Spinal muscle evaluation using the Sorensen test: a critical appraisal of the literature

The effect of an 8-week fitness regime on low back pain and core strength in high-risk professionals

BACKGROUND

Low back pain is prevalent among various populations and greatly impacts their quality of life. Professions that incorporate several working hours combined with heavy labor are the most affected. The aim of this study was to examine the effects of an 8-week core training intervention in emergency personnel.

METHODS

Sixteen randomly selected male participants; police officers (N.=8) and firefighters (N.=8) (mean age: 40.75 years; mean height: 177.69 cm; mean body mass: 85.50 kg) performed various testing procedures that assessed core muscle strength and endurance and filled the Oswestry Disability Index Questionnaire regarding the level of low back pain before and after the intervention. The 8-week intervention consisted of two 45-60-minute sessions per week that included ten core-related exercises.

RESULTS

Statistical analysis; paired samples t-test and Wilcoxon Signed-Rank Test, demonstrated significant effects in the 30-sec sit-up test, the Double Leg Lowering Test and the isometric abdominal strength measurements; P value level of significance was set at P≤0.05. All participants had minimal lower back disability before and after the intervention.

CONCLUSIONS

The results demonstrated that the prescribed regime could improve core strength and endurance in high-risk professionals. The most important finding is that training interventions for emergency personnel are most effective when they incorporate a variety of exercises that target the core musculature in all planes of movement and engage the whole range of motion.

Paraspinal muscle endurance and morphology (PMEM) score: a new method for prediction of postoperative mechanical complications after lumbar fusion

BACKGROUND CONTEXT

Although the relationships between paraspinal muscles and lumbar degenerative disorders have been acknowledged, paraspinal muscle evaluation has not been incorporated into clinical therapies.

PURPOSE

We aimed to establish a novel paraspinal muscle endurance and morphology (PMEM) score to better predict mechanical complications after lumbar fusion.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

A total of 212 patients undergoing posterior lumbar interbody fusion with at least 1 year of follow-up were finally included.

OUTCOME MEASURES

Mechanical complications including screw loosening, pseudarthrosis and other complications like cage subsidence, and patient-reported outcomes were evaluated at last follow-up.

METHODS

The PMEM score comprised 1 functional muscular parameter (the performance time of the endurance test) and 2 imaging muscular parameters (relative functional cross-sectional area [rFCSA] of paraspinal extensor muscles [PEM] and psoas major [PS] on magnetic resonance imaging). The score was established based on a weighted scoring system created by rounding β regression coefficients to the nearest integer in univariate logistic regression. The diagnostic performance of the PMEM score was determined by binary logistic regression model and receiver operating characteristic (ROC) curve with the area under the curve (AUC). Additionally, pairwise comparisons of ROC curves were conducted to compare the diagnostic performance of the PMEM score with conventional methods based on a single muscular parameter. Moreover, differences of mechanical complications and patient-reported outcomes among the PMEM categories were analyzed using Chi-square test with Bonferroni correction.

RESULTS

The PMEM score, calculated by adding the scores for each parameter, ranges from 0 to 5 points. Patients with higher PMEM scores exhibited higher rates of mechanical complications (p<.001). Binary logistic regression revealed that the PMEM score was an independent factor of mechanical complications (p<.001, OR=2.002). Moreover, the AUC of the PMEM score (AUC=0.756) was significantly greater than those of the conventional methods including the endurance test (AUC=0.691, Z=2.036, p<.05), PEM rFCSA (AUC=.690, Z=2.016, p<.05) and PS rFCSA (AUC=0.640, Z=2.771, p<.01). In terms of the PMEM categories, a score of 0-1 was categorized as low-risk muscular state of mechanical complications; 2-3, as moderate; and 4-5, as high-risk state. Moving from the low-risk state to the high-risk state, there was a progressive increase in the rates of mechanical complications (13.8% vs 32.1% vs 72.7%; p<.001), and a decrease in the rates of clinically significant improvement of patient-reported outcomes (all p<.05).

CONCLUSIONS

The PMEM score might comprehensively evaluate paraspinal muscle degeneration and exhibit greater ability in predicting mechanical complications than the conventional evaluations after lumbar fusion. Surgeons might develop individualized treatment strategy tailored to different muscle degeneration statuses reflected by the PMEM score for decreasing the risk of mechanical complications.

Potential of a New, Flexible Electrode sEMG System in Detecting Electromyographic Activation in Low Back Muscles during Clinical Tests: A Pilot Study on Wearables for Pain Management

BACKGROUND

While low back pain (LBP) is the leading cause of disability worldwide, its clinical objective assessment is currently limited. Part of this syndrome arises from the abnormal sensorimotor control of back muscles, involving increased muscle fatigability (i.e., assessed with the Biering-Sorensen test) and abnormal muscle activation patterns (i.e., the flexion-extension test). Surface electromyography (sEMG) provides objective measures of muscle fatigue development (median frequency drop, MDF) and activation patterns (RMS amplitude change). This study therefore assessed the sensitivity and validity of a novel and flexible sEMG system (NSS) based on PEVA electrodes and potentially embeddable in textiles, as a tool for objective clinical LBP assessment.

METHODS

Twelve participants wearing NSS and a commercial laboratory sEMG system (CSS) performed two clinical tests used in LBP assessment (Biering-Sorensen and flexion-extension). Erector spinae muscle activity was recorded at T12-L1 and L4-L5.

RESULTS

NSS showed sensitivity to sEMG changes associated with fatigue development and muscle activations during flexion-extension movements (p < 0.05) that were similar to CSS (p > 0.05). Raw signals showed moderate cross-correlations (MDF: 0.60-0.68; RMS: 0.53-0.62). Adding conductive gel to the PEVA electrodes did not influence sEMG signal interpretation (p > 0.05).

CONCLUSIONS

This novel sEMG system is promising for assessing electrophysiological indicators of LBP during clinical tests.

Prediction of Back Disability Using Clinical, Functional, and Biomechanical Variables in Adults with Chronic Nonspecific Low Back Pain

Background: Researchers are focusing on understanding the etiology and predisposing factors of chronic nonspecific low back pain (CNSLBP), a costly prevalent and disabling disorder. Related clinical, functional, and biomechanical variables are often studied, but in isolation. We aimed to identify key factors for managing CNSLBP by examining the relationship between back disability and related clinical, functional, and biomechanical variables and developed prediction models to estimate disability using various variables. Methods: We performed a cross-sectional correlational study on 100 recruited patients with CNSLBP. Clinical variables of pain intensity (visual analog score), back extensor endurance (Sorenson test), functional variables of the back performance scale, 6 min walk test, and the biomechanical variable C7-S1 sagittal vertical axis were analyzed to predict disability (Oswestry disability index). Results: All variables independently, as well as in multi-correlation, were significantly correlated to disability (p < 0.05). The bivariate regression models were significant between back disability and pain intensity (Y = 11.24 + 2.189x), Sorensen results (Y = 105.48 - 0.911x), the back performance scale (Y = 6.65 + 2.486x), 6 min walk test (Y = 49.20 - 0.060x), and sagittal vertical axis (Y = 0.72 + 4.23x). The multi-regression model showed significant contributions from pain (p = 0.001) and Sorensen results (p = 0.028) in predicting back disability, whereas no significant effect was found for other variables. Conclusions: A multidisciplinary approach is essential not only for the management of but also for the assessment of chronic nonspecific low back pain, including its clinical, functional, and biomechanical characteristics. However, special emphasis should be placed on clinical characteristics, including the intensity of pain and back extensor endurance.

Spine-specific sarcopenia: distinguishing paraspinal muscle atrophy from generalized sarcopenia

BACKGROUND CONTEXT

Atrophy of the paraspinal musculature (PM) as well as generalized sarcopenia are increasingly reported as important parameters for clinical outcomes in the field of spine surgery. Despite growing awareness and potential similarities between both conditions, the relationship between "generalized" and "spine-specific" sarcopenia is unclear.

PURPOSE

To investigate the association between generalized and spine-specific sarcopenia.

STUDY DESIGN

Retrospective cross-sectional study.

PATIENT SAMPLE

Patients undergoing lumbar spinal fusion surgery for degenerative spinal pathologies.

OUTCOME MEASURES

Generalized sarcopenia was evaluated with the short physical performance battery (SPPB), grip strength, and the psoas index, while spine-specific sarcopenia was evaluated by measuring fatty infiltration (FI) of the PM.

METHODS

We used custom software written in MATLAB® to calculate the FI of the PM. The correlation between FI of the PM and assessments of generalized sarcopenia was calculated using Spearman's rank correlation coefficient (rho). The strength of the correlation was evaluated according to established cut-offs: negligible: 0-0.3, low: 0.3-0.5, moderate: 0.5-0.7, high: 0.7-0.9, and very high≥0.9. In a Receiver Operating Characteristics (ROC) analysis, the Area Under the Curve (AUC) of sarcopenia assessments to predict severe multifidus atrophy (FI≥50%) was calculated. In a secondary analysis, factors associated with severe multifidus atrophy in nonsarcopenic patients were analyzed.

RESULTS

A total of 125 (43% female) patients, with a median age of 63 (IQR 55-73) were included. The most common surgical indication was lumbar spinal stenosis (79.5%). The median FI of the multifidus was 45.5% (IQR 35.6-55.2). Grip strength demonstrated the highest correlation with FI of the multifidus and erector spinae (rho=-0.43 and -0.32, p<.001); the other correlations were significant (p<.05) but lower in strength. In the AUC analysis, the AUC was 0.61 for the SPPB, 0.71 for grip strength, and 0.72 for the psoas index. The latter two were worse in female patients, with an AUC of 0.48 and 0.49. Facet joint arthropathy (OR: 1.26, 95% CI: 1.11-1.47, p=.001) and foraminal stenosis (OR: 1.54, 95% CI: 1.10-2.23, p=.015) were independently associated with severe multifidus atrophy in our secondary analysis.

