Graded Exposure Therapy for Fear Avoidance Behaviour After Concussion (GET FAB): protocol for a multisite Canadian randomised controlled trial.

INTRODUCTION: Persistent symptoms after mild traumatic brain injury (mTBI) negatively affect daily functioning and quality of life. Fear avoidance behaviour, a coping style in which people avoid or escape from activities or situations that they expect will exacerbate their symptoms, maybe a particularly potent and modifiable risk factor for chronic disability after mTBI. This study will evaluate the efficacy of graded exposure therapy (GET) for reducing persistent symptoms following mTBI, with two primary aims: (1) To determine whether GET is more effective than usual care; (2) to identify for whom GET is the most effective treatment option, by evaluating whether baseline fear avoidance moderates differences between GET and an active comparator (prescribed aerobic exercise). Our findings will guide evidence-based care after mTBI and enable better matching of mTBI patients to treatments. METHODS AND ANALYSIS: We will conduct a multisite randomised controlled trial with three arms. Participants (n=220) will be recruited from concussion clinics and emergency departments in three Canadian provinces and randomly assigned (1:2:2 ratio) to receive enhanced usual care, GET or prescribed aerobic exercise. The outcome assessment will occur remotely 14-18 weeks following baseline assessment, after completing the 12-week treatment phase. The primary outcome will be symptom severity (Rivermead Post-concussion Symptoms Questionnaire). ETHICS AND DISSEMINATION: Informed consent will be obtained from all participants. All study procedures were approved by the local research ethics boards (University of British Columbia Clinical Research Ethics Board, University of Calgary Conjoint Health Research Ethics Board, University Health Network Research Ethics Board-Panel D). Operational approvals were obtained for Vancouver Coastal Health Research Institute and Provincial Health Services Authority. If GET proves effective, we will disseminate the GET treatment manual and present instructional workshops for clinicians. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov #NCT05365776.

Steps toward the validation of the Trendelenburg test: the effect of experimentally reduced hip abductor muscle function on frontal plane mechanics.

OBJECTIVE: To investigate the validity of the Trendelenburg test (TT) using an ultrasound-guided nerve block (UNB) of the superior gluteal nerve and determine whether the reduction in hip abductor muscle (HABD) strength would result in the theorized mechanical compensatory strategies measured during the TT. DESIGN: Quasi-experimental. SETTING: Hospital. PARTICIPANTS: Convenience sample of 9 healthy men. Only participants with no current or previous injury to the lumbar spine, pelvis, or lower extremities, and no previous surgeries were included. INTERVENTIONS: Ultrasound-guided nerve block. MAIN OUTCOME MEASURES: Hip abductor muscle strength (percent body weight [%BW]), contralateral pelvic drop (cPD), change in contralateral pelvic drop (ΔcPD), ipsilateral hip adduction, and ipsilateral trunk sway (TRUNK) measured in degrees. RESULTS: The median age and weight of the participants were 31 years (interquartile range [IQR], 22-32 years) and 73 kg (IQR, 67-81 kg), respectively. An average 52% reduction of HABD strength (z = 2.36, P = 0.02) resulted after the UNB. No differences were found in cPD or ΔcPD (z = 0.01, P = 0.99, z = -0.67, P = 0.49, respectively). Individual changes in biomechanics showed no consistency between participants and nonsystematic changes across the group. One participant demonstrated the mechanical compensations described by Trendelenburg. CONCLUSIONS: The TT should not be used as a screening measure for HABD strength in populations demonstrating strength greater than 30%BW but should be reserved for use with populations with marked HABD weakness. CLINICAL RELEVANCE: This study presents data regarding a critical level of HABD strength required to support the pelvis during the TT.

Aerobic exercise training in older men and women-Cerebrovascular responses to submaximal exercise: Results from the Brain in Motion study.

