Inter-rater reliability of three standardized functional tests in patients with low back pain

Development and feasibility of a function-based preventive intervention for lifestyle-related disorders

BACKGROUND

The enormous effect of lifestyle-related disorders on health of the global population warrants the development of preventive interventions. Focusing on musculoskeletal health and physical activity may be a way to encourage necessary lifestyle changes by making them more concrete and understandable. The aims of the current study were to develop a function-based preventive intervention aimed at lifestyle-related disorders in physically inactive 40-year-old people and to investigate the feasibility of the intervention. The feasibility study aimed to solve practical and logistical challenges and to develop the intervention based on the experiences of participants and involved clinical personnel according to defined criteria.

METHODS

Development of the standardised functional examination was based on literature-validated tests and clinical reasoning. Development of a risk profile was based on the functional examination and similar profiles which have already proved feasible. The feasibility of the functional examination and risk profile, together with function-based lifestyle counselling was tested on 27 participants in a pilot study with two physiotherapist examinations over a four-month period. Practical results and feedback from participants and collaborating personnel were examined.

RESULTS

The functional examination consists of 20 established tests not requiring specialised equipment or training which were deemed relevant for a middle-aged population and a sub-maximal ergometer test. The risk profile consists of seven functional dimensions: cardiovascular fitness, strength in upper extremity, lower extremity and trunk, mobility, balance and posture, and three non-functional dimensions: weight, self-assessed physical activity and pain. Each dimension contains at least two measures. The participants appreciated the intervention and found it motivating for making lifestyle changes. They found the tests and risk profile understandable and could see them as tools to help achieve concrete goals. The examination required 60-75 min for one physiotherapist. The recruitment rate was low and recruited participants were highly motivated to making lifestyle changes.

CONCLUSION

This project developed a functional test battery and risk profile aimed at inactive 40-year-olds which fulfilled our feasibility criteria. Functional screening and lifestyle counselling were found to be of value to a sub-group of inactive 40-year-olds who were already motivated to improve their health situations.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05535296 first posted on 10/09/2022.

Development of a Functional Bridge Test for Screening Impairments and Disabilities in Hemiplegic Patients with Acute Stroke while on the Bed

OBJECTIVES

To provide a safe and appropriate out-of-bed program for stroke patients, screening for stroke-related functional impairments and disabilities should be performed in advance. However, few tools are available for clinical assessment of out-of-bed mobility while patients are still on bed. We sought to establish the validity and reliability of a newly developed Functional Bridge Test (FBT) for hemiplegic patients with acute stroke.

METHODS

This repeated-measures, observational study was conducted at a stroke care unit at an acute hospital. We assessed the validity of the FBT score, intra-rater and inter-rater reliabilities of the FBT, and concurrent validity of the FBT in stroke patients with hemiplegia. In addition to the original qualitative assessment, the FBT was also assessed quantitatively to evaluate the validity of the FBT score. Outcome measures included stroke severity, lower limb muscle strength, and basic mobility.

RESULTS

We enrolled 32 patients with acute stroke. The newly developed FBT score had high validity. Intra-rater and inter-rater reliabilities (weighted kappa coefficient, 95% confidence interval) showed almost perfect agreement (0.95, 0.88-1.00; 0.98, 0.94-1.00, respectively). The FBT score was significantly associated with stroke severity, physical function, and basic mobility.

CONCLUSIONS

The FBT has sufficient validity and reliability for acute stroke patients with hemiplegia. The advantages of the FBT in a clinical setting are based on its ability to be quickly administered on a bed without the need for specialized equipment. The FBT may help in screening functional impairment and disability in hemiplegic patients with acute stroke before they resume out-of-bed activities.

Intrarater and interrater agreement of a 6-item movement control test battery and the resulting diagnosis in patients with nonspecific chronic low back pain

OBJECTIVE

To investigate the intrarater and interrater agreement of a 6-item test battery in nonspecific chronic low back pain (LBP) and investigate the agreement between raters to assign the resulting movement control (MC) diagnoses.

