Biomedical subjects

Elizabeth J Protas

Publications and source records attributed to Elizabeth J Protas.

11 recordsLinked to original sources

PubMed2005

Physical-performance tests to evaluate mobility disability in community-dwelling elders.

The purposes of this study were to evaluate community-dwelling elderly adults with different levels of perceived mobility with 5 physical-performance tests, determine the cutoff values of the 5 tests, and identify the best tests for classifying mobility status. The community-mobility statuses of 203 community-dwelling elders were classified as able, decreased, or disabled based on their self-reported ability to walk several blocks and climb stairs. They also performed the functional reach, timed 50-ft walk, timed 5-step, timed floor transfer, and 5-min-walk endurance tests. We found in all tests that the "able" outperformed the "decreased" and that the "decreased" outperformed the "disabled," except on the floor-transfer task. The optimum cutoff values of the 5 performance tests were also reported. The 5-min walk and timed 5-step test could best separate the "able" from the "decreased," whereas the 50-ft-walk-test could best differentiate the "decreased" from the "disabled." The results suggest that community-mobility function of older adults can be captured by performance tests and that the cutoff values of the 5-min-walk, 5-step, and 50-ft-walk tests can be used in guiding intervention or prevention programs.

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PubMed2005

Gait and step training to reduce falls in Parkinson's disease.

INTRODUCTION: Frequent falls and risk of injury are evident in individuals with Parkinson's disease (PD) as the disease progresses. There have been no reports of any interventions that reduce the incidence of falls in idiopathic PD. PURPOSE: Assess the benefit of gait and step perturbation training in individuals with PD. DESIGN: Randomized, controlled trial. SETTING: Outpatient research, education and clinical center in a tertiary care Veterans Affairs Medical Center. OUTCOME MEASURES: Gait parameters, 5-step test, report of falls. SUBJECTS: Eighteen men with idiopathic PD in stage 2 or 3 of the Hoehn and Yahr staging. METHODS: Subjects were randomly assigned to a trained or control group. They were asked about any falls 2 weeks prior to and after an 8 week period. Gait speed, cadence, and step length were tested on an instrumented walkway. Subjects were timed while stepping onto and back down from an 8.8 cm step for 5 consecutive steps. Gait training consisted of walking on a treadmill at a speed greater than over ground walking speed while walking in 4 directions and while supported in a harness for safety. Step training consisted of suddenly turning the treadmill on and off while the subject stood in the safety harness facing either forwards, backwards, or sideways. Training occurred 1 hour per day, three times per week for 8 weeks. A two-factor (time and group) analysis of variance with repeated measures was used to compare the groups. RESULTS: Substantial reduction occurred in falls in the trained group, but not in the control group. Gait speed increased in the trained group from 1.28+/-0.33 meters/sec to 1.45+/-0.37 meters/sec, but not in the control group (from 1.26 to 1.27 m/s). The cadence increased for both groups: from 112.8 to 120.3 steps/min for the trained group and 117.7 to 124.3 steps/min for the control group. Stride lengths increased for the trained group, but not the control group. The 5-step test speed increased in the trained group from 0.40+/-0.08 steps/sec to 0.51+/-0.12 steps/sec, and in the control group (0.36+/-0.11 steps/sec to 0.42+/-0.11 steps/sec). CONCLUSION: Gait and step perturbation training resulted in a reduction in falls and improvements in gait and dynamic balance. This is a promising approach to reduce falls for patients with PD.

Accidental Falls↗

PubMed2004

Relevance of aerobic capacity measurements in the treatment of chronic work-related spinal disorders.

