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Biomedical subjects

Valma J Robertson

Publications and source records attributed to Valma J Robertson.

12 recordsLinked to original sources
PubMed2004

Targeted postoperative care improves discharge outcome after hip or knee arthroplasty.

OBJECTIVE: To determine whether targeted postoperative care, based on preoperative risk assessment, can increase the number of patients who are discharged home directly from acute care after elective hip or knee arthroplasty. DESIGN: Quasiexperimental with historical control. SETTING: A public university teaching hospital. PARTICIPANTS: One hundred patients who had an elective hip or knee arthroplasty. INTERVENTIONS: Between January and July 2001, 50 patients had their risk of discharge to extended inpatient rehabilitation assessed preoperatively with a newly developed Risk Assessment and Prediction Tool (RAPT). Postoperative management was targeted on the basis of the identified level of risk. Results were compared with those of a similar group of 50 patients treated between January and July 2000. MAIN OUTCOME MEASURES: Discharge destination, length of stay (LOS), and readmission rates. RESULTS: The percentage of patients discharged directly home increased significantly, from 34% during 2000 to 64% in 2001 (P=.002), with no increase in readmission rates in the 12 months postdischarge. In addition, the mean acute hospital LOS decreased by 1.1 days to 7.5 days in 2001 (P=.02). CONCLUSIONS: Use of the RAPT and targeted postoperative care resulted in more patients being discharged directly home after hip or knee arthroplasty while hospital LOS further decreased.

Aged↗
PubMed2004

The effect of duty cycle and frequency on muscle torque production using kilohertz frequency range alternating current.

We investigated the frequency and duty cycle dependence of maximal electrically induced torque (MEIT) of the wrist extensors. Fifty hertz burst modulated sinusoidal alternating current (AC) in the frequency range 0.5-20 kHz was used, with duty cycles ranging from a minimum (one cycle) to maximum (continuous AC). MEITs were similar at low frequencies but decreased markedly above 2.5 kHz. MEITs also decreased markedly above a 20% duty cycle. Subjective reports of discomfort were fewest at 4 kHz and at duty cycles in the range 20-25%. Our conclusion is that for maximum torque production, a frequency of 1 kHz and a duty cycle of 20% are indicated. When comfort is a major consideration, a frequency of 2.5 kHz provides an acceptable trade-off between MEIT and comfort. The findings also suggest that low duty cycle, burst modulated AC stimulation may be more effective than stimulation using conventional low-frequency pulsed current.

Electric Stimulation Therapy↗
PubMed2004

A comparison of true and premodulated interferential currents.

OBJECTIVE: To compare true and premodulated interferential currents (IFCs) in terms of sensory, motor, and pain thresholds; maximum electrically induced torque (MEIT); and comfort. DESIGN: Repeated-measures design. SETTING: Laboratory setting. PARTICIPANTS: University student and staff volunteers. INTERVENTIONS: Participants were exposed to 4 different conditions, chosen to evaluate 2 fundamental differences between true and premodulated IFCs. The conditions were different combinations of (1) premodulated or constant-amplitude currents applied at the skin and (2) crossed or parallel current paths. MAIN OUTCOME MEASURES: Sensory, motor, and pain thresholds; MEIT; and subjective reports of relative discomfort were recorded for each of the 4 conditions. Motor to sensory threshold ratios were subsequently calculated to assess depth efficiency of stimulation. RESULTS: The major findings were that crossed currents (true IFC) had no advantage over parallel currents (premodulated IFC) in terms of motor to sensory threshold ratio, MEIT, or comfort, and that premodulated currents produced higher torque values and less discomfort than constant-amplitude currents (true IFC). These results contradict the claimed superiority of true IFC. CONCLUSIONS: The findings indicate that premodulated IFC, delivered via 2 large electrodes, may be clinically more effective than the traditional true IFC arrangement in terms of depth efficiency, torque production, and patient comfort.

Adult↗
PubMed2003

Monophasic and biphasic stimulation evoke different responses.

