Effect of Cognitive Load on Anticipatory Postural Adjustment Latency and its Relationship with Pain-Related Dysfunction in Non-specific Chronic Low Back Pain: A Cross-Sectional Study.

INTRODUCTION: This study aimed to investigate the effect of cognitive load on anticipatory postural adjustment (APA) latency in patients with non-specific chronic low back pain (NCLBP) and its relationship with pain-related functional changes. METHODS: A cross-sectional study was conducted from December 15, 2022 to January 25, 2023. Participants were divided into a healthy control group (n = 29) and an NCLBP group (n = 29). Each group was assigned a single task of rapid arm raising and a dual task of rapid arm raising combined with a cognitive load. The cognitive load task was conducted using visual conflict. The APA latency for bilateral trunk muscles was observed using electromyography. The duration of electromyography recording in each task cycle was 28 s. Pain related-functional changes were evaluated using Roland-Morris Disability Questionnaire (RMDQ) before all tasks. RESULTS: The APA latency for the right multifidus was significantly delayed in the NCLBP group [25.38, 95% confidence interval (CI) 13.41-37.35] than in the healthy control group (- 5.80, 95% CI - 19.28 to 7.68) during dual task (p = 0.0416). The APA latency for the right multifidus (25.38, 95% CI 13.41-37.35) and transverse abdominis/internal oblique (29.15, 95% CI 18.81-39.50) were significantly delayed compared with on the left side in the NCLBP group during dual task (- 3.03, 95% CI - 15.18-9.13, p = 0.0220; 3.69, 95% CI - 6.81 to 14.18, p = 0.0363). The latency delay of the right and left multifidus APA in the NCLBP group under the dual-task was positively correlated with RMDQ scores (r = 0.5560, p = 0.0017; r = 0.4010, p = 0.0311). CONCLUSIONS: Cognitive load could induce APA delay in the right trunk muscles and co-activation pattern changes in bilateral trunk muscle APA in patients with NCLBP. The APA onset delay in multifidus is positively related to pain-related daily dysfunction. Trial Registration ChiCTR2300068580 (retrospectively registered in February 23, 2023).

Does m-health-based exercise (guidance plus education) improve efficacy in patients with chronic low-back pain? A preliminary report on the intervention's significance.

BACKGROUND: The utilization of mobile health (m-health) has rapidly expanded during the COVID-19 pandemic, and there is still a lack of relevant clinical data pertaining to chronic low-back pain (CLBP) management. This study was designed to compare the effectiveness of m-health-based exercise (via guidance plus education) versus exercise (via guidance) during CLBP management. METHODS: Participants (n = 40) were randomly assigned to intervention and control groups. The intervention group received m-health-based exercise (via guidance plus education), whereas the control group received m-health-based exercise (via guidance). The exercise prescription video and educational content were sent to participants by the application (app), Ding Talk. Repeated-measures analysis of variance was used to test the baseline's intervention effects, 6-week follow-up, and 18-week follow-up. We selected function (Roland and Morris Disability Questionnaire) and pain intensity (current, mean, and most severe Numeric Rating Scale in the last 2 weeks) as the primary outcomes, changes of negative emotion (depression, anxious), and quality of life as the secondary outcomes. RESULTS: Time's significant effect was found in pain, function, and health-related quality of life in both groups, but time did not show significant interaction effects. Participants were able to use m-based education with their anxiety and depression after treatment, but the relief only lasted until week 6. No differences were found on the aspect of mental health-related quality of life. CONCLUSION: Preliminary findings suggest that m-health-based exercise (via guidance) may be a convenient and effective method to treat CLBP. However, additional health education didn't help more. More rigorous controlled trials are needed to improve the therapeutic effect in future studies. TRIAL REGISTRATION: Chinese Clinical Trials Registry Number ChiCTR2000041459 . Registered on December 26, 2020.

Effects of Custom-made Insoles on Plantar Biomechanics and Upper Extremity Muscle Performance.

