Timothy A. Hanke

Stimulus parameters and inertial load: effects on the incidence of protective stepping responses in healthy human subjects.

OBJECTIVE To test the hypotheses that the incidence of protective stepping in response to sudden translations of the support would (1) increase as a function of both the magnitude of surface displacement and velocity of platform movement, and (2) decrease in association with an increase in external loading applied to the body. DESIGN A log-linear approach was used to analyze the incidence of stepping by testing several models incorporating different platform stimulus parameters (direction, displacement, velocity) and external loading (0% and 20% body weight). SETTING Institutional-based research laboratory. PARTICIPANTS Eight healthy younger adult (21 to 28 years) volunteers. MAIN OUTCOME MEASURES The incidence and number of protective steps served as the primary planned outcome variables. RESULTS Steps occurred more frequently for anterior (83 steps) versus posterior (45 steps) translations. Step occurrence was generally proportional to platform velocity, and increased with displacements up to 15cm, but then plateaued. External loading was associated with a reduction in the number of steps for lower magnitudes of platform motion but had little effect at higher magnitudes. CONCLUSION The tendency to step in response to externally applied disturbances to stance appears to be a complex function of direction, velocity, displacement, and inertial load.

Management of Falls in Community-Dwelling Older Adults: Clinical Guidance Statement From the Academy of Geriatric Physical Therapy of the American Physical Therapy Association

Background Falls in older adults are a major public health concern due to high prevalence, impact on health outcomes and quality of life, and treatment costs. Physical therapists can play a major role in reducing fall risk for older adults; however, existing clinical practice guidelines (CPGs) related to fall prevention and management are not targeted to physical therapists. Objective The purpose of this clinical guidance statement (CGS) is to provide recommendations to physical therapists to help improve outcomes in the identification and management of fall risk in community-dwelling older adults. Design and Methods The Subcommittee on Evidence-Based Documents of the Practice Committee of the Academy of Geriatric Physical Therapy developed this CGS. Existing CPGs were identified by systematic search and critically appraised using the Appraisal of Guidelines, Research, and Evaluation in Europe II (AGREE II) tool. Through this process, 3 CPGs were recommended for inclusion in the CGS and were synthesized and summarized. Results Screening recommendations include asking all older adults in contact with a health care provider whether they have fallen in the previous year or have concerns about balance or walking. Follow-up should include screening for balance and mobility impairments. Older adults who screen positive should have a targeted multifactorial assessment and targeted intervention. The components of this assessment and intervention are reviewed in this CGS, and barriers and issues related to implementation are discussed. Limitations A gap analysis supports the need for the development of a physical therapy–specific CPG to provide more precise recommendations for screening and assessment measures, exercise parameters, and delivery models. Conclusion This CGS provides recommendations to assist physical therapists in the identification and management of fall risk in older community-dwelling adults.

Monitoring community mobility with global positioning system technology after a stroke: a case study.

Background: Stroke survivors often experience difficulty returning to activities and places they deem important to their social, leisure, and occupational aspirations. The extent to which stroke survivors return to community mobility and their ability to navigate and access locations they deem meaningful have not been objectively measured. Purpose: We used global positioning system technology (GPSt) to measure the community mobility of a person poststroke, and assess the relationship between GPSt measures and clinical measures of mobility. Methods: The participant was a 56-year-old man who sustained a right pontine stroke. At discharge from rehabilitation, his Six-Minute Walk Test distance was 73 m. He was fitted with a GPS unit and an accelerometer attached to a single belt and instructed to wear the devices at all times when out of bed. After identifying 10 locations that were important to his goals, he was monitored for 5 separate 1-week periods, on the first, fifth, and ninth weeks and at 6 and 12 months after discharge. Results: During the first 10 weeks, he averaged 7.6 target visits (70%) and 26.7 trips per week. At 1 year, his Six-Minute Walk distance score was 287.5 m. Accelerometry data revealed that he remained primarily sedentary. Target visits and trips per week did not change substantially over the course of 1 year, and compliance wearing the GPS unit was variable. Conclusions: Given the limited correlation in gait speed and distance with target attainment and trips, these outcomes likely measure different constructs for this subject. GPSt may offer insights into participation for stroke survivors following rehabilitation.