METHODS

Thirty patients with chronic LBP (18-30 years) were included in this study. Six raters were trained and rated the videos of the patients during the execution of the tests. After one week, the raters re-watched the videos and repeated the examination. A diagnosis of MC was assigned for each patient. Agreement was analyzed using weighted kappa and prevalence-adjusted and bias-adjusted kappa (PABAK) coefficients.

RESULTS

We showed an acceptable intrarater agreement for the 6-item test battery for four out of six raters, except for one test: prone knee flexion. The results of the interrater agreement between the three pairs of raters showed acceptable agreement levels (k > 0.4), except for two tests, "rocking on all four backward" and "prone knee flexion test." For the diagnosis of MC impairment, acceptable agreement levels (k > 0.4) were observed for five out of six raters for intrarater agreement. For interrater assessment, we found an acceptable agreement between pairs of raters.

CONCLUSION

We showed acceptable levels of agreement between the intrarater and interrater for a 6-item test battery to identify MC impairment, except for two tests. Agreement in the MC diagnoses achieved acceptable levels for five of the six raters (intrarater) and all three pairs of raters (interrater). Such results support the use of the 6-item test battery to detect MC impairment.

Health literacy and health outcomes in patients with low back pain: a scoping review

BACKGROUND

Low back pain is a leading cause of disability worldwide. Health literacy has been associated with pain intensity and pain control. However, there is a paucity of evidence regarding this association. In the field of low back pain research, inconsistent reporting of outcomes has been highlighted. To address this issue a Core Outcome Set has been developed.

OBJECTIVES

The objectives of this scoping review were: (1) The health literacy measures currently employed for low back pain and the aspects of health literacy they include. (2) The low back pain health outcomes included in such work. (3) The extent to which these health outcomes reflect the Core Outcome Set for Clinical Trials in Non-Specific Low Back Pain.

METHODS

The search included thirteen bibliographic databases, using medical subject heading terms for low back pain and health literacy, and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. The eligibility criteria were defined by the Joanna Briggs Institute PCC mnemonic. A thematic framework approach was used for analysis.

RESULTS

The search yielded ten relevant studies for inclusion, amongst which a total of nine health literacy measures and 50 health outcome measures were used. Most health literacy measures focused on functional health literacy, with few assessing communicative and critical health literacy. The health outcomes assessed by the included studies could be broadly categorised into: Pain, Disability, Behaviour, Knowledge and Beliefs, and Resource Utilisation. Most of these outcome measures studied (36 out of 50) did not directly reflect the Core Outcome Set for Clinical Trials in Non-Specific Low Back Pain.

CONCLUSIONS

To allow for comparison across findings and the development of a rigorous evidence base, future work should include the Core Outcome Set for Clinical Trials in Non-Specific Low Back Pain. There is an urgent need to broaden the evidence-base to include regions where low back pain morbidity is high, but data is lacking. Such work demands the incorporation of comprehensive measures of health literacy that have both generic and culturally sensitive components.

Movement Control Impairment and Low Back Pain: State of the Art of Diagnostic Framing

Background and objectives: Low back pain is one of the most common health problems. In 85% of cases, it is not possible to identify a specific cause, and it is therefore called Non-Specific Low Back Pain (NSLBP). Among the various attempted classifications, the subgroup of patients with impairment of motor control of the lower back (MCI) is between the most studied. The objective of this systematic review is to summarize the results from trials about validity and reliability of clinical tests aimed to identify MCI in the NSLBP population. Materials and Methods: The MEDLINE, Cochrane Library, and MedNar databases have been searched until May 2018. The criteria for inclusion were clinical trials about evaluation methods that are affordable and applicable in a usual clinical setting and conducted on populations aged > 18 years. A single author summarized data in synoptic tables relating to the clinical property; a second reviewer intervened in case of doubts about the relevance of the studies. Results: 13 primary studies met the inclusion criteria: 10 investigated inter-rater reliability, 4 investigated intra-rater reliability, and 6 investigated validity for a total of 23 tests (including one cluster of tests). Inter-rater reliability is widely studied, and there are tests with good, consistent, and substantial values (waiter's bow, prone hip extension, sitting knee extension, and one leg stance). Intra-rater reliability has been less investigated, and no test have been studied for more than one author. The results of the few studies about validity aim to discriminate only the presence or absence of LBP in the samples. Conclusions: At the state of the art, results related to reliability support the clinical use of the identified tests. No conclusions can be drawn about validity.

