Assessing the Preservation of Lumbar Lordotic Curvature in Everyday Sitting Conditions Assessed with an Inertial Measurement System.

Background/Objectives: Lumbar lordotic curvature (LLC), closely associated with low back pain (LBP) when decreased, is infrequently assessed in clinical settings due to the spatiotemporal limitations of radiographic methods. To overcome these constraints, this study used an inertial measurement system to compare the magnitude and maintenance of LLC across various sitting conditions, categorized into three aspects: verbal instructions, chair type, and desk task types. Methods: Twenty-nine healthy participants were instructed to sit for 3 min with two wireless sensors placed on the 12th thoracic vertebra and the 2nd sacral vertebra. The lumbar lordotic angle (LLA) was measured using relative angles for the mediolateral axis and comparisons were made within each sitting category. Results: The maintenance of LLA (LLAdev) was significantly smaller when participants were instructed to sit upright (-3.7 ± 3.9°) compared to that of their habitual sitting posture (-1.2 ± 2.4°) (p = 0.001), while the magnitude of LLA (LLAavg) was significantly larger with an upright sitting posture (p = 0.001). LLAdev was significantly larger when using an office chair (-0.4 ± 1.1°) than when using a stool (-3.2 ± 7.1°) (p = 0.033), and LLAavg was also significantly larger with the office chair (p < 0.001). Among the desk tasks, LLAavg was largest during keyboard tasks (p < 0.001), followed by mouse and writing tasks; LLAdev showed a similar trend without statistical significance (keyboard, -1.2 ± 3.0°; mouse, -1.8 ± 2.2°; writing, -2.9 ± 3.1°) (p = 0.067). Conclusions: Our findings suggest that strategies including the use of an office chair and preference for computer work may help preserve LLC, whereas in the case of cueing, repetition may be necessary.

Redundant nerve roots on magnetic resonance imaging can predict ongoing denervation in patients with lumbar spinal stenosis.

INTRODUCTION/AIMS: Redundant nerve roots (RNRs) are abnormally elongated and tortuous nerve roots that develop secondary to degenerative spinal stenosis. RNRs have been associated with poorer clinical outcomes after decompression surgery; however, studies on their clinical characteristics are limited. This study aimed to investigate the association between RNRs and denervation potentials, that is, abnormal spontaneous activity (ASA), on electromyography. METHODS: We retrospectively reviewed data of patients who underwent an electrodiagnostic study of the lower extremities between January 2020 and March 2023. Of these, patients with lumbar central spinal stenosis, as seen on magnetic resonance imaging, were included. We analyzed clinical and imaging data, including presence of ASA, and compared them according to the presence of RNRs. Multivariable logistic regression analysis was employed to identify factors associated with development of ASA. RESULTS: Among the 2003 patients screened, 193 were included in the study. RNRs were associated with advanced age (p < .001), longer symptom duration (p = .009), smaller cross-sectional area of the dural sac at the stenotic level (p < .001), and higher frequency of ASA (p < .001). Higher probability of ASA was correlated with greater RNR severity (p < .001). In the multivariable logistic regression analysis, ASA occurrence was associated with smaller cross-sectional area, multiple stenotic sites, and severe-grade RNRs. DISCUSSION: The presence of RNRs, particularly severe-grade RNRs, was identified as a significant risk factor for the development of ASA on electromyography. This finding may aid physicians in estimating the prognosis of patients with central spinal stenosis.

Long-term effects of lumbar flexion versus extension exercises for chronic axial low back pain: a randomized controlled trial.

This study aimed to compare the long-term effects of flexion- and extension-based lumbar exercises on chronic axial low back pain (LBP). This was a 1-year follow-up of a prospective, assessor-blind, randomized controlled trial. Patients with axial LBP (intensity ≥ 5/10) for > 6 months allocated to the flexion or extension exercise group. Patients underwent four sessions of a supervised treatment program and were required to perform their assigned exercises daily at home. Clinical outcomes were obtained at baseline, 1, 3, 6 months, and 1-year. A total of 56 patients (age, 54.3 years) were included, with 27 and 29 in the flexion and extension groups, respectively. Baseline pain and functional scales were similar between both groups. The mean (± standard deviation) baseline average back pain was 6.00 ± 1.00 and 5.83 ± 1.20 in the flexion and extension groups, respectively. At 1-year, the average pain was 3.78 ± 1.40 and 2.26 ± 2.62 (mean between-group difference, 1.52; 95% confidence interval 0.56-2.47; p = 0.002), favoring extension exercise. The extension group tended to have more improvements in current pain, least pain, and pain interference than the flexion group at 1-year. However, there was no group difference in worst pain and functional scales. In this controlled trial involving patients with chronic axial LBP, extension-based lumbar exercise was more effective in reducing pain than flexion-based exercises at 1-year, advocating lumbar extension movement pattern as a component for therapeutic exercise for chronic LBP.Clinical Trial Registration No.: NCT02938689 (Registered on www.clinicaltrial.gov ; first registration date was 19/10/2016).

