Effect of the muscle coactivation during quiet standing on dynamic postural control in older adults

2013 ◽  
Vol 56 (1) ◽  
pp. 129-133 ◽  
Author(s):  
Koutatsu Nagai ◽  
Minoru Yamada ◽  
Shuhei Mori ◽  
Buichi Tanaka ◽  
Kazuki Uemura ◽  
...  
2020 ◽  
Vol 76 (1) ◽  
pp. 101-107
Author(s):  
Natalie Ganz ◽  
Eran Gazit ◽  
Nir Giladi ◽  
Robert J Dawe ◽  
Anat Mirelman ◽  
...  

Abstract Background Wearable sensors are increasingly employed to quantify diverse aspects of mobility. We developed novel tandem walking (TW) metrics, validated these measures using data from community-dwelling older adults, and evaluated their association with mobility disability and measures of gait and postural control. Methods Six hundred ninety-three community-dwelling older adults (age: 78.69 ± 7.12 years) wore a 3D accelerometer on their lower back while performing 3 tasks: TW, usual-walking, and quiet standing. Six new measures of TW were extracted from the sensor data along with the clinician’s conventional assessment of TW missteps (ie, trip other loss of balance in which recovery occurred to prevent a fall) and duration. Principal component analysis transformed the 6 new TW measures into 2 summary TW composite factors. Logistic regression models evaluated whether these TW factors were independently associated with mobility disability. Results Both TW factors were moderately related to the TW conventional measures (r < 0.454, p < .001) and were mildly correlated with usual-walking (r < 0.195, p < .001) and standing, postural control (r < 0.119, p < .001). The TW frequency composite factor (p = .008), but not TW complexity composite factor (p = .246), was independently associated with mobility disability in a model controlling for age, sex, body mass index, race, conventional measures of TW, and other measures of gait and postural control. Conclusions Sensor-derived TW metrics expand the characterization of gait and postural control and suggest that they reflect a relatively independent domain of mobility. Further work is needed to determine if these metrics improve risk stratification for other adverse outcomes (eg, falls and incident disability) in older adults.


Author(s):  
Eryk Przysucha ◽  
Brontë A. Vollebregt ◽  
Carlos Zerpa

Postural control is attention demanding, and it may be jeopardized when a secondary cognitive task is involved, particularly for older adults. The magnitude of this interference depends on different individual (perceptuo-motor status), task (single vs. dual tasking), and environmental constraints (support surface). The purpose of this research was to examine if older adults may be affected by various types of secondary cognitive tasks, while maintaining quiet standing on different support surfaces. In line with conceptual models, the results indicated that postural control of older adults was compromised when they were required to dual-task, especially when the support surface was challenging. This was a robust finding across all the measures of COP. In regards to the degree to which different attentional tasks affected postural control, the results remained equivocal. From a practical standpoint, the results indicated that older adults should exhibit caution when simultaneously performing a balance and a cognitive task involved particularly when the surface is unsteady.


2010 ◽  
Vol 104 (6) ◽  
pp. 3510-3517 ◽  
Author(s):  
Hyun Gu Kang ◽  
Lewis A. Lipsitz

Distractions affect postural control, but this mechanism is not well understood. Diversion of resources during cognitive stress may lead to decreased motor drive and postural muscle tone. This may appear as decreased postural stiffness and increased postural sway amplitude. We hypothesized that dual tasking leads to decreased stiffness and increased sway amplitude. Postural sway (center of pressure; COP) data were used from 724 participants aged 77.9 ± 5.3 yr, a representative sample of community-dwelling older adults, the MOBILIZE Boston Study cohort. Subjects stood barefoot with eyes open for 30 s per trial on a force plate. Five trials were performed each with and without a serial subtractions-by-3 task. Sway data were fit to a damped oscillator inverted pendulum model. Amplitudes (COP and center of mass), mechanical stiffness, and damping of the sway behavior were determined. Sway amplitudes and damping increased with the dual task ( P < 0.001); stiffness decreased only mediolaterally ( P < 0.001). Those with difficulty doing the dual task exhibited larger sway and less damping mediolaterally ( P ≤ 0.001) and an increased stiffness with dual task anteroposteriorly (interaction P = 0.004). Dual task could still independently explain increases in sway ( P < 0.001) after accounting for stiffness changes. Thus the hypothesis was supported only in mediolateral sway. The simple model helped to explain the dual task related increase of sway only mediolaterally. It also elucidated the differential influence of cognitive function on the mechanics of anteroposterior and mediolateral sway behaviors. Dual task may divert the resources necessary for mediolateral postural control, thus leading to falls.


2020 ◽  
Vol 17 (2) ◽  
pp. 169-176 ◽  
Author(s):  
Wael Maktouf ◽  
Sylvain Durand ◽  
Bruno Beaune ◽  
Sébastien Boyas

Objective: To evaluate the role of obesity in the effects of physical activity (PA) on postural control and functional and physical capacities in the older adults and to assess the effectiveness of a PA program on these capacities. Methods: Six obese (age = 78.8 [3.7] y; body mass index > 30 kg/m2), 7 overweight (age = 80.9 [2.8] y; 25 < body mass index < 30 kg/m2), and 6 normal weight (age = 80.8 [5.7] y; body mass index < 25 kg/m2) older adults performed the time up and go test, the 6-minute walk test, and the Tinetti test. Static and dynamic (forward leaning) postural control tests were also assessed. All these tests were similarly assessed 4 months later, during which only the obese group and overweight group participated in a PA program. Results: Before PA, results of the time up and go test, 6-minute walk test, Tinetti test, quiet standing, and forward lean tests revealed that physical capacities and static and dynamic postural control were impaired in the obese group when compared to the normal weight group. After PA, results of quiet standing, physical and functional tests were improved for obese group. Conclusions: Obesity is an additional constraint to age-related postural control and functional and physical capacities deteriorations. Nevertheless, a PA program is effective in improving balance and functional capacities in obese older adults.


2020 ◽  
Vol 36 (3) ◽  
pp. 178-185
Author(s):  
Gregory S. Walsh ◽  
Daniel C. Low ◽  
Marco Arkesteijn

The aim of this study was to investigate the effects of backpack load carriage on quiet standing postural control and limits of stability (LOS) of older adults. Fourteen older adults (65 [6] y) performed quiet standing and a forward, right, and left LOS test in 3 conditions, unloaded, stable, and unstable backpack loads while activity of 4 leg muscles was recorded. Stable and unstable loads decreased postural sway (main effect , stable P < .001, unstable P < .001), mediolateral (main effect , stable P = .002, unstable P = .018) and anterior–posterior (main effect , stable P < .001, unstable P = .001) fractal dimension, and LOS distance (main effect , stable P = .011, unstable P = .046) compared with unloaded. Rectus femoris (main effect , stable P = .001, unstable P = .010) and gastrocnemius (main effect , unstable P = .027) activity increased in loaded conditions during LOS and quiet standing. Gastrocnemius–tibialis anterior coactivation was greater in unstable load than stable loaded quiet standing (main effect , P = .040). These findings suggest older adults adopt conservative postural control strategies minimizing the need for postural corrections in loaded conditions. Reduced LOS may also increase fall risk when carrying a load. However, there was no difference between unstable and stable loads for postural control variables.


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