Effects of different bed heights on the physical burden of physiotherapists during manual therapy: an experimental study.

This study aimed to determine the effect of physiotherapists' physical burden caused by different bed heights during manual therapy. Thirty-three male physiotherapists performed tasks simulating lumbar massage and passive hip abduction range-of-motion exercise (ROM) on the beds with low height (LH) and adjusted height (AH), with each task performed three times. The anterior inclination angle of the physiotherapist's trunk was measured, the surface electromyograms of the erector spinae and trapezius muscles were recorded, and perceived stress was assessed. The indexes obtained were statistically compared for different bed heights. Additionally, the lumbar disc compression force and flexion torque were estimated. The lumbar burden caused by the excessive bending and the biomechanical burden and perceived stress were stronger at LH than AH. In ROM tasks using the right hand, the muscle activity was lower at the left lumbar region at LH than at AH. At LH, the anterior inclination angle increased and the lumbar muscle activity declined as the number of tasks increased. The burden on the shoulders was not significantly different by bed heights. Our results showed that, when physiotherapists perform manual therapy, it is necessary to adjust the bed height to reduce physical burden and ensure higher quality of service.

Comparison of Pelvic Tilt Before and After Hip Flexor Stretching in Healthy Adults.

OBJECTIVE: The purpose of this study was to assess the association between hip flexor length and pelvic tilt or lumbar lordosis by quantifying the effect of stretching on pelvic tilt and lumbar lordosis. METHODS: We quantified pelvic tilt and lumbar lordosis before and after a single session of passive hip flexor stretching in a sample of 23 male participants. Changes in hip flexor length were also characterized, using a Thomas test protocol to measure passive hip extension in supine lying. We investigated both the mean effect of the stretching protocol and potential correlations between changes in passive hip extension and changes in pelvic tilt or lumbar lordosis. RESULTS: Following the stretching protocol, there was a mean increase of 2.6° (P < .001) in passive hip extension and a corresponding mean reduction of 1.2° (P < .001) in anterior pelvic tilt. However, there was no change in lumbar lordosis, nor were there any meaningful correlations between change in passive hip extension and change in pelvic tilt or lumbar lordosis. CONCLUSION: The results suggest that hip muscle stretching may lead to immediate reductions in pelvic tilt during relaxed standing. Such stretching programs could play an important role in interventions designed to improve standing postural alignment.

Lumbar Spine Kinematics in Asymptomatic People When Changing Body Position From Sitting to Standing.

OBJECTIVE: The purpose of this study was to assess the lumbar spine kinematics in 3 movement axes in asymptomatic individuals in the sit-to-stand (STS) movement performed in a habitual, flexion, or extension manner. METHODS: There were 30 participants (16 women, 14 men), aged 23 to 37 years. Each participant performed an STS test. We registered the total time of the STS movement and the maximum acceleration of the lumbar spine in the vertical, anteroposterior, and mediolateral axes. The examination of the movement pattern was performed with the use of a BTS G-sensor device. RESULTS: The highest movement dynamics in the lumbar spine were observed during the STS performed in a habitual manner in the 3 axes (P < .01). The lowest movement dynamics ere associated with the extension STS pattern. The flexion pattern differed from the habitual one in total performance time in both groups (P < .01). There were no significant differences in kinematic lumbar spine between sexes. CONCLUSION: The kinematics of the STS movement for asymptomatic individuals were characterized by significant variability in the maximum acceleration in the 3 axes. The highest movement dynamics were observed during the STS performed in a habitual manner, and the lowest dynamics with the extension pattern of STS.

Inter-tester Reliability of Lumbar Lordosis Posture Classification Using a Novel Screening Device.

