Factors that influence the risk of falling after spinal cord injury: a qualitative photo-elicitation study with individuals that use a wheelchair as their primary means of mobility

INTRODUCTION

Falls are a concern for wheelchair users with spinal cord injury (SCI). Falls can negatively impact the physical and psychological well-being of fallers. To date, the perspectives of wheelchair users with lived experiences of SCI on the contributors to falls has been understudied. Information about factors that influence fall risk would guide the development of effective fall prevention strategies.

OBJECTIVES

To gain a comprehensive understanding of the factors that influenced the risk of falling as perceived by wheelchair users with SCI.

DESIGN

A qualitative study using photo-elicitation interviews.

SETTING

A Canadian SCI rehabilitation hospital and the participants' home/community environments.

PARTICIPANTS

Twelve wheelchair users living in the community with chronic SCI.

METHODS

Participants captured photographs of situations, places or things that they perceived increased and decreased their risk of falling. Semistructured photo-elicitation interviews were conducted to discuss the content of the photographs and explore perceptions of fall risk factors. A hybrid thematic analysis and the Biological, Behavioural, Social, Economic, and Environmental model were used as a framework to organise/synthesise the data.

RESULTS

Overall, the findings indicated that the risk of falling was individualised, complex and dynamic to each person's life situation. Four main themes were revealed in our analysis: (1) Falls and fall risk caused by multiple interacting factors; (2) Dynamic nature of fall risk; (3) Single factors were targeted to reduce falls and fall-related injuries; and (4) Fall prevention experiences and priorities.

CONCLUSIONS

Each wheelchair user encountered numerous fall risk factors in their everyday lives. Information from this study can be used to set priorities for fall prevention. Fall prevention initiatives should consider a wheelchair user's fall risks in a holistic manner, acknowledging that a person's current situation, as well as anticipating their fall risks and fall prevention needs, will change over time.

Development of an implementation-focused network to improve healthcare delivery as informed by the experiences of the SCI knowledge mobilization network

Context: Implementing research findings into clinical practice is challenging. This manuscript outlines the experiences and key learnings from a network that operated as a community of practice across seven Canadian Spinal Cord Injury (SCI) rehabilitation centers. These learnings are being used to inform a new implementation-focused network involving SCI rehabilitation programs based in Ontario, Canada. Methods: The SCI KMN adapted and applied implementation science principles based on the National Implementation Research Network's (NIRN) Active Implementation Frameworks in the implementation of best practices in pressure injury and pain prevention and management. Results: The SCI KMN was successful in implementing best practices in both pressure ulcer and pain prevention and management across the various participating sites. Other key objectives met were building capacity in implementation methods in site personnel so that project scaling could occur with these skills and expertise applied to numerous other initiatives. Additionally, various papers, abstracts and conference presentation as well as an implementation guide were disseminated to inform the field of implementation science. Conclusion: The key lessons learned from this experience are being used to develop a new implementation-focused network. Features felt to be especially important for the SCI KMN includes a highly representative governance structure, the use of indicators within an overall evaluation framework and the systematic application of implementation processes with shared learnings supporting each site.

The Spinal Cord Injury Pressure Ulcer Scale (SCIPUS): an assessment of validity using Rasch analysis

STUDY DESIGN

Secondary analysis of retrospective data.

OBJECTIVE

The aim of this study was to further validate the Spinal Cord Injury Pressure Ulcer Scale (SCIPUS) using Rasch analysis.

SETTING

Two rehabilitation centers in Canada.

METHOD

Data were collected as part of the Spinal Cord Injury Knowledge Mobilization Network (SCI KMN) initiative. The SCIPUS was completed within 72 h of inpatient admission. Persons admitted for initial rehabilitation in two inpatient spinal cord rehabilitation programs were included in the project.

RESULTS

Data from 886 participants were analyzed, approximately 60% of whom were males. Rasch analyses demonstrated that the SCIPUS, in its current format did not meet criteria required for true measurement. A transformed version of the SCIPUS obtained by deletion of misfitting items and modification of the response scales improved fit to the model and showed preliminary evidence of unidimensionality. The person separation index, however indicated that the scale requires further adjustments of its scoring options.

CONCLUSIONS

In its original form, the SCIPUS does not meet the requirements of the Rasch model and its total score should be used cautiously. However, following some adjustments to the items such as addressing DIF between sites to insure a standardized assessment across sites and adding response options to some of the items, interval-scale measurement should be possible.

