Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT04770103 |
| Other study ID # |
DG020320 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 11, 2021 |
| Est. completion date |
June 30, 2022 |
Study information
| Verified date |
May 2023 |
| Source |
Montana State University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The investigators will evaluate the difference between a commonly accepted paradigm of
balance training (BT) and a more dynamic and task specific form of balance training,
perturbation-based training (PBT) in older adults. BT is a key evidenced based strategy for
preventing falls in older adults, however it needs to be regular (2hours/week) and long term
(>6moths) while the average effect is only moderate (24%). The reason for the moderate effect
on falls is like to be the non-specific stimulus presented during BT. That is, training tends
to be quasi-static and slow and largely based on movements described as strength training.
However, when an individual loses balance, they are most often required to implement a rapid
and dynamic response. Furthermore, while older adults who are unable to recover balance well
have generally lower strength, our recent work has demonstrated that it is not their force
producing capability that limits them. Rather it is the ability to access moderate levels of
muscular force very rapidly and early in the recovery step that differentiates successful
versus unsuccessful recovery of balance. Importantly, the ability to produce an effective and
rapid recovery step is predicative of avoiding future real world falls.
An emerging fall prevention training regimen is perturbation-based training (PBT). PBT
involves rapidly disrupting balance requiring the participant to take rapid steps to recover
balance. This is commonly achieved on a laboratory treadmill equipped with a safety harness
to prevent actual falls during training. By simulating "real-world" balance challenges such
as slips and trips, PBT provides a direct means for learning how to recover balance and avoid
falls. It has been demonstrated that with only a few PBT sessions, older adults make rapid
and dramatic improvements in balance recovery performance, retain the skills long-term and
potentially suffer fewer falls over extended periods. This study builds on the previous
published work of the PI that describes the key factors related to differences in balance
recovery performance, the neuro-motor coordination strategies used during successful and
unsuccessful recovery, and currently unpublished pilot studies indicating the efficacy of
PBT. To date studies have not directly compared BT regimes recommended by the American
College of Sports Medicine (ACSM) against PBT, nor have they evaluated the influence of
training on the incidence of real-world falls. In part this may be because PBT currently
requires the use of expensive, laboratory treadmills and as such is not accessible by the
average independent, community dwelling older adults. A specific randomized study is required
and our overall purpose for this study is to compare the balance recovery performance of
older adults following either BT or PBT, evaluate differences in the incidence of real-world
falls, and develop a safe, effective and portable device for use in future community PBT
training studies. The short-term goals are to determine the effect of PBT versus BT and the
neuro-motor mechanism of improved recovery behavior.
Aim 1: To evaluate differences in balance recovery behavior in older adults following either
balance training (BT) and perturbation-based training (PBT) and the incidence on real-world
falls.
H1: Balance recovery performance will improve in both BT and PBT groups but will be
significantly better in those completing PBT when compared to BT.
H2: Improvements in balance recovery behavior will be related to improved coordination and
neuro-motor control strategies.
H3: Real world loss of balance events will be similar in both BT and PBT but incidence of
resulting falls will be lower in the PBT group.
Description:
APPROACH
1) The main study The main study to investigate the difference between BT and PBT is a
parallel-group randomized controlled trial with 6 months follow-up from baseline to determine
the effect of PBT program on stepping behavior and fall incidence in community-dwelling older
people. The study has been designed in accordance with the Consolidated Standards of
Reporting Trials (CONSORT) statement48.
Participants, recruitment and screening Participants will consist of community-dwelling
adults aged over 65 years without a recent history of falls (one or more falls in the past 12
months). All participants will be required to obtain medical clearance from their general
practitioner prior to participation in the study. Exclusion criteria will be neurological,
cardiovascular or musculoskeletal impairment that adversely affect balance or limit
involvement in the intervention, diagnosis of dementia, cognitive impairment (score<24 on
Mini Mental State Examination after adjustment for age and years of education49), functional
disability/limitation in activities of daily living (Score>3 on Bayer Activities of Daily
Living Scale50), osteoporosis, use of medication that affects balance or causes dizziness
(e.g. psychotropics) and participation in supervised exercise one or more times per week.
Random allocation and concealment Randomization will be performed following baseline
assessment by personnel not involved in recruitment, training or assessments. Participants
will be informed that they will receive one of two treatments. Due to the nature of the
intervention, research personnel administering the treatments cannot be blinded to group
allocation. However, the personnel that perform the prospective falls evaluation will be
blinded to group allocation.
Intervention BT group. This group will undertake 12 weeks of twice weekly BT in accordance
with ACSM guidelines. Training will be conducted in small groups under the supervision of a
trainer. Training will involve mobility, resistance and balance training components.
PBT group. The PBT protocol uses multi-directional surface translations to provoke rapid
compensatory stepping responses to recover balance. The protocol is a modified version of the
stepping (but not grasping) component of the PBT program described by Mansfield et al., which
was designed to improve rapid stepping reactions and minimize foot collisions in accordance
with well-established principles of motor learning including individualization, specificity,
progressive overload, and variability of training. At each session the PBT group will
experience multi- directional disturbances to standing posture (forwards, backwards, left,
right) delivered via translations of a motorized treadmill. 24 perturbations will be
administered in a random sequence (with variation in timing, magnitude and direction) and
interspersed with 30 s treadmill walking. Successful recoveries during training will be
followed by an increase in the degree of difficulty, whereas consecutive failures will result
in a return to the perturbation intensity that had previously been performed successfully.
Our pilot testing indicates that the prescribed peak accelerations on our motorized treadmill
to within ±3% can be achieved. The occurrence of actual falls will be prevented via the use
of a custom safety harness attached to an overhead cable instrumented with a force transducer
used previously. One familiarization trial in each perturbation direction will be performed
at 50% intensity at the beginning of the first training session. Training sessions will be
terminated when the participant completes the planned number of trials or if the participant
elects not to continue (e.g. feels tired, uncomfortable or unwell).
Primary outcome measures The tether-release54 test will be used to determine whether training
effects generalize to balance recovery reactions that are not part of the intervention. Loss
of balance will be induced by releasing participants from static forward lean postures
corresponding to 15%, 20% and 25% of their body weight on a horizontal restraining tether in
accordance with the PI's previous work groups published procedures. Participants will be
instructed to attempt to regain balance by taking a single, rapid step. Full body kinematics
and ground reaction forces will be recorded during all balance recovery tasks using a 3D
motion capture system (12-camera Motion Analysis) and force platforms embedded in the ground
(AMTI, Watertown, USA). Outcome measures will be margin of stability at touchdown of the
stepping leg, step leg kinematics (step length and velocity) and trunk kinematics (trunk
angle and trunk angular velocity). All analysis will be performed using OpenSim57 in
accordance with the PI's and his previous research units published methods.
Secondary outcomes measures Falls frequency will be monitored over the 3 months of the
intervention and following 3 months of follow up with monthly falls diaries. Participants
will return monthly falls diaries (daily entries) to determine frequency, time, location and
cause of falls and related injuries as per consensus recommendations for falls trials52.
OVERALL SUMMARY
The proposed investigation forms the basis of improved understanding of balance recovery
training methods and are important steps for ongoing research into the efficacy of balance
recovery training modes relative to reducing the incidence of falls. In particular, the
proposed study is the necessary precursor to a large prospective study to evaluate the effect
of balance recovery training on health and wellbeing of rural Montanans.
