Reliability, reference values and predictor variables of the ulnar sensory nerve in disease free adults.

OBJECTIVE: The purposes of this descriptive and exploratory study were to examine electrophysiological measures of ulnar sensory nerve function in disease free adults to determine reliability, determine reference values computed with appropriate statistical methods, and examine predictive ability of anthropometric variables. METHODS: Antidromic sensory nerve conduction studies of the ulnar nerve using surface electrodes were performed on 100 volunteers. Reference values were computed from optimally transformed data. Reliability was computed from 30 subjects. Multiple linear regression models were constructed from four predictor variables. RESULTS: Reliability was greater than 0.85 for all paired measures. Responses were elicited in all subjects; reference values for sensory nerve action potential (SNAP) amplitude from above elbow stimulation are 3.3 µV and decrement across-elbow less than 46%. No single predictor variable accounted for more than 15% of the variance in the response. CONCLUSION: Electrophysiologic measures of the ulnar sensory nerve are reliable. Absent SNAP responses are inconsistent with disease free individuals. Reference values recommended in this report are based on appropriate transformations of non-normally distributed data. No strong statistical model of prediction could be derived from the limited set of predictor variables. SIGNIFICANCE: Reliability analyses combined with relatively low level of measurement error suggest that ulnar sensory reference values may be used with confidence.

Examining diagnostic tests: an evidence-based perspective.

Diagnosis is an important aspect of physical therapist practice. Selecting tests that will provide the most accurate information and evaluating the results appropriately are important clinical skills. Most of the discussion in physical therapy to date has centered on defining diagnosis, with considerably less attention paid to elucidating the diagnostic process. Determining the best diagnostic tests for use in clinical situations requires an ability to appraise evidence in the literature that describes the accuracy and interpretation of the results of testing. Important issues for judging studies of diagnostic tests are not widely disseminated or adhered to in the literature. Lack of awareness of these issues may lead to misinterpretation of the results. The application of evidence to clinical practice also requires an understanding of evidence and its use in decision making. The purpose of this article is to present an evidence-based perspective on the diagnostic process in physical therapy. Issues relevant to the appraisal of evidence regarding diagnostic tests and integration of the evidence into patient management are presented.

Hop tests as predictors of dynamic knee stability.

Single leg hop tests are commonly used as physical performance measures of function and are also commonly used to evaluate progress in knee rehabilitation programs, particularly for individuals recovering from anterior cruciate ligament injury or reconstructive surgery. While there is some evidence that hop tests may show promise as a predictive measure for identifying individuals who are at risk for recurrent dynamic instability, further work is needed to clearly define the role of hop test measurements for this purpose. The purposes of this clinical commentary are to review the research that has been done to establish hop tests as a physical performance measure of function, to discuss neuromuscular and biomechanical considerations related to hop performance and dynamic knee stability, to discuss existing evidence that supports the potential for hop tests as a predictor of dynamic knee stability, and to discuss considerations for future studies that are designed to more clearly define the role of hop tests in predicting dynamic knee stability.

Durkan gauge and carpal compression test: accuracy and diagnostic test properties.

STUDY DESIGN: A prospective, criterion-based validity study. OBJECTIVES: To assess the diagnostic properties of the carpal compression test (CCT) when performed with the Durkan carpal tunnel syndrome (CTS) gauge, and to determine the measurement validity of the gauge. BACKGROUND: The CCT has been reported to be highly sensitive (.87-.89) and specific (.93-1.0) in the diagnosis of CTS when it is done with thumb pressure. The accuracy of measurements with the Durkan CTS gauge, however, has not been established and the diagnostic sensitivity and specificity of the CCT when the gauge is used has not been independently confirmed. METHODS AND MEASURES: The study sample included 33 women and 19 men, aged 18 to 85 years (45.7 +/- 13.5 years). The accuracy of the gauge was determined with a force dynamometer and holding frame. Standard nerve conduction studies (NCS) and the CCT were performed on the symptomatic extremity of all subjects. A compatible history and the NCS results were used to confirm CTS. RESULTS: The Durkan gauge registered pressures of 11.94 psi and 15.25 psi at the 12 and 15 psi gauge marks, respectively. Test sensitivity and specificity were .36 (95% CI = .17-.54) and .57 (95% CI = .39-.74), respectively. CONCLUSIONS: Pressure measurements obtained with the Durkan CTS gauge were accurate. The CCT when performed with the Durkan gauge, however, was neither sensitive or specific for the diagnosis of CTS.