Physical inactivity is a leading modifiable risk factor for cardiovascular and cerebrovascular disease, cognitive dysfunction, and global mortality. Regular exercise might mitigate age-related declines in cardiovascular and cerebrovascular function. In this study, we hypothesize that a 6-month aerobic exercise intervention will lead to a decrease in cerebrovascular resistance index (CVRi) and to an increase in cerebral blood flow (CBF) and cerebrovascular conductance index (CVCi) during two submaximal exercise workloads (40% VO2 max and 65 W), intensities that have been shown to be comparable to activities of daily life. Two hundred three low-active healthy men and women enrolled in the Brain in Motion study, completed a 6-month exercise intervention and underwent submaximal and maximal tests pre-/post-intervention. The intervention improved the gas exchange threshold and maximal oxygen consumption (VO2 max), with no change in heart rate at VO2 max, during the treadmill VO2 max test. Heart rate and CVRi decreased from pre-intervention values during both relative (40% VO2 max) and absolute (65 W) submaximal exercise tests. Blood flow velocity in the middle cerebral artery and CVCi increased post-intervention during 40% VO2 max and 65 W. Changes in mean arterial pressure were found only during the absolute component (65 W). Our study demonstrates that aerobic exercise improves not only cardiorespiratory indices but also cerebrovascular function at submaximal workloads which may help to mitigate age-related declines in everyday life. Investigation of the mechanisms underlying the decline in cardiovascular and cerebrovascular capacity with aging has important implications for the maintenance of health and continued independence of older adults.

The effect of the addition of hip strengthening exercises to a lumbopelvic exercise programme for the treatment of non-specific low back pain: A randomized controlled trial.

OBJECTIVES: To compare the efficacy of two exercise programmes in reducing pain and disability for individuals with non-specific low back pain and to examine the underlying mechanical factors related to pain and disability for individuals with NSLBP. DESIGN: A single-blind, randomized controlled trial. METHODS: Eighty participants were recruited from eleven community-based general medical practices and randomized into two groups completing either a lumbopelvic motor control or a combined lumbopelvic motor control and progressive hip strengthening exercise therapy programme. All participants received an education session, 6 rehabilitation sessions including real time ultrasound training, and a home based exercise programme manual and log book. The primary outcomes were pain (0-100 mm visual analogue scale), and disability (Oswestry Disability Index V2). The secondary outcomes were hip strength (N/kg) and two-dimensional frontal plane biomechanics (°) measure during the static Trendelenburg test and while walking. All outcomes were measured at baseline and at 6-week follow up. RESULTS: There was no statistical difference in the change in pain (x¯ = -4.0 mm, t = -1.07, p = 0.29, 95%CI -11.5, 3.5) or disability (x¯ = -0.3%, t = -0.19, p = 0.85, 95%CI -3.5, 2.8) between groups. Within group comparisons revealed clinically meaningful reductions in pain for both Group One (x¯ = -20.9 mm, 95%CI -25.7, -16.1) and Group Two (x¯ = -24.9, 95%CI -30.8, -19.0). CONCLUSIONS: Both exercise programmes had similar efficacy in reducing pain. The addition of hip strengthening exercises to a motor control exercise programme does not appear to result in improved clinical outcome for pain for individuals with non-specific low back pain.

Experimentally reduced hip-abductor muscle strength and frontal-plane biomechanics during walking.

CONTEXT: Researchers have postulated that reduced hip-abductor muscle strength may have a role in the progression of knee osteoarthritis by increasing the external knee-adduction moment. However, the relationship between hip-abductor strength and frontal-plane biomechanics remains unclear. OBJECTIVE: To experimentally reduce hip-abduction strength and observe the subsequent changes in frontal-plane biomechanics. DESIGN: Descriptive laboratory study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Eight healthy, recreationally active men (age = 27 ± 6 years, height = 1.75 ± 0.11 m, mass = 76.1 ± 10.0 kg). INTERVENTION(S): All participants underwent a superior gluteal nerve block injection to reduce the force output of the hip-abductor muscle group. MAIN OUTCOME MEASURE(S): Maximal isometric hip-abduction strength and gait biomechanical data were collected before and after the injections. Gait biomechanical variables collected during walking consisted of knee- and hip-adduction moments and impulses and the peak angles of contralateral pelvic drop, hip adduction, and ipsilateral trunk lean. RESULTS: Hip-abduction strength was reduced after the injection (P = .001) and remained lower than baseline values at the completion of the postinjection gait data collection (P = .02). No alterations in hip- or knee-adduction moments (hip: P = .11; knee: P = .52) or impulses (hip: P = .16; knee: P = .41) were found after the nerve block. Similarly, no changes in angular kinematics were observed for contralateral pelvic drop (P = .53), ipsilateral trunk lean (P = .78), or hip adduction (P = .48). CONCLUSIONS: A short-term reduction in hip-abductor strength was not associated with alterations in the frontal-plane gait biomechanics of young, healthy men. Further research is needed to determine whether a similar relationship is true in older adults with knee osteoarthritis.

