JMPT Abstracts for June 2006 · Volume 29, Number 5

A profile of middle-aged women who consult a chiropractor or osteopath: findings from a survey of 11,143 Australian women.
David Sibbritt, PhD, Jon Adams, PhD, Anne F. Young, PhD

Purpose: The aim of this study is to examine the prevalence of chiropractic and osteopathy use and the profile of chiropractor/osteopath users among middle-aged Australian women.

Methods: This article reports on research conducted as part of the Australian Longitudinal Study on Women's Health. The focus of this article is the middle-aged women who responded to Survey 3 in 2001 when they were between the ages of 50 and 55 years. The demographic characteristics, health status, and health service use of chiropractic/osteopathy users and nonusers were compared using c2 tests for categorical variables and t tests for continuous variables.

Results: We estimate that 16% of middle-aged women consult with a chiropractor or osteopath (after adjustment for the over-sampling of rural women). Area of residence, education, and employment status were all statistically significantly associated with chiropractic and osteopath use. Specifically, women who live in non-urban areas were more likely to consult a chiropractor or osteopath, compared with women who live in urban areas. Women are significantly more likely to consult with a chiropractor/osteopath if they have had a major personal injury in the previous year, and women who use chiropractic/osteopathy are also high users of "conventional" health services.

Conclusions: Chiropractic/osteopathy use among women in Australia is substantial and cannot be ignored by those providing or managing primary health care services for women. It is essential that the interface and communication between chiropractors/osteopaths and other health care providers be highlighted and maximized to establish and maintain effective overall patient coordination and management.

Do exercise balls provide a training advantage for trunk extensor exercises? A biomechanical evaluation.
Janessa D.M. Drake, MSca, Steve L. Fischer, BSc, Stephen H.M. Brown, MHK, Jack P. Callaghan, PhD

Objective: Only a few abdominal muscle exercises have been quantitatively evaluated on both a mat and exercise ball, but the benefits reported for the ball have been equivocally applied to all exercises. The purpose of this study is to evaluate differences in the biological response of muscle activation, lumbar spine posture, and loading variables for extensor exercises performed on two surfaces.

Methods: Bilateral muscle activation was recorded from seven sites (rectus abdominis, external/internal obliques, latissimus dorsi, thoracic/lumbar erector spinae, and multifidus) on eight subjects. Three-dimensional lumbar spine postures and upper body kinematics were recorded while the participants performed the exercises. An electromyography-driven model was used to calculate spinal loading.

Results: Co-contraction of trunk flexor and extensor muscles was reduced by up to 30% for the extension exercises when performed on the ball. Peak muscle activation remained unchanged or decreased, and spinal loading (compression and anterior-posterior shear) decreased when the extension exercises were performed on the ball. The lumbar spine postures attained during the exercises did not differ between surfaces.

Conclusions: The assumption that the use of an exercise ball will always create a greater challenge for the musculoskeletal system was not supported by the findings of this study. Likewise, in a healthy, young population, there does not appear to be any training advantage to performing extensor exercises on a ball versus a mat. However, in a rehabilitation scenario, these exercises performed on a ball could reduce low back loading and hence reduce the potential for reinjury.

Reproducibility of the measurement of active and passive cervical range of motion.
Mirrin Hoppenbrouwers, PT, Martine M.E.M. Eckardt, Karin Verkerk, MSc, Arianne Verhagen, PhD

Objective: The primary aim of this study was to assess the reproducibility of tests for the active and passive range of motion used in the physical examination for patients with neck pain. The secondary aim was to determine whether the history of the patients influences the reproducibility and the prevalence of positive findings.

Methods: Sixty-nine partici-pants were recruited in three physical therapy practices. Two examiners independently performed a physical examination on all participants. The examiners were blinded for patient characteristics (neck pain/no neck pain) and each other's findings. History findings were available for only half the patients with neck pain. Cohen's k was used to express reproducibility.

Results: The reproducibility for active and passive range of motion was moderate (k = 0.52 and 0.54, respectively), but a wide range in k scores was found. Extension of the neck showed good reproducibility for both active and passive movements (k = 0.88 and 0.85), whereas lateral flexion showed poor reproducibility (k = 0.35 and 0.33). Knowledge of history had no influence on the reproducibility and prevalence of positive findings.

