Journal of Geriatric Physical Therapy:
Does the Attentional Demands of Walking Differ for Older Men and Women Living Independently in the Community?
Wellmon, Robert PT, PhD, NCS
Institute for Physical Therapy Education, Widener University, One University Place, Chester, Pennsylvania.
Address correspondence to: Robert Wellmon, PT, PhD, NCS, Institute for Physical Therapy Education, Widener University, One University Place, Chester, PA 19013 (firstname.lastname@example.org).
The author discloses no conflicts of interest.
Background and Purpose. Walking has been shown to be an attentionally demanding task. For older adults, gender-specific differences in gait and falling reported in the literature could arise as a result of the attentional demands of walking. However, differences in how older men and women allocate attention to walking have not been investigated. The purpose of this study was to use a dual-task voice reaction time paradigm to examine gender-specific differences in the attentional demands of walking in older adults who are independent in community ambulation.
Methods. A dual-task paradigm was used to measure voice reaction time (VRT) in older community-dwelling men (n = 29; mean age = 78.40, SD = 6.17 years) and women (n = 33; mean age = 77.01, SD = 6.07 years) under 3 task conditions: sitting in a chair, standing, and walking on a level surface. Between- and within-group differences in dual-task VRT were examined using a 2 (men vs women) by 3 (task condition) repeated-measures analysis of variance. The level of statistical significance was set at 0.05, and a Bonferroni procedure was used for post hoc analyses.
Results. Sitting VRT was similar for men (mean = 454.90, SD = 140.05 milliseconds) and women (mean = 454.49, SD = 94.27 milliseconds). While standing, men had a slightly faster VRT (mean = 444.90, SD = 125.31 milliseconds vs mean = 452.09, SD = 92.82 milliseconds). When walking, VRT increased for both groups in comparison to sitting and standing and older men (mean = 509.11, SD = 142.19 milliseconds) responded faster than older women (mean = 537.55, SD = 122.43). However, the main effect of gender (P = .665) and interaction of gender with task (P = .433) were both not statistically significant. A statistically significant main effect for task (P < .001) indicated that walking VRT (mean = 524.25, SD = 131.71 milliseconds) was significantly longer than both sitting (P < .001, mean = 454.68, SD = 116.89 milliseconds) and standing (P < .001, mean = 448.36, SD = 108.37 milliseconds) VRT.
Discussion. The results demonstrate that the attentional demands of walking are not different for older adult men and women who are independent in community mobility. However, support was provided for the idea that walking is an attentionally demanding activity. In comparison with sitting and standing, walking was more attentionally demanding for both men and women.
Conclusions. A dual-task voice reaction time paradigm revealed that walking is not more attentionally demanding on the basis of gender when comparing community-dwelling older adult men with women.
A growing body of evidence supports the notion that walking is not an automatic activity. Research using dual-task paradigms suggest an associated cognitive cost and links to executive function.1–3 Dual-task approaches, which involve the pairing of a primary task with a secondary task, are frequently used to examine the attentional or cognitive requirements of walking.3,4 Attention, which is seen as one specific element of executive function,5–7 is important to the acquisition of environmental information needed to guide and proactively adapt walking. Changes in primary and/or secondary task performance, arising from simultaneous task completion, indicates that an activity has a cognitive cost and/or is attentionally demanding.8,9 Work by Wright and Kemp10 demonstrated the attentional requirements of walking with an assistive device by utilizing a dual-task task paradigm involving the measurement of changes in probe voice reaction time. Walking with and without an assistive device were the primary tasks. The secondary task, which was performed both alone as a single task and in combination with the primary walking tasks, involved responding verbally to an auditory stimulus. Differences in single and dual-task verbal response time provided support for the increased attentional requirements of walking with an assistive device.
Researchers have utilized a variety of secondary motor and cognitive tasks in combination with walking.1,3 Increasing gait variability, delayed motor reaction time, reduced capacity for communication, and altered cognitive task performance in both young and older adults have all been reported when cognitive or motor tasks are completed concurrently with walking.4,11–17 Performing a cognitive task while walking results in gait changes that are potentially destabilizing for older adults.18–20 Research also shows that walking imposes a greater cognitive burden on older adults when compared to younger adults.4,21,22 For older adults, the reported consequences of walking while concurrently performing another task are often markers for increased fall risk.18,19,23–25 Falling while walking is a common occurrence.26,27
On an annual basis, more than a third of older community-dwelling adults fall.28,29 The consequences can be life altering. After a fall, 20% to 30% of older adults experience injury, such as lacerations/contusions, fractures, or head trauma.30–32 Fall-related injuries lead to a decline in function, reduced quality of life, institutionalization, and increased mortality.31,33–36 The psychological consequences, which includes fear of falling, results in activity restrictions that further increase fall risk.37–39 The consequences of falling and the growing population of older adults in the United States highlight the need to fully explore all of the risk factors that contribute to falls, including those that may be gender specific.