Does the Gillet test assess sacroiliac motion or asymmetric one-legged stance strategies?

OBJECTIVE

The purpose of this study was to quantify the extent to which apparent movements of the posterior superior iliac spine and sacral base areas Gillet sacroiliac motion testing were related to (a) degree of hip flexion and (b) the examiner's palpatory pressure.

METHODS

A preliminary exploratory study quantified relative PSIS/S2 displacements in 10 sacroiliac joints among 5 asymptomatic subjects at 10° increments of hip flexion from 0-90°. A comprehensive follow-up asymptomatic study quantified PSIS/S2 displacements at 0° vs. 30° vs. 90° hip flexion, and for light vs. firm pressure at 30° hip flexion. Displacements measured in pixels on digital photographs were transformed to mm. Mean differences for the various test conditions were evaluated for statistical significance using paired t-testing and Wilcoxon signed rank test.

RESULTS

With light pressure, the left PSIS moved caudal for hip flexion ≤30° during right-legged stance, whereas the right PSIS moved cephalad relative to the sacral base. For hip flexion =90°, both PSISs moved cephalad. The use of firm palpatory pressure abolished the initial caudal movement of the left PSIS, as well as differences in the amount of cephalad PSIS movement at 30° vs. 90° hip flexion.

CONCLUSIONS

The results are consistent with there being left-right differences in gluteus medius and biceps femoris activation among asymptomatic individuals that result in different balancing strategies during one-legged stance. This may create the appearance of relative PSIS/SB displacement, even though the results of Gillet testing can be wholly or partially explained by pelvic obliquity owing to muscle function asymmetry. This study questions the validity of the upright Gillet test for sacroiliac motion.

Movement control tests for the lumbopelvic complex. Are these tests reliable and valid?

This study evaluated inter- and intra-observer reliability and discriminative validity of three movement control tests: 1) standing knee-lift test; 2) static lunge test; and 3) dynamic lunge test. Thirty-eight subjects, 21 with low-back pain and 17 healthy, were video-recorded while performing the tests. Four physical therapists scored the tests according to a standardized protocol and calculated a composite score for each test based on the number of incorrect test components. Inter-observer reliability for the composite scores ranged between 0.68 and 0.80 (ICC 2,k) and intra-observer reliability between 0.54 and0.82 (ICC 2,1). The separate test components ranged between 0.32 and 0.91 (κ_free) for inter-observer reliability and 0.42 and1.00 for intra-observer reliability. Test components showing the highest values were: back extension; arm lowering; and shoulders moving backwards. Components hip hitch, trunk lateral flexion, knee not lifted straight up and hips moving backwards did not reach accepted thresholds. Discriminative validity ranged between 0.47 and 0.56 (AUC). As our results showed an overall good agreement for the composite, scores and for the majority of the included test components the tests can be considered reliable enough. As the tests' discriminative ability was close to "none", they should, however, not be used for diagnostic purposes but should be further evaluated toward predicted validity.

Intertester and intratester reliability of movement control tests on the hip for patients with hip osteoarthritis

Background

Hip joint complaints are a problem associated with increasing age and impair the mobility of a large section of the elderly population. Reliable and valid tests are necessary for a thorough investigation of a joint. A fundamental function of the hip joint is movement control and a test of this function forms a part of the standard examination. Until now there have been few scientific studies which specifically investigate the reliability of measurement tests of movement control of the hip joint. The aim of this study was to examine the intratester and intertester reliability of the movement control tests of the hip joint which are in use in current clinical practice.