Determining Pressure Injury Risk on Admission to Inpatient Spinal Cord Injury Rehabilitation: A Comparison of the FIM, Spinal Cord Injury Pressure Ulcer Scale, and Braden Scale

OBJECTIVE

Assess the utility of the admission Spinal Cord Injury Pressure Ulcer Scale (SCIPUS), Braden Scale, and the FIM for identifying individuals at risk for developing pressure injury during inpatient spinal cord injury (SCI) rehabilitation.

DESIGN

Retrospective cohort.

SETTING

Two tertiary rehabilitation centers.

PARTICIPANTS

Individuals (N=754) participating in inpatient SCI rehabilitation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Logistic regression analysis was performed to determine the utility of the SCIPUS, Braden Scale, and FIM for identifying individuals at risk for developing pressure injury (PI) during inpatient SCI rehabilitation. Sensitivity, specificity, positive predictive value, negative predictive value, false negative rate, odds ratio, likelihood ratio, and area under the curve (AUC) are reported.

RESULTS

The SCIPUS total score and its individual items did not demonstrate acceptable accuracy (AUC≥0.7) whereas the Braden Scale (0.73) and the FIM score (0.74) did. Once items were dichotomized into high and low risk categories, 1 Braden item (friction and shear), 5 FIM items (bathing, toileting, bed/chair transfer, tub/shower transfer, toilet transfer), the FIM transfers subscale, FIM Motor subscale, and the FIM instrument as a whole, maintained AUCs ≥0.7 and negative predictive values ≥0.95. The FIM bed/chair transfer score demonstrated the highest likelihood ratio (2.62) and overall was the most promising measure for determining PI risk.

CONCLUSION

Study findings suggest that a simple measure of mobility, admission FIM bed/chair transfer score of 1 (total assist), can identify at-risk individuals with greater accuracy than both an SCI specific instrument (SCIPUS) and a PI specific instrument (Braden). The FIM bed/chair transfer score can be readily determined at rehabilitation admission with minimal administrative and clinical burden.

Intensive Balance Training for Adults With Incomplete Spinal Cord Injuries: Protocol for an Assessor-Blinded Randomized Clinical Trial

BACKGROUND

Impaired reactive balance control can lead to increased falls in people with neurological impairments. Perturbation-based balance training (PBT), which involves repetitive exposure to destabilizing external perturbations, improves the ability to take reactive steps in older adults and individuals who have had a stroke.

OBJECTIVE

The objective is to investigate whether PBT or conventional intensive balance training (CIBT) results in greater improvements in reactive stepping ability in individuals with chronic incomplete spinal cord injury (iSCI).

DESIGN

The design consists of an assessor-blind randomized clinical trial comparing the efficacy of 2 balance training programs (PBT and CIBT) matched for training duration (thrice weekly for 8 weeks).

SETTING

A tertiary spinal cord injury rehabilitation center is used as the setting.

PARTICIPANTS

Participants include 24 adults with iSCI classified as a C or D on the American Spinal Association Impairment Scale, who are able to stand independently and exhibit moderate trunk control.

INTERVENTION

Both PBT and CIBT involve 24 sessions, each 1 hour long, of individualized static and dynamic balance tasks. However, PBT includes external, unexpected balance perturbations provided manually by the trainer at a frequency of roughly 1 per training minute.

MEASUREMENTS

The primary outcome is the ability to recover balance using a single step during the Lean-and-Release test, a novel method of assessing reactive balance. Secondary outcomes include a number of clinical balance and gait assessments, and the number of falls experienced in a 6-month follow-up period. Semi-structured interviews are conducted 3 months after training completion to gain insight into the participants' perceptions of the impact of the interventions.

LIMITATIONS

A control group receiving "standard care" for balance training is not included.

CONCLUSIONS

This trial will provide physical therapists with insight into the efficacy of 2 forms of balance training for individuals with iSCI.

The application of implementation science for pressure ulcer prevention best practices in an inpatient spinal cord injury rehabilitation program

OBJECTIVES

To implement pressure ulcer (PU) prevention best practices in spinal cord injury (SCI) rehabilitation using implementation science frameworks.

DESIGN

Quality improvement.

SETTING

SCI Rehabilitation Center.

PARTICIPANTS

Inpatients admitted January 2012 to July 2013.