STUDY DESIGN: Prospective cohort study of rehab program completers, comparing aerobic capacity data of chronic lumbar spinal disorder patients (CLSD) to that of chronic cervical spinal disorder (CCSD), collected from a tertiary care facility. OBJECTIVE: We evaluated whether CLSD is associated with different pre- and postrehabilitation aerobic capacity deficits than CCSD, and whether such deficits affect functional restoration outcomes. SUMMARY OF BACKGROUND DATA: Chronic spinal disorder patients are thought to lose aerobic fitness as a component of the deconditioning syndrome. Patients with CLSD often restrict aerobic activities because of back or leg pain, while CCSD patients generally do so to a lesser degree. We hypothesized that those with CLSD would have greater deficits in tests of aerobic fitness than patients with CCSD both before and after treatment. METHODS: From a consecutive cohort of 683 patients with work-related spinal disorders, two groups were identified: patients with CLSD (n = 504; age 40.1 years; 68% male); and patients with CCSD (n = 179; 41.3 years; 43% male). All patients completed an intensive, medically supervised functional restoration program. Before and after the program, patients completed a submaximal bicycle ergometer aerobic capacity test and a psychosocial test battery. A structured clinical interview to determine socioeconomic outcomes was conducted 1 year after the program completion. RESULTS: Of CLSD patients 33% and 11% of CCSD patients (P < 0.001) either failed to produce any torque or could not complete at least 2 stages on the bicycle on preprogram tests (invalid tests). However, all patients had valid bicycle tests at program completion. Nearly two-thirds of the subjects with initially invalid tests in the lumbar group failed to develop any torque, while only one-third of subjects with invalid tests of the cervical group had a similar result. Thus, CLSD is associated with greater prerehabiliation aerobic fitness deficits than CCSD. Overall, there was no significant change in pre to postrehab aerobic capacities for the initially valid test subjects. The initially invalid test subjects achieved similar postrehabilitation scores compared to the valid test subjects, although CLSD patients with initially valid tests performed slightly better at the posttest. Socioeconomic outcomes were the same one year after the program for valid and invalid test subjects. CLSD patients had higher preprogram self reports of disability. The subgroup of the initially invalid test subjects that produced no torque whatsoever (19.3% of CLSD and 3.9% of CCSD) did not differ from the subgroup that failed to complete 2 stages in the pretest of aerobic performance on depression. They had higher pretest self-reported disability. CONCLUSIONS: Although mean aerobic fitness levels for all patients improved during rehabilitation, the improvement is almost entirely accounted for by initially invalid tests becoming valid. Aerobic capacity testing measured with submaximal bicycle ergometry may frequently be invalid when fear-avoidance limits effort, particularly in CLSD. Psychosocial fear-avoidance, as it applies to bicycle ergometry, can be overcome in virtually all patients motivated to complete a tertiary rehabilitation program. As such, prerehabilitation aerobic capacity testing is a poor differentiator of postrehabilitation outcomes.

Adult↗

PubMed2004

Analysis of sEMG during voluntary movement--Part II: Voluntary response index sensitivity.

In this paper, a method for analyzing surface electromyographic (sEMG) data recorded from the lower-limb muscles of incomplete spinal-cord injured (iSCI) subjects is evaluated. sEMG was recorded bilaterally from quadriceps, adductor, hamstring, tibialis anterior, and triceps surae muscles during voluntary ankle dorsiflexion performed in the supine position as part of a comprehensive motor control assessment protocol. Analysis of the sEMG centered on two features, the magnitude of activation and the degree of similarity [similarity index (SI)] of the sEMG distribution to that of healthy subjects performing the same maneuver (n = 10). The analysis calculations resulted in response vectors (RV) that were compared to healthy-subject-derived prototype response vectors resulting in a voluntary response index (VRI). Incomplete SCI subjects (n = 9) were used to test the sensitivity of this analysis method. They were given supported-weight treadmill ambulation training, which is expected to improve or at least not cause a deterioration of voluntary motor control. The VRI provided evidence that the quantitative sEMG analysis method used was able to differentiate between healthy subjects and those with iSCI, characterize individual differences among iSCI subjects, and track motor control changes occurring over time.

Adult↗

PubMed2003

Differential responses to measures of gait performance among healthy and neurologically impaired individuals.