Age-specific changes in gait and rates of falling are different for older men and women. Older women fall more frequently than older men and are more likely to experience injury.26,32,36,40 Gender differences in preferred gait speed, cadence, and other temporal and distance measures have been reported.41 Some of the reported gait differences that are markers for increased fall risk are also seen when cognitive or motor tasks are performed concurrently with walking.42 The underlying causes of gender-specific changes in gait may also be the same factors that increase the attentional requirements of walking.43–45 Therefore, it would be informative to have a better understanding of gender differences related to how older men and women allocate attention to walking. Gender-specific differences in the capacity to either allocate attention while walking or perform other tasks simultaneously when walking could possibly account for differences in the rate of falls among older men and women. Differences in how older men and women allocate attention to walking have not been explored in the literature. The purpose of this study was to use a dual-task voice reaction time paradigm to examine gender-specific differences in the attentional demands of walking in older adults.
Twenty-nine community-dwelling older men (mean age = 78.39 ± 6.06 years) and 33 women (mean age = 78.90 ± 6.41 years) participated in the study. On the basis of self-report, all were independent in both household and community ambulation, which was a requirement to participate in the study. Participant exclusion criteria included (1) reported active musculoskeletal pain localized to the back or lower extremity on the day of testing that limited ability to ambulate; (2) any self-reported medical history of central nervous system involvement; (3) use of any assistive or orthotic devices for ambulation; (4) inability to hear the auditory tone used for the dual-task stimulus; (5) required physical assistance to restore balance during the standing and walking trials; or (6) the rest needed between any ambulation trial exceeded 2 minutes. The study received institutional review board approval, and all participants provided informed consent prior to study entry.
Attentional allocation was examined by measuring the time required to respond verbally to a piezo-electric tone (RadioShack Model 273-054; RadioShack, Fort Worth, Texas) presented under single- and dual-task conditions. The instrumentation used to measure voice reaction time (VRT) consisted of a signal board, constructed by the principle investigator, a digital stop clock (Lafayette Instruments Model 54035; Lafayette Instrument Company, Lafayette, Indiana), a voice-activated relay switch (Lafayette Instruments Model 63040), and a wireless FM microphone system (RadioShack Model 32-1221). A button on the signal board, when pressed, simultaneously activated the auditory stimulus and the digital stop clock. The wireless 49.00 Hz FM microphone system transmitted the verbal response to the voice-activated relay switch that was attached to and stopped the digital clock. The timer provided a digital readout of VRT in milliseconds. The sensitivity of the microphone system and the voice-activated relay switch were both modified as necessary to account for differences in the volume of the participant's voice and to minimize the possibility of extraneous noise triggering the digital stop clock.
Two infrared photocell switches (Lafayette Instruments Model 63501IR) and a digital timer (Lafayette Instruments Model 54035A) were used to measure single- and dual-task gait velocity. The switches were placed parallel to the participant's path of travel and separated by a distance of 3.0 m. Walking past the switches activated and stopped the attached digital timer. The time elapsed was used to calculate gait velocity. Walking velocity from the single-task walking trials was compared with the dual-task condition to determine whether primary task performance (walking) was altered to improve secondary task performance (response to the auditory stimulus). The validity of the dual-task reaction time paradigm requires the participant to maintain primary task performance when presented with the secondary task stimulus.8,46,47 The triggering and switch activation mechanisms were hidden at all times from the participant's view to prevent priming or the anticipation of the presentation of the auditory signal from cues within the environment.
Data collection required approximately 45 minutes and occurred in a room free from noise and distractions located on the campus of Widener University. After being screened for the study's inclusion and exclusion criteria, the participants completed the following balance measures: the Functional Reach Test (FRT), the Timed Get-up and Go Test (TUG), and the Activities-specific Balance Confidence (ABC) Scale. The FRT was developed as a quick balance screen for older adults.48,49 To complete the test, the shoulder of the dominant upper extremity is flexed to the height of the acromion and the participant is instructed to reach forward, as far as possible, without taking a step. A meter stick attached to a wall at the height of the acromion measures distance reached. Developed as a performance-based measure of functional mobility and balance impairment for older individuals, the TUG requires the participant to rise from a chair, walk 3.0 m at preferred pace to a mark placed on the floor and turn around, walk back to the starting point, and return to sitting in the chair.50,51 The test is scored by measuring the amount of time required for completion. The ABC was used to examine self-perceptions of mobility confidence for walking and standing activities.52,53 Balance confidence is determined by averaging the scores on each of the items which are demarcated into 10% increments ranging from 0% to 100%. Higher scores indicate greater confidence in mobility.53
Voice reaction time was measured under 3 task conditions: sitting in a chair, standing without upper extremity support, and while walking on a level surface. Voice reaction time in sitting established baseline single-task performance and was always the first task condition completed. The participants were instructed to vocalize the letter “B,” as quickly as possible, whenever the auditory tone was presented. A total of 15 trials were performed. The first 5 trials were used to set the sensitivity of the VRT measurement system. Once ideal sensitivity was determined, the auditory stimulus was presented 10 more times by the researcher using random delays between trials.
