Computing the local dynamic stability using accelerometer data from inertial sensors has recently been proposed as a gait measure which may be able to identify elderly people at fall risk. However, the assumptions supporting this potential were concluded as most studies implement a retrospective fall history observation. The aim of this study was to evaluate the potential of local dynamic stability for fall risk prediction in a cohort of subjects over the age of 60 years using a prospective fall occurrence observation. A total of 131 elderly subjects voluntarily participated in this study. The baseline measurement included gait stability assessment using inertial sensors and clinical examination by Tinetti Balance Assessment Tool. After the baseline measurement, subjects were observed for a period of one year for fall occurrence. Our results demonstrated poor multiple falls predictive ability of trunk local dynamic stability (AUC = 0.673). The predictive ability improved when the local dynamic stability was combined with clinical measures, a combination of trunk medial-lateral local dynamic stability and Tinetti total score being the best predictor (AUC = 0.755). Together, the present findings suggest that the medial-lateral local dynamic stability during gait combined with a clinical score is a potential fall risk assessment measure in the elderly population.

Considering that most of the falls in elderly population arise during walking, tests derived from walking performance would be desirable for comprehensive fall risk assessment. The analysis of spatial temporal parameters and the center of pressure displacement, which represents the interaction between the human body and the ground, would be beneficial. The aim of this study was to compare spatial temporal gait parameters and their variability and the variability of the center of pressure displacement between elderly fallers and nonfallers during gait at self-selected, defined and fast speeds. A prospective study design was used. At the baseline, measurements of ground reaction force during gait at self-selected, defined and fast walking speeds by two force plates were performed. In addition, the Tinetti balance assessment tool, the Falls Efficacy Scale-International and the Activities-Specific Balance Confidence Scale were used. Mean and coefficient of variation of spatial temporal gait parameters and standard deviations of center of pressure displacement during loading response, midstance, terminal stance and preswing phases were calculated. Comparison of the fallers and nonfallers exhibited no significant difference in clinical tool, scales or spatial temporal parameters. Compared to nonfallers’ increased variability of walking speed at self-selected and defined speed, step width at fast walking speed and center of pressure displacement during preswing phase in medial-lateral directions at defined walking speed was found in fallers. However, application of the Holm-Bonferroni procedure for multiple comparisons exhibited no significant effect of group in any of the gait parameters. In general, our study did not observe an effect of group (fallers vs. nonfallers) on variability of spatial temporal parameters and center of pressure movement during gait. However, walking speed, step width as well as standard deviation of COP displacement in the medial-lateral direction during preswing exhibited a certain potential for distinguishing between elderly fallers and nonfallers.

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Ballet training has been reported to positively influence balance ability. It is not entirely clear how improved balance ability manifests under standing conditions with different demands on postural control. The aim of the study was to compare balance of ballet dancers and non-dancers in a unipedal stance under different conditions. Twenty-five professional ballet dancers and twenty-five controls completed four unipedal standing balance tests: firm surface with eyes open and closed; foam mat surface with eyes open; and firm surface with eyes open immediately after performing ten 360° whole-body turns. The centre of pressure (COP) data were obtained with a force platform and the direction-specific standard deviations, velocities, and sample entropy of the COP displacement were computed. A three-way analysis of variance was used to compare groups, genders, and conditions. For standing immediately after performing ten turns, the postural sway parameters were significantly larger in the control group compared to the ballet dancers in both men and women. In this stance condition the values of postural sway and COP velocities in the control group were larger in the men compared to the women. For both genders in the control group all postural sway and COP velocity parameters were larger in standing with eyes closed and standing after performing 10 turns compared to standing with eyes open on both firm and foam surface. In the ballet dancers all COP velocity parameters were larger in standing with eyes closed compared to all other conditions. The results from the present study indicate that professional ballet dancers do not have a better general balance ability than untrained subjects.

