Static balance tests are conducted in various clinics for diagnosis and treatment adjustment. As a result of population aging, the accessibility of these tests should be increased, in the clinic, and ...for remote patient examination. A number of publications have already conducted static balance evaluations using the sensors embedded in a smartphone. This study focuses on the applicability of using smartphone-based balance assessment on a large scale while considering ease of use, safety, and reliability. The Mon4t
app was used to acquire the postural motion using different smartphone devices, different smartphone locations, and various standing postures. The signals derived from the app were compared to the center of pressure displacement derived from a force plate. The results showed moderate to high agreement between the two methods, particularly at the tandem stance (0.69 ≤
≤ 0.91). Preliminary data collection was conducted on three healthy participants, followed by 50 additional healthy volunteers, aged 65+. The results demonstrated that the Mon4t app can serve as an accessible and inexpensive static balance assessment tool, both in clinical settings and for remote patient monitoring, which is key for enabling telehealth.
In type 1 diabetes, it is important to prevent diabetes‐related complications and postural instability may be one clinically observable manifestation early on. This study was set to investigate ...differences between type 1 diabetics and healthy controls in variables of instrumented posturography assessment to inform about the potential of the assessment in early detection of diabetes‐related complications. Eighteen type 1 diabetics with no apparent complications (HbA1c = 58 ± 9 mmol/L, diabetes duration = 15 ± 7 years) and 35 healthy controls underwent six 1‐min two feet standing postural stability tests on a force plate. Study groups were comparable in age and anthropometric and performed the test with eyes open, eyes closed (EC), and EC head up with and without unstable padding. Type 1 diabetics exhibited greater sway (path length, p = 0.044 and standard deviation of velocity, p = 0.039) during the EC test with the unstable pad. Also, power spectral density indicated greater relative power (p = 0.043) in the high‐frequency band in the test with EC head up on the unstable pad and somatosensory activity increased more (p = 0.038) when the unstable pad was added to the EC test. Type 1 diabetes may induce subtle changes in postural control requiring more active balancing when stability is challenged. Postural assessment using a portable easy‐to‐use force plate shows promise in detecting a diabetes‐related decline in postural control that may be used as a sensitive biomarker of early‐phase diabetes‐related complications.
Force plates have been widely used in various scientific fields to measure ground reaction forces experienced by animals and humans. A force plate that incorporates mechanical springs and non-contact ...displacement sensors offers the advantages of facilely modifying its shape and performance. However, the design protocol was limited to adjusting the plate size and spring constants of the springs supporting the plate at the four corners. Herein, we propose an optimization method for determining the spring constant distribution of a force plate. The proposed design enables the use of simulations to optimize the mechanical properties of the force plate, such as resonant frequency and error due to position. The experimental results demonstrated that the resonant frequency of the fabricated force plate was 133 Hz and the error due to position was within ±5 %. These results confirm that the proposed force plate can be effectively adjusted through optimization.
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•Optimization method for spring constant distribution is proposed for a force plate.•The fabricated force plate realizes a resonant frequency of 133 Hz, error due to position within ±5%.•The ground reaction force measured by the fabricated force plate matches that of a commercially available force plate.
CONTEXTUALIZAÇÃO: A manutenção do equilíbrio e da orientação corporal em humanos é garantida pelo adequado funcionamento do sistema de controle postural. A investigação desse controle tem despertado ...interesse em profissionais de diversas áreas, tais como, Fisioterapia, Educação Física, Engenharia, Física, Medicina, Psicologia, entre outras. OBJETIVOS: Revisar os métodos de análise experimental de dados utilizados para investigação do controle postural em seres humanos e demonstrar o cálculo e rotinas de programação das principais medidas utilizadas na avaliação desse controle. CONCLUSÃO: Os procedimentos experimentais e as medidas utilizadas na avaliação do controle postural apresentados nesta revisão poderão auxiliar na padronização da investigação do controle postural.
To evaluate the concurrent validity and test–retest reliability of common movement, strength, and balance tests using portable uniaxial dual force plates.
Repeated measures cross-sectional study.