Changes in knee biomechanics after a hip-abductor strengthening protocol for runners with patellofemoral pain syndrome.

CONTEXT: Very few authors have investigated the relationship between hip-abductor muscle strength and frontal-plane knee mechanics during running. OBJECTIVE: To investigate this relationship using a 3-week hip-abductor muscle-strengthening program to identify changes in strength, pain, and biomechanics in runners with patellofemoral pain syndrome (PFPS). DESIGN: Cohort study. SETTING: University-based clinical research laboratory. PATIENTS OR OTHER PARTICIPANTS: Fifteen individuals (5 men, 10 women) with PFPS and 10 individuals without PFPS (4 men, 6 women) participated. INTERVENTION(S): The patients with PFPS completed a 3-week hip-abductor strengthening protocol; control participants did not. MAIN OUTCOME MEASURE(S): The dependent variables of interest were maximal isometric hip-abductor muscle strength, 2-dimensional peak knee genu valgum angle, and stride-to-stride knee-joint variability. All measures were recorded at baseline and 3 weeks later. Between-groups differences were compared using repeated-measures analyses of variance. RESULTS: At baseline, the PFPS group exhibited reduced strength, no difference in peak genu valgum angle, and increased stride-to-stride knee-joint variability compared with the control group. After the 3-week protocol, the PFPS group demonstrated increased strength, less pain, no change in peak genu valgum angle, and reduced stride-to-stride knee-joint variability compared with baseline. CONCLUSIONS: A 3-week hip-abductor muscle-strengthening protocol was effective in increasing muscle strength and decreasing pain and stride-to-stride knee-joint variability in individuals with PFPS. However, concomitant changes in peak knee genu valgum angle were not observed.

The relationship between hip-abductor strength and the magnitude of pelvic drop in patients with low back pain.

CONTEXT: It has been theorized that a positive Trendelenburg test (TT) indicates weakness of the stance hip-abductor (HABD) musculature, results in contralateral pelvic drop, and represents impaired load transfer, which may contribute to low back pain. Few studies have tested whether weakness of the HABDs is directly related to the magnitude of pelvic drop (MPD). OBJECTIVE: To examine the relationship between HABD strength and MPD during the static TT and during walking for patients with nonspecific low back pain (NSLBP) and healthy controls (CON). A secondary purpose was to examine this relationship in NSLBP after a 3-wk HABD-strengthening program. DESIGN: Quasi-experimental. SETTING: Clinical research laboratory. PARTICIPANTS: 20 (10 NSLBP and 10 CON). INTERVENTION: HABD strengthening. MAIN OUTCOME MEASURES: Normalized HABD strength, MPD during TT, and maximal pelvic frontal-plane excursion during walking. RESULTS: At baseline, the NSLBP subjects were significantly weaker (31%; P = .03) than CON. No differences in maximal pelvic frontal-plane excursion (P = .72), right MPD (P = 1.00), or left MPD (P = .40) were measured between groups. During the static TT, nonsignificant correlations were found between left HABD strength and right MPD for NSLBP (r = -.32, P = .36) and CON (r = -.24, P = .48) and between right HABD strength and left MPD for NSLBP (r = -.24, P = .50) and CON (r = -.41, P = .22). Nonsignificant correlations were found between HABD strength and maximal pelvic frontal-plane excursion for NSLBP (r = -.04, P = .90) and CON (r = -.14, P = .68). After strengthening, NSLBP demonstrated significant increases in HABD strength (12%; P = .02), 48% reduction in pain, and no differences in MPD during static TT and maximal pelvic frontal-plane excursion compared with baseline. CONCLUSIONS: HABD strength was poorly correlated to MPD during the static TT and during walking in CON and NSLBP. The results suggest that HABD strength may not be the only contributing factor in controlling pelvic stability, and the static TT has limited use as a measure of HABD function.