OBJECTIVE: The purpose of this study was to investigate the inter-tester reliability of lumbar lordosis posture using a novel screening device. METHODS: A total of 33 healthy young male participants participated in the study. Two examiners measured the regional upper and lower lumbar lordosis angles of the participants in the standing position using a flexible ruler. The bent flexible ruler maintained a fixed shape and was transferred to a protractor for angle measurement. Two examiners classified each participant into one of 4 lumbar spine categories and measured the upper and lower regional lumbar lordosis angles. RESULTS: The agreement level between the 2 examiners in assessing healthy participants was 87.9%. The calculated kappa coefficient was 0.79 (95% CI = 0.86-0.97), reflecting a substantial level of agreement. CONCLUSION: Our results suggest that our novel screening device for assessing upper and lower lumbar angles showed good inter-tester reliability in posture classification. Our findings may be useful for health care professionals for managing sagittal lumbar posture in asymptomatic younger individuals; however, more testing is still needed.

Effect of Whole-Body Vibration Exercise on Power Profile and Bone Mineral Density in Postmenopausal Women With Osteoporosis: A Randomized Controlled Trial.

OBJECTIVE: The purpose of this study was to investigate the effect of whole-body vibration (WBV) on muscle work and bone mineral density (BMD) of the lumbar vertebrae and femur in postmenopausal women. METHODS: Forty-three postmenopausal women with low BMD were randomly assigned to WBV and control groups. Both groups received calcium and vitamin D supplementations once daily, while the WBV group additionally received WBV exercise (twice/wk) for 24 successive weeks. Qualisys gait analysis system was used to measure hip power generation by hip extensors (H1S) and flexors (H3S), hip power absorption by hip flexors (H2S), knee power absorption by quadriceps during loading response (K1S) and preswing (K3S), knee power absorption by hamstring (K4S), knee power generation by quadriceps (K2S), ankle power absorption by dorsiflexors (A1S) and plantar flexors (A2S), and ankle power generation by plantar flexors (A3S). Also, dual-energy X-ray absorptiometry was used to measure BMD of the lumbar vertebrae and femur before and after the intervention. RESULTS: There were significant increases (P < .05) in the hip muscle work (H1S, H2S, and H3S), knee muscle work (K1S, K2S, K3S, and K4S), ankle muscle work (A1S, A2S, and A3S) during gait, and BMD of the lumbar vertebrae and femur of the WBV group. However, there were no significant changes (P > .05) in the control group. The posttreatment values of the hip, knee, and ankle muscle work and BMD of the WBV group were significantly (P < .05) higher than the posttreatment values of the control group. CONCLUSION: Whole-body vibration training improved the leg muscle work and lumbar and femoral BMD in postmenopausal women with low BMD.

Three-Dimensional Spinal Position With and Without Manual Distraction Load Increases Spinal Height.

OBJECTIVE: The purpose of this study was to investigate if spinal height increases using 3-dimensional (3-D) spinal position with and without manual distraction load and to assess the correlation between spine height changes and degrees of trunk rotation. METHODS: Fifty-six participants were randomly placed in one of two groups: (1) 3-D spinal position with manual distraction load, and (2) without manual distraction load. Spinal height was measured before and after the interventions using a stadiometer. For the statistical analysis, we used a 2 (Loading status: pre- versus post-intervention height) X 2 (3-D spinal position: with versus without manual distraction load) repeated measures Analysis of Variance (ANOVA) was used to identify significant interaction and main effects. Paired t-tests were used to calculate differences in spinal height changes between the two interventions. Pearson correlation coefficient was used to measure correlations between changes in spinal heights and degrees of trunk rotation. RESULTS: Mean spinal height increase with 3-D spinal position with and without manual distraction load was 6.30 mm (±6.22) and 5.69 mm (±4.13), respectively. No significant interaction effect was present between loading status and 3-D spinal position but a significant main effect in loading status was. Paired t-tests revealed significant differences in spinal heights between pre-and post-3-D spinal position with and without manual distraction load. No significant correlation was measured between trunk rotation and spinal height changes. CONCLUSION: 3-D spinal position with or without distraction load increased spinal height. This suggests that 3-D spinal positioning without manual distraction could be used in home settings to help maintain intervertebral disc (IVD) health.

