The relationship between specific tissue lesions and pain severity in persons with knee osteoarthritis

INTRODUCTION

Pain is the most common symptom in knee osteoarthritis (OA), a leading cause of chronic disability, and a major source of the disability attributable to OA in general. Pain severity in knee OA is variable, ranging from barely perceptible to immobilizing. The knee lesions that contribute to pain severity have received little attention.

OBJECTIVE

To examine whether worse pathology of specific knee tissues - i.e. cartilage, bone (attrition, cysts, bone marrow lesions, and osteophytes), menisci (tears and subluxation), ligaments, and synovium (synovitis/effusion) - is associated with more severe knee pain.

METHODS

One hundred and forty-three individuals were recruited from the community with primary (idiopathic) knee OA, with definite tibiofemoral osteophytes in at least one knee, and at least some difficulty with knee-requiring activity. Knee magnetic resonance (MR) images were acquired using coronal T1-weighted spin-echo (SE), sagittal fat-suppressed dual-echo turbo SE, and axial and coronal fat-suppressed, T1-weighted 3D-fast low angle shot (FLASH) sequences. The whole-organ magnetic resonance imaging (MRI) scoring (WORMS) method was used to score knee tissue status. Since summing tissue scores across the entire joint, including regions free of disease, may dilute the ability to detect a true relationship between that tissue and pain severity, we used the score from the worst compartment (i.e. with the poorest cartilage morphology) as our primary approach. Knee pain severity was measured using knee-specific, 100 mm visual analogue scales. In analyses to evaluate the relationship between knee pain severity and lesion score, median quantile regression was used, adjusting for age and body mass index (BMI), in which a 95% CI excluding 0 is significant.

RESULTS

The increase in median pain from median quantile regression, adjusting for age and BMI, was significant for bone attrition (1.91, 95% confidence interval (CI) 0.68, 3.13), bone marrow lesions (3.72, 95% CI 1.76, 5.68), meniscal tears (1.99, 95% CI 0.60, 3.38), and grade 2 or 3 synovitis/effusion vs grade 0 (9.82, 95% CI 0.38, 19.27). The relationship with pain severity was of borderline significance for osteophytes and cartilage morphology and was not significant for bone cysts or meniscal subluxation. Ligament tears were too infrequent for meaningful analysis. When compared to the pain severity in knees with high scores for both bone attrition and bone marrow lesions (median pain severity 40 mm), knees with high attrition alone (30 mm) were not significantly different, but knees with high bone marrow lesion without high attrition scores (15 mm) were significantly less painful.

CONCLUSION

In persons with knee OA, knee pain severity was associated with subarticular bone attrition, bone marrow lesions, synovitis/effusion, and meniscal tears. The contribution of bone marrow lesions to pain severity appeared to require the presence of bone attrition.

Reliability of assessing end-feel and pain and resistance sequence in subjects with painful shoulders and knees

STUDY DESIGN

Descriptive.

OBJECTIVES

Examine the intrarater and interrater reliability of end-feel and pain/resistance sequence for patients with painful shoulders and knees.

BACKGROUND

Clinicians make diagnostic and intervention decisions based on end-feel and pain/resistance sequence, but few studies have examined agreement within and between physical therapists when assessing subjects with pathology.

METHODS AND MEASURES

Subjects with unilateral knee pain (18 men and 22 women with a mean age of 31.8 +/- 9.5 years) or shoulder pain (21 men and 25 women with a mean age of 34.3 +/- 12.9 years) were examined twice. Two physical therapists used standardized positions to evaluate 2 knee motions and 5 shoulder motions. Evaluators did not interview subjects and were blinded to previous test results. Evaluators applied overpressure and noted the end-feel while subjects identified the moment their pain was reproduced. Following testing, subjects rated their pain intensity. Analyses included: percentage of agreement; kappa, weighted kappa, and maximum kappa coefficients; and confidence intervals. Analyses were repeated for subjects whose pain intensity during testing did not change between examinations.