Relationships Between Skeletal Muscle Mass, Lumbar Lordosis, and Chronic Low Back Pain in the Elderly.

OBJECTIVE: Loss of skeletal muscle mass is known to be associated with multiple morbidities. However, there is a dearth of reports on its association with lumbar lordosis and musculoskeletal pain. The aim of this study was to delineate the cross-sectional relationship between loss of skeletal muscle mass, lumbar lordosis, and chronic low back pain (CLBP). METHODS: A total of 721 medical records were reviewed, and data from 165 older subjects (over 65 years old; 81 men and 84 women) were retrospectively analyzed. Subjects were categorized into either the CLBP group (back pain for more than 6 months; 35 men and 36 women) or the control group (46 men and 48 women). The modified skeletal muscle mass index (MSMI, appendicular skeletal muscle mass [kg]/weight [kg] × 100), assessed by bioelectrical impedance analysis, and lumbar lordotic angle (LLA) were measured and compared between the CLBP group and the control group. The correlation between MSMI and LLA was investigated. RESULTS: The LLA of men and women in the CLBP group was significantly lower than that of the control group (p < 0.05). The MSMI was decreased in the CLBP group compared to the control group (p < 0.05). For both sexes, positive correlations were observed between the MSMI and LLA. CONCLUSION: A close cross-sectional relationship was observed between MSMI, LLA, and CLBP. This suggests a potential interaction between the reduction in skeletal muscle mass and altered lumbar spine sagittal alignment, which could lead to CLBP.

Rural-urban differences of sarcopenia and spinal health in the older women: a comparative observational study.

INTRODUCTION: We aimed to investigate the correlation between spinal sarcopenia, spinal sagittal balance (SSB), and spinal function in older women living in rural areas versus those of the older urban women in our previous study. METHODS: Twenty-five older rural-dwelling women aged more than 70 years were compared with 24 older urban-dwelling women from our previous study. Demographic variables, conventional and spinal sarcopenic indices, variable functional outcome parameters, occupational state, and exercise participation rate were evaluated. We also measured the isometric back extensor strength, radiological parameters for SSB on whole-spine radiography, and volumetric parameters of the lumbar extensor muscle on computed tomography. RESULTS: There were no significant intergroup differences in demographic variables or the prevalence of sarcopenia. Older women in rural areas had greater handgrip strength than those in urban areas (22.7±3.7 kg v 20.0±3.4 kg, p=0.010). However, their mean lumbar lordosis angle was lower (31.7±15.3° v 42.3±11.2°, p=0.012). Isometric back extensor strength was lower in rural women than in urban women. The vocational activity participation rate of rural women was significantly higher (84% v 12.5%, p<0.001), whereas their exercise participation rate was significantly lower (60% v 92%, p<0.001). CONCLUSION: Older women in rural areas had greater handgrip strength and vocational participation rates but lower back extensor strength and exercise participation rates. Therefore, more attention is needed for healthcare services to support their spinal health and exercise habits.

Cost-utility analysis of endoscopic lumbar discectomy following a uniform clinical pathway in the Korean national health insurance system.