Quantifying Lumbar Mobilization With Inertial Measurement Unit.

OBJECTIVE: Lumbar mobilization is a standard intervention for the management of low back pain, yet ways to quantify lumbar mobilization are limited. An inertial measurement unit (IMU) is a small and inexpensive device that can be used to quantify lumbar mobilization. The objective of this study was to determine the validity and reliability of an IMU in measuring the amplitude of displacement of a clinician's hand movement during oscillatory lumbar mobilization. METHODS: An IMU was secured on a clinician's hand during application of mobilization forces at the L4 segment of 16 healthy participants. The validity of the IMU was tested against common laboratory methods of measurements (force plate and motion capture system). The reliability of the IMU measurements was determined between 2 clinicians (inter-rater reliability) and between 2 sessions (intra-rater reliability) by calculating percent error of measurement (%e) and limits of agreement (LOA). The reliability was considered high when |%e| ≤ 10% and |LOA| ≤ 20%; moderate when |%e| 10% to 20% and |LOA| 21% to 40%; and non-acceptable when |%e| > 20% and |LOA| > 40%. RESULTS: The IMU measurements had high correlation with the force plate measurements (rs = 0.94) and high agreement with the motion capture system measurements (%e = 4%, LOA = -11% and 20%). Both the inter-rater reliability (%e = 6%, LOA = -25% and 37%) and the intrarater reliability (%e = -1%, LOA = -29% and 27%) of IMU measurements were moderate. CONCLUSION: The IMU seems to be a valid device to measure the amplitude of a clinician's hand movement. The moderate reliability found in this study may not reflect poor reliability of the IMU as much as inconsistency in reapplication of lumbar mobilization.

Effect of Tai Chi exercise with the same frequency and different exercise duration on the bone mineral density of older women.

BACKGROUND: This study compared the effect of Tai Chi with the same frequency and different session duration on the bone mineral density (BMD) of older women. METHODS: Healthy older women aged 55-70 years were randomly divided into the short-time group (N.=17), long-time group (N.=18), and control group (N.=17). The BMD of L2-4 and the proximal femur were measured at baseline and after 48 weeks of intervention. RESULTS: From 0 to 48 weeks, the respective BMD values of L2-4 and the femoral neck in the short-time and long-time groups increased by 8.8% and 7.5% (P<0.01) and 8.8% and 12.7% (P<0.01), while the BMD of the greater trochanter in the control group decreased by 3.0% (P<0.05). After 48 weeks, the BMD of L2-4 and the femoral neck was greater in the short-time and long-time groups than the control group (P<0.001). CONCLUSIONS: Tai Chi for 30 or 60 minutes five times weekly for 48 weeks improves the BMD of L2-4 and the femoral neck in older women but does not affect the BMD of the greater trochanter and Ward's triangle. Increasing the exercise duration does not increase the effect of Tai Chi on BMD.

Effect of Abdominal Electrical Muscle Stimulation Training With and Without Superimposed Voluntary Muscular Contraction on Lumbopelvic Control.

CONTEXT: Electrical muscle stimulation (EMS) was designed for artificial muscle activation or superimposed training. OBJECTIVES: To compare the effects of 8 weeks of superimposed technique (ST; application of electrical stimulation during a voluntary muscle action) and EMS on the cross-sectional area of the rectus abdominis, lateral abdominal wall, and on lumbopelvic control. SETTING: University research laboratory. DESIGN: Randomized controlled trial. PARTICIPANTS: Fifty healthy subjects were recruited and randomly assigned to either the ST or EMS group. INTERVENTION: The participants engaged with the electrical stimulation techniques (ST or EMS) for 8 weeks. MAIN OUTCOME MEASURES: In all participants, the cross-sectional area of the rectus abdominis and lateral abdominal wall was measured by magnetic resonance imaging and lumbopelvic control, quantified using the single-leg and double-leg lowering tests. RESULTS: There were no significant differences in the cross-sectional area of the rectus abdominis (right: P = .70, left: P = .99) or lateral abdominal wall (right: P = .07, left: P = .69) between groups. There was a significant difference between groups in the double-leg lowering test (P = .03), but not in the single-leg lowering test (P = .88). There were significant differences between the preintervention and postintervention in the single-leg (P < .001) and double-leg lowering tests (P < .001). CONCLUSIONS: ST could improve lumbopelvic control in the context of athletic training and fitness.

