Increased Comfortable Gait Speed Is Associated With Improved Gait Biomechanics in Persons With Chronic Stroke Completing an 8-Week Forced-Rate Aerobic Cycling Intervention: A Preliminary Study.

ABSTRACT: Task-specific gait training is recommended to improve locomotor function after stroke. Our objective was to determine the effects of a forced-rate aerobic exercise intervention on gait velocity and biomechanics in the absence of task-specific gait training. Individuals with chronic stroke ( N = 14) underwent 24 sessions of forced-rate aerobic exercise, at a targeted aerobic intensity of 60%-80% of their heart rate reserve. Change in comfortable walking speed in addition to spatiotemporal, kinematic, and kinetic variables were measured using three-dimensional motion capture. Overground walking capacity was measured by the 6-min walk test. To determine gait biomechanics associated with increased walking speed, spatiotemporal, kinematic, and kinetic variables were analyzed separately for those who met the minimal clinically important difference for change in gait velocity compared with those who did not. Participants demonstrated a significant increase in gait velocity from 0.61 to 0.70 m/sec ( P = 0.004) and 6-min walk test distance from 272.1 to 325.1 meters ( P < 0.001). Those who met the minimal clinically important difference for change in gait velocity demonstrated significantly greater improvements in spatiotemporal parameters ( P = 0.041), ground reaction forces ( P = 0.047), and power generation ( P = 0.007) compared with those who did not. Improvements in gait velocity were accompanied by normalization of gait biomechanics.

An 8-week aerobic cycling intervention elicits improved gait velocity and biomechanics in persons with Parkinson's disease.

BACKGROUND: It is unknown if improvements in gait velocity following an aerobic cycling intervention are accompanied by improved gait biomechanics in individuals with Parkinson's disease (PD) or if gait abnormalities are exaggerated in response to increased velocity. Research question Can an 8-week aerobic cycling intervention elicit improvements in locomotor function in individuals with mild to moderate PD? METHODS: A secondary analysis of data from a randomized clinical trial was conducted in individuals with mild to moderate idiopathic PD (N = 28). Participants were randomized to an aerobic cycling intervention (PDex, N = 14) consisting of 24 sessions at a targeted aerobic intensity of 60-80% of heart rate reserve or to a no intervention control group (PDcontrol, N = 14). Change in comfortable walking speed in addition to gait kinematics, kinetics, and spatiotemporal variables using motion capture were obtained at baseline and end of treatment (EOT). RESULTS: The PDex group made significantly greater improvements in the primary outcome, change in comfortable gait velocity, from 0.86 ± 0.24 m/s at baseline to 1.00 ± 0.23 m/s at EOT compared to the PDcontrol group who declined from 0.91 ± 0.23 m/s at baseline to 0.80 ± 0.29 at EOT (P = 0.002). Improvements in gait velocity for the PDex group were accompanied by improvements in gait kinematics, kinetics, and spatiotemporal parameters, while the PDcontrol group demonstrated slight worsening in all gait parameters over the 8-week period. Significance The 8-week moderate- to high-intensity cycling intervention elicited significantly greater improvements in gait velocity compared to the PDcontrol group. Increased gait velocity was accompanied by normalization of gait biomechanics, rather than an exaggeration of existing gait deviations. Aerobic cycling may be a viable treatment approach to improve gait velocity and gait biomechanics in individuals with mild to moderate PD and may mitigate declines in mobility.

Development of an Inexpensive Harnessing System Allowing Independent Gardening for Balance Training for Mobility Impaired Individuals.

Balance is key to independent mobility, and poor balance leads to a risk of falling and subsequent injury that can cause self-restriction of activity for older adults. Balance and mobility can be improved through training programs, but many programs are not intensive or engaging enough to sufficiently improve balance while maintaining adherence. As an alternative to traditional balance training, harnessed gardening sessions were conducted in an urban greenhouse as an example of a community activity through which balance and mobility can be trained and/or maintained. An inexpensive multidirectional harness system was developed that can be used as an assistive or rehabilitative device in community, private, and senior center gardens to allow balance or mobility-impaired adults to participate in programming. Two wearable sensor systems were used to measure responses to the system: the Polhemus G4 system measured gardeners' positions and center of mass relative to the base of support, and ActiGraph activity monitors measured the frequency and intensity of arm movements in garden as compared to home environments. The harnessed gardening system provides a safe environment for intense movement activity and can be used as a rehabilitation device along with wearable sensor systems to monitor ongoing changes.

A Clinical Decision-Making Framework for the Use of Video Gaming as a Therapeutic Modality.