After establishing baseline single-task VRT performance in sitting, the order of completion of the 2 remaining task conditions was randomly determined to minimize the effects of order. When measuring VRT in standing, participants assumed their preferred posture. Similar to sitting, a total of 15 trails were completed. The first 5 trials were used to re-check the function of the system to make sure the transfer to standing did not alter the microphone position and settings. Prior to the start of the trial, a reminder to vocalize the letter “B,” as quickly as possible, in response to the auditory tone was provided. Data from the remaining trials were used to calculate mean standing VRT.
When measuring VRT during walking, participants were instructed to ambulate at their usual or preferred pace along a 7.0 m path. No specific instructions were given regarding task prioritization. The infrared photocell sensors marked the middle portion of the walkway and was not only used to determine gait velocity but also provided reference points for the researcher to randomly present the auditory stimulus. The first and last 2.0 m of the walkway provided space for acceleration to preferred walking velocity and deceleration, respectively. Participants were informed that the auditory stimulus would not be presented during the first 5 walking trials. Gait data collected during those initial trials established single-task walking performance. Data generated were also used to ensure that the participants maintained primary task performance and did not elect to change the manner of walking to improve response time to the auditory stimulus that was presented in the dual-task condition. Upon completing the initial level walking trials, participants were told that the dual-task stimulus would be presented during some of the remaining 10 walking trials but were unaware that the tone would not be presented every trial. Catch trials were included in the 10 remaining trials to prevent stimulus anticipation that could potentially enhance secondary task performance.47,54 Stimulus and catch trial presentation order was randomly determined at the start of the study.
Measures of balance were examined descriptively using means and standard deviations and an independent sample t test was used to compare the groups. A 2 (gender) by 2 (single- versus dual-task walking velocity) analysis of variance (ANOVA) with repeated measures on the last factor was conducted to explore between- and within-group differences in walking velocity. This analysis was performed to ensure that the participants maintained primary walking task performance during the dual-task condition. A 2 (gender) by 3 (task condition) ANOVA with repeated measures on the last factor was implemented to examine between- and within-group differences in VRT to determine the attentional requirements of walking. Statistical significance was set at P ≤ .05 for all primary analyses and SPSS version 17 (SPSS Inc, Chicago, Illinois) was used. Post hoc differences were explored using a Bonferroni procedure to reduce the possibility of a chance finding and the creation of a type I error.
Tables 1 and 2 provide a summary of the group demographics for age, measures of balance, and walking velocity. Both groups were similar in age, and measures of balance fell within the expected range for nondisabled older adults with low fall risk.48,55–58 There was no statistically significant difference between the groups based on age (t60 = 0.33, P = .745). In general, the means revealed that women participants scored lower than men on all balance measures (Table 1). Men took less time to complete the TUG and also scored higher on the ABC Scale indicating greater confidence in mobility. Overall, scores on the ABC Scale indicate retention of high to moderate levels of physical function typical for older adults who remain active in the community.59 However, the groups did not differ significantly on both the TUG (t60 = 1.17, P = .245) and the ABC (t60 = 1.25, P = .745). The only statistically significant between-group difference for balance was found for the FRT, where men participants reached significantly farther (t60 = 2.18, P = .034).
Gender Differences in the Attentional Requirements of Walking
The descriptive statistics revealed changes in VRT that corresponded to increasing functional task complexity (Figure 1). The means indicate that sitting and standing VRT were faster than walking VRT for both groups. Voice reaction time for men and women were similar in sitting. Standing VRT was slightly faster than sitting for both groups (10 milliseconds for men versus 2.5 milliseconds for women) and men participants responded a little quicker than women (444.90 milliseconds versus 452.09 milliseconds). When walking, VRT became longer for both groups and men responded faster than women. The results from the 2 (gender) by 3 (task condition) ANOVA revealed a significant main effect for task condition (F2,59 = 16.24, P < .001); the main effect of gender (F1,60 = .190, P = .665) and the interaction of group with task (F2,59 = 0.632, P = .433) were both not statistically significant. Post hoc analysis of the main effects of task revealed that there were no statistically significant differences (P = .833) between sitting (n = 62, mean = 454.68, SD = 116.89 milliseconds) and standing (n = 62, mean = 448.36, SD = 108.37 milliseconds) VRT. However, walking VRT (n = 62, mean = 524.25, SD = 131.71 milliseconds) was significantly longer than both sitting (P < .001) and standing (P < .001) VRT. The pattern of statistically significant differences in VRT for the post hoc analysis of the main effect of task indicated that the attentional requirements of walking was significantly greater than both sitting and standing. There were no statistically significant differences in VRT for any of the task conditions based on gender (Figure 1).