Vitamin D and Calcium Supplement Attenuate Bone Loss among HIVInfected Patients Receiving Tenofovir Disoproxil Fumarate/Emtricitabine/ Efavirenz: An Open-Label, Randomized Controlled Trial.

BACKGROUND: Antiretroviral therapy (ART), especially with tenofovir disoproxil fumarate (TDF), has been associated with accelerated bone turnover and leads to significant bone loss. OBJECTIVE: We aimed to determine the effect of vitamin D2 and calcium on bone mineral density (BMD) in HIV-infected patients receiving TDF/emtricitabine (FTC)/efavirenz (EFV). METHODS: A prospective, open-label, randomized controlled study was conducted. Eligible patients were ART naïve HIV individuals who initiated TDF/FTC/EFV. The study group received supplementation with vitamin D2 and calcium carbonate, whereas the control group was administered only ART. The primary outcome was the percentage change in total hip BMD at week 24 compared with baseline. RESULTS: A total of 18 patients were randomized (9 in each group). The mean (standard deviation; SD) total hip BMD significantly decreased from baseline in both groups, from 0.96 (0.14) g/cm2 to 0.93 (0.13) g/cm2 in the study group (p = 0.006) and from 0.87 (0.11) g/cm2 to 0.84 (0.11) g/cm2 in the control group (p = 0.004). The mean (SD) lumbar spine BMD significantly decreased from baseline in both groups, from 1.00 (0.13) g/cm2 to 0.97 (0.13) g/cm2 (p = 0.004) in the study group and from 0.90 (0.09) g/cm3 to 0.86 (0.08) g/cm2 in the control group (p = 0.006). At week 24, the mean (SD) lumbar spine BMD was significantly greater in the study group than in the control group (p = 0.042). However, there were no significant differences in the percentage change of total hip, lumbar spine, and femoral neck BMD between both groups. No adverse events were reported. In conclusion, as early as 24 weeks after TDF initiation, a significant decline in BMD was detected. CONCLUSION: Vitamin D2 and calcium supplements should be considered for HIV-infected patients receiving TDF/FTC/EFV in a resource-limited setting where there are limited ART options (Clinicaltrials. gov NCT0287643).

Inertial Measurement Unit-based Evaluation of Global and Regional Lumbar Spine and Pelvis Alignment in Standing Individuals With a Flat Lumbar Posture.

OBJECTIVE: The purpose of this study was to investigate the global and regional lumbar spine and pelvis postural alignment in standing individuals with a flat lumbar posture using an inertial measurement unit (IMU) system. METHODS: A total of 80 symptomatic young volunteers (25 men and 55 women in their early 20s) were recruited at Inje University in Gimhae, South Korea for this study. Participants stood in a comfortable posture for 5 seconds with IMUs on the T10, L3, and S2 level. Participants were then categorized into 3 groups according to the global lumbar lordosis (GLL) angle (T10-S2): <20°, 20° ≤ GLL angle < 30°, and 30° ≤ GLL angle < 40°. We compared the GLL and regional lumbar lordosis (RLL) angles among the 3 groups. RESULTS: As GLL increased, RLL angles (upper, P = .001; lower, P < .001) tended to increase, whereas the sacrum angle decreased (P < .001). A stepwise regression model showed that the sacrum angle was the single best predictor of GLL in standing participants. Based on IMU measurements, participants with GLL <20° are considered representative of participants with a flat lumbar posture. CONCLUSION: Posture measurements in a standing position conducted to assess lordosis should consider the relationship between GLL and RLL rather than GLL or RLL alone. We found that S2 was the best predictor of GLL.