INTRODUCTION: Full-endoscopic lumbar discectomy (FELD) is a type of minimally invasive spinal surgery for lumbar disc herniation (LDH). Sufficient evidence exists to recommend FELD as an alternative to standard open microdiscectomy, and some patients prefer FELD due to its minimally invasive nature. However, in the Republic of Korea, the National Health Insurance System (NHIS) controls the reimbursement and use of supplies for FELD, but FELD is not currently reimbursed by the NHIS. Nonetheless, FELD has been performed upon patients' request, but providing FELD for patients' sake is inherently an unstable arrangement in the absence of a practical reimbursement system. The purpose of this study was to conduct a cost-utility analysis of FELD to suggest appropriate reimbursements. METHOD: This study was a subgroup analysis of prospectively collected data including 28 patients who underwent FELD. All patients were NHIS beneficiaries and followed a uniform clinical pathway. Quality-adjusted life years (QALYs) were assessed with a utility score using the EuroQol 5-Dimension (EQ-5D) instrument. The costs included direct medical costs incurred at the hospital for 2 years and the price of the electrode ($700), although it was not reimbursed. The costs and QALYs gained were used to calculate the cost per QALY gained. RESULT: Patients' mean age was 43 years and one-third (32%) were women. L4-5 was the most common surgical level (20/28, 71%) and extrusion was the most common type of LDH (14, 50%). Half of the patients (15, 54%) had jobs with an intermediate level of activity. The preoperative EQ-5D utility score was 0.48±0.19. Pain, disability, and the utility score significantly improved starting 1 month postoperatively. The average EQ-5D utility score during 2 years after FELD was estimated as 0.81 (95% CI: 0.78-0.85). For 2 years, the mean direct costs were $3,459 and the cost per QALY gained was $5,241. CONCLUSION: The cost-utility analysis showed a quite reasonable cost per QALY gained for FELD. A comprehensive range of surgical options should be provided to patients, for which a practical reimbursement system is a prerequisite.

A cost-utility analysis between decompression only and fusion surgery for elderly patients with lumbar spinal stenosis and sagittal imbalance.

Lumbar spinal stenosis (LSS) and sagittal imbalance are relatively common in elderly patients. Although the goals of surgery include both functional and radiological improvements, the criteria of correction may be too strict for elderly patients. If the main symptom of patients is not forward-stooping but neurogenic claudication or pain, lumbar decompression without adding fusion procedure may be a surgical option. We performed cost-utility analysis between lumbar decompression and lumbar fusion surgery for those patients. Elderly patients (age > 60 years) who underwent 1-2 levels lumbar fusion surgery (F-group, n = 31) or decompression surgery (D-group, n = 40) for LSS with sagittal imbalance (C7 sagittal vertical axis, C7-SVA > 40 mm) with follow-up ≥ 2 years were included. Clinical outcomes (Euro-Quality of Life-5 Dimensions, EQ-5D; Oswestry Disability Index, ODI; numerical rating score of pain on the back and leg, NRS-B and NRS-L) and radiological parameters (C7-SVA; lumbar lordosis, LL; the difference between pelvic incidence and lumbar lordosis, PI-LL; pelvic tilt, PT) were assessed. The quality-adjusted life year (QALY) and incremental cost-effective ratio (ICER) were calculated from a utility score of EQ-5D. Postoperatively, both groups attained clinical and radiological improvement in all parameters, but NRS-L was more improved in the F-group (p = 0.048). ICER of F-group over D-group was 49,833 US dollars/QALY. Cost-effective lumbar decompression may be a recommendable surgical option for certain elderly patients, despite less improvement of leg pain than with fusion surgery.

Reference Standards for Nerve Conduction Studies of Individual Nerves of Lower Extremity With Expanded Uncertainty in Healthy Korean Adults.

OBJECTIVE: To develop a set of reference standards for tibial motor, common peroneal motor, sural sensory, and superficial peroneal sensory nerve conduction studies (NCSs) with expanded uncertainty in a healthy Korean population. METHODS: Standardized procedures were conducted for individual lower extremity NCSs of 199 healthy participants in their 20s (n=100) and 50s (n=99). Mean values and expanded uncertainties for parameters were analyzed with thorough consideration of multiple uncertainty factors under the International Guide to the Expression of Uncertainty in Measurement. In addition, side-to-side differences in onset latency, amplitude, and nerve conduction velocity (NCV) were analyzed. RESULTS: Mean (reference range) for distal onset latency, baseline to negative peak amplitude, NCV of tibial motor nerve in males in their 20s were 4.3 ms (3.1-5.4 ms), 7.1 mV (3.4-10.9 mV), and 50.7 m/s (42.2-59.3 m/s), respectively; sural sensory nerve baseline to negative peak amplitude in males in their 20s was 21.7 µV (8.3-35.2 µV). Including the aforementioned data, we present a vast dataset of normative mean values and expanded uncertainties for NCSs of the leg in a healthy Korean population. Furthermore, upper limits for normal side-to-side differences for onset latency, amplitude, and NCV of each nerve are suggested. CONCLUSION: To our knowledge, this is the first study to present the reference standards of leg NCSs with consideration for multifactorial uncertainties in an Asian population. We expect these results to help practitioners make reliable and reproducible clinical decisions.