Methods

Sixteen participants with hip joint complaints and 14 without hip joint impairment were recruited. All participants performed five active movement control tests for the hip joint and were video filmed whilst performing these tests. These films formed the basis for the evaluation and were assessed by two independent physiotherapists. For the intertester and intratester reliability calculations specially set weighted kappa values and the calculated percentages were used.

Results

The intertester reliability of the five examined movement control tests of the hip joint showed good to almost perfect values (weighted kappa (wk) = 0.56–0.87). The intratester reliability of the more experienced evaluator A was better in regards to the less experienced evaluator B (average wk = 0.62 vs 0.38).

Conclusion

The visual evaluation of movement control tests of the hip joint is especially reliable when carried out by an experienced evaluator. 4 out of 5 tests also showed good results for intertester reliability and support their use in clinical practice.

The Influence of Centralization and Directional Preference on Spinal Control in Patients With Nonspecific Low Back Pain

STUDY DESIGN

Prospective cohort, test-retest design.

BACKGROUND

Directional preference (DP) with centralization (CEN) and DP without CEN are common pain-pattern responses assessed by Mechanical Diagnosis and Therapy (MDT). Although there is evidence that MDT can reduce pain and disability in the short term by treating the patient with direction-specific exercises concordant with the patient's DP, the mechanism responsible for this is unclear.

OBJECTIVE

To determine whether clinical signs of impaired spinal control improve immediately after eliciting a DP-with-CEN response or a DP-without-CEN response in patients with nonspecific low back pain.

METHODS

Participants underwent a standardized MDT assessment and were classified into the following pain-pattern subgroups: DP with CEN, DP without CEN, or no DP. Clinical signs of impaired spinal control were assessed pre-MDT assessment and post-MDT assessment by an independent examiner. Four spinal control tests were conducted: aberrant lumbar movements while bending forward, the active straight leg raise (ASLR) test, the Trendelenburg test, and the prone instability test. Differences in spinal control pre-MDT assessment and post-MDT assessment were calculated for the 3 pain-pattern subgroups and compared with chi-square tests. We hypothesized that a larger proportion of patients in the DP-with-CEN subgroup would exhibit improved spinal control than patients categorized as DP without CEN or no DP.

RESULTS

Of 114 patients recruited, 51 patients (44.7%) were categorized as DP with CEN, 23 (20.2%) as DP without CEN, and 40 (35.1%) as no DP. Before MDT assessment, between 28.9% (Trendelenburg test) and 63.7% (ASLR test) of patients showed impaired spinal control. After MDT assessment, a larger proportion of patients in the DP-with-CEN subgroup (43%) showed improvement than those in the no-DP subgroup (7%) on aberrant lumbar movements (P = .02). Likewise, more patients in the DP-with-CEN subgroup (50%) improved on the ASLR test than those in the no-DP subgroup (8%, P<.01) or the DP-without-CEN subgroup (7%, P = .01). Changes in Trendelenburg test and prone instability test outcomes did not reach statistical significance.

CONCLUSION

Immediately following MDT assessment, a larger proportion of patients with a DP-with-CEN pain pattern showed improvement in clinical signs of spinal control compared to patients with a DP-without-CEN or no-DP pain pattern. The current study was registered in the Dutch trial registry at http://www.trialregister.nl/trialreg/index.asp (NTR4246).

LEVEL OF EVIDENCE

Therapy, level 2b.

Reliability and Validity of Standing Back Extension Test for Detecting Motor Control Impairment in Subjects with Low Back Pain

INTRODUCTION

Low back pain is a chronic health problem with high socioeconomic impact. Specific diagnosis or treatment approach has not yet effectively established to treat chronic low back pain. Standing Back Extension Test is one of the clinical measures to detect the passive extension subgroup of Motor Control Impairment (MCI); which could have an impact on spinal stability leading to recurrent chronic low back pain. Reliability and validity of this test is not fully established.