Immediate effects and associations between interoceptive accuracy and range of motion after a HVLA thrust on the thoracolumbar junction: A randomised controlled trial.

BACKGROUND: There is paucity in the literature regarding the role of interoceptive accuracy (IAc) at predicting the effectiveness of osteopathic techniques which increase spinal mobility when directed specifically at the thoracolumbar junction (TLJ). AIMS: The study aimed to explore whether a high velocity, low amplitude (HVLA) thrust of the TLJ would increase spinal mobility (measured through Range of Motion; ROM) and change IAc. Also, whether baseline IAc correlated with the post-ROM measures and change in ROM. METHOD: 21 asymptomatic participants were allocated into three conditions in a randomised order. These were; (1) a high velocity low amplitude manipulation of the TLJ; (2) sham (basic touch); and (3) a control (laying supine on a plinth). Before and following each intervention, the participants' spinal ROM was measured using an Acumar digital inclinometer. In addition to this an ECG was used to measure their pre and post condition IAc. RESULTS: There were significant increases in ROM for all condition, however, the HVLA thrust led to a significantly greater increase in ROM (p < 0.001) when compared to the control and sham. Baseline IAc was inversely associated with post-ROM but there was no association with change in ROM. The HVLA thrust did not significantly change IAc scores from pre to post intervention. CONCLUSIONS: HVLA thrust over the TLJ is a useful intervention for increasing spinal ROM. IAc maybe a useful predictor for intervention effectiveness of this technique and spinal area which could in the future be utilised by osteopaths as part of their diagnostics.

The effects of dorso-lumbar motion restriction on energy use and center of mass movement during running.

The effects of restricting dorso-lumbar spine mobility on oxygen consumption in runners was investigated, as was vertical movement of the body's center of mass. Thermoplastic casting material was fashioned into a rigid orthosis and used to restrict spinal motion during running. Volunteers ran on a treadmill at 2.78 m/sec, under normal conditions and with spinal motion restricted. Oxygen consumption was assessed via a Douglas bag set-up. Separately, vertical movement of the center of mass was assessed with a Panasonic recorder. RESULTS: Casted running resulted in an increase in oxygen consumption (p < 0.01). Casted running resulted in less vertical movement of the body's center of mass (p < 0.01). CONCLUSIONS: Spinal mobility has statistically significant effects on the energy used during running and on the vertical movement of the center of mass. A running style that causes the body to use more energy is inefficient and can lead to earlier onset of fatigue. It can make the runner more prone to overuse injuries. We hypothesize that less movement of the center of mass vertically can affect stride length, lead to more strides being used to cover a specific distance and thus could contribute to earlier onset of fatigue and overuse injury. More research needs to be done on this topic.

Changes in Spinal Height After Manual Axial Traction or Side Lying: A Clinical Measure of Intervertebral Disc Hydration Using Stadiometry

OBJECTIVES: The purpose of this study was to determine the immediate effects of a manual therapy technique consisting of axial traction compared with side lying on increased spine height after sustained loading. METHODS: Twenty-one asymptomatic participants were included. Participants either received manual therapy technique consisting of manual axial traction force for 2 consecutive rounds of 3 minutes or sustained side lying for 10 minutes. Spine height was measured using a commercially available stadiometer. Spinal height change was determined from measurements taken after loaded walking and measurements taken after manual therapy. A paired t test was performed to determine if a manual therapy technique consisting of axial traction increased spinal height after a period of spinal loading. RESULTS: A significant increase in height was found after both manual therapy technique and sustained side lying (P < .0001). The mean height gain was 8.60 mm using 3-dimensional axial separation. CONCLUSION: This study is an initial attempt at evaluating the biomechanical effects of manual therapy technique consisting of axial traction. Both manual axial traction force and sustained side-lying position were equally effective for short-term change in spine height after a loaded walking protocol among healthy asymptomatic individuals. This study protocol may help to inform future studies that evaluate spine height after loading.