The use of nonorganic signs and symptoms as a screening tool for return-to-work in patients with acute low back pain.

STUDY DESIGN: A longitudinal cohort study of patients with acute, work-related low back pain undergoing physical therapy treatment. OBJECTIVE: To determine cut-off values maximizing the predictive ability of the nonorganic signs and symptoms in patients with acute, work-related low back pain and to calculate the predictive validity of the signs and symptoms, alone and in combination, using an outcome of return to work within 4 weeks of initiating treatment. SUMMARY OF BACKGROUND DATA: Waddell et al have proposed nonorganic signs and symptoms as screening tools in patients with chronic low back pain for detecting the presence of abnormal illness behavior and identifying patients in need of further evaluation to improve the likelihood of a successful treatment outcome. METHODS: Consecutive patients referred to physical therapy with work-related low back pain of less than 2 weeks' duration were examined for the presence of nonorganic signs and symptoms before initiating physical therapy treatment. The outcome measure used was the ability to return to work without restrictions within 4 weeks of the initial evaluation. RESULTS: Sensitivity, specificity, and likelihood ratios were calculated for all possible cut-off values for the nonorganic signs, symptoms, and the nonorganic index (signs and symptoms). The best cut-off values were two or more signs (negative likelihood ratio = 0.75), three or more symptoms (negative likelihood ratio = 0.62), and an index score of three or more (negative likelihood ratio = 0.59). Area under a receiver operator characteristic curve for the signs, symptoms, and index were 0.60, 0.63, and 0.63, respectively. CONCLUSIONS: Because the nonorganic tests are purported to serve as screening tests, cut-off values were selected that minimized false-negative results. Even with optimal cut-off values, none of the nonorganic tests served as effective screening tools. Other screening tools may prove more effective for the early identification of patients at increased risk for delay in returning to work after an episode of acute low back pain.

Diagnosis and nonoperative management of cervical radiculopathy.

STUDY DESIGN: Qualitative, comprehensive literature review. OBJECTIVE: To discuss and summarize the current peer-reviewed literature related to the management of patients with cervical radiculopathy. BACKGROUND: Cervical radiculopathy is a lesion of the cervical spinal nerve root with a reported prevalence of 3.3 cases per 1000 people; peak annual incidence is 2.1 cases per 1000 and occurs in the fourth and fifth decades of life. Nerve root injury has the potential to produce significant functional limitations and disability. METHODS AND MEASURES: A search of the MEDLINE, CINAHL, and Web of Science databases for the periods 1966, 1982, and 1996, respectively, to December 1999 was conducted using selected keywords and MeSH headings. The bibliography of all retrieved articles were searched and pertinent articles were obtained. The Cochrane Database of Systematic Reviews was also searched. Literature related to the diagnosis, prognosis, and treatment of cervical radiculopathy were thoroughly reviewed and summarized using a critical appraisal approach. RESULTS: Although cervical radiculopathy remains largely a clinical diagnosis, the true diagnostic accuracy of the clinical examination for cervical radiculopathy is unknown. Imaging and electrophysiologic tests are capable of detecting clinically significant problems in many patients and each modality has inherent strengths and weaknesses; technical as well as practical factors affect the choice of procedure. The natural course of cervical radiculopathy appears to be generally favorable but no prognostic or risk factors have been firmly established and the efficacy of various nonoperative treatments for the condition is unknown. CONCLUSION: A clear definition of terms and further research are required to establish definitive diagnostic criteria and effective treatment for the management of patients with cervical radiculopathy.

The effect of stimulatory electrode placement on F-wave latency measurements.