...Sixteen healthy individuals participated in two testing sessions, where they performed 12 different movement, strength, and balance tests. Vertical ground reaction force and centre of pressure data were collected using the VALD ForceDecks simultaneously with ground-embedded laboratory force plates. Concurrent validity was assessed using root mean square error for raw time-series data and Bland–Altman plots for discrete metrics. Test–retest reliability was assessed using intraclass correlation coefficients and minimal detectable changes.
ForceDecks recorded vertical ground reaction forces and center of pressure with high accuracy compared to laboratory force plates. The mean bias between systems was negligible (<2 N or 0.1 mm), with small limits of agreement (<5 N or 1 mm). Overall, 530/674 (79%) showed good or excellent validity (<10% difference) and 611/773 (79%) had good or excellent reliability (intraclass correlation coefficient >0.75). ForceDecks reliability was similar to laboratory force plates (<0.07 intraclass correlation coefficient median difference for all metrics).
Portable uniaxial force plates record highly accurate vertical ground reaction forces and center of pressure during a range of movement, strength, and balance tests. The VALD ForcDecks are a valid and reliable alternative to laboratory force plates when strict standardized testing and data analysis procedures are followed. Users should be aware of the validity and reliability characteristics of the tests and metrics they choose.
Where was WAIR in avian flight evolution? Kuznetsov, Alexander N; Panyutina, Aleksandra A
Biological journal of the Linnean Society,
09/2022, Volume:
137, Issue:
1
Journal Article
Peer reviewed
Abstract
The popular hypothesis that the flapping flight of birds evolved through the stage of wing-assisted incline running (WAIR) is tested through calculations of external forces acting on the ...wings in the downstroke and upstroke during WAIR activity of an adult chukar partridge (Alectoris chukar). Contrary to previous studies of WAIR, it is found that the total vertical impulse provided by the wings is negative (i.e. downward directed). Thus, the wings cancel out about half of the positive (upward-directed) impulse provided by the legs. The function of the wings in WAIR is not to lift the body, but to push it towards the steep slope. It is like a wing, or aerofoil, of a race car, which is tilted at a negative angle of attack to press the car to the ground for greater friction and adhesion of the wheels and to prevent the race car from becoming airborne. The calculated force pattern suggests that the dominant external forces acting on the wings in the sagittal plane during WAIR are not the virtual forces of inertia but the aerodynamic forces. More specifically, it is only the aerodynamic lift that can be responsible for the wing force component acting at right angles to the wingbeat plane in both the downstroke and the upstroke during WAIR. The lift towards the slope during the WAIR upstroke is ensured by separation of the primary flight feathers and their setting at a negative angle of attack. Analysis of the force pattern in the anatomical coordinate space of a bird’s body shows that the main wing muscles in the WAIR downstroke are the humeral retractor muscles and in the WAIR upstroke the humeral elevator muscles. The humeral protractor muscles are not required at all during WAIR. Therefore, the morphologically necessary protractor state of the supracoracoideus muscle in a ‘semi-flying’ ancestor, which is logically explained by the classical hypothesis of a gliding ancestor, does not fit the WAIR hypothesis of flapping flight origin. Wing-assisted incline running should be regarded as a crown locomotor specialization of birds and is not an appropriate model for locomotion in avian ancestors.
AIM. The aim of the study was to develop a comprehensive physical rehabilitation program based on the use of stabiloplatform and balancing platforms and to assess the effectiveness of its use in ...patients in the early period of ischemic stroke at the inpatient stage.
MATERIALS AND METHODS. The study was conducted on the basis of the Department of Restorative Medicine and Rehabilitation of the Medical Complex of the Far Eastern Federal University. Depending on the physical rehabilitation program, three groups were formed by random sampling, comparable in gender, age, presence of risk factors for ischemic stroke, severity of patients. All three groups received drug therapy, neurorehabilitation and physical rehabilitation. The EG1 included patients who were given therapeutic gymnastics classes using balancing platforms. Patients of the EG2 also conducted therapeutic gymnastics classes using balancing platforms and additional training sessions on the stabiloplatform of the ST-150 (Mera-TSP LLC, Russia) with biological feedback. The CG included patients who were engaged in therapeutic physical education under a program provided for neurological patients, which has a general strengthening effect, contributing to the restoration and improvement of self-care skills, balance and movement functions.
