Biomedical subjects
Publications and source records attributed to S V Fisher.
This article provides an overview of impairment rating in the burn survivor. It is not intended to be a complete guide; each jurisdiction and each agency requires the physician to use the necessary required criteria. This article also emphasizes the significant rating differences between agencies and jurisdictions and in the latitude given the health professional in performing the rating.
Three cyclic pressure loads (10 minutes "on" and 5 minutes "off") of 30 or 75 mmHg were applied to the flat anterior surface of the tibia on 11 able bodied (AB) and nine spinal cord injured (SCI) subjects. Transcutaneous PO2 (TcPO2) and PCO2 (TcPCO2), laser Doppler (LD) skin blood flow, velocity, and volume, and the depth of leg indentation (LI) were recorded. In the AB subjects the mean TcPO2 decreased from 31.5 to 27.2 mmHg with the 30 mmHg load. In contrast for the SCI subjects TcPO2 decreased from 32.3 to 7.3 mmHg (significantly differeNt from AB group at p < 0.05). Means of the LD values for volume, velocity, and flow were normalized, giving the highest value of each of the parameters including both the AB and SCI subject during the entire time period a value of 100%. At 30 mmHg loading, the laser LD normalized volume in the AB subjects were 72.5% and 97.0% for the on and off periods, respectively, whereas for the SCI subjects the values were 43.7% and 69.7% for the on and off periods, respectively (significantly different from the AB group at p < 0.05). At 75 mmHg loading, the volume values for the AB subjects were 59.1% and 95.3% for the on and off periods, respectively, whereas for the SCI subjects, the values were 31.6% and 65.4% for the on and off periods, respectively (significantly different from the AB group at p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
This self-directed learning module highlights the general concepts and new advances in the area of orthotics and prosthetics. This general overview is part of the chapter on prosthetics, orthotics, and assistive devices for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation. This section contains essential information on spinal, lower and upper limb orthotics, lower and upper limb prosthetics, juvenile prosthetics, kinesiology, motion analysis, and assistive devices such as canes and crutches. This article establishes a foundation on which the second, third, and fourth articles of this chapter will build. The three articles to follow review newer developments in specialized seating and assistive devices, prosthetics, and the orthotic management of selected disorders.
This self-directed learning module discusses topics in specialized seating, mobility devices, augmented communication, and adaptive equipment. Development, perceptual-motor, and cognitive factors are addressed in regard to appropriate prescription, training, and follow-up. It is part of the chapter on prosthetics, orthotics, and assistive devices for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation.
This self-directed learning module highlights new advances in prosthetics. It is part of the chapter on prosthetics, orthotics, and assistive devices for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation. This section contains information regarding conventional and myoelectric upper limb prosthetics, above-knee (AK) socket designs and materials, and foot and ankle systems. New advances that are covered in this section include the narrow medial-lateral AK socket, the flexible AK socket, and new prosthetic foot and ankle systems. Proper understanding and clinical application of this technology is essential for the optimal prosthetic rehabilitation of the amputee.
This self-directed learning module presents core information and new advances in the orthotic management of problems of the runner and of patients with neurovascular foot ulcers or arthritis. Additional topics covered include a comprehensive approach to positioning and splinting for burns and tone-reducing orthoses for spasticity management. It is part of the chapter on prosthetics, orthotics, and assistive devices for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation.
Continuous pressure under each ischial tuberosity was measured on five ulcer-free patients with quadriplegia for four days as they completed their normal daily activities. Results showed many multihour periods without pressure relief. More than 50% of the time the pressure-time periods were outside of previously reported acceptable limits. The results indicate that quadriplegic patients can sit with ischial tuberosity pressures above the previously reported capillary pressure of 32mmHg for long periods of time without getting an ulcer. This study suggests that other factors beside pressure must be studied in order to develop a better resting surface.
Heart rate (HR) and blood pressure (BP) responses to repeated dynamic and combined dynamic and isometric work bouts of 30 sec, 2 min, and 6 min with equal rest periods at 40% and 80% of Vo2max was studied in five healthy men and five healthy women. Total work duration for each experimental condition was 24 min. The treadmill was used for dynamic work. Subjects pushed a bar horizontally while on the treadmill at 20% of their maximal voluntary strength for isometric work. Results showed that work performed at 40% of Vo2max in 30 sec bouts compared to 6 min bouts reduced HR, BP and the double product (BP X HR) by 11%, 4%, and 14%, respectively. Work performed at 80% of Vo2max in 30 sec bouts of repeated work or rest compared to the 6 min bouts resulted in reducing HR, BP, and double product 28%, 15%, and 39%, respectively. Addition of the isometric load did not significantly change the results. This study suggests that cardiac patients may be able to perform more work safely if it is carried out in short periods alternating with rest periods of equal duration.
