Journal of Orthopaedic & Sports Physical Therapy - Barbara J. Norton, PT, PhD, FAPTA

Diagnosis and Management of a Patient with Knee Pain Using the Movement System Impairment Classification System

Marcie Harris-Hayes, Shirley A. Sahrmann, Barbara J. Norton, Gretchen B. Salsich

STUDY DESIGN: Case report. BACKGROUND: Selecting the most effective conservative treatment for knee pain continues to be a challenge. An understanding of the underlying movement system impairment that is thought to contribute to the knee pain may assist in determining the most effective treatment. Our case report describes the treatment and outcomes of a patient with the proposed movement system impairment (MSI) diagnosis of tibiofemoral rotation. CASE DESCRIPTION: The patient was a 50-year-old female with a 3-month history of left anteromedial knee pain. Her knee pain was aggravated with sitting, standing, and descending stairs. A standardized clinical examination was performed and the MSI diagnosis of tibiofemoral rotation was determined. The patient consistently reported an increase in pain with activities that produced abnormal motions or alignments of the lower extremity in the frontal and transverse planes. The patient was educated to modify symptom-provoking functional activities by restricting the abnormal motions and alignments of the lower extremity. Exercises were prescribed to address impairments of muscle length, muscle strength, and motor control proposed to contribute to the tibiofemoral rotation. Tape also was applied to the knee in an attempt to restrict tibiofemoral rotation. OUTCOMES: The patient reported a cessation of pain and an improvement in her functional activities that occurred with correction of her knee alignment and movement pattern. Pain intensity was 2/10 at 1 week. At 10 weeks, pain intensity was 0/10 and the patient reported no limitations in sitting, standing, or descending stairs. The patient's score on the activities of daily living scale increased from 73% at the initial visit to 86% at 10 weeks and 96% at 1 year after therapy was discontinued. DISCUSSION: This case report presented a patient with knee pain and an MSI diagnosis of tibiofemoral rotation. Diagnosis-specific treatment resulted in a cessation of the patient's pain and an improved ability to perform functional activities. LEVEL OF EVIDENCE: Therapy, level 4.

J Orthop Sports Phys Ther. 2008;38(4):203-213, published online 21 November 2007. doi:10.2519/jospt.2008.2584

KEY WORDS: classification, functional activities, rehabilitation

Focus on Diagnosis

Barbara J. Norton

In this issue of JOSPT, we have included a collection of commentaries that focus on the issue of diagnosis in physical therapy. The idea to create the collection was precipitated by Nancy Zimny's submission of her manuscript entitled ‘‘Diagnostic Classification and Orthopaedic Physical Therapy Practice: What We Can Learn from Medicine.'' Because she makes a number of potentially provocative points, we decided to take advantage of the opportunity to reignite the discussion about diagnosis in physical therapy. We chose to do so by inviting 3 distinguished members of our profession to write commentaries on her article. Dr. Peter O'Sullivan, Dr. Marilyn Moffat, and Dr. Anthony Delitto all graciously accepted our invitation and, as expected, each of them has provided a unique perspective. The author's response to the collection of commentaries provides yet another perspective. Our hope is that each of you will find at least 1 point to discuss further with your colleagues and keep the conversation going.

J Orthop Sports Phys Ther. 2004; 34(3):103-104. doi:10.2519/jospt.2004.0103

Key Words: diagnosis

Differences in Measurements of Lumbar Curvature Related to Gender and Low Back Pain

Barbara J. Norton, Shirley A. Sahrmann, Linda R. Van Dillen

Study Design: Cross-sectional. Objectives: To test the assumption that postural alignment and gender have a bearing on the specific type of low back pain (LBP) a person manifests. Background: Measurements of static sagittal lumbar curvature are used by clinicians in the management of patients with LBP, but no investigator has reported differences in curvature related to specific categories of LBP. Methods and Measures: We used a computer-interfaced, 3-D, electromechanical digitizer to derive curvature angles for the region of the spine between T12-L1 and S2. Trained clinicians examined the subjects and determined their LBP diagnoses. We used t tests to examine differences in curvature between women and men, those with and those without LBP, and those in 4 different categories of LBP. We used x² to examine the relationship between gender and LBP category. Results: Lumbar curvature angle (lordosis) was 13.2° larger for women than for men (t = 6.74; P<.01). There was no difference in lumbar curvature between people with undifferentiated LBP and people without LBP. There were differences in lumbar curvature between people in various categories of LBP, for example, subjects in the lumbar-rotation-with-extension category had 8.4° more lumbar curvature than subjects in the lumbar-rotation-with-flexion category (t = 2.16; P<.05). Based on the frequency distributions, there was a significant relationship between gender and LBP category (x² = 10.19; P<.01). Conclusions: Measurements of lumbar curvature should be expected to differ between men and women and may be related to different types of low back pain.

