Learning from falling: retention of fall-resisting behavior derived from one episode of laboratory-induced slip training

A survey of Israeli physical therapists regarding reactive balance training

BACKGROUND

'Reactive balance training' (RBT) was developed to improve balance reactions to unexpected losses of balance. Although this training method is effective, its practical usage in the field of physical-therapy in Israel and world-wide is still unclear.

AIMS

This study aimed to evaluate the extent of RBT use in physical-therapy clinics in Israel, to identify the significant barriers to/facilitators for implementing RBT in clinical practice among physical therapists, and to determine which aspects of RBT most interest physical therapists in Israel.

METHODS

Physical therapists in Israel completed a survey using a questionnaire regarding their knowledge and use of RBT in their clinical practices. We compared the specific use of RBT among users; non-users; and open-to-use physical therapists. The odds ratios of the facilitators and barriers were calculated using univariate and multivariate logistic regression models.

RESULTS

Four-hundred and two physical therapists responded to a yes/no question regarding their use of RBT. Three-quarters (75.4%) of physical therapists reported using RBT in their practices. The most prevalent barrier cited was insufficient space for setting up equipment and most prevalent facilitator was having a colleague who uses RBT. Most of the respondents wanted to learn more about RBT, and most of the non-users wanted to expand their knowledge and mastery of RBT principles.

CONCLUSIONS

There are misconceptions and insufficient knowledge about RBT among physical therapists in Israel, indicating that they may falsely believe that RBT requires large and expensive equipment, suggesting they categorize RBT as external perturbation training only. Reliable information may help to improve general knowledge regarding RBT, and to facilitate the more widespread implementation of RBT as an effective fall-prevention intervention method.

Rehabilitation clinicians' perspectives of reactive balance training

PURPOSE

Reactive balance training (RBT) aims to improve reactive balance control. However, because RBT involves clients losing balance, clinicians may view that it is unsafe or not feasible for some clients. We aimed to explore how clinicians implement RBT to treat balance and mobility issues.

MATERIALS AND METHODS

Physiotherapists and kinesiologists across Canada who reported that they include RBT in their practices were invited to complete telephone interviews about their experiences with RBT. Interviews were transcribed verbatim, and analysed using a deductive thematic analysis.

RESULTS

Ten participants completed telephone interviews, which lasted between 30-60 min. Participants primarily worked in a hospital setting (inpatient rehabilitation (n = 3); outpatient rehabilitation (n = 2)), and were treated clients with neurological conditions (n = 5). Four main themes were identified: 1) there is variability in RBT approaches; 2) knowledge can be a barrier and facilitator to RBT; 3) reactive balance control is viewed as an advanced skill; and 4) RBT experience builds confidence.

CONCLUSIONS

Our findings suggest a need for resources to make clinical implementation of RBT more feasible.Implications for rehabilitationTrust between the therapist and client improves self-efficacy and feelings of apprehension/fear when conducting reactive balance training.Being creative and improvising with equipment that is readily available in clinics enables reactive balance training, without the need for high-tech equipment.Clinicians should consider using standardized tools with reactive balance control components, such as the Balance Evaluation Systems Test or Performance Oriented Mobility Assessment, to assess balance control.

Effect of reactive balance training on physical fitness poststroke: study protocol for a randomised non-inferiority trial

INTRODUCTION

Regular exercise is essential in the chronic phase of stroke recovery for improving or maintaining function, and reducing the risk of a second stroke. To achieve these goals, multiple components of fitness should be targeted with poststroke exercise, including aerobic capacity, strength and balance. However, following the recommended frequency and duration of each component separately can take a long time and lead to fatigue in people with stroke. Therefore, finding types of exercise that target multiple components of fitness all together is valuable.Reactive balance training (RBT) is a novel type of exercise where individuals repeatedly lose their balance in order to practise balance reactions. When people do RBT, they increase their heart rate and exert forces with their leg muscles which could improve aerobic fitness and muscle strength, respectively. This means that RBT could have the potential to improve multiple components of fitness, simultaneously.

METHODS AND ANALYSIS

This is a randomised controlled non-inferiority trial with internal pilot study. Participants with chronic stroke will be randomly assigned to one of two groups: (1) RBT or (2) aerobic and strength training (AST). Participants in both groups will complete 1 hour of exercise, three times/week for 12 weeks. The primary objective is to determine the effect of RBT on aerobic capacity and knee muscles' strength. The secondary objective is to determine the effects of RBT and AST on balance control and balance confidence. We expect to find that RBT is superior to AST in terms of improving balance control and balance confidence, yet not inferior to AST in terms of its effects on aerobic capacity and strength.

ETHICS AND DISSEMINATION

Research ethics approval has been received. Results will be disseminated directly to study participants at the end of the trial, and to other stakeholders via publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04042961.

