Older adults can improve compensatory stepping with repeated postural perturbations (original) (raw)
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Compensatory Stepping: The Biomechanics of a Preferred Response Among Older Adults
Experimental Aging Research, 2001
The purpose of this study was to evaluate age-related differences in the mechanics of the compensatory stepping response to balance threats. A moving platform was used to disturb the balance of 16 younger (21 to 35 years) and 19 older (68 to 88 years) adults. Backward platform translations consisted of 15-cm displacements with peak accelerations ranging from 9.4 to 15.2 m=s 2 . Older adults were more likely to use a step to recover balance and stepped at lower perturbation magnitudes than younger adults. Group differences were not found in time to step initiation or segmental momentum. The lack of group differences in momentum revealed that lower perturbation accelerations created an equivalent or greater magnitude of body motion in older adults compared to higher
Gait & Posture, 2012
In 2030, nearly one-third of the population in Japan is expected to be more than 65 years old. The aging of society has become a major issue not only in Japan, but also in many other countries [1]. Falling is one of the most serious problems associated with aging. Approximately one-third of adults over 65 years old fall at least once a year [2], and falls represent the major cause of hip fractures. The estimated number of hip fractures worldwide was about 1.7 million in 1990 and will increase to 6.3 million in 2050 even if age-adjusted incidence rates for hip fractures remain stable [3]. In addition to the resulting injuries, falls lead to a fear of falling [4], loss of confidence [5], and greater functional decline in activities of daily living [6]. Preventing falls is thus a major concern around the world. When balance is lost, the individual tries to recover their equilibrium. Strategies for balance recovery can be divided into 'fixed-support' and 'change-in-support' [7]. The fixed-support strategy involves balance recovery within the same base of support (BOS), such as traditional ankle or hip strategies using muscular synergies. The change-in-support strategy represents extending the BOS by compensatory stepping or reaching. This strategy has the potential to achieve regained balance from more robust disturbances than the former strategy [7]. However, the change-insupport strategy is likely to be more demanding and involve cognitive functions, due to the need to rapidly initiate and execute complex limb movements appropriate to the characteristics of the balance disturbance and the constraints of the surrounding environment [8,9]. Age-related changes relating to falls have been reported in compensatory steps [10-12], with the elderly showing a greater tendency to lose lateral stability during stepping. Anticipatory postural adjustments (APAs) are defined as a lateral shift of the center of pressure (COP) toward the swing leg side before taking compensatory steps. During volitional stepping, APAs clearly occur and contribute to the preservation of lateral
Age-dependent differences in lateral balance recovery through protective stepping
Clinical Biomechanics, 2005
Background. Aging appears to present particular problems for lateral balance stability related to falls. Protective stepping is a common strategy for maintaining balance that may be impaired with aging due to changes in neuromusculoskeletal factors. This study assessed the response patterns, kinematics, and single support hip abduction torque during lateral protective stepping for balance recovery in healthy young and elderly adults.
BMC Geriatrics
Introduction The inability to recover from unexpected lateral loss of balance may be particularly relevant to the problem of falling. Aim We aimed to explore whether different kinematic patterns and strategies occur in the first recovery step in single-step trials in which a single step was required to recover from a fall, and in multiple-step trials in which more than one step was required to recover from a fall. In addition, in the multiple-step trials, we examined kinematic patterns of balance recovery where extra steps were needed to recover balance. Methods Eighty-four older adults (79.3 ± 5.2 years) were exposed to unannounced right/left perturbations in standing that were gradually increased to trigger a recovery stepping response. We performed a kinematic analysis of the first recovery step of all single-step and multiple-step trials for each participant and of total balance recovery in the multiple-step trial. Results Kinematic patterns and strategies of the first recovery ...
2021
Introduction—The inability to recover from unexpected lateral loss of balance may be particularly relevant to the problem of falls.Aim—We aimed to explore whether different kinematic patterns and strategies occur in the first recovery step in single-step trials when single step was required to recover from fall and in the multiple-step trials, when more than one step were required to recover from fall. In addition, in the multiple-step trials we examined kinematic patterns of balance recovery where extra steps were needed to recover balance. Methods—Eighty-four older adults (79.3±5.2 years) were exposed to announced right/left perturbations in standing that were gradually increased to trigger a recovery stepping response. We performed kinematic analysis of the first recovery step of all single-step and multiple-step trials for each participant and of total balance recovery in the multiple-step trial.Results—Kinematic patterns and strategies of the first recovery step in the single-s...
Short-term changes in protective stepping for lateral balance recovery in older adults
Clinical Biomechanics, 2012
Background-Fall prevention for older adults is dependent on the ability to maintain protective balance. This study measured the short-term changes of protective stepping following waist-pull perturbations in the medio-lateral direction, to identify what, if any, properties of protective stepping are improved with repeated perturbation exposures. Methods-Sixty waist-pulls (2 directions × 5 intensities × 6 repetitions) from a single session were analyzed separately as early, middle, and late testing periods, for a comparison over time of typical responses. Outcome measures included the number of evoked steps, type of step, incidence of interlimb collisions, and kinematic and kinetic properties of the first step in frequently used crossover-type responses. Findings-Improvements were evident as significantly reduced number of steps and collisions. However, these improvements could not be completely accounted for by significant changes in first step kinematic or kinetic properties. Interpretation-We infer that older individuals experiencing repeated lateral waist-pull perturbations optimize the predictive or feed-forward motor control for balance recovery through stepping.
Human Movement Science, 2019
With the socioeconomic burden associated with falls expected to rise as the average age of the Canadian population increases, research is needed to elucidate the nature of postural responses generated by older adults (OA) following a posture-destabilizing event. This knowledge is even more imperative for novel and difficult tasks, such as gait initiation (GI), a task known to pose a postural threat to stability for OA. A common technique to regain stability following an unexpected perturbation is reactive stepping. A deficiency in the execution of a reactive control strategy following a destabilizing event may be the cause of many unexpected falls in OA. The purpose of this study is to explore age related changes in the nature of these responses during a challenging GI task combined with an unexpected forward perturbation of the support surface. A total of 18 young adults (YA) and 16 OA performed 36 trials containing 20 unexpected perturbations. We calculated step width, length, time and COM velocity in the first unperturbed step and the second perturbed step. Results revealed that, during unperturbed GI, OA had a reduced forward velocity and took shorter, faster steps. Following forward perturbations, OA altered stepping patterns, perhaps to reduce single support duration, via reduced base of support and shorter step length compared to YA. Additionally, OA executed both forward and backwards directed steps however YA only generated forward steps. Regression analyses revealed that reduced forward velocity was predictive of step direction; which is possibly an unfavorable motor control strategy as OA who walk slower generated a posterior directed step immediately following the perturbation. This strategy is of concern as rapid responses by the trail limb are required to recover successfully, and these alterations may be associated with an elevated risk of falls.
Gait & posture, 2017
Although step training improves the ability of quick stepping, some home-based step training systems train limited stepping directions and may cause harm by reducing stepping performance in untrained directions. This study examines the possible transfer effects of step training on stepping performance in untrained directions in older people. Fifty four older adults were randomized into: forward step training (FT); lateral plus forward step training (FLT); or no training (NT) groups. FT and FLT participants undertook a 15-min training session involving 200 step repetitions. Prior to and post training, choice stepping reaction time and stepping kinematics in untrained, diagonal and lateral directions were assessed. Significant interactions of group and time (pre/post-assessment) were evident for the first step after training indicating negative (delayed response time) and positive (faster peak stepping speed) transfer effects in the diagonal direction in the FT group. However, when th...