Background: Poor balance ability is a predictor of injuries of the lower extremity. Multi-intervention proprioception preventive programs, comprising balance training, strength, plyometric, agility, running, and stretching exercises, are effective in improving balance ability and reducing the risk of lower extremity injuries in athletes. Objective: The aim of the study was to examine the effect of a 20-week in-season multi-intervention proprioceptive neuromuscular training program on postural stability in male youth basketball players. Methods: Twenty-one elite male youth basketball players were divided into an intervention group (n = 10, age 17.3 ± 1.3 years) and a control group (n = 11, age 16.5 ± 1.8 years). During the in-season period (20 weeks), the intervention group followed a proprioceptive and neuromuscular training program, three times per week and 20 minutes per session. Balance was tested in a quiet unipedal stance (on both the dominant and non-dominant leg) on a foam mat with eyes open, before and after a 20-week period in both groups. The mean velocities in the medial-lateral and anterior-posterior directions and the mean total velocity of the centre of pressure (COP) displacement were obtained with a force platform. Results: The combined effect (pre-post test × group) showed that intervention resulted in significant improvement in the mean COP velocity for both the dominant and non-dominant limb in the anterior-posterior direction (p = .013 and p < .001, respectively) and in the medial-lateral direction (p = .007 and p < .001, respectively) as well as in the total COP velocity (p = .009 and p < .001, respectively). Conclusions: The specific proprioceptive and neuromuscular training had a positive effect on postural stability for both the dominant and non-dominant limb in basketball players.

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Background: Obesity and overweight are defined as abnormal or excessive fat accumulation and are associated with balance disorders. Objective: To assess the postural stability in a natural stance in overweight and obese women based on center of pressure (CoP) velocity in the anterior-posterior (AP) and medial-lateral (ML) directions. Methods: A total of 102 women categorized according to body mass index into normal weight, overweight and obese categories underwent a measurement of quiet standing with their eyes open (EO) and with their eyes closed (EC). Postural stability was assessed with a force platform. The mean CoP velocity was evaluated in both directions. Results: In the AP direction under EO conditions, obese women swayed significantly faster than normal weight women (1.01 cm/s and 0.80 cm/s). In the ML direction, a higher CoP velocity was observed in normal weight women than in obese women (0.52 cm/s and 0.41 cm/s). Under EC conditions in the AP direction, obese women swayed significantly faster than normal weight women (1.29 cm/s and 0.97 cm/s). In the ML direction, a higher CoP velocity was observed in normal weight women than in obese women (0.65 cm/s and 0.48 cm/s). Conclusions: Results suggest a negative impact of obesity on postural stability in the AP direction. In the ML direction, obese women were more stable than normal weight women, probably due to enlargement of the support base in a natural stance.

For quantifying muscle strength in clinical and research practice, establishing the reliability of measurements, specifically to the procedures used, is essential for credible findings. The objective was to establish the reliability of isokinetic measurement of ankle plantar and dorsal flexors (PF/DF) and invertors and evertors (INV/EV) on an IsoMed 2000 dynamometer. Twenty healthy subjects (10 males, 10 females, mean age: 23.1 ± 3.1 years) completed an isokinetic measurement session. The intraclass correlation coefficient (ICC) and standard error of measurement were assessed for peak torque and work of ankle PF/DF (concentric and eccentric) and INV/EV (concentric) for the preferred and nonpreferred limb. Standardized isokinetic measurements of reciprocal PF/DF and INV/EV muscle actions were associated with ICC ranging from 0.77 to 0.98 for the majority of observed parameters. The exception was work in the eccentric mode in the ankle DF and peak torque in the concentric mode in the ankle INV on the preferred limb, where ICC ranged from 0.64 to 0.71. The IsoMed 2000 isokinetic dynamometer can be reliably employed in future studies for reciprocal ankle PF/DF and INV/EV assessment in healthy adult subjects after implementation of a familiarization session.