CONCLUSION

Our study demonstrates a low correlation between generalized and spine-specific sarcopenia. These findings highlight the risk of misdiagnosis when relying on screening tools for general sarcopenia and suggest that general and spine-specific sarcopenia may have distinct etiologies.

Efficacy of kinesio tape added to lumbar stabilization exercises on adult patients with mechanical low back pain: A randomized, single-blind clinical trial

BACKGROUND

Lumbar stabilization exercises (LSEs) are beneficial for chronic mechanical low back pain (CMLBP). However, further research focusing on intervention combinations is recommended. This study examined the effect of kinesio tape (KT) with LSEs on CMLBP adult patients.

METHODS

A randomized blinded clinical trial was conducted. Fifty CMLBP patients of both genders were assigned into one of two groups and received 8 weeks of treatment: group A (control): LSEs only, and group B (experimental): KT with LSEs. The primary outcome was back disability, measured by the Oswestry disability index. Secondary outcomes included pain intensity, trunk extensor endurance, and sagittal spinal alignment, as indicated by the visual analog scale, Sorensen-test, and C7-S1 sagittal vertical axis, respectively. The reported data was analyzed by a two-way MANOVA using an intention-to-treat procedure.

RESULTS

Multivariate tests indicate statistically significant effects for group (F = 4.42, p = 0.005, partial η2 = 0.148), time (F = 219.55, p < 0.001, partial η2 = 0.904), and group-by-time interaction (F = 3.21, p = 0.01, partial η2 = 0.149). Univariate comparisons between groups revealed significant reductions in the experimental group regarding disability (p = 0.029, partial η2 = 0.049) and pain (p = 0.001, partial η2 = 0.102) without a significant difference in the Sorensen test (p = 0.281) or C7-S1 SVA (p = 0.491) results. All within-group comparisons were statistically significant (p < 0.001).

CONCLUSION

The combination of KT and LSEs is an effective CMLBP treatment option. Although patients in both groups displayed significant changes in all outcomes, the combined interventions induced more significant reductions in back disability and pain intensity.

Testing the Posterior Chain: Diagnostic Accuracy of the Bunkie Test versus the Isokinetic Hamstrings/Quadriceps Measurement in Patients with Self-Reported Knee Pain and Healthy Controls

(1) Background: The isokinetic measurement (IM) of the leg muscles is well established but costly, whereas the Bunkie Test (BT) is a rarely investigated but easy-to-conduct functional test to evaluate the total posterior chain. Although the tests differ in aim and test structures, both have their justification in the assessment process. Therefore, this study evaluated the diagnostic accuracy of the BT and the IM. (2) Methods: 21 participants (9 female, 12 male; age, 26.2 ± 5.26 years; weight 73.8 ± 14.6 kg; height 176.0 ± 9.91 cm) and 21 patients (9 female, 12 male; age, 26.5 ± 5.56 years; weight, 72.6 ± 16.9 kg; height 177.0 ± 10.1 cm) with self-reported pain in the knee performed the IM and the BT. For IM, we calculated the ratio of the knee mean flexor/extensor peak torque (H/Q ratio) for 60°/s and 120°/s, and BT performance was measured in seconds. We classified the IM (<0.6 H/Q ratio) and the BT (leg difference ≥4 s) as binary results according to the literature. We calculated the sensitivity and specificity, which we compared with the Chi-Square test, and the 95% confidence intervals (CI). A p-value of ≤0.05 is considered significant. (3) Results: The sensitivity for the BT was 0.89, 95% CI [0.67, 0.99], and the specificity was 0.52 [0.30, 0.74]. For the IM, the sensitivity was 0.14 [0.03, 0.36] for 60°/s and 0.05 [0.00, 0.24] for 120°/s, and the specificity was 0.70 [0.46, 0.88] for 60°/s and 0.90 [0.68, 0.99] for 120°/s. The results of the Chi-Square tests were significant for the BT (χ2 (1) = 6.17, p = 0.01) but not for the IM (60°/s: χ2 (1) = 0.70, p = 0.40; 120°/s: χ2 (1) = 0.00, p = 0.97). (4) Conclusions: Patients were more likely to obtain a positive test result for the BT but not for the IM.

Understanding the Biering-Sørensen test: Contributors to extensor endurance in young adults with and without a history of low back pain

The Biering-Sørensen test is commonly used to assess paraspinal muscle endurance. Research using a single repetition of the test has provided conflicting evidence for the contribution of impaired paraspinal muscle endurance to low back pain (LBP). This study investigated how Sørensen test duration, muscle activation, and muscle fatigability are affected by multiple repetitions of the test and determined predictors of Sørensen test duration in young adults with and without a history of LBP. Sixty-four young individuals performed three repetitions of the Sørensen test. Amplitude of activation and median frequency slope (fatigability) were calculated for the lumbar and thoracic paraspinals and hamstrings. Duration of the test was significantly less for the 3rd repetition in individuals with LBP. In individuals without LBP, test duration was predicted by fatigability of the lumbar paraspinals. In individuals with LBP, Sørensen test duration was predicted by fatigability of the hamstrings and amplitude of activation of the thoracic and lumbar paraspinals. Our findings demonstrate that it is necessary to amplify the difficulty of the Sørensen test to reveal impairments in young, active adults with LBP. Training programs aiming to improve lumbar paraspinal performance should monitor performance of other synergist muscles during endurance exercise.

Age-Dependent Differences of Paraspinal Muscle Endurance and Morphology in Chinese Community Population Without Chronic Low Back Pain

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

Our aim was to describe age-dependent changes of lumbar paraspinal muscle endurance and morphology in Chinese healthy population. We also explored the relationship between paraspinals endurance and morphology.

METHODS

A total of 181 participants from Chinese community population without chronic low back pain were included. The participants were divided into three groups: young (20-39 years old, n = 29), middle (40-59 years old, n = 93), and elderly (≥ 60 years old, n = 59). The Ito test was performed to evaluate the isometric endurance of paraspinal muscles. The total cross-sectional area (TCSA) and fat infiltration (FI) of multifidus (MF) and erector spinae (ES) were measured at L1-L5 levels on magnetic resonance imaging. Physical activity level was evaluated using the physical activity index and comorbidities were assessed by the modified 5-item frailty index.

RESULTS

The elderly group had a shorter performance time of endurance test than the young group and middle-aged group. Correlation analysis showed that age had a significant correlation with endurance test, the average MF TCSA, MF FI, ES TCSA and ES FI of L1-5. In addition, PAI had a significant correlation with endurance test and MF FI. In multiple linear regression analysis, paraspinals endurance was associated with MF FI, ES FI, physical activity level and comorbidities.

CONCLUSION

Age-related decreases in paraspinals endurance and TCSA, and an increase in FI were revealed. Besides, paraspinal muscles FI, but not TCSA, was negatively associated with the endurance of paraspinals.

Effect of aerobic exercises on patients with chronic mechanical low back pain: A randomized controlled clinical trial

BACKGROUND

Chronic mechanical low back pain (CMLBP) is one of the most prevalent and costly disorders. Determining its most effective treatment approach is a priority for researchers.

PURPOSE

To examine the effects of including aerobic exercise within a conventional therapy regimen for young adults with CMLBP.

METHODS

Fifty CMLBP patients (22 males and 28 females) were randomly and equally assigned to one of two groups to receive the prescribed treatment for 8 weeks. The control group received the traditional program only (infrared, ultrasound, burst TENS, and exercises); for the experimental group, an aerobic training program using a stationary bicycle was added. Back pain intensity was the primary outcome. Secondary outcomes included the Oswestry disability index, back extensor endurance measured by the Sorensen test, and physical performance indicated by the back performance scale and the 6-min walk test. A Two-way MANOVA was used for data analysis.

RESULTS

Multivariate tests revealed statistically significant effects of group (p = 0.002, partial η2 = 0.182), time (p < 0.001, partial η2 = 0.928), and group-by-time interaction (p = 0.01, partial η2 = 0.149). Univariate group-by-time interactions were significant for back disability (p = 0.043), extensor endurance (p = 0.023) and results of the 6-min walk test (p = 0.023) showing greater improvement in the experimental group. However, back pain intensity and the back performance scale revealed no significant group-by-time interactions. Within-group comparisons were significant for all measured variables in both groups (p < 0.001).

CONCLUSION

Although a traditional program of infrared, ultrasound, TENS, and exercises is beneficial for CMLBP treatment, adding aerobic exercises to the program leads to more beneficial outcomes.

Role of the Paraspinal Muscles in the Sagittal Imbalance Cascade: The Effects of Their Endurance and of Their Morphology on Sagittal Spinopelvic Alignment

BACKGROUND

The role of paraspinal muscle degeneration in the cascade of sagittal imbalance is still unclear. This study aimed to compare paraspinal muscle degeneration in the 4 stages of sagittal imbalance: sagittal balance (SB), compensated sagittal balance (CSB), decompensated sagittal imbalance (DSI), and sagittal imbalance with failure of pelvic compensation (SI-FPC). In addition, it aimed to compare the effects paraspinal muscle endurance and morphology on sagittal spinopelvic alignment in patients with lumbar spinal stenosis.

METHODS

A cross-sectional study of 219 patients hospitalized with lumbar spinal stenosis was performed. The isometric paraspinal extensor endurance test and evaluation of atrophy and fat infiltration of the paraspinal extensor muscles and psoas major on magnetic resonance imaging were performed at baseline. Spinopelvic parameters including lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, and the sagittal vertical axis were measured.