AIM

To determine the intra-rater and inter-rater reliability and concurrent validity of the Standing Back Extension Test for detecting MCI of the lumbar spine.

MATERIALS AND METHODS

A total of 50 subjects were included in the study, 25 patients with Non Specific Low Back Pain (NSLBP) (12 men, 13 women) and 25 healthy controls (12 men, 13 women) were recruited into the study. All subjects performed the test movement. Two raters blinded to the subjects rated the test performance as either 'Positive' or 'Negative' based on the predetermined rating protocol. The thickness of Transverse Abdominis (TrA) muscle was assessed using Rehabilitative Ultrasound Imaging (RUSI).

STATISTICAL TEST USED

For reliability, the kappa coefficient with percent agreement was calculated and for assessing the validity Receiver Operator Characteristic (ROC) curves and Area under the Curve (AUC) were constructed.

RESULTS

The standing back extension test showed very good intra-rater (k=0.87 with an agreement of 96%) and good inter-rater (k=0.78 with an agreement of 94%) reliability and high AUC for TrA muscle.

CONCLUSION

The standing back extension test was found to be a reliable and a valid measure to detect passive extension subgroup for MCI in subjects with low back pain.

Steadiness of Spinal Regions during Single-Leg Standing in Older Adults with and without Chronic Low Back Pain

The aims of this study were to compare the steadiness index of spinal regions during single-leg standing in older adults with and without chronic low back pain (LBP) and to correlate measurements of steadiness index with the performance of clinical balance tests. Thirteen community-dwelling older adults (aged 55 years or above) with chronic LBP and 13 age- and gender-matched asymptomatic volunteers participated in this study. Data collection was conducted in a university research laboratory. Measurements were steadiness index of spinal regions (trunk, thoracic spine, lumbar spine, and pelvis) during single-leg standing including relative holding time (RHT) and relative standstill time (RST), and clinical balance tests (timed up and go test and 5-repetition sit to stand test). The LBP group had a statistically significantly smaller RHT than the control group, regardless of one leg stance on the painful or non-painful sides. The RSTs on the painful side leg in the LBP group were not statistically significantly different from the average RSTs of both legs in the control group; however, the RSTs on the non-painful side leg in the LBP group were statistically significantly smaller than those in the control group for the trunk, thoracic spine, and lumbar spine. No statistically significant intra-group differences were found in the RHTs and RSTs between the painful and non-painful side legs in the LBP group. Measurements of clinical balance tests also showed insignificant weak to moderate correlations with steadiness index. In conclusion, older adults with chronic LBP demonstrated decreased spinal steadiness not only in the symptomatic lumbar spine but also in the other spinal regions within the kinetic chain of the spine. When treating older adults with chronic LBP, clinicians may also need to examine their balance performance and spinal steadiness during balance challenging tests.

Comparison of chronic low-back pain patients hip range of motion with lumbar instability

[Purpose] The purpose of this study was to compare differences in hip range of motion between a lumbar stability group and a lumbar instability group of patients with chronic low-back pain. [Subjects] Sixty-nine patients with chronic low-back pain were divided into two groups: a lumbar stability group (n=39) and a lumbar instability group (n=30). [Methods] The patients were assessed using a goniometer to evaluate the hip range of motion at pre-test. Data were analyzed using SPSS 18.0 software for Windows. The experimental data were analyzed using one-way ANOVA, repeated one-way ANOVA, and the t-test, and a significance level of 0.05. [Results] The limitation of hip range of motion of the lumbar instability group was significantly greater than that of the lumbar stability group. [Conclusion] The chronic low-back pain patients showed greater limitation of hip range of motion than healthy persons, and among them, those who had lumbar instability showed greater limitation than those with lumbar stability.