The Variation of Cross-Sectional Area of the Sciatic Nerve in Flexion-Distraction Technique: A Cross-Sectional Study.

OBJECTIVE: The purpose of this study was to compare the cross-sectional area of the sciatic nerve in different positions of spinal manipulation using flexion-distraction technique. METHODS: Thirty healthy participants were assessed in 6 different flexion-distraction technique positions of varying lumbar, knee, and ankle positions. Participants stood in the following 3 positions with the lumbar in the neutral position: (A) with knee extended, (B) with knee flexed, and (C) with the knee extended and ankle dorsiflexion. Participants then stood in the following 3 positions with the lumbar flexed: (D) with the knee extended, (E) with the knee flexed, and (F) with knee extended and ankle dorsiflexion. The cross-sectional area (CSA) of the sciatic nerve was measured with ultrasound imaging in transverse sections in the posterior medial region of the left thigh. The CSA values measured at each position were compared. RESULTS: We analyzed 180 ultrasound images. The cross-sectional area of the sciatic nerve (in mm2) in position B (mean; standard deviation) (59.71-17.41) presented a higher mean cross-sectional area value compared with position D (51.18-13.81; P =.005), position F (48.71-15.16; P = .004), and position C (48.37-16.35; P = .009). CONCLUSION: The combination of knee extension and ankle dorsiflexion reduced the CSA of the sciatic nerve, and flexing the knee and keeping the ankle in the neutral position increased it.

Effects of myofascial release in erector spinae myoelectric activity and lumbar spine kinematics in non-specific chronic low back pain: Randomized controlled trial.

BACKGROUND: Flexion-relaxation response of the lumbar erector spinae has been previously studied after different interventions such as exercise programs or spinal manipulation, in subjects with chronic low back pain. The objective of the study was to investigate the effects of an isolated myofascial release protocol on erector spinae myoelectric activity and lumbar spine kinematics in chronic low back pain. METHODS: Thirty-six participants, with nonspecific chronic low back pain, were randomized to myofascial release group (n = 18) receiving four sessions of myofascial treatment, each lasting 40 min, and to control group (n = 18) receiving a sham myofascial release. Electromyographic and kinematic variables as well as pain and disability questionnaires were analyzed. FINDINGS: There was a bilateral reduction of the flexion relaxation ratio in individuals receiving myofascial release and who did not show myoelectric silence at baseline (right difference M = 0.34, 95% CI [0.16, 0.33], p ≤ .05 and left difference M = 0.45, 95% CI [0.16, 0.73], p ≤ .05). There was also a significant reduction in pain in the myofascial release group (difference M = -9.1, 95% CI [-16.3, -1.8], p ≤ .05) and disability (difference M = -5.6, 95% CI [-9.1, -2.1], p ≤ .05), compared with control group. No significant differences between groups were found for the kinematic variables. INTERPRETATION: The myofascial release protocol contributed to the normalization of the flexion- relaxation response in individuals who did not show myoelectric silence before the intervention, and also showed a significant reduction in pain and disability compared with the sham group.

Maintaining Lumbar Spine Stability: A Study of the Specific and Combined Effects of Abdominal Activation and Lumbosacral Orthosis on Lumbar Intrinsic Stiffness.