Conclusion: The reproducibility for active and passive range of motion is moderate. Knowledge of the patient's history did not influence the reproducibility and prevalence of positive findings.

Interrater reliability of a passive physiological intervertebral motion test in the mid-thoracic spine.
Jean-Michel Brismee, ScD, PT, Dickie Gipson, MPT, Dan Ivie, MPT, Angel Lopez, MPT, Mandy Moore, MPT, Omer Matthijs, PT, Valerie Phelps, PT, Steven Sawyer, PhD, PT, Phillip Sizer, PhD, PT

Objective: To examine the interrater reliability of a passive physiological intervertebral motion (PPIM) test of a mid-thoracic spine motion segment.

Methods: Nineteen males and 22 females with a mean age of 22.7 years (range, 19-40 years) and no known spinal pathologies were tested independently by three certified manual therapy instructors. Investigators performed 3-dimensional segmental mobility testing at a preselected thoracic motion segment. Interrater reliability was assessed with Cohen's k statistics, using three pairwise comparisons for determination of the direction of lateral flexion leading to the greatest amount of segmental rotation.

Results: Percent agreement ranges were 63.4% to 82.5%, with k scores ranging from 0.27 to 0.65.

Conclusion: The PPIM testing demonstrated fair to substantial interrater reliability. A majority of females (91%) demonstrated greatest segmental PPIM motion in contralateral rotation with lateral flexion, whereas a majority of males (90%) demonstrated greatest segmental PPIM motion in ipsilateral rotation with lateral flexion. These findings are applicable to asymptomatic subjects of the same age category. Interrater reliability of three-dimensional PPIM testing is fair to substantial for assessing passive segmental mobility of the mid-thoracic spine.

Interexaminer reliability of the hip extension test for suspected impaired motor control of the lumbar spine.
Donald R. Murphy, DC, David Byfield, DC, Peter McCarthy, PhD, Kim Humphreys, DC, PhD, Amy A. Gregory, DC, Ryan Rochon, DC

Objective: The hip extension test may be a clinical sign of impaired motor control in the lumbar spine, which may have a negative impact on spine stability. The purpose of this study is to evaluate the interexaminer reliability of the hip extension test for suspected dynamic instability of the lumbar spine in patients with chronic low back pain.

Methods: Forty-two patients with chronic low back pain participated in this interexaminer reliability study. Chronic low back pain was defined as pain of greater than seven weeks duration in the area between T12 and the buttocks, with or without leg pain. Two doctors of chiropractic simultaneously observed and independently assessed the left and right prone hip extension test on all 42 patients. Results for both examiners were given to an independent recorder. Each examiner was blinded to the results of the other examiner.

Results: The mean age of subjects was 38 years (SD 12.35); 73.8% were female. Sixty-eight percent (SD 1.72) reported current back pain intensity greater than 5 on an 11-point numerical rating scale. The mean score for the Roland-Morris Low Back Pain and Disability questionnaire was 5.8 (SD 4.34). The k measure of agreement was 0.72 for the left leg and 0.76 for the right leg. This indicated a substantial strength of agreement between examiners for both left and right hip extension tests. For the eight cases of disagreement, rater 1 generally rated the tests as positive, whereas rater 2 consistently rated the tests as negative.

Conclusions: The hip extension test appears to have good reliability in detecting deviation of the lumbar spine from the midline. Validity with regard to the test's ability to distinguish patients with chronic low back pain from normal individuals and its relation to lumbar spine stability remains to be determined.

Effects of visual feedback on manipulation performance and patient ratings.
John J. Triano, DC, PhD, John Scaringe, DC, MS, Jacqueline Bougie, DC, MS, Carolyn Rogers, MS

Objective: This study examined the explicit targeted outcome (a criterion standard) and visual feedback on the immediate change in and the short-term retention of performance by novice operators for a high-velocity, low-amplitude procedure under realistic conditions.