RESULTS

The patients with lumbar spinal stenosis were divided into 67 with SB, 85 with CSB, 49 with DSI, and 17 with SI-FPC. There were significant differences in paraspinal muscle endurance and morphology among the 4 groups. Furthermore, the SI-FPC group had poorer paraspinal muscle endurance than either the SB or the CSB group. In multiple linear regression analysis, paraspinal muscle endurance and the relative functional cross-sectional area of the paraspinal extensor muscles were the independent predictors of the sagittal vertical axis, and the relative functional cross-sectional area of the psoas major was the independent predictor of relative pelvic version.

CONCLUSIONS

This study indicated that paraspinal muscle degeneration is not only an initiating factor in pelvic retroversion but also a risk factor for progression from a compensated to a decompensated stage. Specifically, the impairment of muscle endurance in the CSB stage may be the reason why patients experience failure of pelvic compensation. In addition, paraspinal muscle endurance and muscle morphology (relative functional cross-sectional area of the paraspinal extensor muscles and psoas major) had different clinical consequences.

LEVEL OF EVIDENCE

Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Fatigue task-dependent effect on spatial distribution of lumbar muscles activity

This study aims to identify how spatial distribution of lumbar muscle activity is modulated by different fatigue tasks. Twenty healthy adults performed two different isometric trunk extension endurance tasks (the modified Sorensen test and the inverted modified Sorensen test) until exhaustion. During these tasks, bilateral superficial lumbar muscle activity was recorded using high-density electromyography. The spatial distribution of activation within these muscles was obtained using the centroid coordinates in the medio-lateral and cranio-caudal directions. The effects of task and endurance time (left and right sides) were investigated using repeated measures ANOVA. Results revealed a significant lateral shift of the centroid throughout the fatigue tasks on both sides and no difference between tasks. Significant task × time interaction effects were found for the cranio-caudal direction on both sides showing a significantly more caudal location of the centroid in the modified Sorensen test compared to the inverted test at the beginning of the tasks. Our findings suggest that spatial distribution of lumbar muscle activity is task-dependent in a pre-fatigue stage while an alternative but similar muscle recruitment strategy is used in both tasks to maintain performance in the later stages of muscle fatigue.

Exploring the Interplay of Muscular Endurance, Functional Balance, and Limits of Stability: A Comparative Study in Individuals with Lumbar Spondylosis Using a Computerized Stabilometric Force Platform

Lumbar spondylosis, characterized by degenerative changes in the lumbar spine, often leads to pain, reduced spinal stability, and musculoskeletal dysfunction. Understanding the impact of lumbar spondylosis on musculoskeletal function, particularly lumbar extensor endurance, functional balance, and limits of stability, is crucial for improving the management and well-being of affected individuals. This study aimed to assess lumbar extensor endurance, functional balance, and limits of stability in individuals with lumbar spondylosis compared to age-matched healthy individuals and explore the correlations among these parameters within the lumbar spondylosis group. The lumbar spondylosis group consisted of 60 individuals initially screened by an orthopedician and referred to physical therapy. Age-matched healthy controls (n = 60) were recruited. Inclusion criteria encompassed adults aged 45-70 years for both groups. Lumbar extensor endurance was assessed using the Sorensen test, functional balance with the Berg Balance Scale, and limits of stability using a computerized stabilometric force platform. Lumbar extensor endurance was significantly lower in individuals with lumbar spondylosis compared to healthy controls (23.06 s vs. 52.45 s, p < 0.001). Functional balance, as assessed by the Berg Balance Scale, demonstrated a significant decrement in the lumbar spondylosis group (48.36 vs. 53.34, p < 0.001). Additionally, limits of stability variables, under both eyes-open and eyes-closed conditions, exhibited marked impairments in the lumbar spondylosis group (p < 0.001 for all variables). Within the lumbar spondylosis group, lumbar extensor endurance exhibited significant positive correlations with functional balance (0.46, p < 0.001) and negative correlations with limits of stability variables (r ranging from -0.38 to -0.49, p < 0.01 for all variables). This study underscores the significance of addressing lumbar extensor endurance, functional balance, and stability impairments in the comprehensive management of lumbar spondylosis.

Adults with lower-limb amputation: Reduced multifidi muscle activity and extensor muscle endurance is associated with worse physical performance

Trunk muscles may be an overlooked region of deficits following lower-limb amputation (LLA). This study sought to determine the extent that trunk muscle deficits are associated with physical function following amputation. Sedentary adults with a unilateral transtibial- (n = 25) or transfemoral-level (n = 14) amputation were recruited for this cross-sectional research study. Participants underwent a clinical examination that included ultrasound imaging of the lumbar multifidi muscles, the modified Biering-Sorensen Endurance Test (mBSET), and performance-based measures, that is, the Timed Up and Go (TUG), Berg Balance Scale (BBS), and 10-m Walk Test (10mWT). Associations between trunk muscle metrics and performance were explored with regression modeling, while considering covariates known to impact performance postamputation (p ≤ 0.100). Average ultrasound-obtained, lumbar multifidi activity was 14% and 16% for transfemoral- and transtibial-level amputations, respectively, while extensor endurance was 37.34 and 12.61 s, respectively. For TUG, nonamputated-side multifidi activity and an interaction term (level x non-amputated-side multifidi activity) explained 9.4% and 6.2% of the total variance, respectively. For 10mWT, beyond covariates, non-amputated-side multifidi activity and the interaction term explained 6.1% and 5.8% of the total variance, respectively. For TUG, extensor endurance and an interaction term (level x mBSET) explained 11.9% and 8.3% of the total variance beyond covariates; for BBS and 10mWT, extensor endurance explained 11.2% and 17.2% of the total variance, respectively. Findings highlight deficits in lumbar multifidi activity and extensor muscle endurance among sedentary adults with a LLA; reduced muscle activity and endurance may be important factors to target during rehabilitation to enhance mobility-related outcomes.

The Role of Back Muscle Dysfunctions in Chronic Low Back Pain: State-of-the-Art and Clinical Implications

Changes in back muscle function and structure are highly prevalent in patients with chronic low back pain (CLBP). Since large heterogeneity in clinical presentation and back muscle dysfunctions exists within this population, the potential role of back muscle dysfunctions in the persistence of low back pain differs between individuals. Consequently, interventions should be tailored to the individual patient and be based on a thorough clinical examination taking into account the multidimensional nature of CLBP. Considering the complexity of this process, we will provide a state-of-the-art update on back muscle dysfunctions in patients with CLBP and their implications for treatment. To this end, we will first give an overview of (1) dysfunctions in back muscle structure and function, (2) the potential of exercise therapy to address these dysfunctions, and (3) the relationship between changes in back muscle dysfunctions and clinical parameters. In a second part, we will describe a framework for an individualised approach for back muscle training in patients with CLBP.

Understanding the Biering-Sørensen test: contributors to extensor endurance in young adults with and without low back pain

Impaired paraspinal muscle endurance may contribute to persistent low back pain (LBP) and is frequently assessed using a single repetition of the Biering-Sørensen test. This study investigated how Sørensen test duration, muscle activation, and muscle fatigability are affected by multiple repetitions of the test, and determined predictors of Sørensen test duration in young, active adults with and without a history of LBP. Sixty-four individuals with and without persistent LBP performed 3 repetitions of the Sørensen test. Amplitude of activation and median frequency slope (fatigability) were calculated for the lumbar and thoracic paraspinals and the hamstrings. Duration of the test was significantly less for the 2nd and 3rd repetitions in individuals with LBP. In individuals without LBP, fatigability of the lumbar paraspinals was the best predictor of test duration. In individuals with LBP, Sørensen test duration was predicted by fatigability of the hamstrings and amplitude of activation of the thoracic and lumbar paraspinals. Our findings demonstrate that it is necessary to amplify the difficulty of the Sørensen test to elucidate impairments in young, active adults with LBP. Training programs aiming to improve lumbar paraspinal performance in individuals with LBP should monitor performance of other synergist muscles during endurance exercise.

The contralateral effects of foam rolling on range of motion and muscle performance

A single bout of foam rolling (FR) can acutely increase joint range of motion (ROM) without detrimental effects on subsequent muscle performance. Similarly, long-term FR training can increase ROM, while muscle performance seems to be unaffected. Although the acute and long-term effects of FR on the treated muscle are understood, the impact of FR on the contralateral side is not well known. Therefore, this scoping review aims to summarize the current evidence on the acute and long-term effect of FR on the ipsilateral limb on ROM and muscle performance (i.e., maximum force, rate of force development, jump height) for the contralateral (non-treated) limb. Potential explanatory mechanisms are also discussed. There is evidence that a single bout of FR on the ipsilateral limb increases ROM of the contralateral limb; however, evidence is limited for long-term effects. The most likely mechanism for contralateral ROM increases is a reduced perception of pain. With regard to isolated muscle contractions, no changes in muscle performance (i.e., maximum voluntary isometric contraction, maximum voluntary dynamic contraction) were found in the contralateral limb after a single bout of FR on the ipsilateral limb. Notably, only one study reported large impairments in rate of force development of the contralateral limb following FR on the ipsilateral leg, possibly due to decreased motor unit recruitment. Furthermore, to date there are only two studies examining the long-term FR training of the ipsilateral limb on performance (i.e., maximal strength and jump performance) which reported moderate improvements. Although, trivial to very large changes on a variety of parameters were found in this study, the functional and practical relevance of our findings should be interpreted with caution.