OBJECTIVE: To investigate the effectiveness of molding custom-made insoles for female patients with foot pain. METHODS: The study included 20 patients whose insoles were prescribed according to biomechanical evaluations and molded by repositioning the subtalar joint in its neutral position using a simple set of tools. Plantar biomechanics were measured under the following conditions: static stand, walking at self-comfortable walking speed (CWS) barefoot, walking in patient owned running shoes, and walking in running shoes plus insoles. Each patient's upper arm isometric muscle strength and subjective feelings before and after the insole intervention were assessed. RESULTS: The molded insoles increased plantar contact area both during static standing and walking at CWS compared to the barefoot condition. The insoles also had more evenly distributed plantar contact area and loading rate, with the changes in the medial arch area being most significant. Moreover, the custom-made insole intervention immediately increased maximum resistance and duration of bilateral upper arms, as well as improved foot comfort, especially at the medial arch area during single leg squat tests. CONCLUSION: Molding custom-made insoles by repositioning the subtalar joint in its neutral position can be accomplished with a simple set of tools, making this method highly applicable for a majority of less developed regions. Insoles molded using this method are effective in immediately improving plantar biomechanics disorders and enhancing isometric upper muscle performance in female patients with foot pain.

Exercise for Neuropathic Pain: A Systematic Review and Expert Consensus.

Background: Neuropathic pain (NP), a severe and disruptive symptom following many diseases, normally restricts patients' physical functions and leads to anxiety and depression. As an economical and effective therapy, exercise may be helpful in NP management. However, few guidelines and reviews focused on exercise therapy for NP associated with specific diseases. The study aimed to summarize the effectiveness and efficacy of exercise for various diseases with NP supported by evidence, describe expert recommendations for NP from different causes, and inform policymakers of the guidelines. Design: A systematic review and expert consensus. Methods: A systematic search was conducted in PubMed. We included systematic review and meta-analysis, randomized controlled trials (RCTs), which assessed patients with NP. Studies involved exercise intervention and outcome included pain intensity at least. Physiotherapy Evidence Database and the Assessment of Multiple Systematic reviews tool were used to grade the quality assessment of the included RCTs and systematic reviews, respectively. The final grades of recommendation were based on strength of evidence and a consensus discussion of results of Delphi rounds by the Delphi consensus panel including 21 experts from the Chinese Association of Rehabilitation Medicine. Results: Eight systematic reviews and 21 RCTs fulfilled all of the inclusion criteria and were included, which were used to create the 10 evidence-based consensus statements. The 10 expert recommendations regarding exercise for NP symptoms were relevant to the following 10 different diseases: spinal cord injury, stroke, multiple sclerosis, Parkinson's disease, cervical radiculopathy, sciatica, diabetic neuropathy, chemotherapy-induced peripheral neuropathy, HIV/AIDS, and surgery, respectively. The exercise recommended in the expert consensus involved but was not limited to muscle stretching, strengthening/resistance exercise, aerobic exercise, motor control/stabilization training and mind-body exercise (Tai Chi and yoga). Conclusions: Based on the available evidence, exercise is helpful to alleviate NP intensity. Therefore, these expert consensuses recommend that proper exercise programs can be considered as an effective alternative treatment or complementary therapy for most patients with NP. The expert consensus provided medical staff and policymakers with applicable recommendations for the formulation of exercise prescription for NP. This consensus statement will require regular updates after five-ten years.

Trunk muscle activity during pressure feedback monitoring among individuals with and without chronic low Back pain.

BACKGROUND: Pressure biofeedback unit (PBU) is a widely used non-invasive device to assist core muscle training by providing pressure feedback. The aim this study was to compare the muscle activities of transverse abdominis (TA) and multifidus (MF) at different target pressures (50, 60 and 70 mmHg) of PBU between individuals with and without cLBP. METHODS: Twenty-two patients with chronic LBP (cLBP) and 24 age matched healthy individuals were recruited. Electromyography (EMG) signals were recorded from the TA and MF muscles while the TA and MF were contracted to achieve PBU pressure value of 50, 60 and 70 mmHg in random order. The average EMG amplitude (AEMG) of 3 replicate trials was used in the analysis after normalization to %MVIC. %MVIC is defined as the mean of the three AEMG divided by the AEMG of MVIC. Two-way ANOVA was performed to assess the effects of groups (healthy and cLBP) and the three different target pressures of PBU. Independent sample t-test was conducted to compare between the two groups. Spearman's correlation analysis was performed in the cLBP group to determine potential correlations between EMG activity, NPRS and ODI. RESULTS: The %MVIC of the TA and MF in the cLBP group were higher than the control group at each pressure value (P<0.05). During maximal voluntary isometric contraction (MVIC) of TA and MF, compared with healthy groups, cLBP subjects showed a decrease (TA mean = 47.61 µV; MF mean = 42.40 µV) in EMG amplitudes (P ≤ 0.001). The MVIC of MF was negatively correlated with Numerical Pain Rating Scale (r = - 0.48, P = 0.024) and Oswestry Disability Index (r = - 0.59, P = 0.004). CONCLUSIONS: We measured the trunk muscles activities at different PBU pressure values, which allows the individual to estimate trunk muscle contraction via PBU. Clinicians may be able to confer the data obtained through EMG recordings to adjust the exercise intensity of PBU training accordingly.

