Validity and reliability of a tool for accelerometric assessment of static balance in women

Center of Pressure Behavior in Response to Unexpected Base of Support Shifting: A New Objective Tool for Dynamic Balance Assessment

The translation of the base of support represents a promising approach for the objective assessment of dynamic balance control. Therefore, this study aimed to present a servo-controlled, electrically driven movable plate and a new set of parameters based on the center-of-pressure (CoP) trajectory. Twenty subjects were assessed on a force platform screwed over a movable plate that could combine the following settings: direction (forward (FW) and backward (BW)), displacement (25 mm, 50 mm, and 100 mm), and ramp rate (100 mm/s and 200 mm/s). The subjects underwent two sets of 12 trials randomly combining the plate settings. From the CoP trajectory of the 2.5 s time window after the perturbation, the 95% confidence-interval ellipse (Area95) and the CoP mean velocity (Unit Path) were calculated. Within the same time window, the first peak (FP), the maximal oscillations (ΔCoPMax), and the standard deviation (PPV) of the CoP anterior-posterior trajectory were calculated. The plate direction (p < 0.01), ramp rate (p < 0.001), and displacement (p < 0.01) affected the Area95, FP, and ΔCoPMax, while the Unit Path and PPV were influenced only by the ramp rate (p < 0.001) and displacement (p < 0.001). The servo-controlled, electrically driven movable plate and the CoP-related parameters presented in this study represent a new promising objective tool for dynamic balance assessment.

Accelerometer-based prediction of ground reaction force in head-out water exercise with different exercise intensity countermovement jump

Background

Water jumping exercise is an alternative method to achieve maintenance of bone health and reduce exercise injuries. Clarifying the ground reaction force (GRF) of moderate and high cardiopulmonary exercise intensities for jumping movements can help quantify the impact force during different exercise intensities. Accelerometers have been explored for measuring skeletal mechanical loading by estimating the GRFs. Predictive regression equations for GRF using ACC on land have already been developed and performed outside laboratory settings, whereas a predictive regression equation for GRF in water exercises is not yet established. The purpose of this study was to determine the best accelerometer wear-position for three exercise intensities and develop and validate the ground reaction force (GRF) prediction equation.

Methods

Twelve healthy women (23.6 ± 1.83 years, 158.2 ± 5.33 cm, 53.1 ± 7.50 kg) were recruited as participants. Triaxial accelerometers were affixed 3 cm above the medial malleolus of the tibia, fifth lumbar vertebra, and seventh cervical vertebra (C7). The countermovement jump (CMJ) cadence started at 80 beats/min and increased by 5 beats per 20 s to reach 50%, 65%, and 80% heart rate reserves, and then participants jumped five more times. One-way repeated analysis of variance was used to determine acceleration differences among wear-positions and exercise intensities. Pearson’s correlation was used to determine the correlation between the acceleration and GRF per body weight on land (GRF_VL_BW). Backward regression analysis was used to generate GRF_VL_BW prediction equations from full models with C7 acceleration (C7 ACC), age, percentage of water deep divided by body height (PWDH), and bodyweight as predictors. Paired t-test was used to determine GRF_VL_BW differences between values from the prediction equation and force plate measurement during validation. Lin’s CCC and Bland–Altman plots were used to determine the agreement between the predicted and force plate-measured GRF_VL_BW.

Results

The raw full profile data for the resultant acceleration showed that the acceleration curve of C7 was similar to that of GRFv. The predicted formula was − 1.712 + 0.658 * C7ACC + 0.016 * PWDH + 0.008 * age + 0.003*weight. Lin’s CCC score was 0.7453, with bias of 0.369%.

Conclusion

The resultant acceleration measured at C7 was identified as the valid estimated GRF_VL_BW during CMJ in water.

Effects of an Eccentric Training Protocol Using Gliding Discs on Balance and Lower Body Strength in Healthy Adults

Impaired balance and lower body weakness are the main causes of falls, which are considered to be the major cause of fractures and head injuries in the elderly and are recognised as a serious health problem. The aim of this study is to observe the effect of eccentric training, introducing new technologies (gliding discs), on body composition, lower body strength, balance and quality of life. A quasi-experimental study was carried out with 56 healthy participants who were divided into an experimental group (n = 31) who underwent the protocol consisting of 12 training sessions and a control group (n = 25) who did not undergo the training. Before and after the intervention, all participants underwent a measurement of body composition, the SJ jump, balance with accelerometry and quality of life with the Short Form 12 Health Survey. In the experimental group, statistically significant improvements were found in the variables balance and lower body strength. The application of this training protocol improves lower body strength and the ability to control balance in the adult population.

