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Clinical Relevance for the Veteran
Journal of Rehabilitation Research and
Development Vol. 36 No. 3, July 1999

Clinical Relevance for the Veteran

SUMMARY OF SCIENTIFIC/TECHNICAL PAPERS IN THIS ISSUE
 

Issues of importance reported by persons with lower limb amputations and prostheses.
Marcia W. Legro, PhD; Gayle Reiber, MPH, PhD;
Michael del Aguila, PhD; Megan J. Ajax, BS;
David A. Boone, CP, MPH; Jerrie A. Larsen, RN, CRA;
Douglas G. Smith, MD; Bruce Sangeorzan, MD

Purpose of the Work. This work reports prosthesis-related issues from a diverse group of persons with amputation who wear lower-limb prostheses. Subjects/Procedures. Persons with lower-limb amputations were identified from computerized rosters at the VAMC Seattle, Washington. One hundred fourteen persons participated and completed a prosthesis evaluation questionnaire. They graded how important various characteristics and qualities of their prostheses were to them. Results. Four themes of interest were identified from responses to open-ended questions about living with a prosthesis: fit of the socket, mechanical function of the prosthesis, other qualities of the prosthesis, and adaptation of the person to life with a prosthesis. Relevance to the Veterans Population. Knowledge of veterans' opinions about the quality of their lives since their amputations will help researchers adjust certain aspects of the fit of a prosthesis to a residual limb to eliminate unnecessary suffering.


Prosthetic Loading During Kneeling of Transfemoral Amputees.
Evangelos A. Magnissalis, PhD; Stephan E. Solomonidis, BSc, C.Eng, FIMechE; William D. Spence, MSc; John P. Paul. PhD, FEng; Saeed Zahedi, BSc.

Purpose of the Work. Failure of prosthetic components during kneeling has been reported. This study provides the first objective data on the loads generated during kneeling activities. Subjects and Procedures. The data were acquired by conducting 162 tests on four male amputees wearing prostheses incorporating load measuring transducers and kneeling against two force platforms. Results. The critical areas in a prosthesis, during kneeling, were found to be at the knee and shank. The loads determined were much higher than these developed during level walking. Relevance to Veteran Population. The data obtained were submitted to the International Standards Organisation (ISO) and are now used for guidance in the determination of the test configuration and load values for the standard for structural testing of trans-femoral prostheses. The information given in this paper should be useful to designers in ensuring the production of robust, lightweight prostheses.
Stephan Solomonidis, BSc, FIMechE


Effects of Age and Functional Limitation on Leg Joint Power and Work During Stance Phase of Gait
Chris A. McGibbon, PhD and David E. Krebs, PhD, PT.

Purpose of the Work. Joint power produced during walking is a good index of age related mobility decline. We investigated joint power sensitivity to impairments and aging. Subjects/Procedures. Motion analysis was performed on healthy young, healthy elderly, and disabled elderly subjects while walking. Traditional walking performance measures (such as walking velocity) and less conventional mechanical power produced at the ankle, knee and hip were calculated from the movement data. Results. Differences in walking velocity were observed between young and elder subjects, but not between healthy elders and disabled elders. There were large differences in the amount of ankle power generated at "push off" of stance phase between the healthy elderly and disabled elderly, that were not present between healthy young and healthy elderly. Relevance to the Veteran Population. Traditional walking performance measures may not be sensitive enough to indicate the onset and magnitude of disabling conditions in elders. Decreased ability to generate ankle power during walking, however, may be a better way to discriminate between healthy elders and those at risk for disablement.
Chris A. McGibbon, PhD


Gait Characteristics of Individuals with Multiple Sclerosis Before and After a Six Month Aerobic Training Program
Mary M. Rodgers, PhD, PT; Janet A. Ponichtera-Mulcare, PhD; Deborah L. King, MS; Thomas Mathews, MD.