Single- and Dual-Task Gait Performance
Means and standard deviations for walking velocity are summarized in Table 2. Ambulation velocity was within the expected norms for nondisabled older adults.60 The means revealed that men walked slightly slower than women for both the single- and dual-task conditions. Men walked slightly faster under the dual-task condition than under the single-task condition. The opposite pattern was seen for the women participants who walked slightly slower in the dual-task condition. However, the differences seen between the single- and dual-task conditions may not be meaningful given that the differences did not exceed the minimal detectable change reported in the literature.61 The results of the 2 (gender) by 2 (single- versus dual-task walking velocity) ANOVA revealed that the main effects for gender (F1,59 = 0.915, P = .343) and task (F1,59 = 0.097, P = .757) were both not statistically significant; the interaction of gender with task was also not statistically significant (F1,59 = 1.461, P = .232). The findings indicate that primary task performance, which was walking, was not altered during the dual-task condition to improve secondary task performance on the VRT task. Men and women were similar in their walking velocity.
The study results demonstrate that the attentional demands of walking in a closed environment within a laboratory setting are not different for older adult men and women who are independent in community mobility. When sitting in a chair with back support, older men and women had similar response times (Figure 1) for the baseline single-task VRT condition. The transition from sitting to standing can be assumed to provide a greater balance challenge but did not seem to increase the associated attentional demands of task performance on the basis of the observed differences in VRTs. There were no significant task and gender differences in sitting and standing VRTs. Given the participants' functional capacity based on walking velocity, measures of balance, and self-reported independence in community ambulation, the postural challenge posed by standing on a stable surface without challenge was not sufficient to increase the attentional demands of the task. However, the combinations of more challenging standing balance and cognitive tasks have been shown to increase the attentional demands of standing in older adults.62,63
When examining walking, older men, on average, had a faster VRT than older women; however, those differences did not reach the level of statistical significance. This finding indicates a similar capacity for the allocation of attention to the task of walking on a level surface for the study participants who were not disabled and had low fall risk and who reported being independent in community ambulation. Gender differences might be expected if there were significant differences seen in gait performance, balance, and mobility confidence, which could affect attentional allocation. While older men did reached significantly farther on the FRT, other measures of balance were different but not significantly better based on gender. Older men and women with a similar functional level do not differ in how much attention is required to walk on a level surface.
The results from the examination of between-task differences in VRT clearly indicate that walking had an associated cognitive cost for the study participants. When compared with sitting and standing, walking VRT was significantly longer for both older men and women (Figure 1). Thus, confirmation is provided for what has been previously reported in the literature by other authors who have used dual-task reaction time paradigms.64,65 The importance of the finding relates to potential impact of not having sufficient attentional resources to respond to other environmental stimuli that could contribute to a fall. While the current study was conducted in a laboratory setting, walking in a more open environment, such as in the community, is a more complex task that requires the acquisition of information from a variety of sources to guide ongoing motor actions.66,67 Tripping is a frequent source of falls in older adults.28,29,40,68,69 One plausible explanation is the failure to perceive an environmental feature as having the potential for causing instability or even a fall. Relative to younger adults, older adults frequently allocate greater attention to walking tasks that can lead to delays in responding to environmental features that can cause a loss of balance. Chen and colleagues70 suggest that a 50 or 100 milliseconds delay in responding to an obstacle appearing in the path of travel reduces the chance of successful negotiation. The destabilizing effects of having to complete one or more concurrent tasks while walking, such as talking or engaging in a cognitive task, when add to baseline level of attention required only to walk, may explain why tripping is a frequent cause of falls in older adults or the increased difficulty when walking in an environment containing multiple obstacles. A reduced capacity to direct and divide attention to perform multiple concurrent tasks is associated increased fall risk.3,13,71–73
There were no statistically significant differences in gait velocity when comparing men to women and between the single- and dual-task conditions. Older men in the study walked slower than older women. Gait velocity findings indicated that both groups maintained primary task performance, which was walking, when presented with the secondary dual-task stimulus. Altering walking performance to improve reaction time to the auditory stimulus can make the results difficult to interpret because of the switch in attentional focus.46,47,74 Given the single- and dual-task walking velocity findings, it is a reasonable assumption that VRT changes reflect the increased attentional demands of walking. The robustness of the finding underscores the importance the participants may have placed on walking safely. The participants could have adopted “a posture first strategy,” where attentional priority or focus is prudently shifted to walking to ensure stability.63,75
The application of the findings from this study is limited to community-dwelling older adults who are independent in ambulation. Given the expected level of function for someone residing in the community, there may not be significant differences in the attentional requirements of walking based on gender. More substantial differences based on gender may present when either examining groups of older adults with impairments and whose physiological level of function limit access to community or those who are frail or transitioning to frailty. These groups are more likely to fall while walking and physiological gender differences, such as strength, activity levels, body mass, or flexibility, may make the task of walking more difficult and therefore more attentionally demanding.76–78 Among frail older adults, increased attention during gait has been linked to increased fall risk and limitations in mobility.79–82 Recent work has also suggested a link between changes in executive function and attentional allocation for walking and falls in older adults.42,73,83
What merits additional investigation and cannot be ruled out as influencing how attention was allocated for the level walking task implemented in this study are changes in vision, altered somatosensory function, variations in physical activity levels, and possible early changes in executive function in the older adult group. These factors were not explored in the current study but can potentially influence gait performance and the level of attention that must be allocated during walking.42,73,76–78,83 While the participants were all, by self-report, independent in community ambulation, there could have been underlying mild changes in executive function that would have influenced the study outcome.
