STUDY DESIGN: Controlled laboratory study, repeated-measures design. OBJECTIVES: To compare hip abductor muscle activity during selected exercises using fine-wire electromyography, and to determine which exercises are best for activating the gluteus medius and the superior portion of the gluteus maximus, while minimizing activity of the tensor fascia lata (TFL). BACKGROUND: Abnormal hip kinematics (ie, excessive hip adduction and internal rotation) has been linked to certain musculoskeletal disorders. The TFL is a hip abductor, but it also internally rotates the hip. As such, it may be important to select exercises that activate the gluteal hip abductors while minimizing activation of the TFL. METHODS: Twenty healthy persons participated. Electromyographic signals were obtained from the gluteus medius, superior gluteus maximus, and TFL muscles using fine-wire electrodes as subjects performed 11 different exercises. Normalized electromyographic signal amplitude was compared among muscles for each exercise, using multiple 1-way repeated-measures analyses of variance. A descriptive gluteal-to-TFL muscle activation index was used to identify preferred exercises for recruiting the gluteal muscles while minimizing TFL activity. RESULTS: Both gluteal muscles were significantly (P<.05) more active than the TFL in unilateral and bilateral bridging, quadruped hip extension (knee flexed and extending), the clam, sidestepping, and squatting. The gluteal-to-TFL muscle activation index ranged from 18 to 115 and was highest for the clam (115), sidestep (64), unilateral bridge (59), and both quadruped exercises (50). CONCLUSION: If the goal of rehabilitation is to preferentially activate the gluteal muscles while minimizing TFL activation, then the clam, sidestep, unilateral bridge, and both quadruped hip extension exercises would appear to be the most appropriate.

J Orthop Sports Phys Ther 2013;43(2):54-64. Epub 16 November 2012. doi:10.2519/jospt.2013.4116

KEY WORDS: EMG, gluteus maximus, gluteus medius, hip

STUDY DESIGN: Interrater reliability. OBJECTIVES: (1) To examine the interrater reliability of an existing clinical prediction rule (CPR) to predict the success of lumbar stabilization exercises (LSE), and (2) to examine the interrater reliability of 4 clinical tests that may be useful in determining the need for LSE. BACKGROUND: Physical therapists commonly use LSE to manage patients with low back pain. The clinical efficacy of LSE is unclear. A CPR has been previously suggested to identify patients most likely to benefit from LSE. The passive lumbar extension test, lumbar extension load test, active straight leg raise test, and active hip abduction test are 4 clinical tests that may also suggest the need for LSE. The reliability of these tests has not been established sufficiently. METHODS: Thirty patients with low back pain, who participated in a larger randomized clinical trial, underwent all tests by 2 independent examiners. Kappa coefficients with 95% confidence intervals (CIs) were calculated to establish the interrater reliability of the CPR and individual tests. RESULTS: The interrater reliability of the CPR was excellent (κ = 0.86; 95% CI: 0.65, 1.00). The interrater reliability of the individual items making up the CPR, as well as that of the passive lumbar extension test, was substantial (κ = 0.64-0.73 and κ = 0.76, respectively; 95% CI: 0.46, 1.00). The interrater reliability of the active straight leg raise test (κ = 0.53; 95% CI: 0.20, 0.84) and lumbar extension load test (κ = 0.47; 95% CI: 0.14, 0.78) was moderate. The interrater reliability of the active hip abduction test was poor (κ = –0.09; 95% CI; –0.35, 0.27). CONCLUSION: With the exception of the active hip abduction test, all other clinical tests can be considered sufficiently reliable for clinical use. The relatively small sample size likely contributed to the fairly wide confidence intervals around some of the reliability indices.

J Orthop Sports Phys Ther 2013;43(2):83-90. Epub 14 January 2013. doi:10.2519/jospt.2013.4310

KEY WORDS: clinical prediction rule, low back pain, lumbar segmental instability

STUDY DESIGN: Resident’s case problem. BACKGROUND: Abdominal pain is a common symptom, but not a common diagnosis, of patients referred to physical therapists for examination and intervention. For patients with primary symptoms of abdominal pain, a thorough evaluation must be performed to determine if symptoms are musculoskeletal in nature or of a nonmusculoskeletal origin that would warrant a referral to a different healthcare provider. This report describes the management of 3 adults with primary complaints of abdominal pain who were referred for physical therapy evaluation and treatment. DIAGNOSIS: Two of the patients had secondary symptoms of hip and/or low back pain and had previously undergone extensive medical testing for their chronic abdominal pain, without a definitive diagnosis having been determined. A physical therapy evaluation was conducted, and treatment, including manual physical therapy and exercise, was administered to address all relative impairments, once the physical therapist had determined that the patients’ symptoms were of musculoskeletal origin. The third patient included in this series was referred to a physical therapist with a diagnosis of greater trochanteric versus iliopsoas bursitis. However, the patient had abdominal pain that was more acute in nature and a history and physical examination findings that were concerning for abdominal pain of nonmusculoskeletal origin. Both patients with abdominal pain of musculoskeletal origin showed marked improvement in pain and disability after 7 treatment sessions. The third patient was referred to her primary care physician, and ultrasound examination of the abdomen revealed several intrauterine masses that were consistent with uterine fibroids. Following uterine fibroid embolization, the patient was symptom free. DISCUSSION: Although not routinely managed by physical therapists, abdominal pain is a relatively common patient symptom that can have several causes, both musculoskeletal and nonmusculoskeletal. This paper emphasizes the importance of physical therapists having the necessary differential diagnostic skills to determine if patients with primary symptoms of abdominal pain require physician referral or physical therapist intervention. LEVEL OF EVIDENCE: Differential diagnosis, level 4.