INTERVENTIONS

Implementation of two PU best practices were targeted: (1) completing a comprehensive PU risk assessment and individualized interprofessional PU prevention plan (PUPP); and (2) providing patient education for PU prevention; as part of the pan-Canadian SCI Knowledge Mobilization Network. At our center, the SCI Pressure Ulcer Scale replaced the Braden risk assessment scale and an interprofessional PUPP form was implemented. Comprehensive educational programing existed, so efforts focused on improving documentation. Implementation science frameworks provided structure for a systematic approach to best practice implementation (BPI): (1) site implementation team, (2) implementation drivers, (3) stages of implementation, and (4) improvement cycles. Strategies were developed to address key implementation drivers (staff competency, organizational supports, and leadership) through the four stages of implementation: exploration, installation, initial implementation, and full implementation. Improvement cycles were used to address BPI challenges.

OUTCOME MEASURES

Implementation processes (e.g. staff training) and BPI outcomes (completion rates).

RESULTS

Following BPI, risk assessment completion rates improved from 29 to 82%. The PUPP completion rate was 89%. PU education was documented for 45% of patients (vs. 21% pre-implementation).

CONCLUSION

Implementation science provided a framework and effective tools for successful pressure ulcer BPI in SCI rehabilitation. Ongoing improvement cycles will target timeliness of tool completion and documentation of patient education.

The moveable handhold: a new paradigm to study visual contributions to the control of balance-recovery reactions

Balance-recovery reactions that involve rapid step or reach-to-grasp movements are prevalent and functionally important responses to instability. Successful use of these reactions to recover balance in daily life requires a capacity to modulate the reaction to deal with the continual variation in environmental constraints that occurs as the person moves, i.e. location of objects that can obstruct limb movements or serve as handholds to grasp. The most direct approach to study this involves applying balance perturbations as subjects move within a visually complex environment; however, this approach does not allow precise control over kinematic variables or visual inputs, and is susceptible to strong learning effects. We have therefore developed an alternate approach, wherein the subject is stationary and the relative motion between subject and constraints that normally occurs as a result of ambulation is instead introduced via movement of the surrounding obstacles or handholds. We previously developed a motor-driven "obstacle-mover" to manipulate constraints on step reactions, and now describe an analogous approach to study reach-to-grasp reactions, using a motor-driven "handhold-mover". We anticipate that this paradigm will provide new opportunities to probe CNS control of upright stance, by providing a sensitive indicator of limitations in the neuromusculoskeletal systems. It can also be used to test perturbation-evoked reactions in seated subjects, thereby allowing testing or training of persons who are unable to stand and use of techniques (e.g. TMS, EEG) that can be difficult to perform in free-standing subjects.

Gaze Behavior of Older Adults in Responding to Unexpected Loss of Balance while Walking in an Unfamiliar Environment: a Pilot Study

Purpose

Rapid reach-to-grasp balance-recovery reactions play a critical role in preventing falls. Recent young-adult studies suggest these reactions may be guided using stored visuo-spatial information from the central field, and that peripheral vision may also play an important role. This study used gaze recordings to examine the visual control of reach-to-grasp reactions in older adults.

Methods

A motion platform was configured to simulate a “real-life” environment that included a handrail. Subjects performed an activity that required walking to the end of the platform, which was triggered to move suddenly and unexpectedly as they approached the handrail. Twelve healthy older adults (64-79 years old) were tested and compared to 12 healthy young adults (22-30 years old) tested as part of another study.

Results

Older adults were more than twice as likely as young adults to react to the platform perturbation by grasping the handrail (10/12 versus 4/12), despite being much less likely to visually fixate the handrail after entering the new environment. Grasping errors were remarkably common (5/10 older, 2/4 young), but there was no consistent relationship to the preceding gaze behavior.

Conclusion

Older adults were highly dependent on using a handrail to recover balance, but commonly failed to direct overt visual attention to the rail after entering the unfamiliar environment. The failure to fixate the rail required the reaching movement to be guided using peripheral vision. Further research is needed to determine whether grasping errors can be prevented via interventions that either attract overt attention to the handrail or improve processing of peripheral-field information.