Effect of Stretching of Spastic Elbow Under Intelligent Control in Chronic Stroke Survivors-A Pilot Study.

Objective: To assess the short-term effects of strenuous dynamic stretching of the elbow joint using an intelligent stretching device in chronic spastic stroke survivors. Methods: The intelligent stretching device was utilized to provide a single session of intensive stretching to the spastic elbow joint in the sagittal plane (i.e., elbow flexion and extension). The stretching was provided to the extreme range, safely, with control of the stretching velocity and torque to increase the joint range of motion (ROM) and reduce spasticity and joint stiffness. Eight chronic stroke survivors (age: 52.6 ± 8.2 years, post-stroke duration: 9.5 ± 3.6 years) completed a single 40-min stretching intervention session. Elbow passive and active ROM, strength, passive stiffness (quantifying the non-reflex component of spasticity), and instrumented tendon reflex test of the biceps tendon (quantifying the reflex component of the spasticity) were measured before and after stretching. Results: After stretching, there was a significant increase in passive ROM of elbow flexion (p = 0.021, r = 0.59) and extension (p = 0.026, r = 0.59). Also, elbow active ROM and the spastic elbow flexors showed a trend of increase in their strength. Conclusion: The intelligent stretching had a short-term positive influence on the passive movement ROM. Hence, intelligent stretching can potentially be used to repeatedly and regularly stretch spastic elbow joints, which subsequently helps to reduce upper limb impairments post-stroke.

Mesenchymal Stem Cells Use in the Treatment of Tendon Disorders: A Systematic Review and Meta-Analysis of Prospective Clinical Studies.

OBJECTIVE: To evaluate the efficacy and safety of mesenchymal stem cells (MSCs) therapy in patients with tendon disorders enrolled in prospective clinical studies. METHODS: We systematically searched prospective clinical studies that investigated the effects of MSC administration on human tendon disorders with at least a 6-month follow-up period in the PubMed-MEDLINE, EMBASE, and Cochrane Library databases. The primary outcome of interest was the change in pain on motion related to tendon disorders. Meta-regression analyses were performed to assess the relationship between MSC dose and pooled effect sizes in each cell dose. RESULTS: Four prospective clinical trials that investigated the effect of MSCs on tendon disorders were retrieved. MSCs showed a significant pooled effect size (overall Hedges' g pooled standardized mean difference=1.868; 95% confidence interval, 1.274-2.462; p<0.001). The treatment with MSCs improved all the aspects analyzed, namely pain, functional scores, radiological parameters (magnetic resonance image or ultrasonography), and arthroscopic findings. In the meta-regression analysis, a significant cell dose-dependent response in pain relief (Q=9.06, p=0.029) was observed. CONCLUSION: Our meta-analysis revealed that MSC therapy may improve pain, function, radiological, and arthroscopic parameters in patients with tendon disorders. A strong need for large-scale randomized controlled trials has emerged to confirm the long-term functional improvement and adverse effects of MSC therapies in tendon disorders.

Novel lateral whole-body dual-energy X-ray absorptiometry of lumbar paraspinal muscle mass: results from the SarcoSpine study.