The Focal Mechanical Vibration for Balance Improvement in Elderly - A Systematic Review

Background

Aging has been associated with the progressive depletion of lean mass, reductions in muscle strength and the coordination of the lower extremities, accompanied by decreased gait assurance and balance control. Also, less balance control favors falling which is the leading cause of injury among the elderly. The aim of this systematic review is to identify and evaluate existing evidence regarding the use of focused vibration (FV) to improve balance and reduce the risk of falling during the rehabilitation of elderly populations.

Methods

The PICO question is what are the effects of focal/segmental/local vibration training on the assessment of balance and the risk of falls among the elderly population? A thorough literature review was conducted between May 1, 2009, and June 30, 2019, for studies in English, randomized clinical trials, including crossover and prospective design studies with assessing balance and the risk of falls in elderly populations (age > 60 years).

Results

Eight articles (N = 8) satisfied the inclusion criteria and were considered, of which 6 are RTC, one cross-sectional study and one clinical study, for a total of 635 participants. A total of 6 different vibration devices were used, each of which was associated with different FV frequency and amplitude characteristics and different treatment protocols.

Conclusion

In conclusion, FV can be effective in decreasing the risk of falls and improving the assessment of balance, but more evidence is necessary considering the limits of the studies; however, it does look an important promise during rehabilitative treatment.

Real-Time Back Surface Landmark Determination Using a Time-of-Flight Camera

Postural disorders, their prevention, and therapies are still growing modern problems. The currently used diagnostic methods are questionable due to the exposure to side effects (radiological methods) as well as being time-consuming and subjective (manual methods). Although the computer-aided diagnosis of posture disorders is well developed, there is still the need to improve existing solutions, search for new measurement methods, and create new algorithms for data processing. Based on point clouds from a Time-of-Flight camera, the presented method allows a non-contact, real-time detection of anatomical landmarks on the subject’s back and, thus, an objective determination of trunk surface metrics. Based on a comparison of the obtained results with the evaluation of three independent experts, the accuracy of the obtained results was confirmed. The average distance between the expert indications and method results for all landmarks was 27.73 mm. A direct comparison showed that the compared differences were statically significantly different; however, the effect was negligible. Compared with other automatic anatomical landmark detection methods, ours has a similar accuracy with the possibility of real-time analysis. The advantages of the presented method are non-invasiveness, non-contact, and the possibility of continuous observation, also during exercise. The proposed solution is another step in the general trend of objectivization in physiotherapeutic diagnostics.

Health-Related Quality of Life of Elderly Women with Fall Experiences

This study aimed to describe the health-related quality of life of elderly women with experience in fall treatment as well as to prepare basic data for the development of interventions to improve the quality of life for this group. The study was based on raw data from the 2019 Korea Community Health Survey. Using the SPSS program, the characteristics of the subjects were tested by frequency, percentage, and chi-square test. To establish the impact of fall experience on the health-related quality of life of elderly women, the OR and 95% CI were calculated using multiple logistic regression analysis. Of the 4260 people surveyed, 44.7% of the elderly women said they had a high quality of life, whereas 55.3% of the elderly women said they had a low quality of life. A younger age was associated with a better-rated health-related quality of life. Those who lived in a city and had a high level of education tended to describe a high quality of life. The quality of life was considered high by those who exercised, but low by those who were obese or diabetic. The results of this study can lead to a better understanding of the experiences of elderly women who have experienced falls, and they can be used as basic data for the development of related health programs.

Impact of high-heeled and sport shoes on multi-joint external load profile during walking

BACKGROUND

Previous studies have analysed the effect of wearing high-heeled shoes (HHS) on gait analysis, balance and its relation to health. However, further research is needed to study its effect on the difference of chain reactions in the transfer of body impacts from the lower to the upper limbs.

