[345] VALIDITY OF KNEE HEIGHT MEASUREMENT IN THE PHYSICALLY CHALLENGED AND/OR NEUROLOGICALLY IMPAIRED CHILDREN
Lorry Chen, RD; Mai Calendino, RD
Department of Nutrition, Bloorview MacMillan Centre,
Bloorview Site, Willowdale, Ontario
Sponsor: None listed
PURPOSE--The purpose of this study is to assess the validity of Ross Knee Height Calipers to estimate stature in physically and/or neurologically impaired children. As well, this study will examine how the various methods of measuring height (knee height vs. traditional method--standing, supine, or segmental) influences the calculation of percentage of ideal body weight (%IBW) and thus predict nutritional status.
METHODOLOGY--Subjects included patients referred for nutritional assessment at Bloorview Childrens Hospital for 2 years beginning December 1994. Both males and females, aged 6-19 years, were included. Collection of patient data, including anthropometric measurements (both the traditional methods of measuring height and knee height using the caliper), weight, skinfold measurements, diet, number and type of diagnosis, age, gender, and presence or absence of contractures and spasticity.
PROGRESS--A total of 24 subjects were collected during the initial study period. Due to the small sample size, we extended data collection through the second year and included all patients that met the participation criteria. Currently, 58 subjects have been enrolled and we expect to meet the projected sample size of 100.
PRELIMINARY RESULTS--A positive correlation was found between traditional methods of measuring of height and using the calipers. Also, a positive correlation was found between the two methods of predicting %IBW. However, knee height measurements tend to overestimate IBW (i.e., indicating a better nutritional status) compared to the traditional methods, particularly in individuals at risk for malnutrition. When individuals are adequately or well nourished, %IBW between the two measurements tends to be closer together.
FUTURE PLANS--We continue to recruit a larger sample for further analysis to ascertain the influence of certain covariables on %IBW prediction and determine whether or not this tool can be used in our clinical practice.
[346] OPTOKINETIC TESTING FOR DIAGNOSIS AND REHABILITATION OF BALANCE DISORDERS
Janet E. Shanks, PhD; Robert H.I. Blanks, PhD; Cynthia
G. Fowler, PhD
VA Medical Center, Long Beach, CA 90822; Department of
Anatomy/Neurobiology, University of California, Irvine,
Irvine, CA 92697; Department of Communicative Disorders,
University of Wisconsin-Madison, Madison, WI 53706; email:
shanks.janet-e@longbeach.va.gov;
rhblanks@uci.edu;
cgfowler@facstaff.wisc.edu
Sponsor: Department of Veterans Affairs, VA
Rehabilitation Research and Development Service, Washington,
DC 20420
(Project #C691-2RA)
PURPOSE--The purpose of this study is to generate data on postural sway induced by horizontal optokinetic stimulation in subjects standing on a fixed platform. Balance combines sensory input from the visual, proprioceptive, and vestibular systems with vision being a powerful stabilizer when the proprioceptive and/or vestibular systems are damaged. Postural sway consists of forward-backward and lateral motions, largely about the ankle joints. Although substantial data exist on the changes in postural sway with the eyes open and closed, and during forward-backward or torsional visual motion, sway induced by horizontal optokinetic patterns has not been studied and may provide a challenge to the vestibular and proprioceptive systems, thereby extending the diagnostic value of fixed-platforin posturography.
METHODOLOGY--Basic audiologic evaluations are performed and the vestibular function of each subject is determined by a questionnaire. The posturography system consists of a fixed platform with two independent foot plates with force transducers that resolve the forward-backward and lateral changes in the center of force of a standing subject; a 180° curvilinear projection screen located 1 m from the subject; a shadow projector for visual stimuli; and a support harness to prevent falls. Postural sway is recorded with eyes closed, eyes open against a fixed background, and a background moving at 20, 40, 60, 80, and 100°/sec to the right or left. The moving background consists of a random bar (1×8° visual angle) optokinetic pattern covering 180° in the horizontal plane and 40° in the vertical plane. Each trial consists of 30 sec of postural testing, followed by 30 sec of rest. Optokinetic stimuli are presented binocularly and randomized to prevent order effects. Subjects are given an alerting task to maintain vigilance and instructed to stand in a relaxed vertical posture, hands at their sides and looking in the direction of the screen.
Postural sway is measured as changes in center of force, a time-varying vector defined in the horizontal plane, and computed as a weighted average of the output from six force transducers (three in each foot plate). Data are transferred to a spreadsheet program for analysis and displays of positional sway and sway velocity in the form of a stabilograms (forward-backward, side-to-side, and lateral dimensions).
