Study Design: Counterbalanced, within-subjects experimental design. Objective: To determine the effect of continuous 1-MHz ultrasound, given at 1.5 W/cm² and 2.0 W/cm² for 10 minutes, on tissue temperature in the region of the L4-L5 zygapophyseal joint. Background: Ultrasound is a modality commonly used for the treatment of lower back pain syndromes. Randomized controlled trials supporting the clinical effectiveness for ultrasound in the treatment of any type of lower back condition are lacking. While one purported purpose of ultrasound is the deep-heating effect, it has not been demonstrated that ultrasound can heat tissues in the area of the lumbar zygapophyseal joints, and the specific parameters needed for a heating effect have not been investigated. To aid in the design of the ultrasound intervention for future randomized controlled trials, it would be beneficial to have insight into the thermal effects of ultrasound on tissues of the lumbar spine and the parameters needed to produce a thermal effect. The present study examined the heating effect of ultrasound on periarticular tissue in the lumbar spine.
Methods and Measures: Continuous, 1-MHz ultrasound at intensities of 1.5 W/cm² and 2.0 W/cm² was applied for 10 minutes to the lower back of 6 healthy individuals without lower back pain, while temperature measurements were taken with a hypodermic thermocouple implanted next to the L4-L5 zygapophyseal joint. ANOVA models were used for statistical analysis. Results: Statistical analysis confirmed that the 2.0-W/cm² ultrasound application produced (a)a more rapid increase in temperature over time, (b) a greater overall level of heating, and (c) significantly greater heating 6 minutes after the beginning of ultrasound administration. The mean terminal temperatures (at 10 minutes) obtained during the 1.5-W/cm² and 2.0-W/cm² ultrasound applications were 38.1°C and 39.3°C, respectively. Conclusion: Continuous 1-MHz ultrasound given at either 1.5-W/cm² or 2.0-W/cm² intensity has the capability of heating lumbar periarticular tissue. The higher-intensity ultrasound resulted in greater and faster temperature increase.

J Orthop Sports Phys Ther. 2004;34(12):754-760.

Key Words: heat, low back, lumbar spine, physical agents

Study Design: Multicenter prospective design with a cohort of patients with lateral epicondylalgia commencing physical therapy. Objective: To identify key factors associated with long-term prognosis of conservatively managed lateral epicondylalgia. Background: The response to conservative management of lateral epicondylalgia is inconsistent and the rate of recovery varies widely among individuals. The reasons for these discrepancies are not understood. The identification of factors associated with prognosis will aid in the prediction of patient outcomes. Methods and Measures: Sixty patients with lateral epicondylalgia, recruited from 9 sports medicine clinics and 2 hospital outpatient physical therapy departments in Ontario, Canada, were followed for 6 months. A baseline clinical assessment was conducted on each participant using standard physical therapy techniques. The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and a 100-mm pain visual analog scale (VAS) were completed at baseline and 6 months later. Results: The key factor associated with both 6-month DASH and pain VAS scores was repetitive-work tasks (DASH, 9.8 [P<.01]; pain VAS, 13.1 mm [P = .0105]). A subanalysis indicated that women were more likely than men to have cervical joint signs and, among women, positive cervical articular signs were also associated with higher final DASH and pain VAS scores. Conclusions: Although many of the participants identified sports activities as the cause of their injury, these findings emphasize the importance that a patient’s work tasks can have on recovery of lateral epicondylalgia. This would suggest that management should perhaps focus on workstations, postures, and behaviors.

J Orthop Sports Phys Ther. 2004;34(12):770-780.

Key Words: computer keyboard, computer terminals, physical therapy, prognosis, tennis elbow

Increased volume of a body region is often described as swelling, and can be intra- or extra-articular. Swelling in the lower limb can follow immobilization, surgery, or trauma such as an ankle sprain. Assessment and reduction of swelling should be pursued vigorously, especially after trauma, because fibrinous exudation and swelling of capillary endothelial cells can result in scar tissue formation that impedes rehabilitation. Different methods are used to measure volume of the foot and ankle, such as the figure-of-eight method with a tape, and water displacement volumetry. Water displacement provides a direct measure of volume and is the gold standard or criterion reference for other methods. The foot is immersed into a water-filled tank and the volume of displaced water is measured. The advantage over tape methods is that volume can actually be determined, compared with indirect estimates of volume that only correlate with volume change. One significant disadvantage of water displacement volumetry is that measurements take longer than for tape methods, and it has been argued that volumetry is not efficient because of this extra time. One device that is sometimes used during volumetry is an obturator. An obturator is a device that can be placed within a volumeter to prevent water turbulence or waves from reaching the overflow spout and prolonging the time taken for water to drain. It has been proposed that an obturator (a) increases the volume of displaced water and possibly increases the accuracy of the method, (b) reduces water turbulence from leg movements, and (c) decreases surface tension of the water, thereby improving accuracy. None of these hypotheses has been evaluated, however, even in studies where an obturator was used to improve accuracy. In fact, Petersen et al stated that they did not use an obturator because they found it was of minimal importance in a pilot study. If an obturator does reduce water turbulence during volumetry, a reduction in drainage time (defined as time elapsed from when a body segment is immersed into the volumeter to when dripping ceases) might be observed. We could not find any data that quantify time effects attributable to an obturator, but any reduction in time required to complete a measurement (increasing time efficiency) would address a noted disadvantage of volumetry. In addition, an obturator would be a valuable tool if it did not compromise reliability. The aim of this study, therefore, was to evaluate the effects of an obturator on volumetric measurements, and the time efficiency of the water displacement method.

J Orthop Sports Phys Ther. 2004;34(12):800-804.

Key Words: obturator, volumeter, measurement, foot, ankle

Index by subject of all manuscripts published by the Journal during 2004.

J Orthop Sports Phys Ther. 2004;34(12):823-831.