OBJECTIVES

The aims of the present research were: (a) to compare the effects of wearing HHS on impacts across body joints during walking with sport shoes (SS) as a reference, and (b) to examine such effects at different speeds.

METHODS

Seven well-trained women completed this study. Incremental treadmill walking test were performed with two different footwear: SS and HHS. Inertial devices were used to quantify the chain reactions at selected anatomical lower limbs and trunk locations. Statistical analysis included the Wilcoxon test with ranges and Cohen's d effect size with percentage of differences.

RESULTS

The highest values were found at the heel in both footwear and in both legs (SS: right =0.76 ± 0.27, left = 0.79 ± 0.27; HHS: right = 1.07 ± 0.38, left = 1.11 ± 0.41), while the lowest values were registered at lower and upper back. Furthermore, significant differences were found with the HHS load being higher at all locations (p< 0.05; %=𝑑𝑖𝑓𝑓 12.20-36.36%), influenced by the walking speed. In addition, a strong influence of footwear in the change of the laterality profile was found (p< 0.05).

CONCLUSIONS

These findings suggest that the use of HHS increase the load on the lower limb and the trunk. Until reaching 5 km/h during walking, no significant differences were found between wearing HHS or SS in accelerometer load, producing exponential differences from this speed. The great between-subject variability implies that within-subject analysis is recommended, as it is more related to real clinical practice.

Posture and Health: Are the Biomechanical Postural Evaluation and the Postural Evaluation Questionnaire Comparable to and Predictive of the Digitized Biometrics Examination?

Background: Postural tone alterations are expressions of myofascial and, therefore, of structural, visceral, and emotional disorders. To prevent these disorders, this study proposes a quantitative investigation method which administers a postural evaluation questionnaire and a postural biomechanical evaluation to 100 healthy subjects. Methods: The reliability of the method is studied by comparing both assessments with digitized biometrics. In addition, 50 subjects undergo the biomechanical evaluation form twice, by four different operators, to study the intraoperative repeatability. Results: The results show a satisfactory overlap between the results obtained with the postural evaluation questionnaire and the postural biomechanical evaluation compared to computerized biometrics. Furthermore, intraoperative repeatability in the use of the biomechanical evaluation form is demonstrated thanks to a minimal margin of error. Conclusions: This experience suggests the importance of undertaking this path in both the curative and the preventive sphere on a large scale and on different types of people who easily, and even unknowingly, may face dysfunctional syndromes, not only structural and myofascial but also consequently of the entire body’s homeostasis.

Accelerometric Assessment of Postural Balance in Children: A Systematic Review

The correct development of postural control in children is fundamental to ensure that they fully reach their psychomotor capacities. However, this capacity is one of the least studied in the clinical and academic scope regarding children. The objective of this study was to analyze the degree of implementation of accelerometry as an evaluation technique for postural control in children and how it is being used.

METHODS

A systematic search was conducted in PubMed, SpringerLink, SportsDiscus, Medline, Scopus, and Web of Science with the following terms: balance, postural control, children, kids, accelerometry, and accelerometer.

RESULTS

The search generated a total of 18 articles. Two groups of studies were differentiated: those which exclusively included healthy individuals (n = 5) and those which included children with pathologies (n = 13). Accelerometry is being used in children mainly to assess the gait and static balance, as well as to identify the differences between healthy children and children with developmental disorders.

CONCLUSIONS

Accelerometry has a discrete degree of implementation as an evaluation tool to assess postural control. It is necessary to define a systematic method for the evaluation of postural control in pediatrics, in order to delve into the development of this capacity and its alterations in different neurodevelopmental disorders.

Physical Activity Practice and Optimal Development of Postural Control in School Children: Are They Related?

Background: This study aims to analyze the effect of physical activity practice on the postural control state of school children. If such an effect was detected, the second aim of the study was to identify which specific capacities of postural control benefited the most from physical activity. Methods: A cross-sectional study was performed using a convenience sample of 118 healthy children (54 girls) with a mean age of 10.3 ± 1.2 years. Their weight and height were measured. The accelerometric assessment of balance included four different tests in static balance and walking. Results: Physical activity habit prevalence was 38.9% in girls and 60.9% in boys, and its frequency was 2.3 days per week in girls and 2.8 days in boys. The active children obtained lower accelerations, but the active and sedentary girls showed lower accelerometric values than the active boys. The logistic regression analysis demonstrated the influence of sex on the accelerations of the body (p < 0.001), regardless of the habit of physical activity. Conclusions: Active children have better postural control than sedentary children, although sedentary girls have better balance than active boys. Therefore, physical activity practice seems to favor a more efficient development of postural control, but it cannot level or reverse the effect of the neurophysiological factors that are conditioned by sex.