Purpose of the Work. Although cycle exercise training has been shown to improve aerobic endurance individuals with multiple sclerosis (MS), the carry-over effects to the more functional activity of walking have not been investigated. The goal of this study was to determine the effects of a six month cycling exercise program on the walking ability of individuals with MS. Subjects. Nineteen patients (14 female, 5 male) with MS of differing disability participated in this study. Procedures. Gait analysis was performed before and after the exercise program. The exercise program consisted of cycle exercise three times a week for 30 minutes. Results. Walking speed decreased after training. Other walking characteristics were minimally effected by the training program. Relevance to Veteran Population. It appears that a long term cycling program may be most beneficial for increasing aerobic endurance, and less beneficial to improving gait in individuals with MS.
Mary Rodgers, PhD


Temperature Effects on Surface Pressure-Induced Changes in Rat Skin Perfusion: Implications in Pressure Ulcer Development.
Suryachandra Patel, MD, PhD; Charles F Knapp, PhD; James C Donofrio, PhD; Richard Salcido, MD.

Purpose of the Work. This article describes the effect of increasing temperature on the relationship between skin blood flow and increasing surface pressure, and how these parameters impact skin deformation. Subjects/Procedures. Skin surface pressure was applied over the hips of Fuzzy Rats by a computer-controlled plunger with skin deformation measured by an electronic sensor. Laser light was used to measure the blood flow in the skin while temperature was mildly increased at the surface using an attached heating block. The experimental protocols allowed us to study changes in skin blood flow and deformation of heated and unheated tissue during exposure to surface pressure. Results. It was found that for surface pressures below 18 mmHg, increasing skin temperature significantly increased skin perfusion and tissue stiffness. Relevance to the Veteran Population. This study implies that a mild increase in temperature resulting in a stiffening of the tissue has the potential to reduce both skin breakdown and pressure ulcer formation. Pressure ulcers continue to have a negative impact on important veteran patient populations including the spinal cord injured and the aged.
Suryachandra Patel, MD, PhD


Transcutaneous Oxygen Tension in Subjects With Paraplegia With and Without Pressure Ulcers: A Preliminary Report.
Mon Hsia Liu, BS; David R. Grimm, EdD; Victoria Teodorescu, MD; Steven J. Kronowitz, MD; William A. Bauman, MD.

Purpose of the Work. This study compared transcutaneous oxygen tension (TcpO2), a measure of local oxygen supply to the tissue, in subjects with paraplegia and pressure ulcers (PU-PARA), those with paraplegia and no pressure ulcer (NPU-PARA) and ambulatory subjects (control). Subjects/Procedures. TcpO2 was measured at rest in the supine position using a surface electrode monitoring system, recorded at one minute intervals for five minutes. Results. Mean TcpO2 was significantly lower in the PU-PARA than the NPU-PARA and control groups (23.53±1.83 vs. 58.93±2.53 and 79.70±6.77 mmHg, respectively). The NPU-PARA group also demonstrated significantly lower TcpO2 than controls. Relevance to the Veteran Population. TcpO2 may be an effective method to identify individuals who are susceptible to develop pressure ulcers. The further attenuation of TcpO2 observed in the pressure ulcer group may be a useful tool to help predict whether ulcers will heal with local care or whether additional treatment is required.
Mon Hsia Liu, BS


Knee Kinetics during Functional Electrical Stimulation Induced Cycling in Spinal Cord Injured Subjects: A Preliminary Study.
John C. Franco MD, MS; Karen L. Perell PhD; Robert J. Gregor PhD; A.M. Erika Scremin MD.

Purpose of the Work. This article describes parameters regarding pedaling effectiveness and knee joint loading during functional electrical stimulation induced cycling. Subjects/Procedures. Specialized pedals, which measure forces during bicycling, were used while spinal cord injured (SCI) subjects participated in a functional electrical stimulation induced cycling program. Pedal forces were used to calculate knee joint loading parameters. Results. Pedaling effectiveness was severely compromised, knee joint parameters suggest excessive loading, and the overall analysis revealed an energetically unfavorable knee stabilizing mechanism within the bicycle configuration used. Relevance to the Veteran Population. These findings suggest that the knee joint loading during this exercise modality may be large enough to produce a "trivial fracture" in the compromised lower limbs of individuals with SCI. Future studies involving changes in bicycle configuration and knee joint loading are necessary to maximize the cardiopulmonary and musculoskeletal benefits of functional electrical stimulation induced cycling in the SCI population.
John C. Franco MD, MS