Virtual reality and video gaming offer modulation of more exercise and motor learning parameters simultaneously than other modalities; however, there is a demonstrated need for resources to facilitate their effective use clinically. This article presents a conceptual framework to guide clinical-decision making for the selection, adaptation, modulation, and progression of virtual reality or gaming when used as a therapeutic exercise modality, and two cases as exemplars. This framework was developed by adapting the steps of theory derivation, whereby concepts and parent theories are brought together to describe a new structure or phenomenon of interest. Specifically, motor learning theory, integrated motor control theory, Gentile's Taxonomy of Tasks, and therapeutic exercise principles were integrated to develop this framework. It incorporates person (body segment), environmental, and task demands; each demand is comprised of realm, category, choice, and continuum parameters as motor training considerations and alternatives for decision-making. This framework: (1) provides structure to guide clinical decisions for effective and safe use of virtual reality or gaming to meet therapeutic goals and requirements, (2) is a concise and organized method to identify, document, and track the therapeutic components of protocols and client progression over time; (3) can facilitate documentation for reimbursement and communication among clinicians; and, (4) structures student learning, and (5) informs research questions and methods.

A progressive-individualized midstance gait perturbation protocol for reactive balance assessment in stroke survivors.

Restoration of balance control is a primary focus of rehabilitation after a stroke. The study developed a gait perturbation, treadmill-based, balance assessment protocol and demonstrated that it can be used to quantify improvements in reactive balance responses among individuals post-stroke. The protocol consists of a sequence of fifteen 90-second treadmill walking trials, with a single perturbation applied during the middle third of each trial. Gait was perturbed by rapid acceleration-deceleration of the treadmill belt at mid-stance of the unaffected leg during a randomly selected gait cycle. The initial perturbation magnitude was based on the participant's maximum walking speed and increased or decreased in each trial, based on success or failure of recovery, as determined from an instrumented harness. The protocol was used before and after a 10-week period of therapy in twenty-four stroke survivors. Outcomes included maximum recoverable perturbation (MRP), self-selected gait speed, levels progressed through the algorithm, and falls versus recoveries.Participants were able to take recovery steps in response to the perturbation. Twelve participants completed the full assessment protocol before and after the therapeutic intervention. After the intervention, they had fewer falls and more recoveries (p < 0.001), progressed through more algorithm levels (p = 0.043), had a higher MRP (p = 0.005), and had higher gait speeds. The protocol was found to be feasible in stroke survivors with moderate gait deficits. The data supports the conclusion that this protocol can be used in clinical research to quantify improvements in balance during walking.

Usability of the 'Kinect-ing' with Clinicians Website: A Knowledge Translation Resource Supporting Decisions About Active Videogame Use in Rehabilitation.

Objective: Commercially available active videogames (AVGs) are promising rehabilitation options, but lack of familiarity with game options may limit clinical integration. We evaluated content and format usability of the 'Kinect-ing' with Clinicians (KwiC) website, an online tool that characterizes commercially available games to support clinical decision-making about Kinect™ game use for rehabilitation. Materials and Methods: This study is a cross-sectional online survey of physical therapists (PTs). Participants selected a case scenario and reviewed the KwiC resource for information about five Kinect games. Based on this interaction, participants selected two games that would meet case scenario goals and answered Likert scale and open-ended questions about KwiC usability and usefulness of the content in guiding game selection for clinical case scenarios. Results: Twenty-five PTs participated, six of whom had previous AVG experience. All KwiC items achieved prespecified consensus of 80% "agree" or "strongly agree" on statements evaluating ease of understanding, usefulness, and format usability. There were no differences in ratings between those with and without AVG experience. Participants most appreciated the videos illustrating game play. Eighty-four percent strongly agreed that the KwiC helped them to make a decision about their case scenario. Participants suggested improving the KwiC by including more information about game use with rehabilitation populations. Conclusions: Positive usability feedback supports continued KwiC development efforts to add additional games, expand information about use specific to clinical populations, and broaden the online format to allow opportunities for clinicians to provide feedback and suggestions. We will then evaluate utility of the KwiC in clinical practice.

Two types of slip-induced falls among community dwelling older adults.

