MS is a complex phenomenon. All areas of occupations can be affected, and need to be addressed within occupational therapy and rehabilitation. Clients’ own experiences needs to be elucidated in order to facilitate the reconstruction of self, identity and support the process of adaptation of occupations

The contributions of fibre atrophy, fibre loss, in situ specific force and voluntary activation to weakness in sarcopenia

The contributions of fibre atrophy, fibre loss, in situ specific force and voluntary activation to weakness in sarcopenia remain unclear. To investigate, forty older (20 women; age 72±4yrs) and 31 younger adults (15 women, age 22±3yrs) completed measurements. The knee extensor maximal voluntary torque (MVC) was measured as well as voluntary activation, patella tendon moment arm length, muscle volume and fascicle architecture to estimate in situ specific force. Fibre cross-sectional area (FCSA), fibre numbers and connective tissue contents were also estimated from vastus lateralis biopsies. The MVC, quadriceps volume and specific force were 39%, 28% and 17% lower, respectively, in old compared with young, but voluntary activation was not different. The difference in muscle size was due in almost equal proportions to lower type II FCSA and fewer fibres. Five years later (n=23) the MVC, muscle volume and voluntary activation in old decreased an additional 12%, 6% and 4%, respectively, but there was no further change in specific force. Conclusions: in situ specific force declines relatively early in older age and reduced voluntary activation occurs later, but the overall weakness in sarcopenia is mainly related to loss of both type I and II fibres and type II fibre atrophy

In vivo measurements of muscle specific tension in adults and children

This article is available open access through the publisher’s website at the link below. Copyright @ 2009 The Authors.To better understand the effects of pubertal maturation on the contractile properties of skeletal muscle in vivo, the present study investigated whether there are any differences in the specific tension of the quadriceps muscle in 20 adults and 20 prepubertal children of both sexes. Specific tension was calculated as the ratio between the quadriceps tendon force and the sum of the physiological cross-sectional area (PCSA) multiplied by the cosine of the angle of pennation of each head within the quadriceps muscle. The maximal quadriceps tendon force was calculated from the knee extension maximal voluntary contraction (MVC) by accounting for EMG-based estimates of antagonist co-activation, incomplete quadriceps activation using the interpolation twitch technique and magnetic resonance imaging (MRI)-based measurements of the patellar tendon moment arm. The PCSA was calculated as the muscle volume, measured from MRI scans, divided by optimal fascicle length, measured from ultrasound images during MVC at the estimated angle of peak quadriceps muscle force. It was found that the quadriceps tendon force and PCSA of men (11.4 kN, 214 cm2) were significantly greater than those of the women (8.7 kN, 152 cm2; P 0.05) between groups: men, 55 ± 11 N cm−2; women, 57.3 ± 13 N cm−2; boys, 54 ± 14 N cm−2; and girls, 59.8 ± 15 N cm−2. These findings indicate that the increased muscle strength with maturation is not due to an increase in the specific tension of muscle; instead, it can be attributed to increases in muscle size, moment arm length and voluntary activation level

How to Promote Collaboration and Local Ownership in an Aid Project A Case Study of the Mkula Hospital Project in Tanzania

A case study of a small-scale foreign aid project at a hospital in Mkula, Tanzania, was performed as a part of this thesis. The primary objective of the project was to improve the water supply for the hospital. The researchers, referred to as we, lived in the village of Mkula for eight weeks during the implementation of the project. The purpose of this thesis is to evaluate how collaboration could be improved in the project and how local ownership by the hospital could be promoted. An inductive research methodology was applied starting with the case study at Mkula Hospital. This was followed by a literature review concerning topics chosen after identifying patterns based on our experiences during the project. Throughout the project process we collaborated with the Hospital Management and several local actors. In order to achieve the aim of the project it was important to work closely with the involved actors, since they possessed unique and important knowledge. Cultural barriers resulted in many obstacles during the project, especially in regards to the process of collaboration and utilizing their knowledge. Thereby, we aimed to find a theory that could have been helpful in the project to utilize all experience and competence and accordingly promote the collaboration. We found the theory of Multi-Stakeholder Processes (MSPs) which includes frameworks on how people and organizations can work together despite very different backgrounds. MSPs promote dialogue which can grow to consensus-building, decision-making and generate the necessary commitment to the implementation of practical solutions. The analysis showed that several situations in the project where an open dialogue took place resulted in promoted collaboration. Thereby, a main conclusion of the study is that implementing an involving approach inspired by MSPs could have contributed to the sharing of different experiences, motivations and expectations in an earlier stage. This can facilitate overcoming the cultural barriers identified in the study, such as language, perceptions of time and ethnocentrism. With present dialogue, diverse views can be developed to common strategies and goals. In turn, a more consistent involvement of the Hospital Management throughout the project process could be a way to promote local ownership for Mkula Hospital since solutions can be adapted more to the local context