PROGRESS--Postural sway and sway velocity data have been collected from 135 subjects; 69 have normal hearing for their age and no complaints of dizziness, 6 reported dizziness/vertigo (with 1 undergoing a labyrinthectomy), 3 were postsurgical for acoustic neuroma removal, 10 participated in a test-retest protocol, 15 revealed sensorineural hearing loss, and 32 currently are enrolled in a pilot study to determine the influence of exercise on balance in the well elderly.
RESULTS--Data collection continues to increase the numbers in the nonimpaired control group with ongoing analysis to determine whether differences exist as a function of aging. Subjects with sensorineural hearing loss revealed no statistically significant differences from the control population when matched for age. Of the six subjects with complaints of dizziness/vertigo, three reported their dizziness was controlled with exercise and/or diet and medication and showed results similar to the general study population. Preliminary results from the three subjects with uncontrolled dizziness, revealed abnormal positional and velocity patterns. Analysis of test-retest and post acoustic neuroma removal subjects has not been completed. Data analysis for the 32 subjects enrolled in the exercise program has not begun, as the study is still incomplete.
Preliminary results from all the study groups suggest that evaluation of postural sway, particularly when velocity changes are recorded, could be used for diagnostic evaluation as well as post-surgical monitoring of vestibular compensation.
[347] EVALUATION OF WORD-RECOGNITION PERFORMANCE WITH SENTENCE MATERIALS
Janet E. Shanks, PhD
VA Medical Center, Long Beach, CA 90822
Sponsor: Department of Veterans Affairs, VA
Rehabilitation Research and Development Service, Washington,
DC 20420
(Project #C690-2RA)
No report was received for this issue.
[348] EVALUATION OF CENTRAL AND PERIPHERAL ENHANCEMENT DEVICES FOR DRIVING
Janet P. Szlyk, PhD
VA Westside Medical Center, Chicago, IL 60612
Sponsor: Department of Veterans Affairs, VA
Rehabilitation Research and Development Service, Washington,
DC 20420
(Project #C754-2RA)
No report was received for this issue.
[349] WHEELCHAIR EXERCISE AND DIGITAL ECHOCARDIOGRAPHY FOR THE DETECTION OF HEART DISEASE
W. Edwin Langbein, PhD; Lonnie C. Edwards III, MD; Eric
K. Louie, MD; Ming H. Hwang, MD; Bernard A. Nemchausky,
MD
Hines VA Medical Center, Rehabilitation Research and
Development Center, Hines, IL 60141; Loyola Medical Center,
Department of Medicine, Maywood, IL 60153
Sponsor: Department of Veterans Affairs, VA
Rehabilitation Research and Development Service, Washington,
DC 20420
(Project #B716-RA)
PURPOSE--This investigation will compare the sensitivity, specificity, and predictive value of wheelchair ergometry (WCE), with and without exercise, to digital two-dimensional echocardiography (ECHO) for the detection of myocardial ischemia. The purpose of this research is to establish a cost effective and clinically useful noninvasive diagnostic procedure for detection of coronary artery disease (CAD) in persons with lower limb disabilities.
METHODOLOGY--Patients complete a symptom-limited maximal WCE test with metabolic measurements. An intermittent protocol composed of 2 min stages with a 30 sec pause between stages is used. The initial workload is 6 W with increases of 6 W per stage. The ergometer computer automatically sets the braking resistance and target wheeling speed at the beginning of each stage. Supine pre- and postexercise ECHO images are obtained on a specially designed imaging table adjoined to the WCE. An abnormal exercise electrocardiogram (ECG) is defined as 1 mm horizontal or down sloping ST segment depression occurring 80 msec after the J point. An ECHO study is abnormal when a stress-induced wall motion abnormality or worsening of a resting wall motion abnormality is present. A blind review of the ECHO studies, ECGs, and angiograms is conducted by independent investigators. A wall motion score index (WMSI) is used to quantify the presence, location, and severity of myocardial abnormalities and a percent normal muscle score (%NMS) to define the percentage of normally functioning myocardium. The correlation between wall motion abnormalities and coronary circulation is determined using a two-region distribution model.
PROGRESS--Two hundred and one maximal WCE exercise tests with ECHO have been completed. Eighty-one patients (40 percent) underwent coronary angiographic procedures within 6 months of the WCE exercise tests with ECHO. Follow-up interviews have been completed on 114 subjects.