Preventing falls in older adults: New interventions to promote more effective change-in-support balance reactions

"Change-in-support" (CIS) balance-recovery reactions that involve rapid stepping or reaching movements play a critical role in preventing falls; however, age-related deficits in the neuro-musculoskeletal systems may impede ability to execute these reactions effectively. This review describes four new interventions aimed at reducing fall risk in older adults by promoting more effective CIS reactions: (1) balance training, (2) balance-enhancing footwear, (3) safer mobility aids, and (4) handrail cueing systems. The training program uses unpredictable support-surface perturbations to counter specific CIS control problems associated with aging and fall risk. Pilot testing has demonstrated that the program is well-tolerated by balance-impaired older adults, and a randomized controlled trial is now in progress. The balance-enhancing footwear insole improves control of stepping reactions by compensating for age-related loss of plantar cutaneous sensation. In a clinical trial, subjects wore the insole for 12 weeks with no serious problems and no habituation of the balance-enhancing benefits. The mobility-aid intervention involves changes to the design of pickup walkers so as to reduce impediments to lateral stepping. Finally, work is underway to investigate the effectiveness of handrail cueing in attracting attention to the rail and ensuring that the brain registers its location, thereby facilitating more rapid and accurate grasping.

Interventions to promote more effective balance-recovery reactions in industrial settings: new perspectives on footwear and handrails

"Change-in-support" balance-recovery reactions that involve rapid stepping or reaching movements play a critical role in preventing falls. Recent geriatrics studies have led to new interventions to improve ability to execute these reactions effectively. Some of these interventions have the potential to reduce fall risk for younger persons working in industrial settings. In this paper, we review research pertaining to two such interventions: 1) balance-enhancing footwear insoles designed to improve stepping reactions, and 2) proximity-triggered handrail cueing systems designed to improve reach-to-grasp reactions. The insole has a raised ridge around the perimeter that is intended to improve balance control by providing increased stimulation of sensory receptors on the footsole in situations where loss of balance may be imminent. The cueing system uses flashing lights and/or verbal prompts to attract attention to the handrail and ensure that the brain registers its location, thereby facilitating more rapid and accurate grasping of the rail if and when sudden loss of balance occurs. Results to date support the efficacy of both interventions in geriatric populations. There is also some evidence that these interventions may improve balance control in younger persons; however, further research is needed to confirm their efficacy in preventing falls in industrial settings.

Gaze behavior governing balance recovery in an unfamiliar and complex environment

Visuospatial information regarding obstacles and other environmental constraints on limb movement is essential for the successful planning and execution of stepping movements. Visuospatial control strategies used during gait and volitional stepping have been studied extensively; however, the visuospatial strategies that are used when stepping rapidly to recover balance in response to sudden postural perturbation are not well established. To study this, rapid forward stepping reactions were evoked by unpredictable support-surface acceleration while subjects stood amid multiple obstacles that moved intermittently and unpredictably prior to perturbation onset (PO). To prevent predictive control, subjects performed only one trial (their very first exposure to the perturbation and environment). Visual scanning of the obstacles and surroundings occurred prior to PO in all subjects; however, gaze was never redirected at the obstacles, step foot or landing site in response to the perturbation. Surprisingly, the point of gaze at time of foot-contact was consistently and substantially anterior to the step-landing site. Despite the apparent absence of 'online' visual feedback related to the foot movement, the compensatory step avoided obstacle contact in 10 of 12 young adults and 9 of 10 older subjects. The results indicate that the balance-recovery reaction was typically modulated on the basis of visuospatial environmental information that was acquired and continually updated prior to perturbation, as opposed to a strategy based on 'online' visual control. The capacity to do this was not adversely affected by aging, despite a tendency for older subjects to look downward less frequently than young adults.

Sensitivity of a Hill-based muscle model to perturbations in model parameters

Musculoskeletal simulations of human movement commonly use Hill muscle models to predict muscle forces, but their sensitivity to model parameter values is not well understood. The purpose of this study was to evaluate muscle model sensitivity to perturbations in 14 Hill muscle model parameters in forward dynamic simulations of running and walking by varying each by +/-50%. Three evaluations of the muscle model were performed based on: (1) calculating the sensitivity of the muscle model only, (2) determining the continuous partial derivatives of the muscle equations with respect to each parameter, and (3) evaluating the effects on the running and walking simulations. Model evaluations were found to be very sensitive (percent change in outputs greater than parameter perturbation) to parameters defining the series elastic component (tendon), force-length curve of the contractile element and maximum isometric force. For some parameters, the range of literature values was larger than the model sensitivity. Model evaluations were insensitive to parameters defining the parallel elastic element, force-velocity curve of the contractile element and muscle activation time constants. The derivative method provided similar results, but also provided a generic, continuous equation that can easily be applied to other motions. The sensitivities of the running and walking simulations were reduced compared to the sensitivity of the muscle model alone. Results demonstrate the importance of evaluating sensitivity of a musculoskeletal simulation in a controlled manner and provide an indication of which parameters must be selected most carefully based on the sensitivity of a given movement.