In 31 subjects, psychophysiological sensory perception threshold and the waveform of orthodromic sensory nerve action potentials (SNAPs) produced by constant-current 100-micros monophasic negative pulses were compared to those produced by biphasic (negative-positive) symmetrical pulses (100-micros per phase). In addition, the effects of 200-micros monophasic negative pulses were studied. Graded stimuli were delivered to the index finger, and SNAPs were recorded over the median nerve at the wrist. Perception threshold was significantly different among the three conditions. Furthermore, in 26 subjects, at the lower intensities at which SNAPs first appeared, the evoked potential waveform had two small negative phases with biphasic stimuli, but a single negative phase in response to monophasic pulses. At higher stimulus intensities, all SNAPs had a single large negative phase regardless of the stimulus. These perception and waveform findings suggest that, contrary to historical belief, the trailing positive phase of a biphasic pulse has a stimulating effect at low stimulus intensities.

Action Potentials↗
PubMed2003

Predicting risk of extended inpatient rehabilitation after hip or knee arthroplasty.

This study developed and validated an easily administered method of predicting a patient's risk of needing extended inpatient rehabilitation after hip or knee arthroplasty. Seven factors generated by experts and from the literature were shown to be statistically significantly related to discharge destination (P</=.001). Factor weightings derived from a logistic regression equation and tested on the first 520 cases were used to devise a scoring method. This method was validated using a further 130 cases and the Risk Assessment and Predictor Tool (RAPT) was formulated. The RAPT identified 3 levels of risk of needing extended inpatient rehabilitation after hip or knee arthroplasty, with an accuracy rate of 89% for those most at risk.

Aged↗
PubMed2003

Physical therapists who claimed workers' compensation: a qualitative study.

BACKGROUND AND PURPOSE: Although most physical therapists experience work-related musculoskeletal disorders (WMSDs) at some time, only a small minority claim workers' compensation. This article describes the experiences of a group of therapists with WMSDs who made compensation claims. METHODS: Interviews were used to document the experiences of physical therapists who reported that they had changed their career because of WMSDs. RESULTS AND DISCUSSION: Therapists described their experiences in negative terms and found dealing with the workers' compensation system frustrating and unpleasant. They encountered attitudes that labeled them as malingerers and felt their credibility was questioned. CONCLUSIONS: Physical therapists' experiences of the workers' compensation system were negative, and they were keen to become independent of it. Those who claimed workers' compensation perceived that a compensable claim could limit their employment opportunities, making confidentiality an important issue when treating other health care professionals.

Activities of Daily Living↗
PubMed2002

Occupational health in physiotherapy: general health and reproductive outcomes.

Physiotherapists are exposed to many risk factors in their work environment. Their general health status is largely unknown, and conflicting studies suggest possible adverse reproductive effects of electromagnetic radiation to which they may be exposed. As part of a larger study, a systematic sample of one in four physiotherapists on a state register (N = 824) was surveyed. Each subject completed an eight page questionnaire, answering questions about musculoskeletal and general health, exposure to risk factors, exposure to electrophysical agents and reproductive outcomes. The response rate was 67.8%. The incidence of congenital malformations and miscarriage among physiotherapists was lower than that in the general community. However, physiotherapists who performed hydrotherapy were more likely to report dermatitis, rashes and fungal skin infections. The prevalence of these conditions increased with the number of hours spent doing hydrotherapy. These findings suggest that physiotherapists are unlikely to have an increased risk of negative reproductive outcomes because of their exposure to electrophysical agents. Physiotherapists who perform hydrotherapy, however, have an increased risk of skin complaints.

Adult↗
PubMed2002

Hospital stay and discharge outcomes after knee arthroplasty: implications for physiotherapy practice.

Patient outcomes at discharge from acute care after knee arthroplasty were investigated in a prospective observational outcome study at three Melbourne public acute care hospitals during a five-month period from November 1999 to March 2000. The participants were 105 consecutive patients (35 at each hospital), with a mean age of 71 years. Outcome measures were length of stay, destination (home or rehabilitation), knee range of movement, and functional mobility at discharge from the acute care facility. During the study period, mean hospital length of stay across the three hospitals was 6.5 days, more than 30% less than the Victorian average for the preceding year. In that time, 56% of patients had achieved functional independence sufficient for discharge directly home, however only 36% were actually discharged home. The reasons identified for discharge to rehabilitation despite the achievement of sufficient functional independence included pressure on clinicians to decrease length of stay and the need to make decisions regarding discharge early in the post-operative recovery when the eventual patient outcome may still be unclear. Unnecessary discharges to rehabilitation increase the overall length of stay in the health care system and costs per patient. This finding suggests a method of risk screening is required to assist clinical decision making with regard to discharge.