The demographic, peak hemodynamic, and metabolic measures (mean±one standard deviation) for the subjects were age 62±12 yr, height 175±9 cm, weight 85±16 kg, body mass index 28±5 (moderately obese), heart rate 135±24 beats/min, systolic 168±26 mmHg and diastolic 83±14 mmHg blood pressure, rate pressure product 22548±5407, percentage of age predicted maximal heart rate 85±14, oxygen uptake 16.0±5.0 mL/kg/min, and metabolic equivalents 5.0±1.0. An analysis of the sensitivity, specificity, and prognostic value of WCE with ECHO on the data from the 81 patients who underwent coronary angiography is being completed at the time of this report.
FUTURE PLANS--Substantial numbers of people are prevented from diagnostic treadmill or cycle ergometer stress testing due to a variety of lower limb disabilities. Two dimensional echocardiography in conjunction with WCE may offer a noninvasive, low risk, clinically useful diagnostic test in persons with lower limb disabilities. The relatively low cost and high level of patient acceptance of the test make it an attractive option for diagnosis of CAD, assessment of the efficacy of cardiovascular medications, risk stratification, and evaluation of global and regional ventricular function during stress after myocardial infarction or revascularization. To further establish the effectiveness of WCE with ECHO for detection of CAD in persons with lower limb disabilites the procedure described above should be evaluated at other medical centers.
[350] DEVELOPMENTAL ENHANCEMENT AND APPLICATION OF THE VA-CYBERWARE PROSTHETICS-ORTHOTICS OPTICAL LASER DIGITIZER
Vern L. Houston, PhD, CPO; Carl P. Mason, MSBE; Edward
J. Lorenze, MD; Kenneth P. LaBlanc, BS, CPO; MaryAnne
Garbarini, MA, PT
VA Medical Center, New York, NY 10010
Sponsor: Department of Veterans Affairs, VA
Rehabilitation Research and Development Service, Washington,
DC 20420
(Project #A514-4DA)
PURPOSE--The objectives of this project are to continue refinement and enhancement of the VA-Cyberware Prosthetics-Orthotics Optical Laser Digitizer and to conduct fundamental application studies with the optical digitizer to test and demonstrate its capabilities, effectiveness, and efficiency in quantitatively characterizing the spatial geometry and surface topography of the residual limbs of persons with lower limb amputation and the limb segments of orthotics patients.
METHODOLOGY--To achieve these objectives, the following research protocol has been established:
PROGRESS--Design specifications for a new prosthetics-orthotics optical digitizer prototype were developed, remedying the deficits identified in the original prototype, and further improving and enhancing the capabilities and performance of the digitizer. A new prototype based on these specifications was constructed, and is undergoing rigorous laboratory testing. Work on adapting and optimizing the software modules developed for the original optical digitizer prototype for control, data acquisition, data processing and visualization, and measurement and analysis is continuing. Work on integrating these modules into a single, composite, user-friendly, menu-driven program for use by prosthetics-orthotics clinicians is also underway. A new automated method of testing and calibration, optimizing of the field of view of the digitizer, and enabling correction of measurement data for optical nonlinearities has been developed. Enhancement and optimization of the control, tool path clearance, and the surface contour interpolation and smoothing software for the VA Prosthetics-Orthotics CAM milling machine is being performed. Scans and fittings of amputation and orthotics test subjects for development of CAD system socket and orthosis design templates based on optically digitized residual limb/limb segment measurements is being conducted. Investigations using the optical digitizer to estimate patient limb segment effective joint center trajectories are being conducted.
FUTURE PLANS--Refinement and enhancement of the optical laser digitizer shall continue. When development of the new prototype is completed, expanded application studies with the optical digitizer shall be conducted. Future studies shall include: 1) compilation of a consistent, quantitative prosthetics and orthotics patient database of residual limb/limb segment geometries, measurements, and histories for use in developing improved prosthetic socket and orthosis designs; 2) compilation of a database of patient limb segment contours, areas, and volumes for correlation with, and quantitative assessment of, the efficacy of medical treatment and rehabilitation regimens; and 3) application as an educational instructional aid for presentation and direct visualization of prosthetics and orthotics principles and concepts.
[351] WIRELESS TENS (TRANSCUTANEOUS ELECTRIC NERVE STIMULATOR) STUDY FOR MANAGEMENT OF PAIN: A PILOT STUDY
D. W. Repperger, PhD, PE; Charles C. Ho, MD, PhD; P.
Aukuthota; C. A. Phillips, MD, PE
Armstrong Laboratory, WPAFB, Ohio 45433; Dayton VA
Medical Center, Dayton, Ohio 45428; Wright State University,
Dayton, Ohio 45435
Sponsor: Department of Veterans Affairs, VA
Rehabilitation Research and Development Service, Washington,
DC 20420
(Pilot Project #B93-620PA)
PURPOSE--The purpose of this research is to evaluate the efficacy of a wireless TENS unit to help reduce pain for veterans. It is hoped to simplify present TENS systems by eliminating the long wires that cause problems in their use.