BACKGROUND: Here, we aimed to propose novel lateral whole-body dual-energy X-ray absorptiometry (lateral DXA) as a simple tool for measuring spinal muscle mass and investigate the feasibility of lateral DXA to measure lumbar paraspinal muscle (LPM) mass compared with lumbosacral spine three-dimensional magnetic resonance imaging (3D MRI). METHODS: Twenty consecutive participants were enrolled from a prospective observational cohort (SarcoSpine study). Lateral DXA was scanned with each participant in the lateral decubitus position. The region of interest was defined to analyse the LPM mass. LPM total volume, LPM cross-sectional area at the L3 mid-vertebra and L4/5 mid-disc levels and each signal intensity were measured by 3D MRI. Isokinetic and isometric back extensor muscle strengths as well as back extensor endurance were examined. The correlation between lateral DXA-based mass (weight) and 3D MRI-based LPM volume was analysed. RESULTS: The mean age of the 20 participants (15 women, 5 men) was 72.2 ± 4.9 years. LPM mass by lateral DXA was positively correlated with LPM volume by 3D MRI (ß = 0.333, r = 0.692, p < 0.001) and negatively correlated with signal intensity of the total LPM (ß = -0.263, r = -0.530, p = 0.016). LPM mass was also correlated with appendicular limb muscle mass, handgrip strength and gait speed as well as back extensor endurance (r = 0.620, p = 0.004). CONCLUSIONS: Our data suggest that LPM mass assessed by lateral DXA was positively correlated with LPM volume by 3D MRI in older adults. Lateral DXA may be a potential substitute for the cross-sectional area measurement of LPM mass. Further studies are required to validate this lateral DXA technique.

Measurement and Correction of Stooped Posture during Gait Using Wearable Sensors in Patients with Parkinsonism: A Preliminary Study.

Stooped posture, which is usually aggravated during walking, is one of the typical postural deformities in patients with parkinsonism. However, the degree of stooped posture is difficult to quantitatively measure during walking. Furthermore, continuous feedback on posture is also difficult to provide. The purpose of this study is to measure the degree of stooped posture during gait and to investigate whether vibration feedback from sensor modules can improve a patient's posture. Parkinsonian patients with stooped posture were recruited for this study. Two wearable sensors with three-axis accelerometers were attached, one at the upper neck and the other just below the C7 spinous process of the patients. After being calibrated in the most upright posture, the sensors continuously recorded the sagittal angles at 20 Hz and averaged the data at every second during a 6 min walk test. In the control session, the patients walked with the sensors as usual. In the vibration session, sensory feedback was provided through vibrations from the neck sensor module when the sagittal angle exceeded a programmable threshold value. Data were collected and analyzed successfully in a total of 10 patients. The neck flexion and back flexion were slightly aggravated during gait, although the average change was <10° in most patients in both measurement sessions. Therefore, it was difficult to evaluate the effect of sensory feedback through vibration. However, some patients showed immediate response to the feedback and corrected their posture during gait. In conclusion, this preliminary study suggests that stooped posture could be quantitatively measured during gait by using wearable sensors in patients with parkinsonism. Sensory feedback through vibration from sensor modules may help in correcting posture during gait in selected patients.

Early Quantitative Partial Weight-Bearing Exercise After Periarticular Fractures of the Tibia Using a Lower-Body Positive-Pressure Treadmill: A Case Series.

The partial weight-bearing protocol after lower limb fracture is an important issue in postoperative rehabilitation. Because it is difficult to quantify the actual weight load and provide a constant weight, the protocol is unestablished. By training with a lower-body positive-pressure treadmill and using an in-shoe pressure-measuring device, partial weight-bearing exercise can be performed with quantified loads. This case series illustrates the applicability of an early quantitative partial weight-bearing rehabilitation program using lower-body positive-pressure treadmill with an in-shoe pressure-measuring device after periarticular tibial fractures, which provides a quantitatively predetermined constant load.

Optimal Elbow Positions for Identification of the Radial Collateral Ligament Using Ultrasonography.

BACKGROUND: The standard position for examining the lateral elbow with ultrasonography is an "extended" or "slightly flexed" position. However, because the radial collateral ligament (RCL) is more deeply attached on the lateral epicondyle than the common extensor tendon, an anisotropic artifact of the RCL could be observed in the conventional positions, making it difficult to fully visualize the RCL. OBJECTIVES: To determine optimal elbow positions for accurate identification of the RCL and to explore the relevant landmarks in ultrasonography. DESIGN: Prospective study. SETTING: Tertiary university hospital. PARTICIPANTS: Forty healthy elbows of 20 participants. METHODS: The RCL was evaluated using ultrasonography in six elbow flexion positions (0°, 30°, 60°, 90°, 120°, and 140°). The relative depth, defined as the depth of the capitellum subtracted by the depth of the radial head under ultrasonography, was measured at each angle. The rates of successful identification of ultrasonographic landmarks for localizing the RCL were calculated. After ultrasonography, the optimal elbow position for identifying the RCL was determined by group consensus. MAIN OUTCOME MEASUREMENTS: Relative depth between radial head and capitellum, rates of successful identification of ultrasonographic landmarks, and consensus-based determination of the optimal angle. RESULTS: The relative depth significantly decreased with an increase in the flexion angle (P for trend <.001), approaching zero at the angles of 90° and 120°. The rates of successful identification of the superior tubercle, hyperechogenic line, and anterior and posterior tubercles were 100%, 100%, 90%, and 80%, respectively. In the group consensus, the 90° and 120° flexion angles were selected with the highest frequency (90%; 36/40). CONCLUSION: Our findings suggest that elbow flexion at 90° or 120° is optimal for visualization of the RCL with the least possibility of anisotropy under ultrasonography, suggesting that the elbow should be flexed considerably beyond the conventional extended or slightly flexed position.