Association of accelerometer-measured physical activity, back static muscular endurance and abdominal obesity with radicular pain and non-specific low back pain

Low back pain (LBP) is the leading cause of disability worldwide and often associated with lifestyle factors. However, studies further examining the role of these lifestyle factors in non-specific low back pain in comparison with radicular pain are sparse. The aim of this cross sectional study was to investigate how diverse lifestyle factors are associated with LBP. The study population of 3385 middle aged adults with and without low back pain was drawn from a large Birth 1966 Cohort. Outcome measures were steps per day, abdominal obesity, physical activity and endurance of the back muscles. Back static muscular endurance, abdominal obesity and physical activity were measured by means of the Biering-Sørensen test, waist circumference and a wrist worn accelerometer, respectively. Logistic regression analysis was applied to estimate associations of back static muscular endurance, abdominal obesity and accelerometer-measured physical activity with non-specific low back pain and radicular pain. An additional 1000 steps per day were associated with 4% lower odds of having non-specific low back pain. Participants with abdominal obesity had 46% higher odds of having radicular pain, whereas increases of 10 s in back static muscular endurance and 10 min in daily vigorous physical activity were associated with 5% and 7% lower odds of having radicular pain, respectively. In this population-based study, non-specific low back pain and radicular pain were associated with different lifestyle and physical factors at midlife. Non-specific low back pain was associated only with the average daily number of steps, whereas abdominal obesity was the strongest determinant of radicular pain, followed by vigorous physical activity and back static muscular endurance. The findings of this study contribute to better understand the role of lifestyle factors in both non-specific low back pain and radicular pain. Future longitudinal studies are required to explore causality.

Linear spectrum and non-linear complexity features of lumbar muscle surface electromyography between people with and without non-specific chronic low back pain during Biering-Sorensen test

PURPOSE

This study aimed to investigate the electromyographic parameters of lumbar muscles during the Biering-Sorensen test (BST) in people with and without non-specific chronic low back pain (NCLBP).

MATERIALS AND METHODS

Thirteen healthy controls and thirteen NCLBP patients participated in the current study, where they performed the 90s-BST, while the surface electromyography (sEMG) was recorded from the erector spinae (ES) at L1 and L3 level and lumbar multifidus (LM) at L5 level, bilaterally. Spectral and nonlinear analyses were applied by calculating mean power frequency (MPF), fractal dimension (FD) and the percentage of determinism (%DET) in the 10-second non-overlapping time-windows and EMG-EMG coherence during the first half and second half of the BST. Also, the slopes of the linear fitting curves of MPF, FD and %DET were calculated.

RESULTS

NCLBP group had significantly lower rates of changes in MPF, FD and %DET compared to asymptomatic controls in the ES(L3) and LM. Coherence in left-right LM and in the right ES-LM increased significantly in the gamma band in the Control group with no increase in the NCLBP group.

CONCLUSIONS

Our findings indicated that compared to people with NCLBP, the sEMG signals of lumbar muscles of people without NCLBP were more regular and less complex during the 90s-BST.

Physical clinical care and artificial-intelligence-guided core resistance training improve endurance and patient-reported outcomes in subjects with lower back pain

BACKGROUND

Low back pain is an extremely prevalent issue with an extensive impact, ranging from decreased quality of life to lost years of productivity. Many interventions have been developed to alleviate chronic lower back pain, yet it remains a widespread problem. The objective of this study was to examine the role of artificial intelligence guided resistance training relative to clinical variables in subjects experiencing lower back pain.

METHODS

69 out of 108 enrolled and 92 accrued subjects completed the 8-week intervention. Subjects were randomized into four groups (Control, Training, Clinical, or Combined). The Training cohort received supervised artificial-intelligence-guided core-focused resistance training while the Clinical group received clinical care. The Combined group received both clinical care and artificial-intelligence-guided training and the Control group received no treatment. Participants were evaluated using functional testing and patient-reported outcomes at baseline, 4 weeks, and 8 weeks.

FINDINGS

In the clinical tests, the Clinical and Combined cohorts showed increased total time for isometric extensor endurance and the Clinical cohort increased total distance traveled in the 6-min walk test at 8 weeks. The Training, Clinical, and Combined groups showed improvements in Patient-reported outcomes after 8 weeks. Most of the significant improvements were only seen at the 8-week evaluation for both the clinical evaluations and Patient-reported outcomes. The Control group did not show significant improvements in any outcome measures.

INTERPRETATION

The present data indicate that core-focused interventions, including artificial-intelligence-guided moderate-resistance exercise, can increase objective functional outcomes and patient satisfaction using Patient-reported outcomes in individuals with lower back pain.

Psoas major and lumbar lordosis may correlate with pain episodes during Sorensen test in patients with non-specific low back pain

BACKGROUND

The reason that participants develop pain episodes during the Sorensen test remains unclear. Lumbar lordosis and trunk muscle are important for dynamic stability of the spine; however, their role in pain episodes during the Sorensen test has not yet been discussed.

OBJECTIVE

To investigate the effects of muscular morphology and lumbar curvature on pain development during the Sorensen test in patients with non-specific low back pain (LBP).

METHODS

Ninety-one patients diagnosed with chronic non-specific LBP and underwent the Sorensen test were enrolled. Lumbar lordosis, cross-sectional area and fat infiltration rate of trunk muscle and centroid line of psoas major (dividing into three types: anterior arc, linear and posterior arc) were measured using ImageJ software. All recruited patients were grouped into pain episode and exhaustion groups and were matched for the confounders based on propensity scores. The above parameters were compared between groups and further adjusted for confounding bias.

RESULTS

After adjustment , the mean differences in lumbar lordosis of 12.1 ± 2.3∘ between the two groups in the complete cohort and of 13.9 ± 2.5∘ in the matching cohort remained significant, the exhaustion group had a 0.22-fold and 0.08-fold risk of presenting as linear and posterior arc types, respectively, compared with the pain episode group in the complete cohort (p= 0.008, p= 0.004), the corresponding values were 0.19-fold and 0.05-fold, respectively, in the matching cohort (p= 0.014, p= 0.010). Logistic regression demonstrated that lumbar lordosis, the linear and posterior arc types were significantly associated with pain episode during the test (OR = 0.78, p< 0.001; OR = 4.50, p= 0.038; OR = 9.93, p= 0.033).

CONCLUSIONS

Lower lumbar lordosis and linear and posterior arc types of the psoas major centroid line were possibly relevant to the pain episode during Sorensen test in patients with chronic non-specific LBP.

Sex-related differences in motor control strategies during isometric contractions in the Sorensen test posture with different external loading

BACKGROUND

There is a sex-related difference in strength and endurance in trunk muscles: males have more strength while females have more endurance.

OBJECTIVE

Investigate sex-related differences in motor control strategies in back muscles during isometric contractions (IC) in the Sorensen test posture.

METHODS

Thirty-six healthy and young volunteers performed different tasks: three maximal voluntary contraction (MVC) tests recorded with a bio-feedback force sensor, and followed by five loaded IC (LIC) tests using bodyweight and loads of 0 to 8 kg with a 2-kg step. Surface electromyography was used to measure the activity of bilateral lumbar paravertebral (LP) and quadratus lumborum (QL) muscles.

RESULTS

Sex-related and load-related differences in EMG amplitudes were highlighted during LIC tests. Females showed significantly (p-value = 0.02) greater EMG amplitude for the highest load (8 kg) than males. Besides, significant differences between low (2 and 4 kg) and high (6 and 8 kg) loads for both LP and QL muscles and for both sexes were observed. Finally, for MVC tests, males produced significantly (p-value = 1.02e-4) greater strength during MVC tests (4.25 ± 1.37 N/kg vs 2.60 ± 0.78 N/kg).

CONCLUSION

The results were clinically relevant to bring attention to load strategy during rehabilitation, particularly in females who seemed to recruit the QL muscle more.

The functional lumbar index: Validation of a novel clinical assessment tool for individuals with low back pain

STUDY DESIGN

Retrospective Diagnostic Cohort Study.

LEVEL OF EVIDENCE

Level 3b.

OBJECTIVES

To examine the concurrent and predictive validity of a novel clinical assessment tool, the Functional Lumbar Index (FLI).

BACKGROUND

Lumbar surgeries have increased exponentially in the past decade, adding to healthcare costs without improving outcomes. Limitations in clinicians' abilities to identify those individuals who are most likely to benefit from surgery may be enhanced with an effective physical assessment tool.

METHODS

The FLI was assessed on 291 individuals (179 conservative and 113 pre-surgical) seeking care for low-back pain (LBP) over a 2.5-year period. The FLI consists of several physical performance tests (PPT) with a novel criterion-based scoring system. Pearson correlations and Poisson regression analysis were used to establish concurrent and predictive validity at alpha = 0.05.

RESULTS

The subscale FLI components showed good to excellent inter-rater reliability with intraclass correlation coefficient values as follows: front plank = .993, right side plank = .824, left side plank .861, Sorensen = 0.836, overhead squat = 0.937. A statistically significant, moderate negative correlation was observed between FLI and modified Oswestry Disability Index (r = -0.540, p < .001). Regression analysis showed the FLI as the only significant predictor (p = .004) of failed conservative management for individuals with LBP. An ROC curve showed significant group prediction of the FLI with an AUC of 0.788 (p < .001) and cut-off score of 7.5.

CONCLUSION

The FLI is a reliable and valid measure for predicting failed conservative care management in patients with LBP. Clinicians are encouraged to use the FLI as part of their physical assessment when screening individuals with LBP who might need surgical intervention. Further research is needed to determine validity of the FLI in other patient populations.

PUBLIC TRIAL REGISTRY

N/A.

Compliance with a personalised home exercise programme in chronic low back pain patients after a multidisciplinary programme: A pilot randomised controlled trial

BACKGROUND

Chronic low back pain (CLBP) is a very common problem throughout the world. One treatment possibility is the multidisciplinary programme (MP) in a rehabilitation centre, which provides intensive rehabilitation through physical exercise to quickly improve the patient conditions. Patients nevertheless do not always continue the exercises when they return home. This study thus evaluated compliance with a personalised home-based programme for CLBP patients post-MP.