METHODOLOGY--Over 125 clinical trials have been conducted involving 40 patients from the VA Medical Center, Dayton, OH, who were run with a wireless TENS device and compared to a traditional TENS. The subjects were given a pain questionnaire (Melzack) and objective measurements were taken. A comparison of just noticeable differences was conducted and electric power measurements collected.
PROGRESS--Data were collected only from those patients that received some benefit of TENS to mitigate pain. Of the 39 male and one female subject run, about 90 percent of acceptance to the wireless device was noted.
PRELIMINARY RESULTS--From the perspective of equivalent pain relief for the same amount of electric power utilized, the wireless TENS clearly showed this advantage. An equivalent pain curve comparing the wireless TENS to the traditional device demonstrated that subjects could achieve equivalent pain relief for lesser amounts of electric power, voltage, and current. Two patients experienced pain relief from the wireless TENS who had not received pain relief from the traditional device.
FUTURE PLANS--It is of interest to test that 50 percent of the VA population who do not normally experience pain relief from the traditional TENS devices but may have some pain relief from this new device. Also the prototype developed in this study can be further reduced in size, resulting in even greater efficiency and possibly power savings. Also a method of delivering pain relief by using spatial properties of the electric fields was developed, which expands the manner with which pain can be treated.
[352] HEALTH BEHAVIOURS IN SCHOOL-AGED CHILDREN WITH PHYSICAL DISABILITIES
Catherine Steele, PhD; Douglas Biggar, MD; Joseph
Bortolussi, MSW; Jeffrey Jutai, PhD, CPsych; Ilze Kalnins,
PhD; Beth Ellen Rossen, MSc
Bloorview MacMillan Centre, Toronto, Ontario, M4G 1R8
Canada; email: ortccs@oise.utoronto.ca
Sponsor: Easter Seal Research Institute, Don Mills, Ontario, M3C 3P2 Canada
PURPOSE--Children with physical disabilities are at risk for acquiring secondary disabilities in adulthood, such as heart disease, stroke, respiratory problems, and social and emotional difficulties. The risk of these secondary disabilities can be reduced by adopting healthy lifestyles during childhood. The purpose of this research is to identify the lifestyle behaviors of children with physical disabilities, in order to develop health promotion initiatives for them.
METHODOLOGY--In partnership with 16 Ontario children rehabilitation centres, we administered the same questionnaire (The World Health Organization Cross-national Study on the Health Behaviour of School-Aged Children) as a national research project to 319 children aged 11-16 with physical disabilities, such as amputations, arthritis, cerebral palsy, muscular dystrophy, or spina bifida. We developed the required methodology for interviewing children with a variety of physical disabilities: written format (child completed the survey independently); interview format (child read questions along with research assistant and indicated his/her answer); and interview-intervener format (child read along with research assistant and indicated answers through an intervener).
RESULTS--Our findings showed that lifestyle behaviors of concern to children with a physical disability are: diets high in sugar and fats, lack of exercise, social isolation, and lack of access to information about relevant sexual issues. Our findings also demonstrated that young people with physical disabilities have some healthy lifestyle behaviors and attitudes. They are considerably less likely to smoke or drink, demonstrated no differences in self-esteem and depression, and have more positive attitudes toward parents, teachers, and school.
FUTURE PLANS--During the next year, our goal is to: 1) conduct in-depth analyses of our questionnaire data; 2) develop health promotion initiatives aimed at reducing the prevalence of secondary disabilities; 3) expand our partnerships to guide and support our research, fostering the development and implementation of health promotion initiatives.
[353] RESOURCE UNIT FOR INFORMATION AND EDUCATION
Dudley S. Childress, PhD; Jan Little, MS
Northwestern University, Prosthetics Research
Laboratory, Chicago, Illinois 60611; email:
d-childress@nwu.edu
Sponsor: National Institute on Disability and Rehabilitation Research, Washington, DC 22202
PURPOSE--The Resource Unit for Information and Education (RUIE) disseminates information about the research projects conducted by the Northwestern University Prosthetics Research Laboratory and Rehabilitation Engineering Research Program, (NUPRL and RERP). It also disseminates general information about the field of prosthetics and orthotics. The information goes to amputees and others with disabilities, prosthetists and orthotists, students and individuals engaged in research.
