Problems of older persons using a wheeled walker

Abstract

Wheeled walkers (WWs) are used to improve mobility and for fall prevention in older persons, but not all users are satisfied with the usability of WWs. Intelligent WWs are being developed to improve the usability.
The aim of this study was to support the development of intelligent WWs by investigating possible problems of using a WW.
This study investigated 22 geriatric in-patients (median age 82 years) with and without their WW while opening a door against the direction of walking and passing through. Other possible problems when using WWs were identified by interview.
Walking through the door was faster without than with using the WW (8.71 versus 12.86 s, p < 0.001), while interference between door and WW was documented in 41 of 44 (93 %) cases. Backward walking performance was better when using a WW with regard to gait speed, step width and walk ratio (all p < 0.002). Most referred problems when using a WW were walking downhill (83 %) and uphill (77 %) and obstacle crossing in general (77 %).
Problems with opening a door against the direction of walking and the optimization of downhill and uphill walking as well as obstacle crossing should be regarded when developing an intelligent WW.

Full text

1 23
Aging Clinical and Experimental
Research
ISSN 1720-8319
Aging Clin Exp Res
DOI 10.1007/s40520-015-0410-8
Problems of older persons using a wheeled
walker
Ulrich Lindemann, Michael Schwenk,
Jochen Klenk, Max Kessler, Michael
Weyrich, Franziska Kurz & Clemens
Becker

1 23
Your article is protected by copyright and
all rights are held exclusively by Springer
International Publishing Switzerland. This e-
offprint is for personal use only and shall not
be self-archived in electronic repositories. If
you wish to self-archive your article, please
use the accepted manuscript version for
posting on your own website. You may
further deposit the accepted manuscript
version in any repository, provided it is only
made publicly available 12 months after
official publication or later and provided
acknowledgement is given to the original
source of publication and a link is inserted
to the published article on Springer's
website. The link must be accompanied by
the following text: "The final publication is
available at link.springer.com”.

ORIGINAL ARTICLE
Problems of older persons using a wheeled walker
Ulrich Lindemann
1,2
•Michael Schwenk
1,2
•Jochen Klenk
1,2,3
•Max Kessler
4
•
Michael Weyrich
2,4
•Franziska Kurz
1
•Clemens Becker
1,2
Received: 2 March 2015 / Accepted: 3 July 2015
ÓSpringer International Publishing Switzerland 2015
Abstract
Background Wheeled walkers (WWs) are used to
improve mobility and for fall prevention in older persons,
but not all users are satisfied with the usability of WWs.
Intelligent WWs are being developed to improve the
usability.
Aims The aim of this study was to support the develop-
ment of intelligent WWs by investigating possible prob-
lems of using a WW.
Methods This study investigated 22 geriatric in-patients
(median age 82 years) with and without their WW while
opening a door against the direction of walking and passing
through. Other possible problems when using WWs were
identified by interview.
Results Walking through the door was faster without than
with using the WW (8.71 versus 12.86 s, p\0.001), while
interference between door and WW was documented in 41
of 44 (93 %) cases. Backward walking performance was
better when using a WW with regard to gait speed, step
width and walk ratio (all p\0.002). Most referred prob-
lems when using a WW were walking downhill (83 %) and
uphill (77 %) and obstacle crossing in general (77 %).
Conclusions Problems with opening a door against the
direction of walking and the optimization of downhill and
uphill walking as well as obstacle crossing should be
regarded when developing an intelligent WW.
Keywords Door Older persons Usability Wheeled
walker
Introduction
Physical performance, such as balance while walking or
standing, decreases with age [1]. A wheeled walker (WW)
is frequently used to improve balance and mobility of older
persons [2,3] and to protect those persons from falling [4].
However, those persons falling while using a WW are more
likely to sustain a severe injury when falling, e.g., a hip
fracture [5]. Furthermore, walking performance has been
shown to decrease in a sub-population, i.e., Parkinson
´s
disease patients when using a WW [6]. In general, not all
users are satisfied with the WW and usability and acces-
sibility problems were identified as the main complaints
[7]. With regard to accessibility, opening doors against the
direction of walking and passing through is an obvious
problem. In this situation, the interference of the WW with
the door has to be managed while balance is challenged [8].
A side step could be an appropriate solution in this situa-
tion, but this has been shown to be associated with balance
problems when using a walker, which has limited func-
tionality for sideward movements [9]. To understand the
effect of a WW on gait and balance an assessment of a
daily activity, such as walking through a door, is
&Ulrich Lindemann
ulrich.lindemann@rbk.de
1
Department of Geriatrics and Clinic for Geriatric
Rehabilitation, Robert-Bosch-Hospital, Auerbachstr. 110,
70376 Stuttgart, Germany
2
University Stuttgart Research Initiative Human Factors in
Ageing, Technology and Environment, Stuttgart, Germany
3
Institute of Epidemiology, Ulm University, Helmholzstr. 22,
89081 Ulm, Germany
4
Institute for Automation and Software Engineering,
University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart,
Germany
123
Aging Clin Exp Res
DOI 10.1007/s40520-015-0410-8
Author's personal copy