RESULTS

Intrarater kappa coefficients varied from 0.65 to 1.00 for end-feel, and intrarater weighted kappa coefficients varied from 0.59 to 0.87 for pain/resistance sequence. Most coefficients remained stable or improved for the unchanged subjects. Interrater kappa coefficients for end-feel and weighted kappa coefficients for pain/resistance sequence varied from -0.01 to 0.70. End-feel kappa coefficients remained low for the unchanged subjects, but pain/resistance sequence weighted kappa coefficients improved. Unbalanced distribution affected many coefficients, producing low coefficients even when the percentage of agreement was high.

CONCLUSIONS

The appropriate use of end-feel and pain/resistance sequence data requires reliable data gathering, especially when patients are managed by more than one physical therapist. Intrarater reliability of end-feel and pain/resistance judgments at the knee and shoulder were generally good, especially after accounting for subject change and unbalanced distributions. Interrater reliability, however, was generally not acceptable, even after accounting for these factors.

Construct validity of Cyriax's selective tension examination: association of end-feels with pain at the knee and shoulder

STUDY DESIGN

Descriptive.

OBJECTIVES

To examine the relationship between pain and normal and abnormal-pathologic end-feels during passive physiologic motion assessment at the knee and shoulder. We theorized that abnormal-pathologic end-feels would be more painful than normal end-feels.

BACKGROUND

End-feel testing and pain intensity information are part of physical therapy musculoskeletal patient examinations. End-feels are categorized as normal or abnormal-pathologic. No previous studies have examined the relationship between pain during end-feel testing and the type of end-feel.

METHODS AND MEASURES

Two physical therapists examined subjects with unilateral knee or shoulder pain. Each subject was examined twice. Passive physiologic motions, 2 at the knee and 5 at the shoulder, were tested by applying an overpressure at the end of range of motion using standardized positions. Subjects reported the amount of pain (0-10) immediately after the evaluator recorded the end-feel. Analyses included one-way ANOVAs and post-hoc Tukey's Honestly Significant Difference tests.

RESULTS

Some abnormal-pathologic end-feels were significantly more painful than the normal end-feels at both the knee and the shoulder for all physiologic motions. Among the abnormal-pathologic end-feel categories there were no statistical differences in pain intensity, although small samples in some categories may be responsible for this finding.

CONCLUSION

Abnormal-pathologic end-feels are associated with more pain than normal end-feels during passive physiologic motion testing at the knee or shoulder. Dysfunction should be suspected when abnormal-pathologic end-feels are present.

Ensuring reliability of clinical assessments for SLE trials

Conducting clinical trials in lupus presents unique challenges for the investigator. Since reliable data are crucial for precisely evaluating results, strategies must be in place to ensure that outcome assessments are accurate and consistent throughout a study. This paper reviews reliability in clinical research and specifically with lupus outcome measures. Suggested recommendations for ensuring reliability in lupus trials are provided.

Behaviors that cause clinical instructors to question the clinical competence of physical therapist students

BACKGROUND AND PURPOSE

Clinical instructors (CIs) observe behavior to determine whether students have the skills assumed necessary for safe and effective delivery of physical therapy services. Studies have examined assumptions about necessary skills, but few studies have identified the types of student behaviors that are "red flags" for CIs. This study examined the student behaviors that negatively affect students' clinical performance, which can alert CIs to inadequate performance.

SUBJECTS

Twenty-eight female and 5 male CIs discussed the performance of 23 female and 17 male students who were anonymous.

METHODS

Using questionnaires and semistructured interviews that were taped and transcribed, CIs described demographics and incidents of unsafe and ineffective physical therapy. After reading the transcripts, investigators identified and classified the behaviors into categories and checked their classification for reliability (kappa=.60-.75).

RESULTS

Behaviors in 3 categories emerged as red flags for CIs: 1 cognitive category--inadequate knowledge and psychomotor skill (43% of 134 behaviors)--and 2 noncognitive categories--unprofessional behavior (29.1%) and poor communication (27.6%). The CIs noticed and valued noncognitive behaviors but addressed cognitive behaviors more often with students. Students who did not receive feedback about their performance were unlikely to change their behavior. The CIs used cognitive behaviors often as reasons to recommend negative outcomes.