Neurochemical analysis of primary motor cortex in chronic low back pain

The involvement of the primary motor cortex (M1) in chronic low back pain (LBP) is a relatively new concept. Decreased M1 excitability and an analgesic effect after M1 stimulation have been recently reported. However, the neurochemical changes underlying these functional M1 changes are unknown. The current study investigated whether neurochemicals specific to neurons and glial cells in both right and left M1 are altered. N-Acetylaspartate (NAA) and myo-inositol (mI) were measured with proton magnetic resonance spectroscopy in 19 subjects with chronic LBP and 14 healthy controls. We also examined correlations among neurochemicals within and between M1 and relationships between neurochemical concentrations and clinical features of pain. Right M1 NAA was lower in subjects with LBP compared to controls (p = 0.008). Left M1 NAA and mI were not significantly different between LBP and control groups. Correlations between neurochemical concentrations across M1s were different between groups (p = 0.008). There were no significant correlations between M1 neurochemicals and pain characteristics. These findings provide preliminary evidence of neuronal depression and altered neuronal-glial interactions across M1 in chronic LBP.

A clinical test of lumbopelvic control: development and reliability of a clinical test of dissociation of lumbopelvic and thoracolumbar motion

LBP is often associated with changes in motor control. Some subgroups of LBP have been argued to have a compromised ability to dissociate lumbopelvic movement from that of the thoracolumbar junction. Clinical methods to evaluate this task may aid identification of this LBP subgroup and determine the utility of this information to guide clinical interventions. The study aimed to develop a clinical test to assess the ability to dissociate lumbopelvic movement from that of the thoracolumbar junction, and to evaluate the inter-rater reliability of the test in individuals with and without low back pain (LBP) when performed by experienced and novice therapists. A clinical scale was developed to characterise quality of performance of lumbopelvic motion with limited motion at the thoracolumbar junction. Inter-tester repeatability was measured in three experiments. Test outcomes for pain-free controls were compared between three assessors with different amounts of clinical experience. Test scores for LBP participants were compared between two assessors, and between assessments undertaken from video recordings. Agreement between assessors was tested with weighted Kappa Coefficient. The test had acceptable reliability in pain-free and LBP participants, but was better when undertaken by experienced therapists. Kappa index ranged from 0.81 to 0.66 for live assessments, and 0.62 for video assessments. The results showed that the test is reliable when performed by experienced assessors. The test can assess thoracolumbar movements in different groups of individuals.

Hip abduction weakness in elite junior footballers is common but easy to correct quickly: a prospective sports team cohort based study

BACKGROUND

Hip abduction weakness has never been documented on a population basis as a common finding in a healthy group of athletes and would not normally be found in an elite adolescent athlete. This study aimed to show that hip abduction weakness not only occurs in this group but also is common and easy to correct with an unsupervised home based program.

METHODS

A prospective sports team cohort based study was performed with thirty elite adolescent under-17 Australian Rules Footballers in the Australian Institute of Sport/Australian Football League Under-17 training academy. The players had their hip abduction performance assessed and were then instructed in a hip abduction muscle training exercise. This was performed on a daily basis for two months and then they were reassessed.

RESULTS

The results showed 14 of 28 athletes who completed the protocol had marked weakness or a side-to-side difference of more than 25% at baseline.Two months later ten players recorded an improvement of ≥ 80% in their recorded scores. The mean muscle performance on the right side improved from 151 Newton (N) to 202 N (p<0.001) while on the left, the recorded results improved from 158 N to 223 N (p<0.001).

CONCLUSIONS

The baseline values show widespread profound deficiencies in hip abduction performance not previously reported. Very large performance increases can be achieved, unsupervised, in a short period of time to potentially allow large clinically significant gains. This assessment should be an integral part of preparticipation screening and assessed in those with lower limb injuries. This particular exercise should be used clinically and more research is needed to determine its injury prevention and performance enhancement implications.

Clinical screening tests for assessing movement control in non-specific low-back pain. A systematic review of intra- and inter-observer reliability studies

BACKGROUND

Most people experience back pain at some point during their lives. Reports suggest that core stability interventions in subjects with non-specific low-back pain may increase function, thus decreasing pain. Reliable and validated clinical tests are required for implementing adequate rehabilitation and for evaluating such interventions.

