Valma J Robertson

Predicting risk of extended inpatient rehabilitation after hip or knee arthroplasty

This study developed and validated an easily administered method of predicting a patients 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.

Electrophysical Agents: Implications of their Availability and Use in Undergraduate Clinical Placements

Summary Aim This study investigated the availability and use of electrophysical agents (EPAs) in the clinical placements used by all four years of undergraduate students from two universities with a combined annual intake of approximately 180 students. Method The 206 facilities surveyed were asked to complete and return a questionnaire asking for details of the EPAs available, their use, and reasons for use. Results Over half the 160 responding facilities (78% return rate) used EPAs in at least 50% of all treatments. Ultrasound, hot packs, TENS and interferential were most commonly available and used. Shortwave was relatively commonly available but few facilities used it daily. Discussion The frequent use of modalities unsubstantiated by independent clinical research raises important questions for the profession. In particular, if the modalities have the effects claimed, why is there so little independent evidence of clinical effectiveness; and should educators continue to allocate time and resources to teaching about EPAs not demonstrated as effective? Two approaches for addressing this dilemma are discussed.

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.

Occupational health and safety in physiotherapy: Guidelines for practice

Most physiotherapists (91%) experience work related musculoskeletal disorders (WMSDs) at some time, and one in six makes a career change as a consequence. Many of these disorders are attributed to manual handling of patients. This paper proposes guidelines to reduce the risk of WMSDs based on Australian legislative requirements, the results of a survey of Australian physiotherapists and the literature surrounding injury prevention. These guidelines address the areas of environmental and job design, and the personal physical capabilities of physiotherapists, within the context of law. The paper concludes by calling for further research to explore and develop this area of injury prevention in the physiotherapy profession.

A Randomised Controlled Study of the Outcome of Hydrotherapy for Subjects with Low Back or Back and Leg Pain

Summary Background and purpose: Exercise is frequently selected by physiotherapists to treat patients with low back pain (LBP) or with back and leg pain. Anecdotally a particular form of exercise, group hydrotherapy, is widely accepted as a beneficial and cost-effective method of management. This study was designed to investigate the claimed benefits of group hydrotherapy for subjects with chronic low back pain (CLBP) and back and leg pain. Subjects: A total of 109 adults with LBP or back and leg pain of more than three months duration were randomly assigned to either a hydrotherapy (experimental) or control (delayed hydrotherapy) group; 95 subjects completed the study. Methods: Before and after the four-week‘intervention period’ the following measures were recorded for all subjects in both groups: the ranges of active lumbar flexion and extension and of passive straight leg raise; the levels of lower limb strength, reflex responses, light touch sensation, functional disability using the Oswestry Low Back Pain Disability Questionnaire, and pain using the McGill Pain Questionnaire. All measurements were made and recorded by an experienced physiotherapist unaware of the group assignment of subjects. Results: Analysis with chi-square showed a statistically significant greater number of subjects in the experimental group improved in their function and fewer deteriorated. Subjects whose condition improved on the other measures were typically in the experimental group, while those whose condition deteriorated were typically in the control group. Conclusion and discussion: The findings offer qualified support to anecdotal evidence that group hydrotherapy can benefit subjects with CLBP or back and leg pain.

Sensory, motor, and pain thresholds for stimulation with medium frequency alternating current.

OBJECTIVES To investigate the effect of frequency of alternating current on the sensory, motor, and pain thresholds in normal subjects, and to establish the optimal frequency for motor stimulation with minimal subject discomfort. DESIGN A repeated measures design using two groups of 11 subjects. SETTING A laboratory setting was used. PARTICIPANTS Participants were volunteers who met the inclusion criteria. INTERVENTIONS Alternating current with 20 different carrier frequencies between 1 and 35 kHz, all modulated at 50 Hz, was applied to each subject on two separate occasions. For half the subjects, the frequency was increased or decreased sequentially (reversed on second occasion), and for the other half, it was applied in a different random order on each occasion. MAIN OUTCOME MEASURES The voltage at the sensory threshold was recorded for each applied frequency. This was subsequently repeated for motor and pain thresholds. RESULTS Sensory, motor, and pain thresholds decreased with increasing frequency between 1 kHz and approximately 10 kHz. Above 10 kHz, the thresholds increased. The ratio pain threshold/sensory threshold increased systematically with increasing frequency over the range examined. By contrast, the ratio pain threshold/motor threshold showed a distinct maximum at a frequency of 10 kHz. Marked accommodation to motor and pain fiber stimulation was observed. CONCLUSIONS For comfortable sensory stimulation, a high frequency of alternating current is preferable. Discrimination between pain and motor stimulation is maximal at a frequency of approximately 10 kHz. This suggests that the optimal frequency for comfortable motor stimulation, one that is least likely to elicit pain fiber stimulation, is close to 10 kHz.

Variation in torque production with frequency using medium frequency alternating current

OBJECTIVES To investigate the effect of frequency of alternating current on electrically induced torque in healthy subjects, and to establish an optimum frequency for motor stimulation. DESIGN A repeated-measures design using 12 subjects (part 1) and 3 subjects (part 2). SETTING A laboratory setting was used. PARTICIPANTS Participants were volunteers who met the inclusion criteria. INTERVENTIONS Alternating current with carrier frequencies between 1 and 15kHz, modulated at 50Hz, was applied to each subject on two separate occasions. The frequencies were applied in a different random order on each occasion and different random orders were used between subjects. For part 1 of this study, six frequencies were used: 1, 2, 4, 7, 10, and 15kHz. For part 2, three frequencies were used: 1, 4, and 10kHz. MAIN OUTCOME MEASURES Part 1: The maximum electrically induced torque, defined as the torque induced at the pain threshold, was recorded for each applied frequency. Part 2: The variation of torque with increasing stimulus intensity was recorded for each applied frequency. RESULTS Highest electrically induced torque was produced at the lowest frequency examined (1kHz). Torque decreased systematically with increasing frequency over the frequency range examined. The rate of increase in torque with applied stimulus intensity was also found to decrease systematically with increasing frequency in a way that depended strongly on the skinfold thickness of the subject. CONCLUSIONS Electrical stimulators using an alternating current waveform typically use a carrier frequency in the range of 2kHz to 4kHz for motor stimulation. This study shows that carrier frequencies in this range, modulated at 50Hz, are a compromise between comfort and maximum torque production. For maximum comfort with a low torque, a frequency close to 10kHz is indicated. For maximum torque, a lower frequency of alternating current (1kHz or less) is preferable.

Epistemology, Private Knowledge, and the Real Problems in Physiotherapy

Summary Physiotherapists have recently been advised to learn more about the nature of knowledge to develop the knowledge base of physiotherapy. This proposition is misleading for a number of reasons, including the obvious one that bodies of scientific knowledge have clearly developed in the absence of most contributors knowing about epistemology or theories of the nature of knowledge. Of more significance to physiotherapy, this proposition offers little guidance for the profession in how to develop a knowledge base. An argument is developed for investigating an alternative approach, that of practitioner-scientist. That approach can offer the profession some guidance and is consistent with the aims of physiotherapy.

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.

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‐μs monophasic negative pulses were compared to those produced by biphasic (negative–positive) symmetrical pulses (100‐μs per phase). In addition, the effects of 200‐μs 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. Muscle Nerve 28: 239–241, 2003