J Orthop Sports Phys Ther 2013;43(2):44-53. Epub 14 January 2013. doi:10.2519/jospt.2013.4408

KEY WORDS: abdominal examination, differential diagnosis, hip, low back pain, manual physical therapy

References in the text and in the reference section were amended in the March 2013 Erratum, and the article PDF with the Erratum page included is provided here. Please see: March 2013 Erratum

STUDY DESIGN: Cross-sectional controlled laboratory study. OBJECTIVES: To investigate the function of discrete regions of psoas major (PM) and quadratus lumborum (QL) with changes in spinal curvature and hip position. BACKGROUND: Anatomically discrete regions of PM and QL may have differential function on the lumbar spine, based on anatomical and biomechanical differences in their moment arms between fascicles within each muscle. METHODS: Fine-wire electrodes were inserted with ultrasound guidance into PM fascicles arising from the transverse process (PM-t) and vertebral body (PM-v) and anterior (QL-a) and posterior (QL-p) layers of QL. Recordings were made on 9 healthy participants, who performed 7 tasks with maximal voluntary efforts and adopted 3 sitting postures that involved different spinal curvatures and hip angles. RESULTS: Activity of PM-t was greater during trunk extension than flexion, whereas activity of PM-v was greater during hip flexion than trunk efforts. Activity of QL-p was greater during trunk extension and lateral flexion, whereas QL-a showed greater activity during lateral flexion. During sitting tasks, PM-t was more active when sitting with a short lordosis than a flat (less extended) lumbar spine posture, whereas PM-v was similarly active in both sitting postures. CONCLUSION: Activity of PM-t was more affected by changes in position of the lumbar spine than the hip, whereas PM-v was more actively involved in the movement of the hip rather than that of the lumbar spine. Moreover, from its anatomy, PM-t has a combined potential to extend/lordose the lumbar spine and flex the hip, at least in a flexed-hip position.

J Orthop Sports Phys Ther 2013;43(2):74-82. Epub 5 September 2012. doi:10.2519/jospt.2013.4292

KEY WORDS: fine-wire electromyography, lumbar spine, postural control, respiration

STUDY DESIGN: Single-site, exploratory, cross-sectional design. OBJECTIVE: To identify variables associated with disability related to low back pain (LBP), as measured by the modified Oswestry Low Back Pain Disability Questionnaire (mOSW), in a sample of working adults with nonacute LBP. BACKGROUND: Compared to acute LBP, there is little information available in the literature to identify variables associated with LBP-related disability in working individuals with stage 2 and stage 3 LBP. METHODS: Data analyzed were from working individuals with nonacute LBP (n = 235). The response variable was dichotomized by mOSW score (less than 20 or 20 or greater), and the regressor variables included 27 self-report, sociodemographic, impairment-based, and kinematic measures used to assess individuals with LBP. Logistic regression was used to identify variables associated with mOSW. RESULTS: One hundred eleven subjects had a mOSW score of 20 or greater, and 124 subjects had a mOSW score of less than 20. Logistic regression analysis identified 4 variables associated with LBP-related disability (mOSW): duration of LBP (P = .006), numeric pain rating (P<.0001), Fear-Avoidance Beliefs Questionnaire physical activity subscale (P = .0007), and limits of stability movement velocity in the forward direction (P = .02). The best model had an R²_(u) of 0.25. CONCLUSION: The odds of LBP-related disability (mOSW) in this sample of nonacute working individuals were found to increase with longer duration of LBP, higher numeric pain rating scores, higher Fear-Avoidance Beliefs Questionnaire physical activity subscale scores, and slower limits of stability movement velocity in the forward direction. The identification of limits of stability movement velocity is a novel finding that may support a link between sensorimotor balance deficits and disability in working individuals with nonacute LBP.

J Orthop Sports Phys Ther 2013;43(2):97-104. Epub 22 October 2012. doi:10.2519/jospt.2013.4382

KEY WORDS: chronic LBP, lumbosacral region, occupational health, subacute LBP

The patient was an 11-year-old boy who was referred to a physical therapist for a chief complaint of left anterior/lateral hip pain. Prior to referral to the physical therapist, radiographs were completed and interpreted as normal. Initially, his hip pain did not limit his participation in athletic activities; however, following a prescription of an exercise program, the patient reported worsening left hip pain that caused an inability to participate in lacrosse, as well as 2 episodes of severe night pain. The patient was immediately referred to his physician, where magnetic resonance imaging revealed signs most concerning for an infectious process/osteomyelitis in the region of the proximal femur and greater trochanter.

J Orthop Sports Phys Ther 2013;43(2):106. doi:10.2519/jospt.2013.0404

KEY WORDS: magnetic resonance imaging, osteomyelitis, radiography