OBJECTIVES: To compare gait during a 5-minute walk among healthy individuals, persons with spinal cord injury (SCI), and stroke survivors and to investigate whether simultaneous measures of oxygen consumption enhance information about performance. DESIGN: Descriptive study. SETTING: Veterans Affairs medical center. PARTICIPANTS: Thirty-nine healthy individuals, 10 persons with SCI, and 20 stroke survivors. INTERVENTIONS: Participants were fitted with a portable gas analyzer and walked on a 5-m walkway for 5 minutes. MAIN OUTCOME MEASURES: Measures of walk distance, gait speed, gait energy expenditure (GEE), and gait cost were obtained, along with measures of ventilation (.Ve), ventilation and carbon dioxide production slope (.Ve . .VCo2), oxygen pulse, and heart rate. RESULTS: The SCI group (127.65+/-81.74m) walked less than the stroke survivors (148.80+/-64.3m) or the healthy group (268.90+/-35.01m) but had higher energy demands, as shown by GEE (SCI group, 13.28+/-3.23mL.kg(-1).min(-1); stroke group, 10.18+/-2.14mL.kg(-1).min(-1); healthy group, 9.61+/-1.90mL.kg(-1).min(-1)) and by gait cost (SCI group,.57+/-.40 mL.kg(-1).m(-1); stroke group,.40+/-.52mL.kg(-1).m(-1); healthy group,.18+/-.02mL.kg(-1).m(-1)). Compared with the healthy group, the stroke group had higher .Ve (stroke group, 22.34+/-5.20L/min vs healthy group, 16.11+/-3.22L/min) and .Ve . .VCo2 slope (24.22+/-8.80 vs 18.73+/-5.44, respectively). CONCLUSION: Use of metabolic assessment during the 5-minute walk was feasible and provided further information for evaluating gait performance with the subjects studied.

Adult↗

PubMed2002

Test-retest strength reliability: hand-held dynamometry in community-dwelling elderly fallers.

OBJECTIVE: To determine the reliability of a standardized protocol by using a hand-held dynamometer (HHD) to measure lower-extremity strength in community-dwelling elderly fallers. DESIGN: Within-session test-retest reliability of the HHD. SETTING: Balance laboratory of a university. PARTICIPANTS: A convenience sample of 41 community-dwelling elders (61-90y) who fell at least once in the previous year. INTERVENTION: The strengths of 8 lower-extremity muscle groups bilaterally were tested twice, with an intervening rest period of 15 seconds. MAIN OUTCOME MEASURE: Maximal isometric force. RESULTS: Test-retest intraclass correlation coefficients (ICCs) were high, generally ranging from.95 to.99 for 1 trial (ICC(2,1)) and from.97 to 1.00 for the mean of 2 trials (ICC(2,2)). There were no significant differences in strength values across trials (P>.05). Men had significantly greater strength than women across all muscle groups (P>.05). Right knee extensor strength demonstrated the largest trial-to-trial difference,.54 kg using a single measurement and.39 kg using the mean of both measurements. Among the 3 lower-extremity muscle groups, the ankle showed higher a coefficient of variation (CV=5.1%-7.4%) than the knee (CV=4.6%-5.1%) or the hip (CV=4.2%-6.3%) when using 1 measure. CONCLUSION: By using an HHD and a standardized measurement protocol, a novice tester can obtain reliable lower-extremity strength values in community-dwelling elderly fallers.

Accidental Falls↗

PubMed2002

Gait outcomes after acute stroke rehabilitation with supported treadmill ambulation training: a randomized controlled pilot study.

OBJECTIVE: To investigate gait outcomes with supported treadmill ambulation training (STAT) associated with regular rehabilitation in acute stroke survivors. DESIGN: Randomized controlled trial, pilot study. SETTING: Rehabilitation medicine service at a Veterans Affairs medical center. PARTICIPANTS: Seven acute stroke survivors assigned to regular intervention group and 6 patients assigned to STAT intervention. INTERVENTIONS: Regular intervention consisted of 3 hours daily of physical therapy, kinesiotherapy, and occupational therapy. STAT group received regular rehabilitation with STAT substituted for usual gait training. Participants were tested at baseline, treated for an average of 3 weeks, and retested on discharge. The analysis of covariance procedure was used to test for differences between the 2 approaches. MAIN OUTCOME MEASURES: Functional Ambulation Category Scale, gait speed, walking distance, gait energy expenditure, and gait energy cost. RESULTS: The small sample size did not generate enough power to detect significant differences in any variable. However, medium to large effect sizes of 0.7 and 1.16 standard deviation units were observed for gait energy cost and walk distance, respectively. CONCLUSIONS: This pilot study indicated that STAT is a safe, feasible, and promising intervention for acute stroke survivors. A larger trial is warranted for statistical relevance.