A survey of Canadian healthcare professionals' practices regarding reactive balance training

Background: Perturbation-based balance training (PBT) is a relatively new type of balance training that aims to improve control of reactions to a loss of balance. This study aimed to determine the prevalence of use of PBT in clinical practice, and the most significant barriers and facilitators to implementing PBT in practice.Methods: Health-care professionals across Canada (primarily physiotherapists and kinesiologists) who provide balance training to individuals with balance impairments and/or increased fall risk completed a questionnaire that asked about knowledge and use of PBT in practice.Results: Overall, 76.3% of participants (299/392) reported that they had used PBT in their practices, with 22.4% (88/392) reporting regular PBT use. Lack of knowledge of PBT appeared to be the most significant barrier for those not currently using PBT in their practices, whereas individuals who were familiar with PBT and open to using it in practice experienced barriers related to training, knowledge, human resources, client characteristics, and the practice setting. More than 90% of respondents were interested in learning more about almost all aspects of PBT.Conclusions: These findings could be used to inform development of future educational strategies to increase uptake of PBT in rehabilitation practice.

Treadmill-gait slip training in community-dwelling older adults: mechanisms of immediate adaptation for a progressive ascending-mixed-intensity protocol

The study purpose was to investigate whether older adults could improve their stability against a backward loss of balance (BLOB) after receiving repeated treadmill slips during walking and to see how such adaptive changes would be affected by practice dosage (combination of slip intensity and the number of slips at each intensity). Twenty-five healthy community-dwelling older adults received forty treadmill slips given over eleven blocks at five intensities (P1-P1-P2-P3-P4-P5-P4-P5-P5-P3-P1, larger number indicating higher intensity). Center of mass (COM) stability was calculated as the shortest distance of the instantaneous COM position and velocity relative to the base of support (BOS) from a theoretical threshold for BLOB (larger stability value indicated a better stability against BLOB). Stability, step length, and trunk angle were measured before and after slip onset to reflect proactive and reactive control, respectively. The first slips at each intensity block (i.e., P1, P3, P4, and P5) were compared with the first slips in the last blocks at those intensities to examine main effects of training dosage (intensity and repetition). Improvements in proactive and reactive stability were more pronounced for receiving more slips at larger intensities than fewer slips at smaller intensities. Older adults only demonstrated partial positive scaling effects to proactively, not reactively, establish a more stable initial COM state. The improved proactive stability was associated with an anterior shift of COM position relative to the BOS, resulting from a shorter pre-slip step length. The improved reactive stability was associated with an anterior shift of COM position, resulting from a larger compensatory step length and a faster COM velocity relative to the BOS. Our findings indicated that treadmill-gait slip perturbations elicited similar proactive and reactive control to that from over-ground slip perturbations, but greater slip intensity and repetition might yield more immediate adaptive improvements.

An Initial Passive Phase That Limits the Time to Recover and Emphasizes the Role of Proprioceptive Information

In the present experiments, multiple balance perturbations were provided by unpredictable support-surface translations in various directions and velocities. The aim of this study was to distinguish the passive and the active phases during the pre-impact period of a fall. It was hypothesized that it should be feasible if one uses a specific quantitative kinematic analysis to evaluate the dispersion of the body segments trajectories across trials. Moreover, a multi-joint kinematical model was created for each subject, based on a new 3-D minimally invasive stereoradiographic X-ray images to assess subject-specific geometry and inertial parameters. The simulations allowed discriminating between the contributions of the passive (inertia-induced properties) and the active (neuromuscular response) components during falls. Our data show that there is limited time to adjust the way one fall from a standing position. We showed that the pre-impact period is truncated of 200 ms. During the initial part of a fall, the observed trajectory results from the interaction between the destabilizing external force and the body: inertial properties intrinsic to joints, ligaments and musculotendinous system have then a major contribution, as suggested for the regulation of static upright stance. This passive phase is later followed by an active phase, which consists of a corrective response to the postural perturbation. We believe that during a fall from standing height, it takes about 300 ms for postural responses to start correcting the body trajectory, while the impact is expected to occur around 700 ms. It has been argued that this time is sufficient to change the way one falls and that this makes it possible to apply safer ways of falling, for example by using martial arts fall techniques. Also, our results imply visual and vestibular information are not congruent with the beginning of the on-going fall. This consequence is to be noted as subjects prepare to the impact on the basis of sensory information, which would be uniquely mainly of proprioceptive origin at the fall onset. One limitation of the present analysis is that no EMG was included so far but these data are the subject of a future study.