OBJECTIVE

This systematic literature overview seeks to assess the risk of bias and summarise the results of articles assessing the inter-and intra-observer reliability of clinical screening tests for movement control in subjects with non-specific low-back pain.

METHOD

A search was conducted in electronic search engines up until October 2011. The terms 'low-back pain', 'test', 'movement control', 'motor control' and 'physical examination' were defined and used. An appraisal tool (QAREL) was used to assess the risk of bias. Results of the studies were summarised.

RESULTS

Eight studies were included and assessed. All examined inter-observer reliability and three also examined intra-observer reliability. The grading of the studies varied from five to nine positive items out of eleven possible. Inter-observer reliability ranged between poor and very good agreement. Intra-observer reliability ranged between moderate and very good agreement.

CONCLUSION

Most of the tests are presented in studies conducted with a high risk of bias. Their clinical implications can therefore not be suggested. Two tests, prone knee bend and one leg stance are assessed across studies with moderate and good reliability respectively and presented in studies conducted with a lower risk of bias. Their utilisation in clinical work may be recommended.

Does trochanteric transfer eliminate the Trendelenburg sign in adults?

BACKGROUND

Premature closure of the proximal femoral growth plate results in coxa brevis, which usually is associated with insufficiency of the hip abductors. Distal and lateral transfer of the greater trochanter sometimes is recommended to correct this problem. Most of what is known arises from studies of children and adolescents.

QUESTIONS/PURPOSES

We asked whether this procedure in adults with coxa brevis would eliminate hip abductor insufficiency and would improve their hip function based on the Harris hip score (HHS).

PATIENTS AND METHODS

We prospectively followed 11 patients, aged 19 to 55 years (mean, 40 years) who had distal and lateral trochanteric transfer. All patients had pain and a positive Trendelenburg test before surgery. This test was performed at the latest followup by three observers and the interobserver reliability was determined by the kappa coefficient. The HHS was obtained before surgery and at the latest followup. The minimum followup was 25 months (mean, 52 months; range, 25-77 months).

RESULTS

Insufficiency of the hip abductors was eliminated in seven (according to two observers) and eight (according to one observer) of the 11 patients after surgery; the kappa coefficient ranged from 0.79 to 1.0. The mean HHS improved from 64 points preoperatively to 76 points at the final followup. The two patients with preexisting severe osteoarthritis of the hip had the worst final scores and persisted with a positive Trendelenburg test at the final followup.

CONCLUSIONS

Distal and lateral transfer of the greater trochanter can eliminate insufficiency of the hip abductors and improve joint function in adult patients with coxa brevis and we believe should be considered for patients without severe osteoarthritis of the hip.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Postural balance in low back pain patients: Intra-session reliability of center of pressure on a portable force platform and of the one leg stand test

Low back pain (LBP) patients have poorer postural control compared to healthy controls, and the importance of assessing and addressing balance is a matter of debate. In the clinic, balance is often tested by means of the one leg stand test (OLST) while research often employs center of pressure (CoP) on a force platform. Portable force platforms might be of clinical relevance, but their reliability for LBP patients in a clinical setting has not been demonstrated. As LBP patients are more dependent on vision compared to healthy controls, the ratio of tests performed with eyes open and eyes closed (Romberg Ratio) might be of clinical interest. This study aimed to assess postural balance in LBP patients by analyzing intra-session reliability of CoP parameters on a portable force platform, the Romberg Ratio, and the OLST. Furthermore, we aimed to determine whether CoP parameters and OLST measure identical aspects of postural stability. We examined 49 LBP patients and found acceptable reliability of the CoP parameters' trace length and velocity, whereas reliability regarding C90 area, the Romberg Ratio, and the OLST was poor. Correlations between the CoP parameters and OLST were insignificant. Reliability of trace length and velocity is acceptable and can be used as parameters when assessing CoP in LBP patients.