Biomedical subjects

D A Boone

Publications and source records attributed to D A Boone.

11 recordsLinked to original sources

PubMed2001

Effect of trans-tibial prosthesis pylon flexibility on ground reaction forces during gait.

This study explored the effects of trans-tibial prosthesis pylon flexibility on ground reaction forces (GRFs) associated with walking and step-down. Four (4) active subjects with unilateral trans-tibial amputation and pylon lengths ranging from 4.9 cm to 25.9 cm were studied wearing an aluminium (rigid) pylon and a nylon (more flexible) pylon. Ground reaction forces were collected for the amputated limb during walking at pre-measured self-selected velocity and when stepping down from a 20 cm box. Pylon material significantly affected the magnitudes and patterns of GRFs in both tests. During walking, the most notable differences were seen in the anteroposterior (AP) direction. With the flexible pylon, the AP propulsive peak was greater (p=0.031), and the irregularities in the AP force curve were reduced. Additionally, when walking with the flexible pylon, the vertical peak associated with weight acceptance occurred earlier (p=0.010), the vertical terminal stance peak occurred later (p=0.012), and stance time was longer (p=0.010). During step-down, the vertical loading rate (p=0.010) and the peak vertical force (p=0.010) were greater with the more flexible pylon. Subjective feedback indicated that subjects could distinguish between the two pylons and felt that the nylon component was more comfortable, more flexible, and would enable them to walk more quickly. These results suggest that the pylon may be an influential component of the prosthesis with respect to gait and comfort, and that some degree of flexibility is desirable.

Adult↗

PubMed2000

Custom design in lower limb prosthetics for athletic activity.

In summary, the prosthetist is the best source of information with regard to the fast-changing lower extremity prosthetics technology for sports. The needs and desires of the amputee should be outlined and balanced with the cost of the desired components and design. In many cases, one carefully designed prosthesis can serve in dual roles for everyday ambulation and certain athletic activities. In other cases, the amputee is limited severely by a prosthesis that is not designed for a specific activity. Using a prosthesis for activities that it was not designed to accommodate can cause physical injury to the amputee as well as structural failure of the device. A properly designed and fitted prosthesis can open a whole new world of activity to the amputee and helps him or her to reach the desired a vocational goals.

Activities of Daily Living↗

PubMed1999

Phantom limb, residual limb, and back pain after lower extremity amputations.

This study describes the sensations and pain reported by persons with unilateral lower extremity amputations. Participants (n = 92) were recruited from two hospitals to complete the Prosthesis Evaluation Questionnaire which included questions about amputation related sensations and pain. Using a visual analog scale, participants reported the frequency, intensity, and bothersomeness of phantom limb, residual limb, and back pain and nonpainful phantom limb sensations. A survey of medication use for each category of sensations also was included. Statistical analyses revealed that nonpainful phantom limb sensations were common and more frequent than phantom limb pain. Residual limb pain and back pain were also common after amputation. Back pain surprisingly was rated as more bothersome than phantom limb pain or residual limb pain. Back pain was significantly more common in persons with above knee amputations. These results support the importance of looking at pain as a multidimensional rather than a unidimensional construct. They also suggest that back pain after lower extremity amputation may be an overlooked but very important pain problem warranting additional clinical attention and study.

Adult↗

PubMed1999

Issues of importance reported by persons with lower limb amputations and prostheses.

The purpose of this paper is to report prosthesis-related issues of importance that were identified by a diverse group of persons living with lower limb amputations (LLA) and prostheses. These perceptions and themes validate some old assumptions and challenge others, report both common and unusual experiences, and indirectly identify the information level of our respondents concerning prostheses. Persons with LLA were identified from computerized rosters at a level one regional trauma center and at the VA Puget Sound Health Care System-Seattle, Division. Inclusion criteria specified that respondents were to: 1) be one or more years post-unilateral amputation at the Syme's level (ankle disarticulation) or higher, 2) use their prosthesis at least 5 days a week, 3) read English, and 4) be able to provide informed consent. Respondents completed the Prosthesis Evaluation Questionnaire-field version (PEQ) and the standard form (SF)-36, a health status measure. Of 114 persons who agreed to participate, 92 (85% male, mean age 55 years) responded to the questionnaire and graded the personal importance of various characteristics and qualities of their prosthesis. The number of years since their last amputation ranged from 1 to 53 years. Four Themes of Interest were identified from responses to open-ended questions about living with a prosthesis. These themes included the fit of the socket with the residual limb, aspects of the mechanical functioning of the prosthesis, other nonmechanical qualities, and advice about adaptation to life with a prosthesis with support from others. Future research is recommended to adjust aspects of the fit of the prosthesis with the residual limb. Implementing periodic check-up visits could uncover problems and eliminate unnecessary suffering.