Neuromuscular and Kinematic Adaptation in Response to Reactive Balance Training - a Randomized Controlled Study Regarding Fall Prevention

Slips and stumbles are main causes of falls and result in serious injuries. Balance training is widely applied for preventing falls across the lifespan. Subdivided into two main intervention types, biomechanical characteristics differ amongst balance interventions tailored to counteract falls: conventional balance training (CBT) referring to a balance task with a static ledger pivoting around the ankle joint versus reactive balance training (RBT) using externally applied perturbations to deteriorate body equilibrium. This study aimed to evaluate the efficacy of reactive, slip-simulating RBT compared to CBT in regard to fall prevention and to detect neuromuscular and kinematic dependencies. In a randomized controlled trial, 38 participants were randomly allocated either to CBT or RBT. To simulate stumbling scenarios, postural responses were assessed to posterior translations in gait and stance perturbation before and after 4 weeks of training. Surface electromyography during short- (SLR), medium- (MLR), and long-latency response of shank and thigh muscles as well as ankle, knee, and hip joint kinematics (amplitudes and velocities) were recorded. Both training modalities revealed reduced angular velocity in the ankle joint (P < 0.05) accompanied by increased shank muscle activity in SLR (P < 0.05) during marching in place perturbation. During stance perturbation and marching in place perturbation, hip angular velocity was decreased after RBT (P from TTEST, P_t < 0.05) accompanied by enhanced thigh muscle activity (SLR, MLR) after both trainings (P < 0.05). Effect sizes were larger for the RBT-group during stance perturbation. Thus, both interventions revealed modified stabilization strategies for reactive balance recovery after surface translations. Characterized by enhanced reflex activity in the leg muscles antagonizing the surface translations, balance training is associated with improved neuromuscular timing and accuracy being relevant for postural control. This may result in more efficient segmental stabilization during fall risk situations, independent of the intervention modality. More pronounced modulations and higher effect sizes after RBT in stance perturbation point toward specificity of training adaptations, with an emphasis on the proximal body segment for RBT. Outcomes underline the benefits of balance training with a clear distinction between RBT and CBT being relevant for training application over the lifespan.

Perturbation exercises during treadmill walking improve pelvic and trunk motion in older adults-A randomized control trial

BACKGROUND

Most falls among older adults occur while walking. Pelvic and trunk motions are required to maintain stability during walking. We aimed to explore whether training that incorporates unexpected loss of balance during walking that evokes balance recovery reactions will improve pelvic, thorax, and trunk kinematics at different walking speeds.

METHODS

Fifty-three community-dwelling older adults (age 80.1 ± 5.6 years) were randomly allocated to an intervention group (n = 27) or a control group (n = 26). Both groups received 24 training sessions over 3 months. The intervention group received unexpected perturbation of balance exercises during treadmill walking, while the control group performed treadmill walking only. The primary outcome measures were the pelvic, thorax, and trunk motion. The secondary outcome measures were stride times, length, and width.

RESULTS

Compared to control, participation in the intervention program led to improvement in pelvic and trunk transverse rotations especially at participants' preferred walking speed. No improvement where found in pelvic list while thorax transverse rotation improved in both groups.

CONCLUSIONS

Pelvic and trunk transverse motion, parameters previously reported to deteriorate during aging, associated with gait stability and a risk factor for falls, can be improved by gait training that includes unexpected loss of balance.

Natural Product Inspired N-Terminal Hsp90 Inhibitors: From Bench to Bedside?

The 90 kDa heat shock proteins (Hsp90) are responsible for the conformational maturation of nascent polypeptides and the rematuration of denatured proteins. Proteins dependent upon Hsp90 are associated with all six hallmarks of cancer. Upon Hsp90 inhibition, protein substrates are degraded via the ubiquitin-proteasome pathway. Consequentially, inhibition of Hsp90 offers a therapeutic opportunity for the treatment of cancer. Natural product inhibitors of Hsp90 have been identified in vitro, which have served as leads for the development of more efficacious inhibitors and analogs that have entered clinical trials. This review highlights the development of natural product analogs, as well as the development of clinically important inhibitors that arose from natural products.

Perturbation training can reduce community-dwelling older adults' annual fall risk: a randomized controlled trial

BACKGROUND

Previous studies indicated that a single session of repeated-slip exposure can reduce over 40% of laboratory-induced falls among older adults. The purpose of this study was to determine to what degree such perturbation training translated to the reduction of older adults' annual falls risk in their everyday living.

METHODS

Two hundred and twelve community-dwelling older adults (≥65 years old) were randomly assigned to either the training group (N = 109), who then were exposed to 24 unannounced repeated slips, or the control group (N = 103), who merely experienced one slip during the same walking in the same protective laboratory environment. We recorded their falls in the preceding year (through self-reported history) and during the next 12 months (through falls diary and monitored with phone calls).

RESULTS

With this single session of repeated-slip exposure, training cut older adults' annual risk of falls by 50% (from 34% to 15%, p < .05). Those who experienced merely a single slip were 2.3 times more likely to fall during the same 12-month follow-up period (p < .05) than those who experienced the 24 repeated slips. Such training effect was especially prominent among those who had history of falls.

CONCLUSION

A single session of repeated-slip exposure could improve community-dwelling older adults' resilience to postural disturbances and, hence, significantly reduce their annual risk of falls.