METHODS

A randomised controlled single-blind trial was conducted. Thirty patients were randomised into two groups and participated in an MP for 4 weeks. They were then given an exercise booklet for home rehabilitation. In addition, each patient in the experimental group constructed a personalised exercise programme with a physiotherapist. The control group was only encouraged to continue the exercises at home. To assess therapeutic compliance, both groups were asked to document each completed exercise in a logbook. In addition, pain intensity, flexibility, muscle endurance, activity limitations, participation restrictions, and beliefs about physical activity were assessed at the beginning and end of the MP and again after 12 weeks at home.

RESULTS

Compliance was good for all activities in both groups, but there were no significant differences between groups. All participants improved on the criteria by the end of MP, and both groups maintained the improvements in most of the criteria at 3-month follow-up.

CONCLUSION

This study showed the effectiveness of an MP for CLBP in the short and medium term. However, future research should focus on longer-term compliance.

Effectiveness of resisted training through translation of the pelvis in chronic low back pain

BACKGROUND

Resisted training of the trunk muscles improves outcomes in chronic low back pain (CLBP). The Itensic b-effect machine was designed to provide resisted training through posterior translation of the pelvis in a seated, forward-tilted position, in contrast with traditional machines that involve extension of the trunk.

OBJECTIVE

To study the effectiveness of lumbopelvic training on the Itensic b-effect machine in individuals with CLBP.

METHODS

Participants were allocated to 4 weeks of either progressive Itensic (I) training in addition to an education/exercise (EE) program (I+EE group, n= 23) or the education/exercise program alone (EE group, n= 22).

PRIMARY OUTCOME

Roland Morris Disability Questionnaire (RMDQ).

SECONDARY OUTCOMES

pain (0-10 numeric rating scale), trunk extensor endurance (Sorensen test), motor control (thoraco-lumbar dissociation test) and mobility (finger-to-floor test).

RESULTS

RMDQ score improved more in the I+EE group than in the EE group (with a between-group difference at the pos-test). Pain and mobility improved in the I+EE group only, motor control improved in both groups with no between-group difference and the Sorensen test did not improve significantly in either group.

CONCLUSIONS

Resisted posterior pelvic translation using the Itensic machine in addition to an education/exercise program improved disability, pain and mobility more than the education/exercise program alone.

Impairments in trunk muscles performance and proprioception in older adults with hyperkyphosis

BACKGROUND AND OBJECTIVES

Thoracic hyperkyphosis is one of the most common postural deformities in the geriatric population. This study investigated whether trunk proprioception, muscle strength, and endurance differ between older adults with hyperkyphosis and the age-matched control group. This study also aimed to explore the association of kyphotic posture with muscle performance, position sense, and force sense.

METHODS

Ninety-seven elderly volunteers (61 with hyperkyphosis and 36 normal controls) participated in this cross-sectional study. The kyphosis degree, trunk position sense, force sense, back muscle strength, and endurance were assessed in all participants.

RESULTS

The results showed lower back extensor strength and endurance, also higher force and position sense error in the hyperkyphotic group than the control group. In addition, the findings revealed that back extensor strength and endurance, as well as trunk position sense, were associated with kyphotic posture in older adults.

DISCUSSION AND IMPLICATIONS

This study suggests that back extensor strength and endurance and trunk position sense and force sense are potentially modifiable impairments associated with thoracic kyphosis in older adults with hyperkyphosis. It seems monitoring these potentially contributing factors would be helpful in the assessment and treatment of hyperkyphotic older individuals.

Correlations between paraspinal extensor muscle endurance and clinical outcomes in preoperative LSS patients and clinical value of an endurance classification

Background

Few study has investigated how paraspinal muscle endurance deteriorates in lumbar spinal stenosis (LSS) patients. In addition, little information is available on the relationship between clinical outcomes and the endurance of paraspinal muscles.

Objective

To explore the correlation between paraspinal extensor muscle endurance, quality of life (QOL) and sagittal spinopelvic alignment. Besides, we attempted to propose a paraspinal extensor muscle endurance test (PEMET) classification for identifying the severity of clinical symptoms and sagittal imbalance in LSS patients.

Methods

171 hospitalized LSS patients and 100 healthy controls from the community were prospectively enrolled in this study. The paraspinal extensor endurance test was performed at baseline according to Ito test. The LSS patients were stratified into three groups based on the performance time of endurance test: grade I (<10s); grade II (10–60s); and grade III (>60s). Clinical measures of QOL included the visual analog scale scores (VAS) for back pain and leg pain and the Oswestry Disability Index (ODI). Sagittal alignment was analysed by standing posteroanterior and lateral whole spine X-ray in LSS patients.

Results

The LSS group had a significantly shorter performance time of the endurance test than the control group. The paraspinal muscle endurance significantly correlated with VAS-back, VAS-leg, ODI, pelvic tilt, lumbar lordosis and sagittal vertical axis (SVA; all p < 0.05). In binary logistic regression, the performance time of the endurance test was an independent factor of both poor functional status (ODI >40; p = 0.005, OR = 0.985) and global sagittal imbalance (SVA >50 mm; p = 0.019, OR = 0.985). Based on PEMET classification, moving from the grade III group to the grade I group, there was progressive worsening in VAS-back and ODI (all adjusted p < 0.05). Moreover, the grade I group had significantly greater VAS- leg, less LL and greater SVA than the other two groups (all adjusted p < 0.05).

Conclusion

Paraspinal muscle endurance was associated with QOL and sagittal spinopelvic alignment in LSS patients. A PEMET classification system has been constructed and has shown a correlation with QOL and sagittal imbalance.

Translational potential statement

The PEMET classification system proposed in this study could be available for identifying the severity of clinical symptoms and sagittal imbalance during preoperative evaluation in LSS patients.

Comparison between the Original- and a Standardized Version of a Physical Assessment Test for the Dorsal Chain - A Cohort-Based Cross Sectional Study

This cohort-based cross-sectional study compares the original (OV) and a newly developed standardized version (SV) of the Bunkie Test, a physical test used to assess the dorsal chain muscles. Twenty-three participants (13 females, 10 males; median age of 26 ± 3 years) performed the test, a reverse plank, with one foot on a stool and the contralateral leg lifted. In the SV, the position of the pelvis and the foot were predefined. The test performance time (s) and surface electromyography (sEMG) signals of the dorsal chain muscles were recorded. We performed a median power frequency (MPF) analysis, using short-time Fourier transformation, and calculated the MPF/time linear regression slope. We compared the slopes of the linear regression analysis (between legs) and the performance times (between the OV and SV) with the Wilcoxon test. Performance times did not differ between SV and OV for either the dominant (p = 0.28) or non-dominant leg (p = 0.08). Linear regression analysis revealed a negative slope for the muscles of the tested leg and contralateral erector spinae, with a significant difference between the biceps femoris of the tested (-0.91 ± 1.08) and contralateral leg (0.01 ± 1.62) in the SV (p = 0.004). The sEMG showed a clearer pattern in the SV than in the OV. Hence, we recommend using the SV to assess the structures of the dorsal chain of the tested leg and contralateral back.

Comparison of erector spinae fatigability between female patients with Parkinson's disease and healthy individuals: a cross sectional pilot study

BACKGROUND

Postural abnormality is one of the main symptoms of Parkinson's disease (PD). The erector spinae muscles play an important role in maintaining an upright posture, but the fatigability of the erector spinae in patients with PD is unknown. The purpose of this study was to compare the trunk extension maximum voluntary contraction (MVC) and the fatigability of the erector spinae between female patients with PD and healthy volunteers.

METHODS

Th participants of this cross-sectional pilot study comprised 19 patients with PD and nine healthy volunteers matched for sex, age, and physical characteristics as a control group. The MVC of all participants was measured, and after sufficient rest, the Sørensen back endurance test was conducted to the point of exhaustion. The muscle activity of the erector spinae during the Sørensen back endurance test was measured using surface electromyography. The median frequency (MF) slope, which is an index of fatigability, was calculated from the recorded surface muscle activity by means of power spectrum analysis using a Fast Fourier transformation.

RESULTS

Nine of the 19 patients with PD were unable to perform the Sørensen back endurance test, and a lower proportion of the PD group were able to perform it compared with the control group. The MVC of those patients with PD who were able to perform the Sørensen back endurance test was lower than that of the control group, and the time for which the pose could be maintained was shorter. There was no significant difference between the MF slope on the left and right side in the PD group, and it was higher on both sides than in the control group.

CONCLUSION

This is the first study to demonstrate a reduction of maximum muscle strength and great fatigability of the erector spinae in patients with PD. This discovery strongly underlines the need for paraspinal muscle training from an early stage with the aim of preventing the progression of postural abnormality in patients with PD.

No alteration of back muscle oxygenation during isometric exercise in individuals with non-specific low back pain

The aim of our study was (I) To compare back muscle oxygenation and perfusion as well as Biering–Sorensen muscle endurance (BSME) test holding times between chronic non-specific low back pain (CNSLBP) patients and asymptomatic controls matched for age, body mass index (BMI), sex and physical activity, and (II) to investigate factors associated with BSME holding times. Muscle perfusion (tHb) and oxygenation (SmO₂) were measured by near-infrared spectroscopy (NIRS) based oximetry in three back muscles during the BSME. Reliability of tHb and SmO₂ was assessed in a separate sample. BSME holding time and SmO₂ were compared between patients (n = 45) and controls (n = 45) and factors associated with BSME holding time were assessed using multiple linear regression. Reliability for SmO₂ was excellent (ICC = 0.87–0.99). THb showed poor to moderate reliability and was not further used. Groups differed for BSME holding time (P = 0.03), pain intensity (P ≤ 0.0005) and subcutaneous tissue thickness (P = 0.01) but not for NIRS measures. Physical activity and BMI were associated with BSME holding times. Insufficient muscle oxygenation does not seem to be a major factor contributing to CNSLBP. Future investigation should evaluate other determinants of BSME holding times, such as motivation and recruitment of auxiliary muscles.