recommended in combination with standard laboratory
measures [10].
Another approach to prevent interference of the door
with the WW is to walk backwards with the walking aid
while opening the door. However, backwards navigation of
most WWs is limited, due to fixed rear wheels. Only front
wheels are 360°rotatable for convenient navigation.
Backward walking without using an assistive device has
been investigated in different cohorts of age and perfor-
mance. A decrease in performance with age has been
shown with more walking performance deficits in fallers
than in non-fallers [11]. Although walking backwards with
a WW seems to be a frequent daily activity of older persons
with impaired walking performance. This phenomenon has
not been investigated so far.
Today smart technology is able to improve usability of
mechanical devices, such as a WW. Based on expert
opinion and possible technical solutions, intelligent walk-
ers are being developed focusing on obstacle avoiding,
powered impulsion and navigation technology [12–14].
However, there was no identification of problems of the
users in advance and there is no evidence that these tech-
nical solutions are relevant for older persons using a WW.
Although smart walkers are probably the most studied aids
in the field of robotic assistance designed for disabled
individuals or persons at risk of disability, basic knowledge
about how and where WWs are helpful or not is still
lacking.
The aim of this study was to support the development of
intelligent WWs by investigating possible problems of
older adults while using a WW. We used typical real-life
scenarios including walking through a door and walking
backwards. We hypothesized that task difficulty increases
when passing through a door while using a WW reflected
by an increased ambulation time (versus without WW) and
interferences between WW and door. Furthermore, we
hypothesized that backward walking performance decrea-
ses while using a WW in comparison to walking without
WW. The rationale for this hypothesis is that here the WW
is not used according to the arrangement of the wheels. In
addition, it was aimed to identify other possible problems
when using a WW by conducting a semi-structured
interview.
Methods
Subjects and design
For the experimental part of this cross-sectional study 22
patients (median age 82 years, inter-quartile range
79–86.3 years, 50 % men) were recruited from a geriatric
rehabilitation clinic in the south–west of Germany. All
participants used their own WWs with 4 wheels, of which
the front wheels were 360°rotatable for navigation and the
rear wheels were fixed. Most of the participants (n=14;
64 %) were novice WW users and the mean duration of
usage of the remaining participants (n=8) was
33.1 months. They had to be able to walk forwards as well
as backwards with and without the WW for at least 5 m.
Exclusion criteria were unilateral functional impairment,
such as stroke or recent hip replacement and inability to
follow verbal instructions. The group is described in detail
in Table 1. The study was approved by the ethical com-
mittee of the University of Tu
¨bingen. All participants gave
written informed consent.
Outcome parameters and protocol
At a distance of 2.3 m, participants stood in front of a
standard door without any automatic function and opening
against the direction of walking. They were instructed to
walk to the door, open it, walk through the door and close it
all at their habitual pace. The task was performed with and
without WW in random order. Time to perform this task
was taken from a video and the faster of 2 trials was used as
outcome parameter. The number of interferences between
WW and door was recorded over all 44 trials. Interference
was defined as an interruption of the opening of the door,
caused by sideward or backward movement of the WW.
Rating from video was performed by 2 independent
investigators (UL, FK). After the experiment the partici-
pants were asked if passing through the door was easier
with or without using the WW.
In addition, participants walked at their own pace for-
wards with their WW over an instrumented walkway
(GAITRite
Ò
, CIR Systems, Haverton, USA) and thereafter
they walked backwards with and without WW in random
order. The mean of 2 trials was taken for analysis with gait
speed, step width and walk ratio, i.e., step length divided
by step frequency [15], as outcome parameters.
Table 1 Description of all 22 participants (50 % men) of the
experimental study
Median IQR Min–Max
Age (years) 82 79–86.3 73–90
Height (cm) 157.5 153.3–167.8 148–176
Weight (kg) 66.0 61.0–74.5 50–82
BMI (kg/m
2
) 26.3 22.7–28.5 20.3–33.7
Co-morbidities (n) 3 2–5 1–9
Chair Rise (n/30 s) 10.0 8.8–11.3 8–13
Habitual gait speed (m/s) 0.70 0.51–0.88 0.45–1.11
IQR inter-quartile range, BMI body mass index
Aging Clin Exp Res
123
Author's personal copy