Low skeletal muscle mass and radiographic osteoarthritis in knee, hip, and lumbar spine: a cross-sectional study.

BACKGROUND: Although several studies have shown that low skeletal muscle mass is correlated with knee osteoarthritis, no studies have investigated the correlation between skeletal muscle mass and hip and lumbar spine osteoarthritis (OA). AIM: This study aimed to delineate the relationship between low skeletal muscle mass and radiographic OA (ROA) of the knee, hip, and lumbar spine. METHODS: This is a cross-sectional study using the public data obtained from the Fifth Korean National Health and Nutrition Examination Survey (2010-2011). We included subjects aged ≥ 50 years who completed the surveys (3813 subjects). ROA was assessed by knee, hip, and lumbar spine radiographs and defined as Kellgren/Lawrence (KL) grade of at least 2 in the knee and lumbar spine, whereas KL grade ≥ 1 in the hip. Multivariate logistic regression analyses were performed to evaluate the effects of low skeletal muscle mass on radiographic joint degeneration. RESULTS: Appendicular skeletal muscle mass (ASM) was higher in subjects with healthy joints than in subjects with knee and lumbar spine ROA (18.9 ± 0.1 kg vs. 17.1 ± 0.2 kg, P < 0.0001 and 18.6 ± 0.1 kg vs. 17.4 ± 0.2 kg, P < 0.0001, respectively), whereas it was higher in those with ROA than in those with healthy hip (17.9 ± 0.1 kg vs. 19.1 ± 0.2 kg P < 0.0001). On multivariate logistic regression analysis, lower skeletal muscle mass independently associated with knee ROA [odds ratio (OR) 1.348; 95% confidence interval (CI) 1.037-1.752]. However, it was inversely associated with lumbar spine ROA (OR 0.786; 95% CI 0.623-0.991). CONCLUSION: Low skeletal muscle mass was independently associated with knee ROA alone, whereas it was inversely associated with lumbar spine ROA. These opposite results might originate from measuring the area of ASM.

Lumbar Stability in Healthy Individuals and Low Back Pain Patients Quantified by Wall Plank-and-Roll Test.

BACKGROUND: Low back pain (LBP) has been linked to the degree of lumbar stability, but evaluating lumbar stability has remained a challenge. Previous research has shown that inertial sensors could be used to quantify motor patterns during the wall plank-and-roll (WPR) test, and that LBP may cause deviations in movement from the general motor patterns observed in healthy individuals. OBJECTIVE: To generalize the lumbar motor patterns during the WPR test in healthy individuals, and to analyze the effect of aging and LBP on the motor patterns during the WPR test. DESIGN: A descriptive, exploratory research with a convenience sample. This study is registered at the Clinical Research Information Service (Korea) under public trial registration numbers KCT0002481 and KCT0002533. SETTING: A biomechanics laboratory of a tertiary university hospital. PARTICIPANTS: 57 healthy individuals (23 men 36.7 ± 15.4 years old and 34 women 42.4 ± 17.7 years old) and 17 patients (5 men 48.4 ± 10.9 years old and 12 women 33.7 ± 9.9 years old) with axial LBP. METHODS: Participants performed the WPR test with 2 inertial sensors placed on the thoracic spine and sacrum. Relative angles between the sensors were calculated to quantify and examine lumbar motion in 3 anatomical planes: axial twist, kyphosis-lordosis, and lateral bending. MAIN OUTCOME MEASURES: General motor patterns during the WPR test in healthy participants were examined, stratified based on age, and changes based on age were analyzed. Motor patterns of LBP patients were compared with those from the healthy group. RESULTS: Movement in the kyphosis-lordosis and lateral bending axes showed little variation in healthy participants, whereas in the axial twist axis there were 2 dominant patterns. A χ 2 test revealed that the distributions of 2 motor patterns in the axial twist axis between the younger group and the older group were significantly different (P < .05). Furthermore, the older group had decreased lordosis at the static position (P = .02) and at the maximal rotating position (P = .03). Compared with the healthy group, LBP patients showed increasing lateral bending at the maximal rotating position (P = .007) and increased lateral bending excursion angle (P = .04) during the WPR test. CONCLUSIONS: A general lumbar motor pattern was observed during the WPR test in the healthy participants, but age contributed to variations in this general pattern. Comparison of motor patterns between healthy individuals and LBP patients revealed a different type of variation in the LBP patients. The results presented should be scrutinized with further research, characterizing specific variations in different subgroups of LBP patients. LEVEL OF EVIDENCE: III.