The Effect of Equipment-Based Pilates (Reformer) Exercises on Body Composition, Some Physical Parameters, and Body Blood Parameters of Medical Interns

BACKGROUND

Pilates is a type of exercise that exerts positive effects on body composition and general health. This study set out to investigate the effects of equipment-based Pilates (reformer) exercise on body composition, some physical parameters, and blood parameters of medical interns showing a tendency toward sedentary life.

MATERIALS AND METHODS

The experimental group (EG) comprising 22 healthy internship students in the medical faculty performed Pilates reformer exercises for nine weeks. The control group (CG) consisted of 18 students who did not engage in any exercise program. The baseline and final parameters of all the participants were measured.

RESULTS

The mean age of the experimental group (EG) was 23.68±1.29 years, while that of the control group (CG) was 24.78±3.44 (p=0.089). A significant difference was evident between the performance pre-test and post-test scores of the EG (p<0.05). However, a significant positive difference was noted only between the waist pre-test and post-test results in the body composition measurements (p<0.05). A significant rise in HDL and fasting blood sugar levels and a decrease in insulin levels was observed in the post-exercise biochemical parameters measured in the EG (p=0.05). When the EG and CG were compared, a significant difference was found only in HDL cholesterol values in relation to the differences between the pre-test and the post-test groups (p=0.024).

CONCLUSION

The positive data from performance tests, especially with its HDL-increasing and insulin-lowering effects in the EG, implicate that Pilates reformer exercises can produce a favorable effect on the healthy living standards of medical interns.

Test-retest reliability of a load cell setup, Ito, and timed loaded standing tests for measuring muscle strength and endurance in older adults with and without hyperkyphosis

BACKGROUND

The association of back muscle weakness with greater thoracic kyphosis has been widely documented. Reliable and easy-to-use techniques are needed to monitor changes in muscle function over time and assess the effectiveness of therapeutic interventions. Therefore, the present study aimed to evaluate the test-retest reliability of a designed load-cell setup and two clinical tests, namely Ito and Timed loaded standing (TLS) tests for measuring back muscle function (i.e., strength and endurance) in older adults with and without hyperkyphosis.

METHOD

Fifty-three older people (28 with thoracic hyperkyphosis and 25 normal age-matched controls) completed the present test-retest reliability study. A two-way random model of the Intraclass Correlation Coefficient (ICC_2,3) was used to estimate relative reliability. Absolute reliability was assessed by calculating Standard Error of the Measurements (SEM) and Minimal Detectable Change (MDC).

RESULTS

The findings showed excellent test-retest reliability in all performed tests for this population (ICC = 0.95-0.99). In addition, the MDC values for measuring endurance time via load cell, Ito, and TLS tests in the hyperkyphosis group, were 16.5, 28.2, and 35.1 s, respectively. These values ranged from 36 to 39 s for the control group.

CONCLUSION

The present study suggests high test-retest reliability of the designed load-cell setup, Ito, and TLS for assessing back extensor muscle strength and endurance in older adults with and or without hyperkyphosis.

Updated Integrated Framework for Making Clinical Decisions Across the Lifespan and Health Conditions

The updated Integrated Framework for Clinical Decision Making responds to changes in evidence, policy, and practice since the publication of the first version in 2008. The original framework was proposed for persons with neurological health conditions, whereas the revised framework applies to persons with any health condition across the lifespan. In addition, the revised framework (1) updates patient-centered concepts with shared clinical decision-making; (2) frames the episode of care around the patient's goals for participation; (3) explicitly describes the role of movement science; (4) reconciles movement science and International Classification of Function language, illustrating the importance of each perspective to patient care; (5) provides a process for movement analysis of tasks; and (6) integrates the movement system into patient management. Two cases are used to illustrate the application of the framework: (1) a 45-year-old male bus driver with low back pain whose goals for the episode of care are to return to work and recreational basketball; and (2) a 65-year-old female librarian with a fall history whose goals for the episode of care are to return to work and reduce future falls. The framework is proposed as a tool for physical therapist education and to guide clinical practice for all health conditions across the lifespan.

Study protocol for a prospective cohort study identifying risk factors for sport injury in adolescent female football players: the Karolinska football Injury Cohort (KIC)

INTRODUCTION

Football is a popular sport among young females worldwide, but studies concerning injuries in female players are scarce compared with male players. The aim of this study is to identify risk factors for injury in adolescent female football players.

METHODS AND ANALYSIS

The Karolinska football Injury Cohort (KIC) is an ongoing longitudinal study that will include approximately 400 female football academy players 12-19 years old in Sweden. A detailed questionnaire regarding demographics, health status, lifestyle, stress, socioeconomic factors, psychosocial factors and various football-related factors are completed at baseline and after 1 year. Clinical tests measuring strength, mobility, neuromuscular control of the lower extremity, trunk and neck are carried out at baseline. Players are followed prospectively with weekly emails regarding exposure to football and other physical activity, health issues (such as stress, recovery, etc), pain, performance and injuries via the Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSTRC-O). Players who report a substantial injury in the OSTRC-O, that is, not being able to participate in football activities, or have reduced their training volume performance to a moderate or major degree, are contacted for full injury documentation. In addition to player data, academy coaches also complete a baseline questionnaire regarding coach experience and education.

ETHICS AND DISSEMINATION

The study was approved by the Regional Ethical Review Authority at Karolinska Institutet, Stockholm, Sweden (2016/1251-31/4). All participating players and their legal guardians give their written informed consent. The study will be reported in accordance with the Strengthening the Reporting of Observational studies in Epidemiology. The results will be published in peer-reviewed academic journals and disseminated to the Swedish football movement through stakeholders and media.

Physiotherapy combined with therapeutic neuroscience education versus physiotherapy alone for patients with chronic low back pain: A pilot, randomized-controlled trial

Objectives

The aim of this study was to investigate the effect of therapeutic neuroscience education (TNE) combined with physiotherapy on pain, kinesiophobia, endurance, and disability in chronic low back pain (CLBP) patients.

Patients and methods

Between November 2016 and December 2017, a total of 31 patients with CLBP (5 males, 26 females; mean age: 42.3±10.8 years; range, 20 to 58 years) were randomly allocated to receive physiotherapy combined with TNE (experimental group, EG, n=16) and physiotherapy alone (control group, CG, n=15). All participants received physiotherapy consisting of five sessions per week for a total of three weeks. In addition to physiotherapy, the EG received TNE sessions consisting of two sessions per week for a total of three weeks. The primary outcomes were pain intensity as assessed by Visual Analog Scale (VAS) and kinesiophobia by Tampa Scale for Kinesiophobia (TSK), while and the secondary outcomes were trunk muscle endurance as assessed by the partial curl-up test (trunk flexor endurance [TFE]) and modified Sorensen test (trunk extensor endurance [TEE]) and disability by Roland-Morris Disability Questionnaire (RMDQ).

Results

All patients completed the study. The median VAS, TSK, TFE, TEE, and RMDQ scores for the EG significantly improved after three weeks, while there was only significant improvement in the VAS, TSK, and RMDQ scores in the CG. The TSK decreased more in the EG than in the CG. The significant difference was evident in TSK and TFE in favor of the EG (p<0.05).

Conclusion

These results suggest that the combination of TNE with physiotherapy can improve kinesiophobia and trunk flexor muscle endurance of patients with CLBP in the short-term.

Paraspinal strength and electromyographic fatigue in patients with sub-acute back pain and controls: Reliability, clinical applicability and between-group differences

BACKGROUND

Paraspinal muscle strength and fatigue are considered important in low back pain (LBP) prevention and rehabilitation. High reliability of paraspinal strength and electromyographic (EMG)-fatigue parameters has not been universally reported. Moreover, the discriminative validity of these parameters requires further exploration, under the threat of potentially poor reliability of the methods examined.

AIM

To investigate the reliability and discriminative validity of paraspinal strength and EMG-related fatigue in subjects with recurrent LBP and healthy participants.

METHODS

Test-retest measurements were performed in 26 healthy and 66 LBP volunteers, for reliability. Paraspinal isometric maximal and mean strength were determined with a maximum voluntary isometric contraction (MVIC) protocol, performed in a custom-made device. For the fatigue test, participants performed a 60% MIVC level continuous isometric contraction of the paraspinals, in conjunction with EMG analysis from 4 muscle sites of the lumbar spine. Initial median frequency (IMF), the median frequency slope (MFslope), as well as the root mean square (RMS) slope EMG parameters were used as fatigue measures. Data were analysed with repeated measures ANOVA for test-retest differences. For reliability, the intraclass correlation coefficient (ICC_3,1), standard error of the measurement (SEM) and the smallest detectable difference (SDD) were reported. Group-related differences for fatigue measures were analysed with a Multivariate Analysis of Covariance, with age, weight and strength as covariates.