Base of support feedback in gait rehabilitation.

The purpose of this study was to investigate the effect of feedback information about base of support in gait rehabilitation. Sixteen individuals with hemiparesis resulting in narrow base of support, were randomly placed into two equal groups, experimental and control. The experimental group was provided with a portable device that provided extrinsic auditory feedback information about base of support incorporated in the functional context of conventional gait therapy, whereas the control group received a conventional gait therapy only. Changes in step width with treatment were assessed with step print technique. The experimental group of subjects improved their step width with treatment from 0.09±0.003 m to 0.16±0.006 m while individuals assigned to the control group showed smaller improvement from 0.099±0.004 m to 0.13±0.003 m. While both groups demonstrated statistically significant improvement (p<0.05), the level of recovery of step width seen in the experimental group was greater.

Electromyographic analysis of postural responses during standing leg flexion in adults with hemiparesis

The purpose of this study was to examine muscle activation patterns during standing leg single leg flexion in adults with hemiparesis. Specifically, the electromyographic activation patterns of the flexing limb biceps femoris and gluteus medius, and the stance limb gluteus medius muscles were analyzed as a function of whether the muscles were paretic or not. Delayed activation of the affected flexing side gluteus medius, as compared with unaffected flexing side gluteus medius, resulted in it being activated simultaneous with the flexing biceps femoris rather than preceding it as was previously found in healthy subjects. This suggests a temporal change in the sequential mode of coordination of the postural and intended components of the task. In addition, the magnitude of the electromyographic integrals of both the affected and unaffected flexing side gluteus medius in the early propulsive phase of the task was significantly reduced in comparison with healthy subjects. These alterations can be attributed to spatial alterations in the sequential form of organization or to a shift to a different mode of neural control in order to perform a relatively novel task. These results suggest a potential adaptive capacity in these individuals.

Automated Extraction of Community Mobility Measures from GPS Stream Data Using Temporal DBSCAN

Inferring community mobility of patients from GPS data has received much attention in health research. Developing robust mobility (or physical activity) monitoring systems relies on the automated algorithm that classifies GPS track points into events (such as stops where activities are conducted, and routes taken) accurately. This paper describes the method that automatically extracts community mobility measures from GPS track data. The method uses temporal DBSCAN in classifying track points, and temporal filtering in removing noises (any misclassified track points). The result shows that the proposed method classifies track points with 88% accuracy. The percent of misclassified track points decreased significantly with our method (1.9%) over trip/stop detection based on attribute threshold values (10.58%).

Lateral rhythmic unipedal stepping in younger, middle-aged, and older adults.

Purpose: Voluntary and protective stepping performance changes with age. This has implications for the problem of falls in older adults. The purpose of this study was to examine the influence of metronome paced stepping practice on selfselected preferred rhythmic unipedal stepping performance in the medial‐lateral direction among younger, middle‐aged and older adults. Methods: Thirty‐two healthy adult subjects (10 younger, 10 middle‐aged, 12 older) participated. They performed rhythmic lateral stepping with their dominant limb at their preferred pace before and after 6 trials of metronomepaced stepping. Results: Older subjects had longer stride periods than young and middle‐aged subjects prior to metronome pacing. Older subjects exhibited a 25% decrease in preferred stride period between pre‐ and postpacing trials. This is compared to a 15% and 11% decrease exhibited by middle‐aged and younger subjects respectively. Preferred stride period was similar for older subjects as compared to younger and middleaged subjects after paced practice. Modification of the stride period occurred mainly during the stance phase of rhythmic stepping. Conclusions: Comparable stride periods across groups after pacing suggest stepping performance is modifiable. Brief intervals of paced stepping may offer older adults a short‐term benefit to stepping performance.