Monopodal Postural Stability Assessment by Wireless Inertial Measurement Units Through the Fast Fourier Transform

OBJECTIVES

(1) To describe the fast Fourier transform (FFT) multijoint as monopodal postural stability measurement in well-trained athletes, (2) to compare the within-subject FFT between laterality, joints, and body segments, and (3) to establish the within- and between-subject relationship between joints.

METHODS

Twelve national-level basketball players participated voluntarily in this investigation. The participants performed two 60-second repetitions of a monopodal stability test (1 repetition with each lower limb), separated by 3 minutes of active recovery. All tests were recorded by 4 WIMU PRO™ inertial devices located on the ankle, knee, lumbar spine, and thoracic spine. The main variable was total acceleration, where the FFT was applied.

RESULTS

The higher instability results were found in the ankle and in the nondominant lower limb (dominant = 1.131 [0.122] a.u. (arbitrary units); nondominant = 1.141 [0.172] a.u). In the body segment analysis, the greater percentage of differences (%diff) were shown between lumbar spine and knee in the dominant (%diff = -2.989%; d = 0.87) and nondominant (%diff = -3.243%; d = 0.90) lower limb. Finally, very large between-subjects variability was found in all joints and body segments.

CONCLUSIONS

The described protocol is proposed for monopodal postural stability assessment, being useful to provide information about the stability of joints and the body segment between joints. Besides, a within-subject analysis is recommended, and the FFT calculation will enable a linear analysis of each test.

Reliability of accelerometric assessment of balance in children aged 6-12 years

BACKGROUND

Development and evaluation of an accelerometers technique for collecting data for asses balance had reported difficulty due to equilibrium reactions and continuous bursts. The aim of this study is to determine the reliability and internal consistency of accelerometric measurements, related to static equilibrium and gait in children aged 6 to 12 years.

METHODS

This descriptive and cross-sectional study involved 70 healthy children (50% girls) with a mean age of 9 years old. At the height of the 4th lumbar vertebra and directly on the skin, an accelerometer was placed on each participant. All of them had to complete four trials three times: balancing on one leg with eyes closed and eyes open, dynamic balancing on one leg on a foam mat, and normal gait.

RESULTS

Results show that tests performed in older children had higher internal consistency than those performed in younger children (vertical axis r = 0.82, sagittal axis r = 0.77, and perpendicular axis r = 0.74). Tests performed in children aged 8 years or older presented a strong correlation between trials (r > 0.71). The three static equilibrium tests obtained reliability values between 0.76 y 0.84. On the contrary, gait test obtained inferior and poorer results (0.6 < r < 0.71).

CONCLUSIONS

This method of assessment obtained positive results as an instrument for the quantitative assessment of balance in school-aged children. Values obtained for the three one-leg balance and static tests,were more strongly correlated than the normal gait test for all axes.

Percentiles and Reference Values for the Accelerometric Assessment of Static Balance in Women Aged 50-80 Years

The identification of factors that alter postural stability is fundamental in the design of interventions to maintain independence and mobility. This is especially important for women because of their longer life expectancy and higher incidence of falls compared to men. The objective of this study was to construct the percentile box charts and determine the values of reference for the accelerometric assessment of the static balance in women. For this, an observational and cross-sectional study with a sample composed of 496 women (68.8 ± 10.4 years old) was conducted. The measurement of accelerations used a triaxial accelerometer during three tests: two tests on the ground in monopodal support and a test on a mat with monopodal support for 30 s each. In all of the variables, an increase in the magnitude of the accelerations was detected as the age advanced. The box charts of the percentiles of the tests show the amplitude of the interquartile ranges, which increased as the age advanced. The values obtained can be used to assess changes in static balance due to aging, trauma and orthopaedic and neurodegenerative alterations that may alter postural stability and increase the risk of falling.