While dual-task probe reaction time paradigms have been shown to a valid indicator of attentional cost, exploring the effects of the secondary cognitive task on walking performance is also indicated as a future direction of study. A complimentary dual-task approach to what was implemented in this study involves an examination changes in walking performance arising from the concurrent and continuous performance of a cognitive or mental task while walking. The focus of this approach is on changes in walking, such as reductions in gait speed or increasing stride and stance variability, arising out of the concurrent performance of a cognitive task. This line of work has demonstrated that performing a concurrent cognitive task while walking leads to increased gait variability.11,12,84 Typical cognitive tasks include counting or spelling words backwards, and memory, or mental manipulations involving spatial areas of the brain. Older men and women may perform cognitive tasks differently, which could potentially lead to destabilizing gait alterations that are associated with falls and a different study outcome.
The study findings provide insight into age-specific attentional requirements of walking based on gender for nondisabled older adults. On the basis of the dual-task paradigm used, older men and women who are independent in community ambulation demonstrate a similar capacity to allocate attention when walking. The results of the study are consistent with previous reports in the literature indicating that walking is an attentional demanding task for older adults. Additional investigation exploring the capabilities of older adults who are more functionally limited is necessary to see how gender might influence the attentional requirements of walking.
1. Al-Yahya E, Dawes H, Smith L, Dennis A, Howells K, Cockburn J. Cognitive motor interference while walking: a systematic review and meta-analysis. Neurosci Biobehav Rev. 2011;35:715–728.
2. Lord S, Rochester L. Walking in the real world: concepts related to functional gait. N Z J Physiother. 2007;35:126–130.
3. Yogev-Seligmann G, Hausdorff JM, Giladi N. The role of executive function and attention in gait. Mov Disord. 2008;23:329–342; quiz 472.
4. Woollacott M, Shumway-Cook A. Attention and the control of posture and gait: a review of an emerging area of research. Gait Posture. 2002;16:1–14.
5. Stuss DT, Levine B. Adult clinical neuropsychology: lessons from studies of the frontal lobes. Annu Rev Psychol. 2002;53:401–433.
6. Chayer C, Freedman M. Frontal lobe functions. Curr Neurol Neurosci Rep. 2001;1:547–552.
7. Sarter M, Gehring WJ, Kozak R. More attention must be paid: the neurobiology of attentional effort. Brain Res Rev. 2006;51:145–160.
8. Abernethy B. Dual-task methodology and motor skills research: some applications and methodological constraints. J Hum Movem Stud. 1988;14:101–132.
9. Abernethy B, Summers J, Ford S. Issues in the measurement of attention. In: Duda JL, ed. Advances in Sport and Exercise Psychology Measurement. Morgantown, WV: Fitness Information Technology, Inc; 1998:173–193.
10. Wright DL, Kemp TL. The dual-task methodology and assessing the attentional demands of ambulation with walking devices. Phys Ther. 1992;72:306–312; discussion 313–305.
11. Hollman JH, Kovash FM, Kubik JJ, Linbo RA. Age-related differences in spatiotemporal markers of gait stability during dual task walking. Gait Posture. 2007;26:113–119.
12. Priest AW, Salamon KB, Hollman JH. Age-related differences in dual task walking: a cross sectional study. J Neuroeng Rehabil. 2008;5:29.