Activities of Daily Living↗

PubMed1999

Step activity monitor: long-term, continuous recording of ambulatory function.

In many areas of research and medicine, objective data describing an individual's ambulatory function are sought as useful indicators of that person's condition. Normally, detailed measurements are taken over short periods of time within a controlled laboratory setting. To complement this approach, Prosthetics Research Study has developed a small, unobtrusive instrument that continuously records a simple measure--step counts per unit time--as an individual goes about normal daily life. The Step Activity Monitor (SAM) is approximately the size and weight of a pager and is worn at the ankle. It can detect steps with better than 99% accuracy across a wide range of gait styles for adults, children, and large animals. During monitoring, step counts are recorded at consecutive, adjustable time intervals over weeks to months at a time. Recording at 1-min intervals for a minimum of 2 weeks is recommended. Once monitoring is completed, the data are transferred to a computer, and the levels and patterns of step activity can be analyzed. This article provides a detailed description of the SAM, guidelines for use, results of accuracy and reliability testing, case study descriptions demonstrating the ability to measure differences that result from medical interventions or changes in health status, and a discussion of considerations pertinent to long-term monitoring of activity.

Activities of Daily Living↗

PubMed1997

Design and pilot testing of the DVA/Seattle Footwear System for diabetic patients with foot insensitivity.

Clinical epidemiology studies suggest the majority of lower limb amputations were preceded by a minor traumatic event, often footwear-related, and lower limb ulcers. To reduce foot trauma and ulcers, the diabetic patient with foot insensitivity has unique footwear needs. To address these needs for patients not requiring custom shoes, the DVA/Seattle Footwear System was developed. The six components of this system include: 1) a specially designed shoe last based on the geometry of the diabetic foot and research findings on foot regions at highest risk of ulceration, 2) a depth-inlay shoe, "Custom Stride by PRS," designed to be paired with either a custom-fabricated cork insole or a preformed polyurethane insole, 3) a laser digitizing system that captures 3-D plantar foot contours, 4) DVA/Seattle ShapeMaker software adaptation for modifying plantar surface contours and applying free-form and template modifications to increase or relieve loading, 5) software that translates files into code used by a milling machine to define the cutting path and carve cork blockers into custom insoles, and 6) a preformed polyurethane insole thicker than a typical insole to accommodate the extra volume and the interior dimensions of the shoe. A 6-month pilot cross-over trial of 24 diabetic male veterans without prior foot ulcers was conducted to determine the feasibility of producing, and the safety of wearing, these depthinlay shoes and both types of insoles. During the first 4 weeks, patients were assigned to the study shoes and one type of insole. During the next 4 weeks, they wore the other type of insole, and during the final 4 months, they chose which pair of insoles to wear with the study shoes. Over 150 person-months of footwear observation revealed no breaks in the cutaneous barrier with use of either cork or polyurethane insoles and the study shoes. Patient compliance with the footwear was 88%. Patients were highly satisfied with the appearance, stability, and comfort of the shoes and the comfort of both types of insole. However, 75% of the patients noted that the study shoes felt heavier than their customary shoes. Further research is needed to determine the long-term effectiveness of footwear in prevention of foot ulcers in the population at highest risk for diabetic reulceration and amputation.

Aged↗

PubMed1995

Prosthetic history, prosthetic charges, and functional outcome of the isolated, traumatic below-knee amputee.