CONCLUSION AND DISCUSSION

Clinical instructors need to identify unacceptable cognitive and noncognitive behaviors as early as possible in clinical experiences. Evidence suggests that they should discuss their concerns with students and expect students to change.

Laxity in healthy and osteoarthritic knees

OBJECTIVE

Although it is a cause of osteoarthritis (OA) in animal models, laxity in human knee OA has been minimally evaluated. Ligaments become more compliant with age; whether this results in clinical laxity is not clear. In theory, laxity may predispose to OA and/or result from OA. Our goals were to examine the correlation of age and sex with knee laxity in control subjects without OA, compare laxity in uninvolved knees of OA patients with that in older control knees, and examine the relationship between specific features of OA and knee laxity.

METHODS

We assessed varus-valgus and anteroposterior laxity in 25 young control subjects, 24 older control subjects without clinical OA, radiographic OA, or a history of knee injury, and 164 patients with knee OA as determined by the presence of definite osteophytes. A device was designed to assess varus-valgus laxity under a constant varus or valgus load while maintaining a fixed knee flexion angle and thigh and ankle immobilization. Radiographic evaluations utilized protocols addressing position, beam alignment, magnification, and landmark definition; the semiflexed position was used, with fluoroscopic confirmation.

RESULTS

In the controls, women had greater varus-valgus laxity than did men (3.6 degrees versus 2.7 degrees; 95% confidence interval [95% CI] of difference 0.38, 1.56; P = 0.004), and laxity correlated modestly with age (r = 0.29, P = 0.04). Varus-valgus laxity was greater in the uninvolved knees of OA patients than in older control knees (4.9 degrees versus 3.4 degrees; 95% CI of difference 0.60, 2.24; P = 0.0006). In OA patients, varus-valgus laxity increased as joint space decreased (slope -0.34; 95% CI -0.48, -0.19; P < 0.0001) and was greater in knees with than in knees without bony attrition (5.3 degrees versus 4.5 degrees; 95% CI of difference 0.32, 1.27; P = 0.001).

CONCLUSION

Greater varus-valgus laxity in the uninvolved knees of OA patients versus older control knees and an age-related increase in varus-valgus laxity support the concept that some portion of the increased laxity of OA may predate disease. Loss of cartilage/bone height is associated with greater varus-valgus laxity. These results raise the possibility that varus-valgus laxity may increase the risk of knee OA and cyclically contribute to progression.

Does laxity alter the relationship between strength and physical function in knee osteoarthritis?

OBJECTIVE

Since strengthening interventions have had a lower-than-expected impact on patient function in studies of knee osteoarthritis (OA) and it is known that laxity influences muscle activity, this study examined whether the relationship between strength and function is weaker in the presence of laxity.

METHODS

One hundred sixty-four patients with knee OA were studied. Knee OA was defined by the presence of definite osteophytes, and patients had to have at least a little difficulty with knee-requiring activities. Tests were performed to determine quadriceps and hamstring strength, varus-valgus laxity, functional status (Western Ontario and McMaster Universities Osteoarthritis Index Physical Functioning subscale [WOMAC-PF] and chair-stand performance), body mass index, and pain. High and low laxity groups were defined as above and below the sample median, respectively.

RESULTS

Strength and chair-stand rates correlated (r = 0.44 to 0.52), as did strength and the WOMAC-PF score (r = -0.21 to -0.36). In multivariate analyses, greater laxity was consistently associated with a weaker relationship between strength (quadriceps or hamstring) and physical functioning (chair-stand rate or WOMAC-PF score).

CONCLUSION

Varus-valgus laxity is associated with a decrease in the magnitude of the relationship between strength and physical function in knee OA. In studies examining the functional and structural consequences of resistance exercise in knee OA, stratification of analyses by varus-valgus laxity should be considered. The effect of strengthening interventions in knee OA may be enhanced by consideration of the status of the passive restraint system.