Prediction of sarcopenia using a combination of multiple serum biomarkers.

Sarcopenia is a gradual loss of skeletal muscle mass and function with aging. Given that sarcopenia has been recognized as a disease entity, effective molecular biomarkers for early diagnosis are required. We recruited 46 normal subjects and 50 patients with moderate sarcopenia aged 60 years and older. Sarcopenia was clinically identified on the basis of the appendicular skeletal muscle index by applying cutoff values derived from the Asian Working Group for Sarcopenia. The serum levels of 21 potential biomarkers were analyzed and statistically examined. Interleukin 6, secreted protein acidic and rich in cysteine, macrophage migration inhibitory factor, and insulin-like growth factor 1 levels differed significantly between the normal and sarcopenia groups. However, in each case, the area under the receiver operating characteristics curve (AUC) was <0.7. Subsequent combination of the measurements of these biomarkers into a single risk score based on logistic regression coefficients enhanced the accuracy of diagnosis, yielding an AUC value of 0.763. The best cutoff value of 1.529 had 70.0% sensitivity and 78.3% specificity (95% CI = 2.80-21.69, p < 0.0001). Combined use of the selected biomarkers provides higher diagnostic accuracy than individual biomarkers, and may be effectively utilized for early diagnosis and prognosis of sarcopenia.

Development of a pressure sensor system for unobtrusive monitoring of abdominal muscle activities.

Surface electromyogram (sEMG) is often used by to objectively measure muscular activity during rehabilitation exercises. sEMG is accurate, but it is unsuitable for uses outside the clinic, and patients can benefit from an unobtrusive device which can be readily used to ubiquitously measure abdominal muscle activation. In this study, we present a pressure sensor system which can be latched onto a belt to measure abdominal muscle activation. sEMG and pressure sensor output were measured in 15 healthy young males during isometric trunk flexion exercise (public trials registration number, KCT0002351), and the results were highly correlated (median R > 0.939). As initial contact force can change the pressure sensor sensitivity, the experiment was performed at two different levels of belt tightness, but the correlations did not significantly improve after tightening the belt, suggesting that the system can be used to ubiquitously and unobtrusively monitor abdominal muscle activity with minimal discomfort.

Recovery of Proprioception in the Upper Extremity by Robotic Mirror Therapy: a Clinical Pilot Study for Proof of Concept.

A novel robotic mirror therapy system was recently developed to provide proprioceptive stimulus to the hemiplegic arm during a mirror therapy. Validation of the robotic mirror therapy system was performed to confirm its synchronicity prior to the clinical study. The mean error angle range between the intact arm and the robot was 1.97 to 4.59 degrees. A 56-year-old male who had right middle cerebral artery infarction 11 months ago received the robotic mirror therapy for ten 30-minute sessions during 2 weeks. Clinical evaluation and functional magnetic resonance imaging (fMRI) studies were performed before and after the intervention. At the follow-up evaluation, the thumb finding test score improved from 2 to 1 for eye level and from 3 to 1 for overhead level. The Albert's test score on the left side improved from 6 to 11. Improvements were sustained at 2-month follow-up. The fMRI during the passive motion revealed a considerable increase in brain activity at the lower part of the right superior parietal lobule, suggesting the possibility of proprioception enhancement. The robotic mirror therapy system may serve as a useful treatment method for patients with supratentorial stroke to facilitate recovery of proprioceptive deficit and hemineglect.