PURPOSE: To review the prosthetic history, prosthetic charges, and functional status of traumatic, isolated, unilateral below-knee amputees at select intervals following amputation. METHODS: This descriptive study was conducted among patients admitted to Harborview Medical Center between 1980 and 1987 who survived initial trauma, and who required an isolated, below-knee amputation. Hospital and prosthetist records were abstracted to calculate the number of prostheses fabricated and the prosthetic charges since initial amputation. Functional outcomes were determined by personal interview and self-administration of the SF-36 Health Status Profile. RESULTS: The average age of patients was 36 with the age range extending from 19 to 59 years. The prosthetic history and prosthetic charges were determined from the medical record and the billing records of the prosthetist. Exact charges were determined for 15 of the 20 patients. During the first 3 years, the mean number of prostheses acquired per patient was 3.4 (range 1-5), with average total prosthetic charges of $10,829 (range $2,558-$15,700). Over the first 5 years the mean number of prostheses acquired per patient was 4.4 (range 2-8), with average total prosthetic charges of $13,945 (range $6,203-$20,070). The SF-36 Health Status Profile scores were significantly decreased from published normal aged-matched scores in the categories of physical function and role limitations because of physical health problems and pain. Scores were not significantly different from published normal aged-matched scores in the other five categories: role limitations due to emotional problems, social functioning, mental health, energy/fatigue, and health perception.

Adult↗

PubMed1994

Automated fabrication of mobility aids: review of the AFMA process and VA/Seattle ShapeMaker software design.

Computer-aided design and manufacture of prosthetic and orthotic devices has recently moved out of the laboratory into clinical use. The Department of Veterans Affairs Rehabilitation Research and Development Service has directed coordinated evaluation and development projects of this emerging technology under the name: Automated Fabrication of Mobility Aids or AFMA. One of the major results of the effort was the creation of mobility aid design software (ShapeMaker) concurrent with AFMA clinical testing of preexisting systems and development efforts. In order to provide a foundation for future discussions regarding AFMA, this paper provides a descriptive review of the AFMA processes and a review of the conceptual basis for the ShapeMaker AFMA software development.

Artificial Limbs↗

PubMed1992

Automated fabrication of mobility aids (AFMA): below-knee CASD/CAM testing and evaluation program results.

In 1988 the Department of Veterans Affairs Rehabilitation Research and Development Service, under the directorship of Margaret J. Giannini, M.D., began a nationally directed computer-aided design and computer-aided manufacturing (CAD/CAM) research program for the Automated Fabrication of Mobility Aids (AFMA). Under this program CAD/CAM research and development centers were established at the Prosthetics Research Study in Seattle, WA; at Northwestern University and the VA Lakeside Medical Center in Chicago, IL; and at the VA Medical Center and New York University Medical Center in New York, NY. These three centers conducted a collaborative program: (a) to introduce CAD/CAM technologies to prosthetists, physicians, therapists, and rehabilitation health care professionals in the United States; (b) to evaluate the feasibility of using CAD/CAM systems in clinical prosthetics settings; (c) to test and evaluate the University College London-Bioengineering Center's and the University of British Columbia-Medical Engineering Resource Unit's respective systems for the computer-aided design and computer-aided manufacture of prosthetic sockets (CASD/CAM) for below-knee amputees; and, (d) to obtain quantitative data for refinement of the CASD/CAM systems tested, and for the development of new, enhanced, more efficacious, and expedient systems.

Adult↗

PubMed1990

An angular alignment measurement device for prosthetic fitting.

A device to measure socket/shank angular alignment in a prosthesis equipped with a Berkeley Adjustable Leg is described. Angular alignment in the sagittal plane can be measured over the entire 20-degree range with a repeatability of 1 degree. This device can be a useful prosthetics fitting, teaching, and research tool.

Amputation, Surgical↗

PubMedDate not supplied

State-of-the-art research in lower-limb prosthetic biomechanics-socket interface: a review.

Scientific studies have been conducted to quantify attributes that may be important in the creation of more functional and comfortable lower-limb prostheses. The prosthesis socket, a human-machine interface, has to be designed properly to achieve satisfactory load transmission, stability, and efficient control for mobility. The biomechanical understanding of the interaction between prosthetic socket and the residual limb is fundamental to such goals. The purpose of this paper is to review the recent research literature on socket biomechanics, including socket pressure measurement, friction-related phenomena and associated properties, computational modeling, and limb tissue responses to external mechanical loads and other physical conditions at the interface. There is no doubt that improved biomechanical understanding has advanced the science of socket fitting. However, the most recent advances in the understanding of stresses experienced at the residual limb have not yet led to enough clinical consensus that could fundamentally alter clinical practice. Efforts should be made to systematically identify the major discrepancies. Further research should be directed to address the critical controversies and the associated technical challenges. Developments should be guided to offer clinicians the quantification and visualization of the interaction between the residual limb and the prosthetic socket. An understanding of comfort and optimal load transfer as patterns of socket interface stress could culminate in socket design expert systems.

Amputation Stumps↗