Descriptive parameters
Habitual gait speed (forward) and the number of sit-to-
stand transfers over 30 s at maximum pace [16] were used
as functional descriptive parameters. In the last named
assessment the protocol was modified that the use of
armrests was allowed. Furthermore, the older participants
were screened for co-morbidities by questionnaire [17]ina
standardized interview.
Statistics
Due to the small sample size median and inter-quartile
range (IQR), as well as non-parametric tests (Wilcoxon
rank-sum test) were used to describe parameters and dif-
ferences between conditions, respectively. The significance
level of all statistical procedures was set to a=5 % (two-
sided). All analyses were conducted using SPSS version 16
software (SPSS Inc., Chicago, IL, USA).
Interview
To identify possible problems when using a WW, a semi-
structured interview was conducted with 60 patients (mean
age 82.0 years, 67 % women) using a WW in the same
geriatric rehabilitation clinic. The cohort included 29
(48 %) first-time users, starting usage during in-patient
rehabilitation, and 31 (52 %) long-time users with a mean
usage of 30 months. We asked if they ever had experienced
a fall while using their WW. Problems were asked with
regard to walking in different directions, indoors and out-
doors, up- and downhill, in curves, through a door and on
the spot, over obstacles and on uneven surface, and with
regard to sitting on the WW and carrying things with the
WW, using the WW during the sit-to-stand transfer and
using the WW in different situations in the community,
attending doctor’s appointment, visiting friends or using
public transportation. An example of these questions is:
‘‘When you walk indoor with your WW, do you feel safe/
the device is helpful or do you feel unconfident/the device
is hindering?’’ If the participants opted unconfident/hin-
dering, the question was ‘‘What is the problem?’’
Results
Walking through the door was faster without using the
WW than with using the WW (8.71 s, IQR 7.81–10.19
versus 12.86 s, IQR 10.76–14.29; p\0.001). Interference
between door and WW was documented in 41 of 44 (93 %)
cases with an example shown in Fig. 1. Directly after the
experiment, 13 (59 %) older adults rated walking through
the door without using the WW easier, for 6 patients
(27 %) there was no difference and 3 patients (14 %) rated
walking through the door with the use of their WW easier.
Walking forwards with the WW was performed faster,
with smaller step width and with a higher walk ratio than
walking backwards with WW. Walking backwards with
WW was performed faster, with smaller step width and
with a higher walk ratio than walking backwards without
WW. With regard to walking performance, all differences
between walking conditions were statistically significant
(all p\0.002) and are described in detail in Table 2.
Three out of 60 (5 %) patients had ever experienced a fall
while using their WW. Walking downhill (83 %) and uphill
(77 %) and walking outdoors over uneven ground (73 %) were
major problems identified by interview in the cohort of 60
patients using a WW. Obstacle crossing in general was a
problem for 77 % of a ll interviewed patients. Here, stairs in the
context of public transportation (70 %), leaving/entering the
own apartment (60 %) and doctors surgeries, visiting phar-
macies etc. (35 %) were a common problem. Also, walking
indoors (25 %) and outdoors (10 %) and carrying objects
indoors (7 %) and outdoors (10 %) while crossing obstacles
were further problems. Walking backwards with their WW
was a problem for 27 % of the patients. The problems during
walking and obstacle crossing are also shown in Fig. 2.
Fig. 1 Interference of the wheeled walker with the door during
opening against the direction of walking, showing not-rotatable back
wheels (1), rotatable front wheels (2) and a back wheel with lost
contact to the ground (3)
Aging Clin Exp Res
123
Author's personal copy