13. Srygley JM, Mirelman A, Herman T, Giladi N, Hausdorff JM. When does walking alter thinking? Age and task associated findings. Brain Res. 2009;1253:92–99.
14. Dubost V, Kressig RW, Gonthier R, et al. Relationships between dual-task related changes in stride velocity and stride time variability in healthy older adults. Hum Mov Sci. 2006;25:372–382.
15. Wellmon R, Pezzillo K, Eichhorn G, Lockhart W, Morris J. Changes in dual-task voice reaction time among elders who use assistive devices. J Geriatr Phys Ther. 2006;29:74–80.
16. Kemper S, Herman RE, Lian CH. The costs of doing two things at once for young and older adults: talking while walking, finger tapping, and ignoring speech or noise. Psychol Aging. 2003;18:181–192.
17. Montero-Odasso M, Casas A, Hansen KT, et al. Quantitative gait analysis under dual-task in older people with mild cognitive impairment: a reliability study. J Neuroeng Rehabil. 2009;6:35.
18. Barak Y, Wagenaar RC, Holt KG. Gait characteristics of elderly people with a history of falls: a dynamic approach. Phys Ther. 2006;86:1501–1510.
19. Nordin E, Moe-Nilssen R, Ramnemark A, Lundin-Olsson L. Changes in step-width during dual-task walking predicts falls. Gait Posture. 2010;32:92–97.
20. Springer S, Giladi N, Peretz C, Yogev G, Simon ES, Hausdorff JM. Dual-tasking effects on gait variability: the role of aging, falls, and executive function. Mov Disord. 2006;21:950–957.
21. Siu K-C, Chou L-S, Mayr U, Donkelaar Pv, Woollacott MH. Does inability to allocate attention contribute to balance constraints during gait in older adults? J Gerontol A Biol Sci Med Sci. 2008;63:1364–1369.
22. Ojha HA, Kern RW, Lin CH, Winstein CJ. Age affects the attentional demands of stair ambulation: evidence from a dual-task approach. Phys Ther. 2009;89:1080–1088.
23. Lundin-Olsson L, Nyberg L, Gustafson Y. “Stops walking when talking” as a predictor of falls in elderly people. Lancet. 1997;349:617.
24. Sparrow WA, Bradshaw EJ, Lamoureux E, Tirosh O. Ageing effects on the attention demands of walking. Hum Mov Sci. 2002;21:961–972.
25. Chen HC, Schultz AB, Ashton-Miller JA, Giordani B, Alexander NB, Guire KE. Stepping over obstacles: dividing attention impairs performance of old more than young adults. J Gerontol A Biol Sci Med Sci. 1996;51:M116–M122.
26. Talbot LA, Musiol RJ, Witham EK, Metter EJ. Falls in young, middle-aged and older community dwelling adults: perceived cause, environmental factors and injury. BMC Public Health. 2005;5:86.
27. Painter JA, Elliott SJ, Hudson S. Falls in community-dwelling adults aged 50 years and older: prevalence and contributing factors. J All Health. 2009;38: 201–207.
28. Tinetti ME, Speechley M, Ginter SF. Risk factors for falls among elderly persons living in the community. N Engl J Med. 1988;319:1701–1707.
29. Berg WP, Alessio HM, Mills EM, Tong C. Circumstances and consequences of falls in independent community-dwelling older adults. Age Ageing. 1997;26:261–268.
30. Sterling DA, O'Connor JA, Bonadies J. Geriatric falls: injury severity is high and disproportionate to mechanism. J Trauma. 2001;50:116–119.
31. Stalenhoef PA, Crebolder HFJM, Knottnerus JA, Van Der Horst FGEM. Incidence, risk factors and consequences of falls among elderly subjects living in the community. Eur J Public Health. 1997;7:328–334.
32. Stevens JA, Sogolow ED. Gender differences for non-fatal unintentional fall related injuries among older adults. Inj Prev. 2005;11:115–119.
33. Kiel DP, O'Sullivan P, Teno JM, Mor V. Health care utilization and functional status in the aged following a fall. Med Care. 1991;29:221–228.
34. Tinetti ME, Williams CS. Falls, injuries due to falls, and the risk of admission to a nursing home. N Engl J Med. 1997;337:1279–1284.
35. Alexander BH, Rivara FP, Wolf ME. The cost and frequency of hospitalization for fall-related injuries in older adults. Am J Public Health. 1992;82:1020–1023.
36. Schiller JS, Kramarow EA, Dey AN. Fall injury episodes among noninstitutionalized older adults: United States, 2001–2003. Adv Data. 2007:1–16.
37. Tinetti ME, Mendes de Leon CF, Doucette JT, Baker DI. Fear of falling and fall-related efficacy in relationship to functioning among community-living elders. J Gerontol. 1994;49:M140–M147.