J Orthop Sports Phys Ther. 2004;34(9):524-534. doi:10.2519/jospt.2004.1570

Key Words: lordosis, lumbar curvature, posture, spine

Understanding Statistical Power

Michael J. Strube, Barbara J. Norton
This article provides an introduction to power analysis so that readers have a basis for understanding the importance of statistical power when planning research and interpreting the results. A simple hypothetical study is used as the context for discussion. The concepts of false findings and missed findings are introduced as a way of thinking about type I and type II errors. The primary factors that affect power are described and examples are provided. Finally, examples are presented to demonstrate 2 uses of power analysis, 1 for prospectively estimating the sample size needed to insure finding effects of a known magnitude in a study and 1 for retrospectively estimating power to gauge the likelihood that an effect was missed. J Orthop Sports Phys Ther. 2OO1;31(6):3O7-315. Key Words: effect size, power analysis

Trunk Rotation-Related Impairments in People With Low Back Pain Who Participated in 2 Different Types of Leisure Activities: A Secondary Analysis

Shirley A. Sahrmann, Cheryl A. Caldwell, Nancy J. Bloom, Barbara J. Norton, Mary Kate McDonnell, Linda R. Van Dillen

Study Design: Cross-sectional, secondary analysis. Objectives: To examine whether there were differences in the numbers and types of impairments on examination between 2 groups of people with low back pain (LBP), those who participated in symmetric leisure activities and those who participated in asymmetric leisure activities. Background: It has been proposed that people who repeatedly perform an activity that involves trunk movements and alignments in the same direction will develop strategies that are generalized to many activities. The repeated use of these strategies is proposed to contribute to impairments identifiable on examination and to LBP. Methods and Measures: Forty males and 40 females (mean ± SD age, 41.4 ± 13.9 years) with LBP who reported participation in either a symmetric or an asymmetric leisure activity participated in a standardized examination. Responses from 10 trunk-rotation-related impairment tests were analyzed using the Mann-Whitney U and chi-square statistics. Results: Thirty people participated in asymmetric leisure activities and 50 people participated in symmetric leisure activities. The total number of rotation-related impairments was different for the 2 groups (U = 1112, P<.01). The asymmetric group displayed more total rotation-related impairments (median, 4.0; range, 7) than the symmetric group (median, 2.0; range, 6). A greater percentage of the asymmetric group displayed more impairments on 5 out of 10 individual tests, as compared to the symmetric group (P≤.05 for all comparisons). Conclusions: Our results provide preliminary data to suggest that trunk-rotation related impairments, identified on examination, may be related to the general type of movements and alignments used repeatedly by patients with LBP.

J Orthop Phys Ther. 2006;36(2):58-71. doi:10.2519/jospt.2006.2161

Key Words: examination, lumbar spine, spinal disorders, sports

Comparisons Among Noninvasive Methods for Measuring Lumbar Curvature in Standing

Kelly Hensler, Barbara J. Norton, Dequan Zou
Physical therapists commonly examine the postural alignment and curvature of the low back region in patients with low back pain, presumably because of an assumed relationship between postural alignment and dysfunction. As an adjunct to visual observation, clinicians may also use a special device to obtain noninvasive measurements of the curvature. Many different devices have been used, but a largely unanswered question is whether the measurements obtained with the various devices can be used interchangeably. Based on the literature, the 2 types of devices that appear to be used most commonly are inclinometers and flexible rulers. This technical note concludes that regardless of the device used � inclinometer or Metrecom, a microcomputer-interfaced, electromechanical, three-dimensional (3D) digitizer, the results for tangent method measurements were similar. Trigonometric method measurements taken with the Metrecom were larger than tangent method measurements obtained with either the inclinometer or Metrecom. The difference between actual and predicted depth of the curve was a large and significant predictor of the difference between tangent and trigonometric measurements. The use of the trigonometric method with a computer-interfaced digitizer, such as the Metrecom, may be preferable compared to the use of an inclinometer if information about the depth of the curve is of particular importance for either research or clinical purposes. Additional testing is required to generate age- and gender-specific referent values, as well as to assess the sensitivity and specificity of the measures for categorization of spinal conditions. J Ortho Sports Phys Ther. 2002; 32(8):405-414.

Movement System Impairment-Based Categories for Low Back Pain: Stage I Validation

Shirley A. Sahrmann, Barbara J. Norton, Cheryl A. Caldwell, Nancy J. Bloom, Mary Kate McDonnell, Linda R. Van Dillen
Study Design: Cross-sectional study of patients with mechanical low back pain (MLBP). Objective: To test the construct validity of 3 categories of a movement system impairment-based classification proposed for use with patients with MLBP. Background: A pathoanatomic basis for directing treatment has not proven useful in a wide variety of patients with MLBP. In addition, there is a paucity of data describing the movement system impairments that characterize many of the pathoanatomically based MLBP diagnoses. Because of the mechanical nature of MLBP, a system based on groups of signs and symptoms relevant to conservative management needs to be developed. Methods and Measures: A movement system impairment-based classification was proposed that defined 5 categories of MLBP based on the findings from a standardized examination. Using the examination, 5 physical therapists examined a total of 188 patients with MLBP. A principal components analysis with an oblique rotation was conducted. Eigenvalues were plotted and a scree test was used to determine the number of factors to retain. A split-sample cross-validation procedure was conducted to verify the factor structure. Results: Three factors were identified in both samples: 2 factors related to symptoms with lumbar rotation and lumbar extension alignments or movements, and 1 factor related to signs of lumbar rotation with different alignments and movements. Conclusion: Our results provide support for 3 factors related to 3 of the 5 proposed categories: lumbar rotation with extension, lumbar rotation, and lumbar extension. The existence of these 3 factors provides preliminary evidence for specific clusters of tests of alignment and movement impairments that could be used in classifying patients with MLBP into movement-system-related categories.

J Ortho Sports Phys Ther. 2003;33:126-142.

Key Words: classification, impairment, low back pain, principal components analysis, validity