RESULTS

Isometric strength presented statistically significant between-day differences (P < 0.01), however these did not exceed 10% (healthy: 7.2%/LBP-patients: 9.7%) and ICC reliability values were excellent, yet test-retest error was increased for the patient group (healthy: ICC_3,1: 0.92-0.96, SEM: 5.72-5.94 Hz, SDD: 18.51%-18.57%/LBP-patients: ICC_3,1: 0.91-0.96, SEM: 6.49-6.96, SDD: 30.75%-31.61%). For the frequency data, IMF reliability was excellent (healthy: ICC_3,1: 0.91-0.94, SEM: 3.45-7.27 Hz, SDD: 9.56%-20.14%/patients: ICC_3,1: 0.90-0.94, SEM: 6.41-7.59 Hz, SDD: 17.75%-21.02%) and of MF raw and normalised slopes was good (healthy: ICC_3,1: 0.78-0.82, SEM: 4.93-6.02 Hz, SDD: 13.66-16.67%/LBP-patients: ICC_3,1: 0.83-0.85, SEM: 6.75-7.47 Hz, SDD: 18.69%-20.69%). However, the reliability for RMS data presented unacceptably high SDD values and were not considered further. For discriminative validity, less MVIC and less steep MFslopes were registered for the patient group (P < 0.01).

CONCLUSION

Reliability and discriminative ability of paraspinal strength and EMG-related frequency parameters were demonstrated in healthy participants and patients with LBP.

Musculoskeletal Disorders in Tyre Manufacturing Workers

Background

Tyre manufacturing workers are at risk of developing WRMSDs as their job repeatedly involves elevated arm postures, lifting of tyres, pushing or pulling trolleys, trunk bending and twisting.

Aim

To assess WRMSDs in tyre manufacturing workers.

Methodology

This was an observational study involving 99 tyre manufacturing workers. Persons with any history of recent trauma, major hospitalization or surgery in past 12 months were excluded. Workers were screened according to Nordic questionnaire for assessing the musculoskeletal disorders and REBA analysis was done. They were also assessed for flexibility of hamstring using AKE test and isometric endurance of back extensors using Sorenson test.

Results

97% workers were under 30 years of age and 91% were males. The average duration of work was 27 months. In the past 12 months, 36% workers reported low back pain, 24.2% shoulder pain, 24.2% neck pain, 19% knee pain and 20% ankle/foot pain. REBA analysis revealed TBR and PCR manufacturing workers to be at higher and lower end of medium risk category, respectively. Average AKE values were 39.45⁰ and 38.45⁰ on the right and left, respectively, indicating that hamstring tightness was common, average back muscle endurance was 40.68 sec. However, AKE or back muscle endurance was not statistically related to back pain (P > 0.05).

Conclusion

Tyre workers showed involvement of multiple joints. LBP was predominant complaint but was not related to hamstrings tightness or back muscle endurance.

Assessment of Lumbar Extensor Muscles in the Context of Trunk Function, a Pilot Study in Healthy Individuals

A comprehensive assessment of trunk function, including the lumbar extensor muscles, appears to be important in various conditions affecting axial musculature. This pilot cross-sectional observational study aimed to define a battery of tests that comprehensively assess trunk muscle function (strength and muscular endurance). Sixty subjects without low back pain (LBP) underwent measurement of isometric lower back extensor strength using a hand-held dynamometer (HHD) in three positions; measurement of respiratory muscle strength; and Biering-Sørensen, prone-plank, and side-bridge tests. The repeatability, short-term and long-term reliability using the HHD device in different postural positions was confirmed. The greatest isometric lower back extensor strength was generated in the sitting position by male subjects. Time of effort in the Biering-Sørensen test was longer in women and older subgroups than in men and younger individuals, although this was not the case for the other two muscular endurance tests. This pilot monitoring of trunk muscle strength and endurance in healthy volunteers may lead to a better understanding of trunk muscle function. Based on this methodological background, the authors aim to use the defined battery of tests in their further studies in a group of patients with LBP and certain neuromuscular diseases to verify its usefulness in clinical practice.

Functional and morphological lumbar multifidus characteristics in subgroups with low back pain in primary care

BACKGROUND

Since the contribution of the lumbar multifidus(LM) is not well understood in relation to non-specific low back pain(LBP), this may limit physiotherapists in choosing the most appropriate treatment strategy.

OBJECTIVES

This study aims to compare clinical characteristics, in terms of LM function and morphology, between subacute and chronic LBP patients from a large clinical practice cohort compared to healthy controls.

DESIGN

Multicenter case control study.

METHOD

Subacute and chronic LBP patients and healthy controls between 18 and 65 years of age were included. Several clinical tests were performed: primary outcomes were the LM thickness from ultrasound measurements, trunk range of motion(ROM) from 3D kinematic tests, and median frequency and root mean square values of LM by electromyography measurements. The secondary outcomes Numeric Rating Scale for Pain(NRS) and the Oswestry Disability Index(ODI) were administered. Comparisons between groups were made with ANOVA, p-values<0.05, with Tukey's HSD post-hoc test were considered significant.

RESULTS

A total of 161 participants were included, 50 healthy controls, 59 chronic LBP patients, and 52 subacute LBP patients. Trunk ROM and LM thickness were significantly larger in healthy controls compared to all LBP patients(p < 0.01). A lower LM thickness was found between subacute and chronic LBP patients although not significant(p = 0.11-0.97). All between-group comparisons showed no statistically significant differences in electromyography outcomes (p = 0.10-0.32). NRS showed no significant differences between LBP subgroups(p = 0.21). Chronic LBP patients showed a significant higher ODI score compared to subacute LBP patients(p = 0.03).

CONCLUSIONS

Trunk ROM and LM thickness show differences between LBP patients and healthy controls.

Combined exercise and nutrition intervention for spinal sarcopenia: A pilot study protocol

INTRODUCTION

Spinal sarcopenia is a multifactorial disorder associated with the atrophy of and fatty changes to the paraspinal muscles. We previously developed the concept of spinal sarcopenia in community-dwelling older adults and investigated the association between conventional sarcopenic indices and spinal sarcopenia. However, interventional studies of spinal sarcopenia are lacking. This pilot study will aim to evaluate the effectiveness of a combined exercise and nutrition intervention for treating spinal sarcopenia.

METHODS AND ANALYSIS

This open-label single-arm prospective study will include 35 community-dwelling older women who were diagnosed with spinal sarcopenia in our previous cohort study. The 12-week combined intervention will consist of back extensor strengthening exercise and nutritional supplementation. The primary outcome of this study will be isometric back extensor strength after the 12-week intervention. All functional and radiographic outcomes will be measured at 0, 12, and 24 weeks post-intervention. The data will be analyzed using the intention-to-treat principle.

The Relationship between Reactive Balance Control and Back and Hamstring Strength in Physiotherapists with Non-Specific Back Pain: Protocol for a Cross-Sectional Study

Back pain is one of the most costly disorders among the worldwide working population. Within that population, healthcare workers are at a high risk of back pain. Though they often demonstrate awkward postures and impaired balance in comparison with healthy workers, there is no clear relationship between compensatory postural responses to unpredictable stimuli and the strength of related muscle groups, in particular in individuals with mild to moderate back pain. This paper presents a study protocol that aims to evaluate the relationship between peak anterior to peak posterior displacements of the center of pressure (CoP) and corresponding time from peak anterior to peak posterior displacements of the CoP after sudden external perturbations and peak force during a maximum voluntary isometric contraction of the back and hamstring muscles in physiotherapists with non-specific back pain in its early stages. Participants will complete the Oswestry Disability Questionnaire. Those that rate their back pain on the 0–10 Low Back Pain Scale in the ranges 1–3 (mild pain) and 4–6 (moderate pain) will be considered. They will undergo a perturbation-based balance test and a test of the maximal isometric strength of back muscles and hip extensors. We assume that by adding tests of reactive balance and strength of related muscle groups in the functional testing of physiotherapists, we would be able to identify back problems earlier and more efficiently and therefore address them well before chronic back disorders occur.

Trunk muscle endurance, strength and flexibility in rural subsistence farmers and urban industrialized adults in western Kenya

OBJECTIVES

High trunk muscle endurance, strength, and moderate flexibility reportedly help maintain musculoskeletal health, but there is evidence for tradeoffs among these variables as well as sex differences in trunk muscle endurance and strength. To test if these observations extend similarly to both men and women in nonindustrial and industrial environments, we investigated intra-individual associations and group and sex differences in trunk muscle endurance, strength, and flexibility among 74 (35 F, 39 M; age range: 18-61 years) adults from the same Kalenjin-speaking population in western Kenya. We specifically compared men and women from an urban community with professions that do not involve manual labor with rural subsistence farmers, including women who frequently carry heavy loads.

METHODS

Trunk muscle endurance, strength, and flexibility were measured with exercise tests and electromyography (EMG).

RESULTS

We found a positive correlation between trunk extensor strength and endurance (R = .271, p ≤ .05) and no associations between strength or endurance and flexibility. Rural women had higher trunk extensor and flexor endurance, EMG-determined longissimus lumborum endurance, and trunk extensor strength than urban women (all p ≤ .05). Rural women had higher trunk extensor and flexor endurance than rural men (both p ≤ .05). Urban women had lower trunk flexor and extensor endurance than urban men (both p ≤ .01).

CONCLUSIONS

High levels of physical activity among nonindustrial subsistence farmers, particularly head carrying among women, appear to be associated with high trunk muscle endurance and strength, which may have important benefits for helping maintain musculoskeletal health.

Test-Retest Reliability and Known-Groups Validity of Trunk Muscle Tests in People With Multiple Sclerosis: A Cross-Sectional, Case-Control Study

OBJECTIVE

Research on muscle performance testing reliability in people with multiple sclerosis (MS) has focused on limb performance while less is known about trunk strength and endurance. This work aims to 1) establish test-retest reliability of trunk flexion, lateral flexion, and extension strength tests, and plank, side bridge, and Biering-Sørensen endurance tests in people with MS and matched healthy controls (HCs); 2) analyze known-groups validity of these tests in people with MS and HCs; 3) to compare groups for side-to-side differences; and 4) to describe the relationships between trunk performance and functional mobility tests.