The effect of joint mobilization as a component of comprehensive treatment for primary shoulder impingement syndrome

Primary shoulder impingement syndrome is a common shoulder problem which, if treated ineffectively, can lead to more serious pathology and expensive treatment. This study examined whether subjects receiving joint mobilization and comprehensive treatment (hot packs, active range of motion, physiologic stretching, muscle strengthening, soft tissue mobilization, and patient education) would have improved pain, mobility, and function compared with similar patients receiving comprehensive treatment alone. Subjects were eight men and six women (mean age = 52.9 years) with primary shoulder impingement syndrome (superolateral shoulder pain, decreased active humeral elevation, limited overhead function). Following random assignment to experimental (N = 7) and control groups (N = 7), three blinded evaluators tested 24-hour pain (visual analog scale), pain with subacromial compression test (visual analog scale), active range of motion (goniometry), and function (reaching forward, behind the head, and across the body in an overhead position) before and after nine treatments. One-tailed analyses of covariance (baseline values as covariates) showed that the experimental group had less 24-hour pain and pain with subacromial compression test but no differences in range of motion and function (Mann-Whitney U) compared with controls. The experimental group improved on all variables, while the control group improved only on mobility and function (one-tailed, paired t tests; Wilcoxon matched pairs). Age, side of dominance, duration of symptoms, treatment attendance, exercise quality, and adherence had no effect on the outcomes. Results may be affected by inadequate sample size, minimal capsular tightness, insensitive functional scale, nonspecific motion measurements, position at which mobilization treatment was given, or a strong effect of comprehensive treatment. Mobilization decreased 24-hour pain and pain with subacromial compression test in patients with primary shoulder impingement syndrome, but larger replication studies are needed to assess more clearly mobilization's influence on motion and function.

The effect of a soft collar, used as normally recommended or reversed, on three planes of cervical range of motion

Clinicians recommend soft cervical collars to immobilize the cervical spine following trauma. They apply them either as intended by the manufacturer or reversed (collar rotated 180 degrees), purportedly to achieve limitation in a specific direction. This study investigated the effectiveness of soft cervical collars in limiting cervical range of motion when worn as recommended or reversed. All planes of cervical range of motion of 50 volunteer subjects without current or past cervical dysfunction were measured under three conditions (no collar, recommended use, and reversed) using the Orthopedic Systems Inc. Computerized Anatometry-6000 Spine Motion Analyzer. The instrument has been previously shown to produce measures with high reliability and to correlate strongly with known angular measures. Within subjects analyses of variance indicated significant differences in all six ranges of motions among the three conditions. Post hoc paired t tests showed that wearing a collar either as recommended or reversed decreased motion compared with not wearing a collar, and that the position of the collar affected range of motion in three of the six motions. Differences in range can be attributed to location of the collar closure and initial head posture. Soft cervical collars can physically limit motion when worn either way.

Interrater reliability of craniosacral rate measurements and their relationship with subjects' and examiners' heart and respiratory rate measurements

BACKGROUND AND PURPOSE

The evaluation of craniosacral motion is an approach used by physical therapists and other health professionals to assess the causes of pain and dysfunction, but evidence for the existence of this motion is lacking and the reproducibility of the results of this palpatory technique has not been studied. This study examined the interexaminer reliability of craniosacral rate and the relationships among craniosacral rate and subjects' and examiners' heart and respiratory rates.

SUBJECTS

Participants were 12 children and adults with histories of physical trauma, surgery, or learning disabilities. Three physical therapists with expertise in craniosacral therapy were the examiners.

METHODS

One of three nurses recorded heart and respiratory rates of both subject and examiner. The examiner then palpated the subject to determine craniosacral rate and reported the findings to the nurse. Each subject was examined by each of the three examiners.

RESULTS

Reliability was estimated using a repeated-measures analysis of variance and the intraclass correlation coefficient (2,1). Significant differences among examiners and the scatter plot of rates showed lack of agreement among examiners. The ICC was -.02. The correlations between subject craniosacral rate and subject and examiner heart and respiratory rates were analyzed with Pearson correlation coefficients and were low and not statistically significant.