BACKGROUND: Two potential interventions for enhancing lumbar stability are to actively increase abdominal muscle activity, either through the abdominal drawing-in maneuver (ADIM) or bracing, and passively increase lumbar stiffness using a lumbosacral orthosis (LSO). OBJECTIVE: To compare the increase in lumbar stiffness after 2 active interventions (ADIM versus bracing) and 1 passive intervention (LSO), and to evaluate the combined effect of active (abdominal bracing) and passive interventions. METHODS: In this experimental and comparative study, lumbar stiffness, a surrogate measure of lumbar stability, was estimated in 25 healthy individuals during 7 trunk perturbation conditions: (1) control, (2) ADIM, (3) bracing at 5% of right external oblique maximal voluntary activation (5% bracing), (4) bracing at 10% of right external oblique maximal voluntary activation (10% bracing), (5) LSO, (6) LSO plus 5% bracing, and (7) LSO plus 10% bracing. Electromyographic biofeedback of the external oblique was provided on a monitor, while ultrasound was used for the ADIM to ensure a sustained contraction of the transversus abdominis. RESULTS: The ADIM, 5% bracing, and 10% bracing active interventions generated comparable lumbar stiffness. However, considering that bracing can range from 10% to 20%, it may be superior to hollowing, as further estimated with a mixed-effect statistical model. Combining bracing and an LSO resulted in an additive effect on lumbar stiffness. CONCLUSION: Bracing and ADIM produced comparable lumbar stiffness, as they were performed at the same overall abdominal activation levels (5% and 10% maximal voluntary activation). The independent effects of bracing and LSO raises the possibility of combining these interventions in some circumstances. J Orthop Sports Phys Ther 2019;49(4):262-271. Epub 18 Jan 2019. doi:10.2519/jospt.2019.8565.

The relationship between serum fibroblast growth factor 23, Klotho, and lumbar spine bone mineral density in northern Chinese postmenopausal women.

OBJECTIVES: Changes in serum protein levels of fibroblast growth factor 23 (FGF23) and Klotho resulting from bone metabolism are still controversial. The purpose of this study was to observe the relationship between FGF23 and Klotho serum proteins and lumbar spine bone mineral density (LBMD) in northern Chinese postmenopausal women. METHODS: This was a community-based cross-sectional study carried out in Shenyang, a northern Chinese city. The study included 355 postmenopausal women with an average age of 62.92 ±â€Š8.78 years. FGF23 and Klotho serum proteins were measured using a sandwich enzyme immunoassay. LBMD was examined using dual-energy X-ray absorptiometry. Pearson's correlation and regression analyses were performed to investigate the associations among them. RESULTS: The LgKlotho was positively correlated with LBMD (r = 0.105). There was a linear relationship between LgKlotho serum levels and LBMD (P = 0.007) after adjusting for BMI, and the relationship still existed after adjustments for many confounding variables (P = 0.045), including age, BMI, systolic blood pressure, diastolic blood pressure, total protein, total bilirubin, high-density lipoprotein cholesterol, fasting blood glucose, serum calcium, estimated glomerular filtration rate, serum uric acid, estradiol, cigarette smoking, alcohol consumption, milk intake, calcium and vitamin D supplements, physical exercise, and fracture history in postmenopausal women. FGF23 serum levels were, however, not significantly associated with LBMD. CONCLUSIONS: Klotho was positively correlated with LBMD, and there was a linear relationship between Klotho serum protein levels and LBMD; however, the levels of serum Klotho were not independently associated with reduced LBMD in northern Chinese postmenopausal women. Moreover, serum FGF23 levels were not significantly related to LBMD in this sample population.

Comparison of bone turnover markers in peripheral blood and bone marrow aspirate.