The Robotized Workstation Master for Tetraplegic Users: Description and Evaluation
Michel Busnel, MD; Riadh Cammoun, ENG; Françoise Coulon-Lauture, ENG; Jean-Marie Détriché, PhD; Gérard Le Claire, MD; Bernard Lesigne, PhD

Purpose of the Work. This article describes the design and the development of a robotized workstation intended for tetraplegic users with the goal of improving their autonomy and thus their quality of life. Subjects/Procedures. After a need analysis performed with medical doctors, researchers and tetraplegic users realized and evaluated several prototypes of the workstation Master in French rehabilitation centers. Results. About one hundred individuals have successfully tested the workstation over a period of 2 years. The configured operator interface gives access, in real time, to four functions the can be combined: a robotic arm with two running modes: automatic and /or direct, an environment control system, and office software. Relevance to the Veteran Population. Such a system offers several advantages to persons without motricity of upper limbs, mainly fuctional tetraplegics. It is potentially an important tool for domestic and vocational applications, promoting the rehabilitation of tetraplegics in society.
Bernard Lesigne, PhD


Multiresolutional Modification of Speech Signals for Hearing Impaired Listeners.
Osman Eroul, MSc, PhD and rfan Karagöz, MSc, PhD.

Purpose of the Work. This study describes an algorithm that is used to modify speech signals for hearing impaired listeners. Subjects/Procedures. The proposed method makes the use of multiresolutional analysis in association with speech modification algorithms. The algorithm modifies the wavelet coefficients of the speech in order to obtain a more intelligible speech signal. The performance of the algorithm has been evaluated using both normal and hearing impaired subjects. Results. Listening tests showed that the proposed algorithm increases the quality and intelligibility of the modified speech over the well-known modification algorithms. The preliminary test results also suggest that multiresolutional modification algorithm can be used to overcome the deterioration of peripheral ability. Relevance to the Veteran Population. The algorithm can be used in the implementation of digital hearing instruments regarded as having a function complementary to that of conventional hearing aids.
Osman Eroul, MSc, PhD


New On-line Parameters for Analysis of Dynamic Foot Pressures in Neuropathic Feet of Hansen's Disease Subjects
Mahesh M Bhatia, MS and Mothiram K. Patil, DSc.

Purpose of the Work. This paper describes new on-line parameters for analysis of dynamic foot pressures in neuropathic feet of Hansen's disease subjects. Subjects/Procedures. The foot pressures during walking are measured by using a long optical pedobarograph and a specially developed on-line image processing software. Two new on-line parameters are obtained by considering peak foot pressures, body weight, walking velocity, and duration of 50% of peak pressure. Results. The mean values of the new foot pressure parameters, for various classes of Hansenīs disease subjects, are found to be significantly different from those of the normal subjects and on-line calculation of these helps in quickly assessing the areas of the feet subjected to high and long duration loading. Relevance to the Veteran Population. The foot areas, with no plantar sensation and both the parameters being high, are at a great risk of ulceration and this information can aid the clinician to prescribe suitable footwear to prevent plantar ulcers at an early stage.
Mahesh M Bhatia, MS


Three-dimensional Foot Modelling and Analysis of Stresses in Normal and Early Stage Hansen's Disease with Muscle Paralysis
Shanti Jacob, PhD and Mothiram K. Patil, DSc

Purpose of the Work. This paper describes three-dimensional foot modeling and analysis of stresses in normal and early stage Hansen's disease with muscle paralysis that could possibly help in understanding disintegration of tarsal bones in Hansen's disease. Subjects/Procedures. Stress analysis is carried out on three-dimensional foot models of normal and Hansen's disease subjects by finite element technique simulating quasi-static walking phases of heel-strike, mid-stance, and push-off. Results. The analysis shows that the highest stresses occur during push-off phase in certain areas and joints of the foot bones of a normal subject and these stresses increase by 25-50% in early stage Hansen's disease with muscle paralysis. Relevance to the Veteran Population. The high stress concentration areas in the foot bones are of great importance since it is found from clinical reports that in certain Hansen's disease subjects, these areas of the bones get disintegrated if subjected to osteoporosis due to decreased mechanical strength of the bone caused by Hansen's disease.
Shanti Jacob, PhD

 

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