Kinematic and kinetic characteristics of stepping over a 10-cm-high obstacle in older adults (original) (raw)
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Strategies for obstacle crossing in older adults with high and low risk of falling
Journal of Physical Therapy Science, 2016
Tripping is a frequent cause of falls among aging adults. Appropriate limb movements while negotiating obstacles are critical to trip avoidance. The aim of our study was to investigate the mechanics of obstacle crossing in older adults at low or high risk of falling. [Subjects and Methods] Twenty community-dwelling adults aged ≥55 years, were evaluated with the Tinetti Balance and Gait scale and classified as being at high or low risk of falling. Between-group comparisons of kinematics were evaluated for obstacle heights of 10%, 20%, and 30% of leg length. [Results] The high-risk group demonstrated greater toe-obstacle clearance of the leading leg. Increasing obstacle height led to increased maximal toe-obstacle clearance, toe-obstacle distance, and shortened swing phase of the leading limb. Adaptation of clearance height was greater for the trailing leg. Individuals at high risk of falling demonstrated less symmetry between the leading and trailing legs and a narrower step width, features that increase the likelihood of tripping. [Conclusion] Kinematic parameters of obstacle clearance, including the symmetry index described in our study, could provide clinicians with a quick screening tool to identify patients at risk of falling and to evaluate outcomes of training programs.
Gait & Posture, 2004
Previous research suggests that older adults may have difficulty attending to simultaneous tasks. This study was conducted to determine how concurrent performance of a secondary cognitive task influences walking and stepping over an obstacle in community dwelling older adults. Twenty-one men and women with a mean age of 73.4 years (S.D. = 5.3) participated in the study. Subjects performed a gait task both alone (single-task condition) and in combination with a cognitive task that involved reciting numbers (dual-task condition). In the gait task, each subject walked at his/her fastest speed along a 10-m walkway and stepped over an obstacle designed to simulate a door threshold. Paired t-tests were used to compare gait parameters (10 m gait speed, gait speed during obstacle approach and negotiation, medial-lateral center of pressure excursion and velocity during obstacle negotiation, foot clearance over the obstacle, step length and foot position relative to the obstacle) and cognitive task performance under single and dual-task conditions. Toe-obstacle distance was greater and obstacle-heel distance was reduced under dual-task conditions. Performance of the remaining gait parameters did not change with the addition of a secondary cognitive task. Cognitive task performance decreased under dual-task conditions. These community dwelling older adults demonstrated minimal or no change in measured gait parameters during simultaneous performance of a cognitive task. The observed decrement in cognitive task performance suggests that subjects may have placed a higher priority on gait performance.
The journals of gerontology. Series A, Biological sciences and medical sciences, 2013
BACKGROUND: Falls leading to disability are common occurrences with advancing age. Stepping is a natural protective option for maintaining balance and preventing falls. There are directionally dependent challenges for protective stepping associated with falls among older individuals. The aim of this study was to determine the stepping response patterns evoked by different directions of externally applied postural disturbances in younger and older adults and in relation to falls. METHODS: Seventy-five community-dwelling adults were tested: 26 younger adults and 49 older adults. Fall history of older participants was tracked prospectively for 1 year after testing. Steps were randomly evoked in 12 directions by a motorized waist-pull system. The number of recovery steps, type of stepping strategy, and first step kinematic characteristics were determined. RESULTS: Younger participants mainly used single recovery steps regardless of the perturbation direction. For the older groups, multiple steps occurred predominantly and were least for the forward-backward directions and greatest for the lateral directions. Trials with three or more recovery steps were increased laterally only for the fallers. Overall, fallers initiated stepping earliest, but other stepping characteristics were similar between the groups for forward-backward perturbations. Aging differences in stepping strategies for diagonal and lateral perturbations included numerous interlimb collisions. Adaptive changes in stepping characteristics between forward and lateral perturbations were also observed in relation to age and risk of falls. CONCLUSIONS: These results indicated an age-associated reduction in balance recovery effectiveness through stepping particularly for the lateral direction among older individuals at greater risk for falls.
Falls in Older People: Effects of Age and Blurring Vision on the Dynamics of Stepping
Investigative Opthalmology & Visual Science, 2005
PURPOSE. The risk of falling increases dramatically with age, and visual impairment is known to be an important risk factor. Therefore, it is highly pertinent to assess the effects of age and vision on the performance of everyday tasks linked to falling, such as stepping from one level to another. METHODS. Nine young (age, 26 Ϯ 4 years) and ten elderly (age, 72 Ϯ 5 years) subjects performed a stepping-up task of three different heights. Their stepping strategies with blurred and optimally corrected vision were compared. Center of mass (CM), center of pressure (CP) dynamics (in the mediolateral and anteroposterior directions), and foot clearance parameters were determined, and statistical regression modeling was applied. RESULTS. Elderly subjects spent 20% more time (P ϭ 0.03) than young subjects during double support and they had reduced anteroposterior CM-CP divergence (P Ͻ 0.001) during double support and slower anteroposterior (P Ͻ 0.001) and mediolateral (P ϭ 0.002) CM velocities during initiation of movement and single limb support. Blur caused similar adaptations, such as increased toe clearance, across both age groups, though mediolateral (ML) CM-CP divergence in elderly subjects was significantly more reduced than in young subjects (P Ͻ 0.001). CONCLUSIONS. Findings indicate, in general, that older subjects used a more cautious and controlled stepping strategy. However, the lack of significant age differences in toe clearance suggests this strategy was mainly aimed at reducing ML instability rather than increasing margins of safety regarding toe clearance.
The Effect of a Cognitive Task on Voluntary Step Execution in Healthy Elderly and Young Individuals
Journal of the American Geriatrics Society, 2000
OBJECTIVES: To investigate voluntary step behavior of healthy elderly individuals during single-and dual-task conditions and to compare it with those of young subjects. DESIGN: Laboratory-based study. SETTING: Tests of healthy elderly and young individuals from senior community centers and from the university population in Boston, Massachusetts. PARTICIPANTS: Sixty-six elderly and 12 young subjects. MEASUREMENTS: Forward, sideways, and backward rapid voluntary stepping performed as a reaction time task while standing on a force platform and (1) awaiting a cutaneous cue (single task) and (2) awaiting a cutaneous cue while performing an attention-demanding Stroop task (dual task).
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