Normative and critical criteria for iliotibial band and iliopsoas muscle flexibility.

CONTEXT: The Ober and Thomas tests are subjective and involve a "negative" or "positive" assessment, making them difficult to apply within the paradigm of evidence-based medicine. No authors have combined the subjective clinical assessment with an objective measurement for these special tests. OBJECTIVE: To compare the subjective assessment of iliotibial band and iliopsoas flexibility with the objective measurement of a digital inclinometer, to establish normative values, and to provide an evidence-based critical criterion for determining tissue tightness. DESIGN: Cross-sectional study. SETTING: Clinical research laboratory. PATIENTS OR OTHER PARTICIPANTS: Three hundred recreational athletes (125 men, 175 women; 250 in injured group, 50 in control group). MAIN OUTCOME MEASURE(S): Iliotibial band and iliopsoas muscle flexibility were determined subjectively using the modified Ober and Thomas tests, respectively. Using a digital inclinometer, we objectively measured limb position. Interrater reliability for the subjective assessment was compared between 2 clinicians for a random sample of 100 injured participants, who were classified subjectively as either negative or positive for iliotibial band and iliopsoas tightness. Percentage of agreement indicated interrater reliability for the subjective assessment. RESULTS: For iliotibial band flexibility, the average inclinometer angle was -24.59 degrees +/- 7.27 degrees . A total of 432 limbs were subjectively assessed as negative (-27.13 degrees +/- 5.53 degrees ) and 168 as positive (-16.29 degrees +/- 6.87 degrees ). For iliopsoas flexibility, the average inclinometer angle was -10.60 degrees +/- 9.61 degrees . A total of 392 limbs were subjectively assessed as negative (-15.51 degrees +/- 5.82 degrees ) and 208 as positive (0.34 degrees +/- 7.00 degrees ). The critical criteria for iliotibial band and iliopsoas flexibility were determined to be -23.16 degrees and -9.69 degrees , respectively. Between-clinicians agreement was very good, ranging from 95.0% to 97.6% for the Thomas and Ober tests, respectively. CONCLUSIONS: Subjective assessments and instrumented measurements were combined to establish normative values and critical criterions for tissue flexibility for the modified Ober and Thomas tests.

Suspected mechanisms in the cause of overuse running injuries: a clinical review.

CONTEXT: Various epidemiological studies have estimated that up to 70% of runners sustain an overuse running injury each year. Although few overuse running injuries have an established cause, more than 80% of running-related injuries occur at or below the knee, which suggests that some common mechanisms may be at work. The question then becomes, are there common mechanisms related to overuse running injuries? EVIDENCE ACQUISITION: RESEARCH STUDIES WERE IDENTIFIED VIA THE FOLLOWING ELECTRONIC DATABASES: MEDLINE, EMBASE PsycInfo, and CINAHL (1980-July 2008). Inclusion was based on evaluation of risk factors for overuse running injuries. RESULTS: A majority of the risk factors that have been researched over the past few years can be generally categorized into 2 groups: atypical foot pronation mechanics and inadequate hip muscle stabilization. CONCLUSION: Based on the review of literature, there is no definitive link between atypical foot mechanics and running injury mechanisms. The lack of normative data and a definition of typical foot structure has hampered progress. In contrast, a large and growing body of literature suggests that weakness of hip-stabilizing muscles leads to atypical lower extremity mechanics and increased forces within the lower extremity while running.