The present project consists of 2 studies (study 1 & study 2) and is an extension of a recently conducted study in healthy young adults. The overarching goals of the project are to provide insight into (i) the development of cautious gait…
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
In de studies die hier voorliggen worden de effecten van normale veroudering onderzocht.
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
1. Normalized step length: Defined as the distance between centers of pressure
(CoP) of the feet at initial foot contact, normalized for leg length.
2. Normalized step time: defined as the time between two subsequent initial
foot contacts, normalized for leg length.
3. Step width: defined as the absolute difference between the local minimum/
maximum CoP position during the consecutive contralateral single support phases
of each stride.
4. Step length ratio, defined as (step length left - step length right)/ (step
length left + step length right).
5. Step time ratio, defined as (step time left - step time right)/ (step time
left + step time right).
6. Margin of Stability, defined as the distance between the extrapolated centre
of mass (XCoM) and the CoP at contralateral foot lift. The XCoM is defined as
CoM (i.e. the Centre of Mass) + VCoM*W0, where VCoM is the instantaneous
velocity of the CoM and W0 is the gravitational acceleration.
Secondary outcome
1. Falls efficacy scale international
2. Perceived physical activity
3. Dutch General Self-efficacy Scale
Background summary
Walking is a controlled sequence of falls, and therefore a challenging and
dangerous activity. This is especially evident in people with reduced walking
capacity due to natural ageing or pathology. People often perceive these
vulnerabilities and develop a cautious walking strategy: they walk slower and
with shorter and wider steps. This walking strategy is a complex and somewhat
paradoxical phenomenon: although it is intended to protect against upcoming
perturbations, it can also cause an unstable gait and lead to falls. As of yet,
we know little about the underlying mechanisms of cautious gait. Recently, a
protocol has been developed at the dept. of Human Movement Sciences / UMCG
enables the controlled and safe investigation of cautious gait by imposing
simulated slips on a treadmill. This makes it possible to better understand
cautious gait and develop fall prevention interventions for the elderly.
Study objective
The present project consists of 2 studies (study 1 & study 2) and is an
extension of a recently conducted study in healthy young adults. The
overarching goals of the project are to provide insight into (i) the
development of cautious gait strategies and (ii) to determine the effect of age
on this development. More specifically, study 1 will determine (i) whether
responses to a warning ('you may experience a slip from now on') differ between
young and old, (ii) whether an experimentally induced cautious gait pattern
differs between young and old and (iii ) whether the time that the cautious
gait pattern persists after no more slips are offered, differs between young
and old. In study 2 it will be determined whether the unexpected presentation
of an unexpected stimulus to the other leg than where the cautious gait pattern
was conditioned to, results in different adjustments in the elderly than for
the young.
Study design
In both study 1 and study 2, a quasi-experimental design will be used with
repeated measures, in which a group of young and a group of older adults will
be exposed to a series of experimentally induced slips. The experiments involve
4 different phases (i.e. a baseline phase, a warning phase, a perturbation
phase, and a washout phase).
Intervention
In studies 1 and 2 a computer-controlled split-belt treadmill (M-Gait; Motek,
Amsterdam, NL) will be used. The belt movement can be reversed with a high
acceleration to induce slip-like perturbations. Belt-speed will be set to -1.2
m/s in both studies.
In study 1, 20 healthy young (18-30) participants and 20 healthy older (65-80)
participants will be included. First, they will walk on the treadmill during
the *baseline phase* (phase I) for 320 strides, while walking speed is fixed at
-1.2 m/s. Next, during the *warning phase*, participants will be warned that
they may experience a slip, although no actual slip will be presented (phase
II; 200 strides). During the *perturbation phase* (phase III), a series of 30
slip-like perturbations will be presented to the right leg (10-12 minutes).
During the *washout phase* (phase IV; 210 strides), no more perturbations will
be presented, but the participants will not be informed about this.
In study 2, 20 healthy young (18-30) participants and 20 healthy older (65-80)
participants will be included. Phases I, II, and IV will be identical to study
1.In phase III, perturbations will be presented consistently to either the left
or right leg for 29 perturbations (10-12 minutes). The final perturbation will
be presented to the other leg (e.g. a participant will experience slips
presented to the left leg 29 times before the final slip will be presented to
the right leg).
Study burden and risks
During the experiment, participants are fitted in a safety harness that is
suspended from the ceiling. The harness will be adjusted so that participants
will not be able to touch the belts with their knees. Handrails are located at
each side of the treadmill for stabilization purposes. An emergency button (to
stop the treadmill belts immediately) is attached to these handrails, which is
easy to reach in case of an emergency. Additionally, the experimenter can
manually stop the protocol in case of calamities. Finally, light cells are
located at the front and rear end of the treadmill, which will stop the belts
when the participant walks too far to the front or rear end of the belt. The
researchers are certified to use the equipment. Overall, testing may be slight
fatiguing but should not lead to excessive discomfort.
Because the studies focus on the effects of age, different age groups need to
be included. Eventually, results may help in the construction of better falls
prevention programs.
Antonius Deusinglaan 1
Groningen 9713 AV
NL
Antonius Deusinglaan 1
Groningen 9713 AV
NL
Listed location countries
Age
Inclusion criteria
1. Participant is healthy
2. Is able to walk for 30 minutes without problems
3. Meets the age requirements at the time of inclusion (18-30 or 65-80)
Exclusion criteria
1. Neurological, orthopedic, visual, sensorimotor, vestibular or other
impairments and injuries that are known to affect walking and/or balance
2. Participants should not have any prior experience with similar experimental
paradigms
3. Recent hip or knee arthroplasty ( < 24 months)
4. Body Mass Index > 30
5. For study 2 only: participation in study 1
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL72310.042.19 |