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Five ulcer free tetraplegic subjects who are unable to do lift-offs were studied on four separate days on two types of wheelchair cushions to measure the pressures underneath the ischial tuberosities. Small electrical pressure transducers and a tape-recorder were utilised. The average pressures on the ROHO and foam cushions were 71.5 and 105.4 mmHg respectively. The average time between push-ups greater than 1 second and greater than 5 seconds was 72.1 and 96.2 minutes. The average pressures and the time between push-ups was greatly in excess of the usually suggested skin care regime. The data would suggest that the relative importance of pressure and pressure relief in the aetiology of decubitus ulcers should be re-examined.
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Energy consumption data were obtained on 8 normal subjects ambulating with underarm crutches, using a 3-point gait at 30, 40, 50, 60, 70, and 80 meters per minute (m.min-1) on level terrain, and 40, 60m.min-1 on a 5% grade, and climbing 19-cm stairs at 16 and 24 steps/minute. The subjects ambulated without crutches at 30, 50, 70m.min-1 on the level, 60m.min-1 on a 5% grade, and stairs at 16 and 24 steps/minute. Oxygen consumption (VO2) and ventilation data were obtained from a portable device. Respiratory quotients were determined from samples of expired gas. Maximal upper extremity(bicycle ergometer) and lower extremity (treadmill) stress tests were determined. The energy cost (oxygen consumption) VO2.wt-1 (ml.min-1.kg-1) of ambulating with underarm crutches compared to normal walking was approximately twice as great. The heart rate (HR) and VO2 for any given rate of vertical rise tested was less with crutch stair climbing than with crutch walking. There was no difference in VO2 or HR when ambulating with underarm compared to forearm (Lofstrand) crutches.
The cardiovascular (CV) stress of crutch walking was studied in 8 normal subjects ambulating with under arm crutches at 30, 40, 50, 60, 70 and 80m.min-1 on the level, at 40 and 60m.min-1 up a 5% grade, and climbing stairs at the rate of 16 and 24 stairs/min. A progressive exercise stress test was performed on each subject using a hand-cranked bicycle ergometer for the upper extremities and treadmill for the lower extremities. Heart rates (HR) were significantly higher than in normal walking at equivalent O2 uptake (VO2) levels. The HR slope versus VO2 for each crutching activity was similar to that obtained for the upper extremities stress test. This suggests that crutching acts as an upper extremity activity in terms of CV stress. Using the ventilatory equivalent (VE/(VO2), the estimated anaerobic threshold point started at 60m.min-1 for level crutching. It was estimated that a subject with a pulse rate limit of 140bpm could either crutch at 60m.min-1 (2.2mi.hr-1) or run at 134m.min-1 (5mi.hr-1).
A study was conducted to investigate the pressure relief patterns under the ischial tuberosities in group of 12 paraplegic subjects. A small electrical pressure transducer was taped over each ischial tuberosity, and each subject had a thermistor taped near one tuberosity. The subjects were instrumented in the morning and allowed to go about their normal activities for the day sitting on a 4-inch foam cushion. The subjects sat at pressures greater than 150, greater than 90, and greater than 30 mmHg for 17.6 percent, 53.5 percent, and 91.8 percent of the time, respectively. The subjects sat on the average for 10.1 min without doing a pushup with a duration greater than 1 sec and sat on the average for 29.6 min without doing a pushup with a duration greater than 5 sec. Two of the subjects sat for periods greater than 60 min for greater than 75 percent of the time (ignoring pushups less than 5 sec) and greater than 65 percent of the time ignoring pushups less than 1 sec. The average time between pushups was within the generally accepted limits to prevent ulcers--10-30 minutes. A few of the subjects had occasional long periods of uninterrupted pressure greater than what is thought to be required to produce ulcers--and did not develop them.
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This study evaluated the effectiveness of the ROHO Balloon Wheelchair Cushion in distributing pressure on the skin over the ischial tuberosities in healthy subjects. Surface skin temperatures over the ischial tuberosities and thighs of the subjects were also measured. Pressure recordings were obtained by placing a pressure sensor between the wheelchair cushion and the skin overlying the ischial tuberosities. For comparison, pressures were recorded while the same subjects sat on a 4-inch foam cushion supported on a plywood board. Skin surface temperatures on the 2 cushions were recorded on separate occasions under the ischial tuberosity and the posterior thigh during a 30-minute test period. The results indicate no important difference in resting pressures when the subjects sat on either the 4-inch foam cushion or the balloon cushion. Neither was there an important difference in pressure when the cushion was inflated to greater than the manufacturer's recommendations or when it was covered with a commercially designed cover. The average increase in skin temperature over the tuberosity was 1.9C and over the thigh, 2.6C.
The literature concerning ambulation of normal and disabled persons--amputees, hemiplegics, and paraplegics--is reviewed. Also reviewed are studies of the energy cost of ambulating with assistive devices and of wheelchair locomotion. According to an average of the results available from the literature, a normal expenditure (Ee) of 0.063 kcal/min/kg and 0.00764 kcal/meter/kg. The disabled person walks more slowly, to avoid incurring an increase in Ec/minute. The more disabled the person, the more determinants of gait lost; thus, the more slowly he walks and the less efficient he becomes in terms of Ee/kcal/unit distance. The importance of a common terminology when measuring the energy cost of ambulation and the need to allow subjects to walk at their own most comfortable walking speed are stressed.