Detecting Stop Episodes from GPS Trajectories with Gaps

Given increased access to a stream of data collected by location acquisition technologies, the potential of GPS trajectory data is waiting to be realized in various application domains relevant to urban informatics—namely in understanding travel behavior, estimating carbon emission from vehicles, and further building healthy and sustainable cities. Partitioning GPS trajectories into meaningful elements is crucial to improve the performance of further analysis. We propose a method for detecting a stay point (where an individual stays for a while) using a density-based spatial clustering algorithm where temporal criterion and gaps are also taken into account. The proposed method fills gaps using linear interpolation, and identifies a stay point that meets two criteria (spatial density and time duration). To evaluate the proposed method, we compare the number of stay points detected from the proposed method to that of stay points identified by manual inspection. Evaluation is performed on 9 weeks of trajectory data. Results show that clustering-based stay point detection combined with gap treatment can reliably detect stop episodes. Further, comparison of performance between using the method with versus without gap treatment indicates that gap treatment improves the performance of the clustering-based stay point detection.

Community mobility after stroke: a systematic review

Abstract Background Stroke is the leading cause of severe disability and many survivors report long-term physical or cognitive impairments that may impact their ability to achieve community mobility (CM). Purpose: To determine the extent to which people with chronic stroke achieve CM compared to age-matched norms or non-neurologically impaired controls. Methods The StrokEDGE outcome measures were searched to identify validated tools that included >25% of items addressing CM. MEDLINE, CINAHL, Google Scholar, PubMed, PEDro and the Cochrane databases were searched from 2001 to 2015 with the identified outcome measures cross-referenced against search terms related to stroke and CM. Inclusion criteria: utilized a validated CM outcome measure, chronic (>3 months post) stroke survivors, and randomized controlled trial, observational or cohort study design. One reviewer screened the studies and performed data extraction and three performed quality appraisal. Fourteen studies met all inclusion criteria. Results Stroke survivors have impaired CM as demonstrated by 30–83% of normative or non-stroke subject CM scores. As time post-stroke increased, CM improved only slightly. Factors found to correlate with the CM were age, education, general well-being, emotional state, motor function and coordination, independence in activities of daily living, balance, endurance and driving status. Limitations of this review include a relatively high functioning cohort, no meta-analysis and reliance on outcome measures not specifically designed to measure CM. Conclusion Survivors of stroke may experience a significant decrease in CM compared to people without neurological injury. Rehabilitation addressing motor function, coordination, independence in activities of daily living, balance and endurance may be important for achieving higher levels of CM. Outcome measures directly addressing CM are needed.

Predictors of functional outcomes in adults with traumatic spinal cord injury following inpatient rehabilitation: A systematic review.

Context: Despite functional improvements during rehabilitation, variable functional outcomes were reported when patients with Spinal Cord Injury (SCI) return to society. Higher functioning individuals at discharge can experience a decrease in independent mobility (i.e. Motor Functional Independence Measure (mFIM) Score) by one-year follow-up. However, functional gains after discharge have also been reported and associated with recovery. Objective: To identify, categorize and rank predictors of mFIM score for patients with SCI following inpatient rehabilitation, both at the time of discharge and at one-year follow-up. Methods: Data sources included CINAHL, PubMed, ERIC, Google Scholar, and Medline for literature published from February 2000 to February 2015. Quality and risk of bias of included studies was assessed using the Risk of Bias Assessment Instrument for Prognostic Factor Studies (QUIPS). Significant predictors of mFIM score were categorized using the domains of the International Classification of Function and Disability model ICF and ranked based on how frequently they were significant predictors of mFIM score. Results: Twenty-seven predictors of mFIM score spanning the ICF domains were identified among seven studies. At discharge, variables in the Body Structure and Function domain were the most consistent predictors of mFIM score. At one-year follow-up, variables in the Activity and Participation domain were the most consistent predictors of mFIM score. Contextual factors were the least frequent predictors at both discharge and one-year follow-up. Conclusion: This systematic-review assists clinicians setting realistic goals that maximize functional independence at the time of discharge and after reintegrating to society.