METHODS

Fifteen people with MS (median Expanded Disability Status Scale = 3) and 15 HCs underwent 2 trunk isometric strength and endurance testing sessions. Mobility was evaluated by Timed Up-and-Go test. Intraclass correlation coefficient, SEM, and minimal detectable change (MDC) were calculated. Between-group differences in trunk performance were tested using the t test for independent measures. Between-group differences in an asymmetry index were analyzed by independent t test. Bivariate correlations between trunk tests and mobility were also examined.

RESULTS

All trunk tests showed good-to-excellent relative reliability in both groups (intraclass correlation coefficient > 0.71). Regarding absolute reliability, strength tests were associated with low intersession variability in both groups (MDC: MS, 11.23%-36.45%; HCs, 26.60%-31.98%). Conversely, endurance tests showed higher variability scores in people with MS (MDC: MS, 69.55%-116.50%; HCs, 29.57%-54.40%). People with MS displayed significantly lower trunk performance. Likewise, the asymmetry index showed significantly higher scores in people with MS for endurance assessment but not in strength tests. Significant correlations were detected in people with MS between Timed Up-and-Go and several trunk tests (r = 0.63-0.70).

CONCLUSIONS

SEM and MDC scores revealed similar consistency and variability between groups for strength tests, whereas higher variability was observed for endurance tests in people with MS. Trunk strength tests are reliable and present discriminant validity to distinguish mildly disabled people with MS from HCs. Conversely, the high measurement error and variability of the endurance tests may hinder their application in intervention programs.

IMPACT

Determining the reliability and validity of the tests currently used to assess trunk function is of the greatest importance for people with MS (who show not only impaired trunk function but also wide fluctuations in performance), as it requires consistent and accurate measurements that are sensitive enough to detect minimal changes induced by rehabilitation.

Lumbopelvic sagittal standing posture associations with anthropometry, physical activity levels and trunk muscle endurance in healthy adults

Background

Various factors, inherited and acquired, are associated with habitual spinal postures.

Objective

The purpose of this study was to identify the relationships between trunk muscle endurance, anthropometry and physical activity/inactivity and the sagittal standing lumbopelvic posture in pain-free young participants.

Methods

In this study, 112 healthy young adults (66 females), with median (IQR) age of 20 years (18.2-22 years), without low back pain, injury or trauma were included. Lumbar curve (LC) and sacral slope (SS) angles were measured in standing with a mobile phone application (iHandy level). Anthropometric, physical activity/inactivity levels (leisure-time sport involvement and sitting hours/day) and abdominal (plank prone bridge test) and paraspinal (Sorensen test) isometric muscle endurance measures were collected.

Results

LC and SS angles correlated significantly ( r = 0 . 80 , p < 0 . 001 ). Statistically significant differences for both LC ( p = 0 . 023 ) and SS ( p = 0 . 013 ) angles were identified between the male and female participants. A significant negative correlation was identified between the abdominal endurance time and LC ( r =- 0 . 27 , p = 0 . 004 ); however, the power of this result (56%) was not sufficiently high. The correlation between abdominal endurance and SS was non-significant ( r =- 0 . 17 , p = 0 . 08 ). In addition, no significant associations were identified between either of the sagittal lumbopelvic angles (LC-SS) in standing and the participants' body mass index (BMI), paraspinal endurance, leisure-time sport involvement or sitting hours/day.

Conclusion

The potential role of preventive exercise in controlling lumbar lordosis via enhancement of the abdominal muscle endurance characteristics requires further confirmation. A subsequent study, performed in a larger population of more diverse occupational involvement and leisure-time physical activity levels, is proposed.

Graded activity with and without daily-monitored-walking in patients with type 2 diabetes with low back pain: secondary analysis of a randomized-clinical trial

Background

Graded activity is gradually emerging as a preferred choice in improving psychosocial outcomes including pain self-efficacy, fear-avoidance beliefs, and back-pain beliefs in the general population with low back pain (LBP). Such evidence is, however, lacking among patients with concomitant LBP and type-2 diabetes mellitus (T2DM). This secondary analysis of a randomized control trial aimed to compare the efficacy between graded activity augmented with additional daily-monitored-walking and graded activity alone on disability, pain self-efficacy (PSE), fear-avoidance beliefs (FAB), back-pain beliefs (BPB) and glycaemic control (HbA1c) in patients with concomitant LBP and T2DM.

Methods

Fifty-eight patients with concomitant LBP and T2DM were randomised into two groups, graded activity with daily-monitored-walking group (GAMWG = 29) or (graded activity group (GAG = 29) in this 12-week single-blind trial. Both groups received graded activity (home/work-place visits, back school and sub-maximal exercises) while the GAMWG received additional daily-monitored-walking. Disability and selected psychosocial outcomes were assessed at weeks 0, 4, 8 and 12 using Roland-Morris disability, fear-avoidance behaviour, pain self-efficacy and back belief questionnaires. Glycaemic control was assessed at weeks 0 and 12 using a point-of-care system (In2it, Biorad Latvia). Data were analysed using mean, median, Friedman’s ANOVA, Mann-Whitney test and t-tests.

Results

Participants’ mean age was 48.3 ± 9.4 years (95%CI: 45.6, 50.9) while 35.3% were males. The GAMWG participants (n = 25) had better outcomes (P < 0.05) than GAG participants (n = 26) on PSE (1.0, 3.0; r = − 0.1) and FAB (0.01, − 2.0; r = − 0.1) at week 4, LBP-related disability (0.01, − 2.0; r = − 0.2) at week 8 and glycaemic control at week 12 (− 0.59 ± 0.51%,-0.46 ± 0.22%). No other between-group comparisons were statistically significant.

Conclusion

Graded activity with daily-monitored-walking provided earlier improvements on disability, pain self-efficacy, fear-avoidance beliefs, and glycaemic control, but not back pain beliefs, in patients with concomitant LBP and T2DM.

Trial registration

PACTR201702001728564; 26 July, 2016 (retrospectively registered).

Influence of Wearing Ballistic Vests on Physical Performance of Danish Police Officers: A Cross-Over Study

Purpose: We aimed to investigate the influence of wearing a ballistic vest on physical performance in police officers. Methods: We performed a cross-over study to investigate the influence of wearing a ballistic vest on reaction and response time, lumbar muscle endurance and police vehicle entry and exit times. Reaction and response time was based on a perturbation setup where the officers’ pelvises were fixed and EMG of lumbar and abdominal muscles was recorded. We used a modified Biering–Sørensen test to assess the lumbar muscle endurance and measured duration of entry and exit maneuvers in a variety of standard-issue police cars. Results: There was a significant difference of 24% in the lumbar muscle endurance test (no vest: 151 s vs. vest: 117 s), and the police officers experienced higher physical fatigue after the test when wearing a vest. Furthermore, officers took longer to both enter and exit police cars when wearing a vest (range: 0.24–0.56 s) depending on the model of the vehicle. There were no significant differences in reaction and response times between the test conditions (with/without vest). Discussion and Conclusion: Wearing of a ballistic vest significantly influenced the speed of movement in entry and exit of police cars and lumbar muscle endurance, although it does not seem to affect reaction or response times. The ballistic vest seems to impair performance of tasks that require maximal effort, which calls for better designs of such vests.

Muscular Fitness and Work Ability among Physical Therapists

The Work Ability Index (WAI) is a validated and widely used tool in occupational research. However, normative values for physical therapists (PTs) by age and sex are lacking. Although the nature of PTs' work is physically demanding, it is unknown whether muscular fitness is associated with their WAI. This study sought to provide reference WAI data for Spanish PTs and to evaluate the association between PTs' muscular fitness and WAI. Data on WAI of 1005 PTs were collected using a questionnaire. A subgroup (n = 68) performed a battery of physical tests including grip strength, push-ups and back-extension endurance. Associations between muscular fitness and WAI were evaluated using logistic regression controlling for various confounders. PTs aged 50 years or older had lower WAI scores than their younger counterparts. PTs with high back-extension endurance scored 3.5 (95% CI) higher in the WAI than those with low endurance. No associations were found between grip strength or number of push-ups and WAI. Our findings seem to highlight the importance of muscular fitness in PTs, especially the back-extension endurance.

Notions of "optimal" posture are loaded with meaning. Perceptions of sitting posture among asymptomatic members of the community

BACKGROUND

Notions of "optimal" posture are widespread in modern society and strongly interconnected with preconceived beliefs.

OBJECTIVES

To quantitatively evaluate spinal posture among members of the community during habitual sitting, and when asked to assume an "optimal" posture.

DESIGN

Observational study.

METHODS

Marker-based kinematic analyses of the head, spine, and pelvis were conducted on 100 individuals. Habitual sitting posture and self-perceived "optimal" posture, and whether participants believed that their habitual sitting reflected an "optimal" posture, were evaluated. The Wilcoxon signed-rank test assessed angular differences between the two postures adopted. Exploratory post-hoc analyses were conducted by using the Mann-Whitney U test to assess differences between genders.

RESULTS

None of the participants stated that their habitual sitting was "optimal". Statistically significant differences were observed in most of the measured angles (p < 0.001) between habitual and self-perceived "optimal" posture. In habitual sitting posture, a significant interaction with gender was found only in the thoracolumbar (p < 0.05) and pelvic (p < 0.001) angles, with small effect sizes. In self-perceived "optimal" posture females were more extended in the head, upper thoracic, lower thoracic, lumbar and pelvic (p < 0.01) regions, than the males.

CONCLUSIONS

A group of young, asymptomatic participants, consistently changed their habitual sitting posture to a more upright posture when asked to assume an "optimal" sitting posture, although the amount of change observed varied between spinal regions. These findings also highlight gender differences in not just habitual sitting posture, but also the degree to which habitual sitting posture is modified when trying to assume an "optimal" sitting posture.