Little is known about the landing behavior of the trailing (recovery) foot and ensuing types of falls following a forward slip in walking. The purposes of this study were to (1) determine if community-dwelling older adults experienced bilateral slips at the same rate as had been previously observed for young adults during over-ground walking; (2) determine if fall rate in older adults was dependent on slip type (unilateral vs. bilateral); and (3) identify differences in spatiotemporal variables of the trailing leg step between unilateral and bilateral slips. One-hundred-seventy-four participants experienced an unannounced, unrehearsed slip while walking on a 7-m walkway. Each trial was monitored with a motion capture system and bilateral ground reaction force plates. Although the experimental design, developed with original data from a young adult population, favored bilateral slips, more older adults (35%) than anticipated (10% previously observed in young, p<0.001) displayed a unilateral slip. The probability of fall was equal in the two types of slips. Eighty-two people recovered from the slip, while the remaining 92 (53%) fell. These 92 were classified into two exclusive categories based on the heel distance at the time of fall arrest using cluster analysis: those which resembled a fall into a "splits" position (n=47) or a feet-forward fall (n=45). All (100%) unilateral slips led to splits falls, as expected. Yet, not all bilateral slips (only 83%) resulted in feet-forward falls. A longer forward recovery step with a prolonged step time led to both feet slipping, nearly together, hence a feet-forward fall.

Dynamic gait stability, clinical correlates, and prognosis of falls among community-dwelling older adults.

OBJECTIVE: To establish an accurate measure for prognostic assessment of fall risk in community-dwelling older adults, this study examined the prediction accuracy of a dynamic gait stability measure and common clinical tests for slip-related falls among these adults. DESIGN: Participants were tested for their fall-risk likelihood on a slip-test. SETTING: Biomechanics research laboratory. PARTICIPANTS: Community-dwelling older adults (N=119; ≥65y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants performed a battery of clinical tests, including Berg Balance Scale, Timed Up & Go (TUG) test, static posturography, isometric muscle strength, and bone density. They were then exposed to an unannounced slip during gait. The dynamic stability during unperturbed gait was measured based on the center of mass position and velocity relative to the limits of stability against backward falling. Accuracy of each measure was examined for prediction of slip outcome (fall or recovery). RESULTS: On the slip, 59 participants fell, 56 recovered their balance, and 4 were harness-assisted. Dynamic stability predicted fall outcome with 69% accuracy. Except for TUG and bone density, no other measure could differentiate fallers from nonfallers; TUG predicted 56% of fall outcomes. CONCLUSIONS: Reproduction of actual falls provides a new benchmark for evaluating the prognostic power of different performance-based assessment tools. The TUG was able to better predict fall outcome than other clinical measures; however, the new dynamic gait stability measure was more sensitive than TUG in its prediction of falls. Ultrasound bone scan could be used to screen older adults for fall risk.

Adaptability to perturbation as a predictor of future falls: a preliminary prospective study.

BACKGROUND: Falls often result from failed responses to unexpected, externally applied perturbations. Whether performance-based, reaction-based, and/or adaptation-based assessment tools can predict future fails among community-dwelling older adults is unknown. PURPOSE: This preliminary prospective study examined the relationship between older adults' future fall risk and their reactive responses and adaptations to repeated slips, and their functional status. METHODS: Thirteen community-dwelling adults (>64 years) were exposed initially to a session of repeated slips. About 30 months later, self-reported falls experience data were collected for the preceding year from these participants. Slip outcome (fall, loss of balance, or recovery), slip score (weighted sum of slip outcomes), Timed Up and Go scores, and future fall incidence were recorded. RESULTS: Four participants who reported at least 1 fall had significantly higher slip scores than the rest. In contrast, neither failed recovery on the first slip nor a higher TUG score predicted greater odds of future falls. CONCLUSION: Community-dwelling older adults' adaptability to externally imposed perturbations may reveal their future fall risk.

Feasible stability region in the frontal plane during human gait.

The inability to adequately control the motion of the center of mass (COM) in the frontal plane may result in a loss of balance causing a sideways fall during human gait. The primary purposes of this study were (1) to derive the feasible stability region (FSR) in the mediolateral direction, and (2) to compare the FSR with the COM motion state taken from 193 trials among 39 young subjects at liftoff during walking at different speeds. The lower boundary of the FSR was derived, at a given initial COM location, as the minimum rightward COM velocity, at liftoff of the left foot, required to bring the COM into the base of support (BOS), i.e., the right (stance) foot, as the COM velocity diminishes. The upper boundary was derived as the maximum rightward COM velocity, beyond which the left foot must land to the right of the right foot (BOS) in order to prevent a fall. We established a 2-link human model and employed dynamic optimization to estimate these threshold values for velocity. For a range of initial COM positions, simulated annealing algorithm was used to search for the threshold velocity values. Our study quantified the extent to which mediolateral balance can still be maintained without resorting to a crossover step (the left foot lands to the right of the BOS) for balance recovery. The derived FSR is in good agreement with our gait experimental results.