38. Tennstedt S, Howland J, Lachman M, Peterson E, Kasten L, Jette A. A randomized, controlled trial of a group intervention to reduce fear of falling and associated activity restriction in older adults. J Gerontol B Psychol Sci Soc Sci. 1998;53:P384–P392.
39. Zijlstra GA, van Haastregt JC, van Eijk JT, van Rossum E, Stalenhoef PA, Kempen GI. Prevalence and correlates of fear of falling, and associated avoidance of activity in the general population of community-living older people. Age Ageing. 2007;36:304–309.
40. Campbell AJ, Borrie MJ, Spears GF, Jackson SL, Brown JS, Fitzgerald JL. Circumstances and consequences of falls experienced by a community population 70 years and over during a prospective study. Age Ageing. 1990;19:136–141.
41. Callisaya ML, Blizzard L, Schmidt MD, McGinley JL, Srikanth VK. Sex modifies the relationship between age and gait: a population-based study of older adults. J Gerontol A Biol Sci Med Sci. 2008;63:165–170.
42. de Bruin ED, Schmidt A. Walking behaviour of healthy elderly: attention should be paid. Behav Brain Funct. 2010;6:59.
43. Callisaya ML, Blizzard L, Schmidt MD, McGinley JL, Lord SR, Srikanth VK. A population-based study of sensorimotor factors affecting gait in older people. Age Ageing. 2009;38:290–295.
44. Lord SR, Ward JA, Williams P, Anstey KJ. Physiological factors associated with falls in older community-dwelling women. J Am Geriatr Soc. 1994;42:1110–1117.
45. Lord SR, Ward JA. Age-associated differences in sensori-motor function and balance in community dwelling women. Age Ageing. 1994;23:452–460.
46. Damos DL. Dual-task methodology: Some common problems. In: Damos DL, ed. Multiple-Task Performance. Bristol, PA: Taylor & Francis Inc; 1991.
47. Fisk AD, Schneider W, Derrick WL. A methodological assessment and evaluation of dual-task paradigms. Curr Psychol Res Rev. 1986–87;5:315–327.
48. Duncan PW, Weiner DK, Chandler J, Studenski S. Functional reach: a new clinical measure of balance. J Gerontol. 1990;45:M192–M197.
49. Weiner DK, Duncan PW, Chandler J, Studenski SA. Functional reach: a marker of physical frailty. J Am Geriatr Soc. 1992;40:203–207.
50. Mathias S, Nayak US, Isaacs B. Balance in elderly patients: the “get-up and go” test. Arch Phys Med Rehabil. 1986;67:387–389.
51. Podsiadlo D, Richardson S. The timed “Up & Go”: a test of basic functional mobility for frail elderly persons. J Am Geriatr Soc. 1991;39:142–148.
52. Myers AM, Powell LE, Maki BE, Holliday PJ, Brawley LR, Sherk W. Psychological indicators of balance confidence: relationship to actual and perceived abilities. J Gerontol A Biol Sci Med Sci. 1996;51:M37–M43.
53. Powell LE, Myers AM. The Activities-specific balance confidence (ABC) scale. J Gerontol A Biol Sci Med Sci. 1995;50A:M28–M34.
54. Salmoni A, Sullivan J, Starkes J. The attentional demands of movements: a critique of the probe technique. J Motor Behav. 1976;8:161–169.
55. Lusardi MM, Pellecchia GL, Schulman M. Functional performance in community living older adults. J Geriatr Phys Ther. 2003;26:14–22.
56. Pondal M, del Ser T. Normative data and determinants for the timed “up and go” test in a population-based sample of elderly individuals without gait disturbances. J Geriatr Phys Ther. 2008;31:57–63.
57. Shumway-Cook A, Brauer S, Woollacott M. Predicting the probability for falls in community-dwelling older adults using the Timed Up & Go Test. Phys Ther. 2000;80:896–903.
58. Lajoie Y, Gallagher SP. Predicting falls within the elderly community: comparison of postural sway, reaction time, the Berg balance scale and the Activities-specific Balance Confidence (ABC) scale for comparing fallers and non-fallers. Arch Gerontol Geriatr. 2004;38:11–26.
59. Myers AM, Fletcher PC, Myers AH, Sherk W. Discriminative and evaluative properties of the activities-specific confidence (ABC) scale. J Gerontol: Med Sci. 1998;53A:M287–M294.
60. Bohannon RW. Population representative gait speed and its determinants. J Geriatr Phys Ther. 2008;31:49–52.
61. Perera S, Mody SH, Woodman RC, Studenski SA. Meaningful change and responsiveness in common physical performance measures in older adults. J Am Geriatr Soc. 2006;54:743–749.