METHODOLOGY--Information dissemination is accomplished through the publication of Capabilities, a quarterly newsletter, the Activity Report of progress on projects, and a Prosthetics-Orthotics Resource Guide. In addition, we hold consumer and technical advisory panel meetings, compile bibliographies on prosthetics and orthotics, and maintain a World Wide Web Site (http:www.repoc.nwu.edu/) featuring movies of research results, lists of support groups, our Prosthetics-Orthotics Resource Guide, lists of personnel, and bibliographies. We provide listings with National Rehabilitation Information Center (NARIC) and maintain a Help Line, available on (312) 908-6524 (voice) or (312) 908-6526 (FAX/TDD).
PROGRESS--Three publications, Capabilities, the Activity Report, and the Prosthetics-Orthotics Resource Guide, were re-initiated in the past year following a short period when we were without a project director. Extensive networking activities were initiated with VA, NIDRR, and other government agencies. Consumer services that have been initiated recently include a listings of support groups for persons with amputation, sources for acquiring assistive technology information, and agencies providing services to people with disabilities. All are available on the Web Site or in print.
Consumer feedback is formally acquired through regular meetings of the Consumer Advisory Panel (CAP) of the RERP. The group meets annually. The CAP, which consists of consumer advocates and persons with disabilities, held a joint meeting June 1996, with members of the NURERC Technical Advisory Panel. Their recommendations stressed the need for continued dissemination of research results to consumers and others, and that more research be conducted on orthoses. Such research is part of the schedule of studies on aided ambulation.
RESULTS--At this writing, visitors to our web site totaled 21,478 since January 1995. During the past year, over 950 consumers, prosthetists, orthotists, and others were served by email and U.S. mail. Subscriptions to Capabilities has doubled in the past year to 2,100.
[354] ORDERLY RECRUITMENT OF MOTOR UNITS WITH TRIPOLAR NERVE CUFF ELECTRODES
Moshe Solomonow, PhD; Richard V. Baratta, PhD; Robert D.
D'Ambrosia, MD
Bioengineering Laboratory, Department of Orthopaedic
Surgery, Louisiana State University Medical Center, New
Orleans, LA 70112
Sponsor: National Science Foundation, Arlington, VA 22330
PURPOSE--We seek to develop an electrical stimulation methodology by which motor units are stimulated orderly (small ones first and progressively larger ones) as opposed to the commonly used "reverse" recruitment in widespread practice. This allows more precise control of force generation with near linear relations to stimulus amplitude, while minimizing fatigue and unreliability of the force output.
METHODOLOGY--A technique developed and evolved since the late 1970s consists of a tripolar or two bipolar cuff electrodes placed on the nerve. One electrode provides supramaximal stimulus pulses with variable frequency to constitute "firing rate control," while the second electrode provides high frequency pulses (600 pps) with increasing or decreasing amplitude to constitute the "motor units recruitment control."
PROGRESS--Since different skeletal muscles utilize different action potential firing rates and motor units recruitment strategies, such strategies should be followed closely in electrical stimulation systems if fine, stable, and fatigue-free contractions are anticipated. A stimulation system capable of manipulating muscle force in an infinite combination of strategies was designed and tested utilizing linearly increasing firing rate and recruitment. Further evolution of the system allows more complex stimulation strategies to be obtained such as those described in the physiological literature for some muscles. Specifically, the firing rate controller provides a two-segment piece-wise linear increase such that strategies resembling that of the FDI and deltoid/biceps could be closely duplicated.
Additionally, a new tripolar cuff electrode has been developed which effectively replaced the previously used two bipolar electrodes. The performance and validation of the system were determined as well, and the technique was validated by numerous studies investigating muscle properties, models and EMG characteristics. Based on the long-term experience with this evolving technique, its potential for use in a high performance FES system is highly promising.
[355] MECHANORECEPTORS IN THE KNEE, SHOULDER, ELBOW AND WRIST LIGAMENTS
Moshe Solomonow, PhD; Carole Wink, PhD; Robert D.
D'Ambrosia, MD; Carlos A. Guanche, MD;
Bioengineering Laboratory, Department of Orthopaedic
Surgery, Louisiana State University Medical Center, New
Orleans, LA 70112
Sponsor: National Science Foundation, Arlington, VA 22330
PURPOSE--Our early work shows that the anterior cruciate ligament is well endowed with various types of mechanoreceptors which are the elementary infrastructure necessary for the ligamento-muscular protective reflex discussed elsewhere in this report.
PROGRESS--More recently, we discovered that the ligament bands in the shoulder capsule are also endowed with mechanoreceptors and that a reflex arc exists there as well. Ongoing work explored and confirmed that there are mechanoreceptors in the elbow and wrist ligaments as well, further establishing the hypothesis that the ligaments of every joint may have a significant sensory role in the function of the joint.
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Last revised Wed 05/26/1999