RESULTS AND DISCUSSION. Despite advances in medical practice, the task of eliminating the consequences of a stroke remains unresolved. Disability after a stroke is a large percentage, and the search for new technologies to solve the problem of restoring lost body functions, improving the quality of life, returning to normal work is especially significant today. Before the start of comprehensive physical rehabilitation, when analyzing the results of the primary study of patients who had a stroke, according to various tests, movement disorders, imbalances, postural balance were observed. All patients had self-care and mobility problems and needed outside help, all had reduced quality of life scores. The results of the final (after completion of the physical rehabilitation course) testing of maintaining vertical posture and balance, mobility, balance, restoration of social independence and quality of life of stroke patients made it possible to prove the effectiveness of the treatment gymnastics complex using unstable balancing platforms and training on stabiloplatform.
CONCLUSION. The developed comprehensive physical rehabilitation program using unstable balancing platforms and training on stabiloplatform to a greater extent than the traditional therapeutic physical culture program provided for neurological patients contributed to increasing the degree of independence, self-care and mobility in everyday life, reducing the level of personal and situational anxiety, improving the psycho-emotional status of patients.
This study aimed to compare force plate, motion analysis, and mobile application methods for calculating vertical jump height. Twenty-nine male college students (age: 22.4 ± 1.0 years; height: 178.1 ...± 6.2cm; body weight: 71.2 ± 8.0 kg) voluntarily participated in the study. Two countermovement jumps (CMJ) with 1-minute intervals on a force platform (BERTEC 4060-10) were performed. The countermovement jump performances were captured using an iPhone 11 (Apple Inc., USA). The experimental setup involved using three high-speed cameras, specifically the My Jump 2 and SIMI Motion 7.5. Obtained results from hip displacement (HD) data with motion analysis system showed that participants had significantly lower vertical jump height calculated from motion capture (p = 0.01; -8.3 ± 3.86, 95%CI; MyJump2-SIMI_HD = 1.24/3.30). It was also found that calculations from left and right foot displacement were higher than My Jump 2 results (95%CI; MyJump2-SIMI_RF = 0.66/2.93) and 95%CI (MyJump2-SIMI_LF) = (-0.63/2.65). In contrast, force plate calculations, known as the gold standard in the literature, were very similar to My Jump (95%CI; MyJumpII-FP) = (2.38/4.01). The findings indicate that the My Jump 2, used for assessing vertical jump height, may be a reliable alternative for determining vertical jump height instead of setting up gold standard methods. Individuals' athletic performance abilities and birth, gender, and sports preferences should be considered. Finally, when coaches or sports scientists intend to measure CMJ, My Jump 2 application can be recommended as a laboratory application as well as a practical and valid measurement method, especially for field applications.
Abstract Impaired standing balance has a detrimental effect on a person's functional ability and increases their risk of falling. There is currently no validated system which can precisely quantify ...center of pressure (COP), an important component of standing balance, while being inexpensive, portable and widely available. The Wii Balance Board (WBB) fits these criteria, and we examined its validity in comparison with the ‘gold standard’—a laboratory-grade force platform (FP). Thirty subjects without lower limb pathology performed a combination of single and double leg standing balance tests with eyes open or closed on two separate occasions. Data from the WBB were acquired using a laptop computer. The test–retest reliability for COP path length for each of the testing devices, including a comparison of the WBB and FP data, was examined using intraclass correlation coefficients (ICC), Bland–Altman plots (BAP) and minimum detectable change (MDC). Both devices exhibited good to excellent COP path length test–retest reliability within-device (ICC = 0.66–0.94) and between-device (ICC = 0.77–0.89) on all testing protocols. Examination of the BAP revealed no relationship between the difference and the mean in any test, however the MDC values for the WBB did exceed those of the FP in three of the four tests. These findings suggest that the WBB is a valid tool for assessing standing balance. Given that the WBB is portable, widely available and a fraction of the cost of a FP, it could provide the average clinician with a standing balance assessment tool suitable for the clinical setting.
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