BACKGROUND AND PURPOSE: The purpose of this study was to compare the effects of two commonly used stimulating electrode placements on F-wave latency. SUBJECTS: Fifty healthy subjects aged 20 to 47 years were tested. METHODS: F-waves were obtained from median and ulnar nerves bilaterally. A total of 200 nerves were tested. RESULTS: A paired t-test indicated a statistically significant difference in F-wave latency between the two stimulating electrode placements. Stepwise linear regression equations demonstrated that our results were consistent with previously published studies. CONCLUSION AND DISCUSSION: Although a statistically significant difference exists between the two techniques, the magnitude of the difference is not likely to be clinically important. Therefore, the most important factor may be to use a consistent technique when investigating potential neuropathies.

Development of a patient-reported measure of function of the knee.

The purpose of the present study was to demonstrate the reliability, validity, and responsiveness of the Activities of Daily Living Scale of the Knee Outcome Survey, a patient-reported measure of functional limitations imposed by pathological disorders and impairments of the knee during activities of daily living. The study comprised 397 patients; 213 were male, 156 were female, and the gender was not recorded for the remaining twenty-eight. The mean age of the patients was 33.3 years (range, twelve to seventy-six years). The patients were referred to physical therapy because of a wide variety of disorders of the knee, including ligamentous and meniscal injuries, patellofemoral pain, and osteoarthrosis. The Activities of Daily Living Scale was administered four times during an eight-week period: at the time of the initial evaluation and after one, four, and eight weeks of therapy. Concurrent measures of function included the Lysholm Knee Scale and several global measures of function. The subjects also provided an assessment of the change in function, with responses ranging from greatly worse to greatly better, at one, four, and eight weeks. The Activities of Daily Living Scale was administered to an additional sample of fifty-two patients (thirty-two male and twenty female patients with a mean age of 31.6 years [range, fourteen to sixty-six years]) before and after treatment within a single day to establish test-retest reliability. Factor analysis revealed two dominant factors: one that reflected a combination of symptoms and functional limitations and the other, only symptoms. The internal consistency of the Activities of Daily Living Scale was substantially higher than that of the Lysholm Knee Scale (coefficient alpha, 0.92 to 0.93 compared with 0.60 to 0.73), resulting in a smaller standard error of measurement for the former scale. Validity was demonstrated by moderately strong correlations with concurrent measures of function, including the Lysholm Knee Scale (r = 0.78 to 0.86) and the global assessment of function as measured on a scale ranging from 0 to 100 points (r = 0.66 to 0.75). Analysis of variance with repeated measures revealed significant improvements in the score on the Activities of Daily Living Scale during the eight weeks of physical therapy (F2,236 = 108.13; p < 0.0001); post hoc testing indicated that the change in the score at eight weeks was significantly greater than the change at four weeks and that the change at four weeks was significantly greater than that at one week (p < 0.0001 for both). As had been hypothesized, the patients in whom the knee had somewhat improved had a significantly smaller change in the score, both at four weeks (F1,189 = 33.50; p < 0.001) and at eight weeks (F1,156 = 22.48; p < 0.001), compared with those in whom the knee had greatly improved. The test-retest reliability coefficient (intraclass correlation coefficient[2,1]) was 0.97. These results suggest that the Activities of Daily Living Scale is a reliable, valid, and responsive instrument for the assessment of functional limitations that result from a wide variety of pathological disorders and impairments of the knee.

Management of acute calcific tendinitis of the shoulder.

Calcific deposits located within the tendons of the rotator cuff are frequently seen in patients presenting with shoulder pain. The pathogenesis of calcific tendinitis and the optimum management of patients presenting with acute symptoms are unclear. This paper reviews the incidence, proposed etiologies, and a unique treatment approach of rotator cuff calcific tendinitis. A case report of a patient with acute calcific tendinitis and subsequent shoulder motion and strength deficits is presented. A rational evaluation and treatment plan is outlined, which includes management and posttreatment changes, and radiographic findings are discussed. A team-management approach by physical therapy and orthopaedics services is emphasized.