Methods: This study used a single-blind randomized experimental design. Forty healthy male (n = 26) and female (n = 14) chiropractic student volunteers with no formal training in spinal manipulative therapy participated. Biomechanical parameters of an L4 mammillary push spinal manipulation procedure performed by novice operators were quantified. Participants were randomly assigned to two groups and paired. One group received visual feedback from load-time histories of their performance compared with a criterion standard before a repeat performance. Participants then performed a 10-minute distractive exercise consisting of National Board of Chiropractic Examiners review questions. The second group received no feedback. An independent rating of performance was conducted for each participant by his/her partner. Results were analyzed separately for biomechanical parameters for partner ratings using the Student t test with levels of significance (P < 0.01) adjusted for repeated testing.

Results: Expressed in percent change for each individual, visual feedback was associated with change in the biomechanical performance of group 2, a minimum of 14% and a maximum of 32%. Statistical analysis rating of the performance favored the feedback group on four of the parameters (fast, P < 0.0008; force, P < 0.0056; precision, P < 0.0034; and composite, P < 0.0016).

Conclusion: Quantitative feedback, based on a tangible conceptualization of the target performance, resulted in immediate and significant improvement in all measured parameters. Newly developed skills were retained at least over short intervals even after distractive tasks. Learning what to do with feedback on one's own performance may be more important than the classic teaching of'how to do it.

Chiropractors' perceptions about intimate partner violence: a cross-sectional survey.
Heather M. Shearer, DC, Mary L. Forte, DC, Sonia Dosanih, MSW, David J. Mathews, PsyD, Mohit Bhandari, MD

Objective: The aim of this study is to assess chiropractors' attitudes, beliefs, knowledge, and experience about intimate partner violence (IPV).

Methods: This cross-sectional survey was developed by members of the Violence Against Women Health Research Collaborative. The survey was disseminated to a voluntary, nonrandom convenience sample of chiropractors attending a three-day continuing education seminar. Surveys were distributed at the entrances of the seminar session rooms and placed on luncheon tables. Respondents returned surveys to collection boxes.

Results: Ninety-three doctors of chiropractic completed the survey. Respondents estimated that only 5.2% (95% confidence interval, 3.3%-7.0%) of their female patients were victims of IPV. General knowledge of IPV was good among respondents. Knowledge of clinical indicators and victim's management was fair to poor. Only 22% of respondents identified the most commonly injured body regions among battered women. Lack of knowledge, personal discomfort, and time constraints were all cited as barriers to IPV screening.

Conclusions: Our survey indicates that doctors of chiropractic underestimate the prevalence of IPV among their female patients. Like other health care specialists, chiropractors cite multiple IPV screening barriers, especially lack of knowledge. Doctors of chiropractic would benefit from education and training in IPV to enable them to better identify and assist patients who are victims of IPV.

Applying the item response theory to classroom examinations.
Douglas M. Lawson, DC, MSc, PhD

Objective: The purpose of this research project was to determine if the item response theory (IRT) can successfully be applied to smaller-sized class examinations.

Methods: The Rasch mathematical model (RMM) was selected from the family of IRT models because of its ability to work with smaller sample sizes. Two simulated examinations were created for 100 students by 100-item dichotomous examinations. Examination 2 contained 20 items common with those in examination 1. Examination 1 was systematically exposed to randomly missing student responses and to entire items being removed to determine the robustness of the RMM to missing data. The two examinations were then analyzed with the RMM individually and then in combination. Student scores and IRT measures were compared to determine if the IRT could successfully place the students from the two examinations on the same metric of measure.

Results: The student measures were not affected when up to 20% of the student responses were randomly missing. Student measures continued to have high reliability and correlated with full matrix measures for up to 40% of items being dropped from the examination. Student scores and IRT measures correlated highly when the two examinations were combined.

Conclusions: The RMM can be successfully applied to small-sized class examinations, such as those at chiropractic, medical, and other health profession institutions. It is possible to place candidates from different administrations on the same metric of measure if there is as little as a 20% overlap of items between examinations. The RMM could assist faculty in determining if differences in candidate scores are caused by ability or item difficulty.