DISCUSSION AND CONCLUSIONS

Measurements of craniosacral motion did not appear to be related to measurements of heart and respiratory rates, and therapists were not able to measure it reliably. Measurement error may be sufficiently large to render many clinical decisions potentially erroneous. Further studies are needed to verify whether craniosacral motion exists, examine the interpretations of craniosacral assessment, determine the reliability of all aspects of the assessment, and examine whether craniosacral therapy is an effective treatment. [Wirth-Pattullo V. Hayes KW. Interrater reliability of craniosacral rate measurements and their relationship with subjects' and examiners' heart and respiratory rate measurements.

Intraobserver and interobserver reliability of asymptomatic subjects' thoracolumbar range of motion using the OSI CA 6000 Spine Motion Analyzer

Because spinal range of motion (ROM) is assessed routinely in clinical and research settings, a technique is needed that can be performed comfortably, quickly, and reliably. The purpose of this study was to determine if ROM data from asymptomatic subjects measured with the OSI CA 6000 Spine Motion Analyzer (OSI SMA) are reliable within and between observers. Thoracolumbar ROM, from approximately T7 to S2, was measured in all three planes in eight male and 13 female asymptomatic adult subjects (mean age = 29.7 years, SD = 5.6; mean height = 1.7 m, SD = 3.4, mean weight = 78.25 kg, SD = 34.6). A standardized protocol was used to fit each subject with appropriate hardware. Foot placement at a comfortable foot angle was standardized by the use of a template. Subjects performed three practice trials of flexion, extension, right and left sidebending, and right and left rotation. During testing, subjects performed four trials of each maximal pain-free motion. The hardware was completely removed and replaced by the same examiner, and ROM trials in all three planes were repeated. The same procedure was completed by a second examiner. Repeated measures analysis of variance and intraclass correlation coefficients (ICC [2,1] were used to analyze intra- and interobserver data. Intraobserver ICCs were 0.89 or higher for all motions. Interobserver ICCs were 0.85 or higher for all motions. Measurements of thoracolumbar ROM using the OSI SMA are sufficiently reliable within and between observers for clinical assessment and research purposes.

An examination of Cyriax's passive motion tests with patients having osteoarthritis of the knee

BACKGROUND AND PURPOSE

We explored the construct validity and test-retest reliability of the passive motion component of the Cyriax soft tissue diagnosis system. We compared the hypothesized and actual patterns of restriction, end-feel, and pain/resistance sequence (P/RS) of 79 subjects with osteoarthritis (OA) of the knee and examined associations among these indicators of dysfunction and related constructs of joint motion, pain intensity, and chronicity.

SUBJECTS

Subjects had a mean age of 68.5 years (SD = 13.3, range = 28-95), knee stiffness for an average of 83.6 months (SD = 122.4, range = 1-612), knee pain averaging 5.6 cm (SD = 3.1, range = 0-10) on a 10-cm visual analogue scale, and at least a 10-degree limitation in passive range of motion (ROM) of the knee.

METHODS

Passive ROM (goniometry, n = 79), end-feel (n = 79), and P/RS during end-feel testing (n = 62) were assessed for extension and flexion on three occasions by one of four experienced physical therapists. Test-retest reliability was estimated for the 2-month period between the last two occasions.

RESULTS

Consistent with hypotheses based on Cyriax's assertions about patients with OA, most subjects had capsular end-feels for extension; subjects with tissue approximation end-feels for flexion had more flexion ROM than did subjects with capsular end-feels, and the P/RS was significantly correlated with pain intensity (rho = .35, extension; rho = .30, flexion). Contrary to hypotheses based on Cyriax's assertions, most subjects had noncapsular patterns, tissue approximation end-feels for flexion, and what Cyriax called pain synchronous with resistance for both motions. Pain intensity did not differ depending on end-feel. The P/RS was not correlated with chronicity (rho = .03, extension; rho = .01, flexion). Reliability, as analyzed by intraclass correlation coefficients (ICC[3,1]) and Cohen's kappa coefficients, was acceptable (> or = .80) or nearly acceptable for ROM (ICC = .71-.86, extension; ICC = .95-.99, flexion) but not for end-feel (kappa = .17, extension; kappa = .48, flexion) and P/RS (kappa = .36, extension; kappa = .34, flexion).