62. Brown LA, Shumway-Cook A, Woollacott MH. Attentional demands and postural recovery: the effects of aging. J Gerontol A Biol Sci Med Sci. 1999;54:M165–M171.
63. Shumway-Cook A, Woollacott M, Kerns KA, Baldwin M. The effects of two types of cognitive tasks on postural stability in older adults with and without a history of falls. J Gerontol A Biol Sci Med Sci. 1997;52:M232–M240.
64. Lajoie Y, Teasdale N, Bard C, Fleury M. Upright standing and gait: are there changes in attentional requirements related to normal aging? Exp Aging Res. 1996;22:185–198.
65. Lajoie Y, Teasdale N, Bard C, Fleury M. Attentional demands for static and dynamic equilibrium. Exp Brain Res. 1993;97:139–144.
66. Shumway-Cook A, Patla AE, Stewart A, Ferrucci L, Ciol MA, Guralnik JM. Environmental demands associated with community mobility in older adults with and without mobility disabilities. Phys Ther. 2002;82:670–681.
67. Patla AE. Mobility in complex environments: implications for clinical assessment and rehabilitation. J Neurol Phys Ther. 2001;25:82–90.
68. Blake AJ, Morgan K, Bendall MJ, et al. Falls by elderly people at home: prevalence and associated factors. Age Ageing. 1988;17:365–372.
69. Lord SR, Ward JA, Williams P, Anstey KJ. An epidemiological study of falls in older community-dwelling women: the Randwick falls and fractures study. Aust J Public Health. 1993;17:240–245.
70. Chen HC, Ashton-Miller JA, Alexander NB, Schultz AB. Effects of age and available response time on ability to step over an obstacle. J Gerontol. 1994;49:M227–M233.
71. Di Fabio RP, Zampieri C, Henke J, Olson K, Rickheim D, Russell M. Influence of elderly executive cognitive function on attention in the lower visual field during step initiation. Gerontology. 2005;51:94–107.
72. Hausdorff JM, Schweiger A, Herman T, Yogev-Seligmann G, Giladi N. Dual-task decrements in gait: contributing factors among healthy older adults. J Gerontol A Biol Sci Med Sci. 2008;63:1335–1343.
73. Herman T, Mirelman A, Giladi N, Schweiger A, Hausdorff JM. Executive control deficits as a prodrome to falls in healthy older adults: a prospective study linking thinking, walking, and falling. J Gerontol A Biol Sci Med Sci. 2010;65:1086–1092.
74. Pashler H, Johnston JC. Attentional limitations in dual-task performance. In: Pashler H, ed. Attention. East Sussex, UK: Psychology Press, Ltd.; 1998:155–189.
75. Bloem BR, Valkenburg VV, Slabbekoorn M, Willemsen MD. The multiple tasks test: development and normal strategies. Gait Posture. 2001;14:191–202.
76. Fone S, Lundgren-Lindquist B. Health status and functional capacity in a group of successfully ageing 65–85-year-olds. Disabil Rehabil. 2003;25:1044–1051.
77. Fiser WM, Hays NP, Rogers SC, et al. Energetics of walking in elderly people: factors related to gait speed. J Gerontol A Biol Sci Med Sci. 2010;65:1332–1337.
78. McKean KA, Landry SC, Hubley-Kozey CL, Dunbar MJ, Stanish WD, Deluzio KJ. Gender differences exist in osteoarthritic gait. Clin Biomech. 2007;22:400–409.
79. Beauchet O, Dubost V, Herrmann F, Rabilloud M, Gonthier R, Kressig RW. Relationship between dual-task related gait changes and intrinsic risk factors for falls among transitional frail older adults. Aging Clin Exp Res. 2005;17:270–275.
80. Beauchet O, Annweiler C, Dubost V, et al. Stops walking when talking: a predictor of falls in older adults? Eur J Neurol. 2009;16:786–795.
81. Lundin-Olsson L, Nyberg L, Gustafson Y. Attention, frailty, and falls: the effect of a manual task on basic mobility. J Am Geriatr Soc. 1998;46:758–761.
82. Beauchet O, Dubost V, Stierlam F, et al. [Influence of a specific cognitive task on spatial-temporal walking parameters in elderly frail individuals]. Presse Med. 2002;31:1117–1122.
83. van Iersel MB, Kessels RPC, Bloem BR, Verbeek ALM, Olde Rikkert MGM. Executive functions are associated with gait and balance in community-living elderly people. J Gerontol A Biol Sci Med Sci. 2008;63:1344–1349.
84. van Iersel MB, Ribbers H, Munneke M, Borm GF, Rikkert MG. The effect of cognitive dual tasks on balance during walking in physically fit elderly people. Arch Phys Med Rehabil. 2007;88:187–191.
aging; attention; dual task; women; men; older adult; walking
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