Activities of Daily Living↗
PubMed2002

Optimal frequencies for electric stimulation using medium-frequency alternating current.

OBJECTIVE: To determine the effect of single cycles of alternating current of various frequencies on sensory and motor thresholds and on relative thresholds (motor threshold/sensory threshold). DESIGN: Repeated-measures design. SETTING: Laboratory setting. PARTICIPANTS: University student and staff volunteers (N=16; mean age, 34y). INTERVENTIONS: Single cycles of sinewave frequencies between 1 and 35kHz were delivered at 50Hz. The frequencies were applied in a random order. MAIN OUTCOME MEASURES: The motor and sensory thresholds were recorded at each applied frequency. RESULTS: Both sensory and motor thresholds showed a smooth decrease to a minimum at approximately 3kHz. The relative threshold reached a minimum close to 9kHz. Comparison with previous studies showed that although absolute thresholds reach a minimum at a frequency that depends on electrode size, the frequency at which the relative threshold is a minimum was independent of electrode size and independent of whether the stimulus was applied as single pulses or in burst mode. CONCLUSIONS: The optimal frequency for transcutaneous stimulation using medium-frequency alternating current depends on the outcome measure used. It would therefore be desirable for clinical stimulators to provide a selection of carrier frequencies.

Adult↗
PubMed2002

Vastus medialis electrical stimulation to improve lower extremity function following a lateral patellar retinacular release.

STUDY DESIGN: A single-case study design. OBJECTIVES: To examine the effect of electrical stimulation of the vastus medialis muscle on stiffness, pain and function for a patient with delayed functional progress following a lateral patellar retinacular release. BACKGROUND: Five months after an arthroscopic lateral patellar retinacular release, the patient, although highly motivated, had made little progress using routine exercises and taping. METHODS AND MEASURES: An electrical stimulation program producing approximately 300 contractions daily of the vastus medialis muscle was implemented. The electrical stimulation applied for 33 of the 36 days was a rectangular and balanced biphasic pulse of 625-micros duration, 70-Hz frequency, 8-second peak on-time, 3-second off-time, 1-second ramp-up, and 0.5-second ramp-down. Objective measures of stair climbing and hopping, together with the subjective measure of therapist-palpated superomedial patella displacement force, were recorded for each treatment visit. Other subjective measures were the patient's daily recordings of knee pain and stiffness. RESULTS: Patient-reported stiffness reduced rapidly as the actual and cumulative number of daily contractions of the vastus medialis muscle increased. After 8 days of electrical stimulation, the patient was able to ascend stairs unassisted and after another 21 days to hop unsupported. CONCLUSIONS: Stiffness rapidly reduced and function started to improve once the electrical stimulation program was implemented. Recovery during the 36 days of treatment with electrical stimulation was greater than during the previous 5 months using other methods. Compliance was not an issue, nor was muscle soreness.

Arthroscopy↗
PubMed2002

Work-related musculoskeletal disorders and the culture of physical therapy.

BACKGROUND AND PURPOSE: Knowledge, skills, relationships, and attitudes of caring and working hard are all thought to be valued by physical therapists. This article explores how physical therapists see themselves, in light of some of these values, when they experience work-related musculoskeletal disorders (WMSDs). The article also explores the ways in which these values may compete with each other, and it suggests how this may contribute to the onset of WMSDs and to therapists' behavior following a WMSD. SUBJECTS AND METHODS: Eighteen therapists who had made a career change after a WMSD participated in interviews that were designed to gain insight into the attitudes and beliefs of therapists who had had a WMSD. RESULTS: Participants did not anticipate WMSDs, and they typically believed their physical therapy knowledge and skills would have prevented WMSDs from occurring. They saw themselves as knowledgeable and caring and indicated that these characteristics were highly valued by the profession. Their need to demonstrate these attributes sometimes resulted in behaviors that contributed to the development of their WMSDs and made them worse after their onset. DISCUSSION AND CONCLUSION: The cultural values of physical therapists may make it difficult for them to do their jobs in a way that minimizes the risk of WMSDs. The study identified a potential conflict between the therapists' need to (1) demonstrate their ability to work hard and care for their patients and (2) appear knowledgeable and skilled by remaining injury free.

Adult↗