CONCLUSION AND DISCUSSION

The use of a quantitative definition of the capsular pattern, end-feels, and P/RS as indicators of knee OA should be reexamined. The validity of the P/RS as representing chronicity and the reliability of end-feel and the P/RS are questionable. More study of the soft tissue diagnosis system is indicated.

Differential strength decline in patients with osteoarthritis of the knee: revision of a hypothesis

A quadriceps-to-hamstring isometric peak torque ratio (Q/H ratio) of approximately 2.0 is considered necessary for appropriate knee biomechanics. Lower ratios may affect the function of persons with osteoarthritis (OA) and the progression of the disease. This study examined the isometric Q/H ratio in subjects with and without OA of the knee and explored the effect of age, pain, and joint enlargement on the ratio. Twenty-one pairs of subjects (OA, control) were matched on age (mean = 62.6 years; SD = 13.9), gender (F = 17, M = 4), and leg dominance (Dominant = 10, Nondominant = 11). Isometric quadriceps and hamstring peak torque, knee pain, and joint enlargement were measured. Paired t-tests demonstrated that the OA group had significantly lower quadriceps peak torque than the control group but did not have significantly lower hamstring peak torque or gravity-corrected isometric Q/H ratio. Age correlated with the ratio in subjects without OA (rho = -0.46; P = 0.03) but not in subjects with OA. Pain was not significantly correlated with the ratio in either group. Joint enlargement correlated with the ratio in the OA group (rho = -0.45; P = 0.03). The gravity-corrected isometric Q/H ratio appears to decrease with age in subjects without OA. In subjects with OA, the Q/H ratio appears not to change with disease, pain, or age. Joint enlargement may decrease the ratio and merits further study.

The effect of awareness of measurement error on physical therapists' confidence in their decisions

This study examined whether physical therapists understand the meaning of measurement error and whether information about measurement error affects their decisions. One of four versions of two physical therapy problems was mailed to 500 randomly selected physical therapists. Therapists were asked to define reliability and error of measurement, to estimate the error of measurement of two assessments, and to make decisions about an intervention based on specific measurements. They were also asked to rate their confidence in those decisions. Problems varied on the presence or absence of measurement information and on the difference between an observed measurement and a criterion measurement against which the observed measurement must be compared to make a decision. The response rate was 62%; respondents represented a typical profile of practicing physical therapists. The therapists understood reliability, but they did not correctly describe the relationship between reliability and error of measurement. Their estimates of the error of measurement of the two assessments were reasonable for only one procedure. The presence or absence of measurement information and difference between observed and criterion measurements affected their confidence, albeit inappropriately, in only one problem. Confidence was not affected by the therapists' level of experience, type of reading, formal study, or degree earned. Therapists responded to the two problems differently. The problems involved different measures, roles, utilities, and structures. The process of decision making does not generalize to all decision types. Measurement principles and strategies of use in decision making must be emphasized in physical therapy curricula so that physical therapists can consider the quality of their assessment data in making clinical decisions.

Differential muscle strength decline in osteoarthritis of the knee. A developing hypothesis

The ratio of quadriceps to hamstrings muscle strength (Q/H ratio) is important for the stability of the knee and for protection from excessive stress. The purpose of this study was to explore whether the Q/H ratio is altered in patients with osteoarthritis (OA). Subjects were 43 patients with physician-diagnosed OA of the knee (mean age, 65.61 years; SD, 12.74). Isometric knee flexor and extensor strength was measured with a hand-held dynamometer. Both muscle groups were weak, with relatively greater weakness in the quadriceps muscles. The mean Q/H ratio of 1.43 (SD, 0.39) was below ratios reported for young healthy adults (2.0). The low Q/H ratio might be caused by the inability to correct the measurement for gravity, but a liberal estimate of gravity correction raised the ratio only to 1.71 (SD, 0.47). The low Q/H ratio was probably not caused by physiologic changes due to aging, because the correlation between the ratio and age was low (-0.04). Since the correlation of the Q/H ratio with the usual level of pain (measured by a visual analogue scale) was negative (-0.26), the low ratio might be explained by reflex inhibition due to pain associated with disease.