A further problem identified by interview were the not-
rotatable back wheels which limited navigation during
walking sidewards (32 %), walking through a door (25 %)
and turning on the spot (15 %). With regard to using the
WW during the sit-to-stand transfer, 83 % of all patients
indicated not fixing the brakes as a major problem.
Discussion
This study identified serious problems when using a WW
during more complex walking tasks such as passing a door.
In contrast to straight walking, where no interference of the
WW with the environment occurs, motor performance
declined substantially during a complex mobility task
requiring sideward shifting. On the same note, this study
shows that a WW provides advantages during straight
backwards walking. Previous studies found similar results
for forward walking [2]. Our study results demonstrate pros
and cons of using a WW by combining the assessment of a
daily task and standard laboratory testing [10].
The longer time to walk through the door in our study is
likely an indicator of interference between WW and door.
Given a higher stability of walking performance when
using a WW [2], a longer time would be acceptable, but the
high number of interferences between WW and door points
out the incident of instability while opening and passing
through the door. Although our experimental result was
confirmed by the 59 % of patients, who rated walking
through the door to be easier without using a WW, the
awareness of this problem was less than half and likely
underestimated in our interviewed cohort. In our experi-
ment, the impossibility of a movement with the WW to the
side because of not-rotatable rear wheels is comparable to
Table 2 Walking performance
of all 22 participants (50 %
men) of the experimental study
Forward with WW
Median (IQR)
Backward with WW
Median (IQR)
Backward without WW
Median (IQR)
Gait speed (m/s) 0.70 (0.51–0.88) 0.36 (0.28–0.43) 0.31 (0.24–0.34)
Step width (cm) 8.1 (6.9–9.8) 16.1 (12.9–17.7) 20.7 (15.8–23.0)
Walk ratio 0.54 (0.47–0.60) 0.28 (0.22–0.40) 0.22 (0.16–0.28)
All differences between conditions were p\0.002
WW wheeled walker, IQR inter-quartile range
Fig. 2 Problems of older in-
patients (n=60) during
walking and problems with
obstacles when using the
wheeled walker
Aging Clin Exp Res
123
Author's personal copy

the challenging situation when using a walker without
wheels [9]. One potential solution could be the imple-
mentation of smart technology. An intelligent WW, which
may be able to recognize its interference with a door
caused by, could release the fixation of its back wheels.
This way, the WW could be moved to the side, but still
provide assistance during walking in this balance chal-
lenging situation.
In our study, the decrease of walking performance
during backward walking was documented by slower gait
speed, broader step width and a smaller walk ratio, which is
associated with falls risk during forward walking [18].
Decreases in gait speed and step width are in line with
another study with a cohort of 62 older adults showing a
68 % faster backward walking gait speed, but walking
without an assistive device [11]. The limitation of visual
control while walking backwards may have caused these
changes in performance, which then can be regarded as a
necessary adaptation. Since the difference between for-
wards and backwards walking performance is considerable
in our study and in another study without using an assistive
device [11], the calculation of a forward/backward per-
formance ratio with and without WW may be helpful for
assessment of walking performance in older adults.
The use of the WW while walking backwards improved
walking performance, which is in line with the literature
based on forward walking [2]. Findings are contradictory to
our hypothesis. We expected that the WW would interfere
with the subjects
´ability to ambulate backwards due to the
reverse arrangement of the wheels. However, our results
show that gait performance was better during backwards
walking with WW reflected by a higher velocity and walk
ratio and reduced step with as compared to waling without
WW. Furthermore, our results indicate an overestimation of
problems during backward walking in our interview cohort.
The results of our interview-based identification of
problems when using a WW, which are partly confirmed by
the result of our experimental study, may help to develop
an intelligent WW. Here, the support and deceleration
during uphill and downhill walking, respectively, a case
sensitive release of the rear wheels and a support for
obstacle crossing may be relevant issues. In addition, our
results may help designing a test protocol to show the
advantages of intelligent WWs during real-life situations
which were identified as problematic in the present study.
Another aspect of using intelligent WWs could be moni-
toring specific parameters related to mobility-related
quality of life and health. For instance, the walking dis-
tance per day, an important marker of physical activity
level, could be easily measured by adding simple tech-
nology. Furthermore, vertical force applied at the handle
could be measured to estimate upper extremity weight
bearing, which might be a parameter for monitoring
rehabilitation progress. Also, detection of a WW in hori-
zontal, i.e., lying position, could indicate a fall, which in
turn could initiate an alarm call.
As a limitation of our study, the small sample size
makes it hard to generalize our results. Nevertheless, a
small sample size is rather expected to provide statistical
trends than clear results, as in the experimental part of our
study. Furthermore, only one of the several problems
identified by our interviews was approached in the exper-
imental part of our study. Future studies should investigate
more of these problems to provide issues worth to be
solved by an intelligent walker.
In conclusion, opening a door against the direction of
walking caused interference between WW and, door and
was identified as one problem when using a WW. Devel-
oping an intelligent WW, this possible safety problem
should be regarded. In contrast, backward walking per-
formance was improved by using a WW. For evaluation of
future intelligent WWs, a combination of task specific tests
and standard laboratory tests is recommended.
Acknowledgments The authors thank Aaron Haslbauer, Karin
Kampe and Elisabeth Petrias for data collection and technical support
and the authors thank Aileen Currie for proofreading the manuscript.
Compliance with ethical standards
Conflict of interest This work was supported by the Robert Bosch
Foundation as the owner of the Robert-Bosch-Hospital where the
study was conducted. The authors declare that they have no conflict of
interest.
Ethical standards All procedures performed in studies involving
human participants were in accordance with the ethical standards of
the institutional research committee and with the 1964 Helsinki
declaration and its later amendments or comparable ethical standards.
Informed consent Informed consent was obtained from all indi-
vidual participants included in the study.
References
1. Steffen TM, Hacker TA, Mollinger L (2002) Age- and gender-
related test performance in community-dwelling elderly people:
6-min walk test, Berg Balance Scale, Timed Up and Go Test, and
gait speeds. Phys Ther 82:128–137
2. Bateni H, Maki BE (2005) Assistive devices for balance and
mobility: benefits, demands, and adverse consequences. Arch
Phys Med Rehabil 86:134–145
3. Salminen AL, Brandt A, Samuelsson K et al (2009) Mobility
devices to promote activity and participation: a systematic
review. J Rehabil Med 41:697–706
4. Graafmans WC, Lips P, Wijlhuizen GJ et al (2003) Daily phys-
ical activity and the use of a walking aid in relation to falls in
elderly people in a residential care setting. Zeitschrift Fu
¨r
Gerontologie Und Geriatrie 36:23–28
5. Van Riel KMM, Hartholt KA, Panneman MJM et al (2014) Four-
wheeled walker related injuries in older adults in the Netherlands.
Inj Prev 20:11–15
Aging Clin Exp Res
123
Author's personal copy