Analysis of Variance↗

PubMed2002

Performance-based gait tests for acute stroke patients.

OBJECTIVE: Qualitative measures may not differentiate severity of deficits after an acute or subacute stroke. The aim of this study was to contrast the utility of performance-based gait tests with qualitative measures in a sample of acute stroke patients. DESIGN: Twenty acute stroke subjects had their performance-based gait measured by gait speed, walking distance, gait energy expenditure, and gait energy cost. They were also qualitatively evaluated for cognition, functional outcomes, motor impairment, and Functional Ambulation Category. RESULTS: Strong and significant correlations were observed among performance-based gait tests. Qualitative scales indicated moderate to minimal deficits in each domain evaluated, although they were not correlated among themselves, except for Functional Ambulation Category and FIM and FIM and Mini-Mental State Exam. Functional Ambulation Category correlated with performance-based gait tests. CONCLUSIONS: Performance-based gait tests are feasible to conduct during early recovery after a stroke and allow better discrimination among the patients than qualitative measures.

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PubMed2002

Back pain, physical function, and estimates of aerobic capacity: what are the relationships among methods and measures?

OBJECTIVES: To establish the correlations of measures of self-reported disability, self-efficacy, physical performance, level of pain, and estimates of aerobic capacity (PvO2 ) in subjects with low back pain. DESIGN: Fifty-one low back pain subjects, ranging in age from 26 to 65 yr, entered the study. Participants completed the Roland-Morris Disability Questionnaire and the self-efficacy questionnaire. Physical performance was evaluated by the loaded-reach test, sit/stand test, 5-min walk test, 50-foot walking test, and time to roll from right to left. Pain intensity and pain affect were measured using two visual analog scales. PvO2 was predicted from an equation. RESULTS: The correlation coefficient among the physical performance outcomes ranged from 0.47 to 0.78. Pain measures had low correlations with measures of function but stronger correlations with other self-report measures. The disability measure correlated moderately with physical performance. Correlations between PvO2 and all other measurements were minimal, except for the 5-min walk test. CONCLUSION: Performance and disability were more consistent in evaluating low back pain. PvO2 failed to correlate with most other aspects of low back pain. This study suggests that aerobic capacity might not be a primary concern for patients with low back pain.

Adult↗

PubMed2002

Supported treadmill training for gait and balance in a patient with progressive supranuclear palsy.

BACKGROUND AND PURPOSE: Impaired balance, gait disturbances, and frequent falls are common problems in people with progressive supranuclear palsy (PSP). This case report describes the use of a modified body weight support treadmill training program to reduce falls and improve the balance and gait of a patient with PSP. CASE DESCRIPTION: The patient was a 62-year-old man diagnosed with PSP. His major problems were impaired balance and frequent, abrupt falls. METHODS: Physical therapy included walk training, balance perturbation, and step training using body weight support with a treadmill. Training sessions lasted 11/2 hours and occurred 3 days a week for 8 weeks. Fall incidence, balance, and gait were assessed before, during, and after the program. OUTCOMES: The patient reported fewer falls during and after training. Balance and gait improved after training. DISCUSSION: This case report is the first to report fall reduction, improved gait, and improved balance following physical therapy for a person with PSP.

Accidental Falls↗

PubMedDate not supplied

Reliability of measures of gait performance and oxygen consumption with stroke survivors.

This study assessed the reliability of gait performance with concurrent measures of oxygen consumption (VO2) in stroke survivors (SS). Nine male SS (60.00 +/- 15.08 yr) had a recent history of stroke (44.56 +/- 51.35 days since the stroke) and were receiving rehabilitation. Four had a right cerebrovascular accident (CVA), and five had a left CVA. Subjects walked without assistance, although three used a single cane to complete the test. Within 30 minutes, subjects completed two trials of a 5 min walk while walking back and forth on a 5 m walkway wearing a portable gas analyzer to collect samples of gases. The intraclass correlation coefficient (ICC) was used to assess reliability. The ICC for gait energy expenditure, walk distance, gait speed, and gait energy cost were 0.64, 0.97, 0.95, and 0.97, respectively. Assessment of gait performance with concurrent measures of VO2 is a reliable procedure with SS.

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