Effect of ultrasound on mobility in osteoarthritis of the knee. A randomized clinical trial

Ultrasound increases soft tissue extensibility and may be an effective adjunct in the treatment of knee contractures secondary to connective tissue shortening. A randomized clinical trial was conducted to determine the effectiveness of ultrasound in relieving stiffness and pain in patients (age mean = 67.5 years, SD = 13.0) who had osteoarthritis (OA) and a chronic knee contracture. Subjects received 12 treatments of exercise preceded by either ultrasound (n = 34) or sham ultrasound (n = 35) and a blinded evaluation at baseline, after treatment, and 2 months after treatment. MANCOVA controlling for baseline scores showed that there were no significant differences in knee active range of motion (ROM) (goniometry) or pain (visual analogue scale) between experimental and control groups. Possible explanations for the no difference finding involve dosage issues, muscle shortening, transiency of effects, and the effects of exercise. Paired t-tests revealed that both groups significantly improved (p less than 0.05) in active ROM, pain, and gait velocity, and maintained improvement for at least 2 months. Although ultrasound may not contribute to the management of patients with chronic knee stiffness and OA, benefits of the exercise program and increased activity secondary to program participation probably influenced the overall improvement.

A simple method to measure gait for use in arthritis clinical research

This report describes and discusses a simple, inexpensive method to quantify step length, stride width, cadence (steps per minute), and velocity (centimeters per second) for use as outcome measures in arthritis clinical trials. The method involves footprint recordings taken during gait on pressure-sensitive paper. Data from 42 adults with osteoarthritis of the knee and a brief review of the literature suggest that gait measurements using this method are reliable, valid, and practical.

Therapeutic ultrasound in the treatment of musculoskeletal conditions

This paper presents a quantitative synthesis of the literature addressing the effectiveness of ultrasound in selected musculoskeletal conditions. Pain and range of motion appear to improve following ultrasound treatment in acute periarticular inflammatory conditions and osteoarthritis, but not in chronic periarticular inflammatory conditions. Placebo response and experimenter expectancy bias can not be ruled out as explanations for the positive results. The literature concerning the therapeutic efficacy of ultrasound for pain and immobility in musculoskeletal conditions is therefore inconclusive. Well-designed clinical trials are needed to resolve this question.

Reliability of a new device used to measure shoulder subluxation

The purposes of the study were to determine the reliability of a new device used to quantify shoulder subluxation and to estimate its standard error of measurement. The device is an L-shaped thermoplastic jig with a metric tape measure embedded in it. A sliding beak-like marker, which can be anchored with a thumbscrew, is used to identify landmarks and to measure the amount of subluxation. Eight male and two female hemiplegic subjects, 40 to 80 years old, consented to be measured for subluxation. Three standardized subluxation measurements were taken by one investigator to determine the reliability with a single rater. One measurement was taken by a second investigator and compared with the first measurement obtained by the first investigator to determine the reliability using more than one rater. Both investigators were experienced physical therapists. Each measurement was read by the other investigator, who disassembled the jig and cleaned the marks from the patient between measurements. For both analyses, an analysis of variance for repeated measurements reflected no differences between measurements attributable to raters. The unbiased intraclass correlation coefficient for a single measurement by a single rater was .89 (p less than .01) and for more than one rater was .74 (p less than .01). The standard error of measurement was +/- 0.77 mm for a single rater and +/- 1.20 mm for more than one rater. We recommend the jig as a tool to measure shoulder subluxation in patients.

Stability of Compounded Latex

Thickening experiments with compounded latex are described showing the maximum thickening effect of zinc oxide when at a concentration of less than 1 per cent on the dry rubber content of a 60 per cent latex compound. Gelation tests with sodium fluorsilicate indicate that the curve relating the pH of gelation to the zinc oxide concentration is closely related to the curve showing the effect on the viscosity of the zinc oxide concentration. A theory is proposed to account for the maximum thickening effect.