6. Bryant MS, Pourmoghaddam A, Thrasher A (2012) Gait changes
with walking devices in persons with Parkinson’s disease. Disabil
Rehabil Assist Technol 7:149–152
7. Brandt A, Iwarsson S, Stahl A (2003) Satisfaction with rollators
among community-living users: a follow-up study. Disabil
Rehabil 25:343–353
8. Simoneau M, Teasdale N, Bourdin C et al (1999) Aging and
postural control: postural perturbations caused by changing the
visual anchor. J Am Geriatr Soc 47:235–240
9. Bateni H, Heung E, Zettel J et al (2004) Can use of walkers or
canes impede lateral compensatory stepping movements? Gait
Posture 20:74–83
10. Tung JY, Chee JN, Zabjek KF et al (2014) Combining ambula-
tory and laboratory assessment of rollator use for balance and
mobility in neurologic rehabilitation in-patients. Disabil Rehabil
Assist Technol. doi:10.3109/17483107.2014.908243
11. Fritz NE, Worstell AM, Kloos AD et al (2013) Backward walking
measures are sensitive to age-related changes in mobility and
balance. Gait Posture 37:593–597
12. Rentschler AJ, Cooper RA, Blasch B et al (2003) Intelligent
walkers for the elderly: performance and safety testing of VA-
PAMAID robotic walker. J Rehabil Res Dev 40:423–431
13. Umea University (2014) Biotech Umea
˚—developing an intelli-
gent rollator. http://www.biotechumea.se/developing-an-intelli
gent-rollator. Accessed 22 July 2014
14. University of Stuttgart (2014) Institut fu
¨r Automatisierungs-
und Softwaretechnik. http://www.ias.uni-stuttgart.de/?page_id=
46&demo_id=18. Accessed 17 July 2014
15. Sekiya N, Nagasaki H (1998) Reproducibility of the walking
patterns of normal young adults: test-retest reliability of the walk
ratio (step-length/step-rate). Gait Posture 7:225–227
16. Jones CJ, Rikli RE, Beam WC (1999) A 30-s chair-stand test as a
measure of lower body strength in community-residing older
adults. Res Q Exerc Sport 70:113–119
17. Groll DL, To T, Bombardier C et al (2005) The development of a
comorbidity index with physical function as the outcome. J Clin
Epidemiol 58:595–602
18. Callisaya ML, Blizzard L, McGinley JL et al (2012) Risk of falls
in older people during fast-walking–the TASCOG study. Gait
Posture 36:510–515
Aging Clin Exp Res
123
Author's personal copy