BACKGROUND: Bone remodeling takes place in the bone marrow environment. We investigated if levels of bone turnover markers (BTMs) differ between bone marrow and peripheral blood, if the bone marrow is an independent compartment, and how well the measurements in bone marrow correlate with bone mineral density. METHODS: Sixty-six men participated in a placebo controlled study designed to evaluate the effect of 16 weeks supplementation with resveratrol on bone mineral density and BTM. Bone marrow aspirates and blood samples were drawn at baseline and at week 16. Procollagen I N-terminal propeptide (PINP), C-terminal telopeptide of type I collagen (CTx), osteocalcin, bone specific alkaline phosphatase (BAP), and osteoprogeterin (OPG) were analyzed. Bland-Altman analysis was used to compare measurements across compartment to detect possible systematic or proportional differences. Paired t-test was performed if no proportional difference was revealed at the difference vs concentration plot. RESULTS: Measurements of PINP, CTx, and BAP differed proportionally between compartments depending on concentration; at low concentrations absolute values were only slightly different, while at higher average concentrations the levels were much higher in bone marrow than blood. Osteocalcin measures in bone marrow were systematically and significantly lower than in blood (mean ±â€¯SD; 14.4 µg/L ±â€¯5.3 µg/L versus 21.7 µg/L ±â€¯6.0 µg/L respectively, p < 0.001). OPG measures were comparable between compartments (p = 0.69). CTx and OPG measured in blood were negatively associated with lumbar spine BMD (ß = -0.22, p = 0.05 and ß = -0.02, p = 0.02, respectively), whereas both markers measured in bone marrow were not (p = 0.60 and p = 0.50 respectively). None of the BTMs, bone marrow or blood, were associated with total hip BMD. DISCUSSION: The levels of most BTMs differed significantly between bone marrow and peripheral blood, while OPG was comparable. Levels of PINP, CTx, and BAP differed between compartments depending on concentration, suggesting bone marrow to represent a compartment separate from the general circulation. Unexpectedly, osteocalcin was lower in the marrow, a gradient that was independent of concentration. BTMs measured in bone marrow did not show any association with bone mineral density. Although further studies are needed to investigate potential explanatory causes of the differences, BTMs in bone marrow do not seem to contribute further to fracture risk assessment.

Vertebral strength prediction from Bi-Planar dual energy x-ray absorptiometry under anterior compressive force using a finite element model: An in vitro study.

Finite element models (FEM) derived from qCT-scans were developed as a clinical tool to evaluate vertebral strength. However, the high dose, time and cost of qCT-scanner are limitations for routine osteoporotic diagnosis. A new approach considers using bi-planar dual energy (BP2E) X-rays absorptiometry to build vertebral FEM using synchronized sagittal and frontal plane radiographs. The purpose of this study was to compare the performance of the areal bone mineral density (aBMD) measured from DXA, qCT-based FEM and BP2E-based FEM in predicting experimental vertebral strength. Twenty eight vertebrae from eleven lumbar spine segments were imaged with qCT, DXA and BP2E X-rays before destructively tested in anterior compression. FEM were built based on qCT and BP2E images for each vertebra. Subject-specific FEM were built based on 1) the BP2E images using 3D reconstruction and volumetric BMD distribution estimation and 2) the qCT scans using slice by slice segmentation and voxel based calibration. Linear regression analysis was performed to find the best predictor for experimental vertebral strength (Fexpe); aBMD, modeled vertebral strength and vertebral stiffness. Areal BMD was moderately correlated with Fexpe (R2 = 0.74). FEM calculations of vertebral strength were highly to strongly correlated with Fexpe (R2 = 0.84, p < 0.001 for BP2E model and R2 = 0.95, p < 0.001 for qCT model). The results of this study suggest that aBMD accounted for only 74% of Fexpe variability while FE models accounted for at least 84%. For anterior compressive loading on isolated vertebral bodies, simplistic loading condition aimed to replicate anterior wedge fractures, both FEM were good predictors of Fexpe. Therefore FEM based on BP2E X-rays absorptiometry could be a good alternative to replace qCT-based models in the prediction of vertebral strength. However future work should investigate the performance of the BP2E-based model in vivo in discriminating patients with and without vertebral fracture in a prospective study.