Effects of Different Sling Settings on Electromyographic Activities of Selected Trunk Muscles: A Preliminary Research.

INTRODUCTION: The supine and prone sling exercise may facilitate activation of the local trunk muscles. Does the side-lying sling exercise activate trunk muscles more easily than the supine and prone training with sling settings? Clinical work has shown that the side-lying sling exercise could reduce pain in patients with unilateral low back pain (LBP), but the mechanism behind it is unclear. The fundamental purpose of this preliminary study was to examine the electromyography (EMG) characteristics of trunk muscles during different sling lumbar settings on sixteen healthy adults. METHODS: Amplitude and mean power frequency (MPF) of EMG signals were recorded from the transversus abdominis (TA), rectus abdominis (RA), multifidus (MF), erector spinae (ES), gluteus maximus (Gmax), and gluteus medius (Gmed) muscles while the subjects performed the supine lumbar setting (SLS), prone lumbar setting (PLS), left side-lying lumbar setting (LSLS), and right side-lying lumbar setting (RSLS). RESULTS: During SLS and PLS, TA and MF showed significantly higher activity than RA and ES on the same side, respectively. The EMG activities of ES, TA, MF, Gmax, and Gmed had significant differences between the different sides during LSLS and RSLS, and the dominant-side muscles showed higher activity than the other side. There was no significant difference in core trunk muscles between different sling lumbar settings-only that the SLS of the MF/ES ratio was significantly higher than LSLS and RSLS. CONCLUSIONS: Sling exercises can be an effective measure to enhance MF and TA EMG activity, and the side-lying position can increase dominant-side Gmax and Gmed activity. Side-lying sling training does not activate more core muscles than the supine and prone training. Supine and prone exercise should be preferred over SLT to stabilize the lumbar region because of its high local/global muscle ratio.

Abnormal Spontaneous Brain Activity in Acute Low-Back Pain Revealed by Resting-State Functional MRI.

OBJECTIVE: Neuroimaging studies have revealed that low-back pain (LBP) alters spatiotemporal dynamics of the blood oxygen level-dependent signal in response to persistent noxious stimulus. This study aimed to investigate changes in spontaneous neural activity of various brain regions in acute LBP using resting-state functional magnetic resonance imaging and amplitude of low-frequency fluctuation (ALFF). DESIGN: Twelve healthy subjects underwent two separate resting-state functional magnetic resonance imaging scans at health status as baseline and after intramuscular injection of hypertonic saline (0.5 mL, 5%) into the back muscles to induce acute LBP. RESULTS: Compared with baseline, acute LBP showed decreased ALFF in the right posterior cingulate cortex/precuneus and left primary somatosensory cortex (S1) but increased ALFF in the right medial prefrontal cortex, right middle temporal gyrus, bilateral inferior temporal gyrus, bilateral insula, right anterior cingulate cortex, and left cerebellum. In addition, significant negative correlations were observed between visual analog scale scores and ALFF of the bilateral medial prefrontal cortex, left inferior frontal gyrus, left S1, right anterior cingulate cortex, and left middle temporal gyrus. CONCLUSIONS: These findings suggest that abnormally spontaneous neural activity involving some brain regions are responsible for sensory, affective, and cognitive functions, which may be implicated in the underlying pathophysiology of acute LBP.

Systematic back muscle exercise after percutaneous vertebroplasty for spinal osteoporotic compression fracture patients: a randomized controlled trial.

OBJECTIVE: To analyze the clinical significance of postoperative back muscle exercises after percutaneous vertebroplasty for spinal osteoporotic compression fracture patients. DESIGN: Clinical randomized controlled trials of parallel group nonpharmacologic study. SETTING: Patients practised back muscle exercises in the spinal surgery department, rehabilitation department and at their residences. SUBJECTS: Osteoporotic compression fracture patients who had undergone percutaneous vertebroplasty and processed sufficient muscle strength to participate in the training were studied. INTERVENTIONS: Patients were randomized into two groups, which were titled A and B. General postoperation therapy, including antiosteoporotic medications and education, was offered to all patients. Group B patients received additional systematic back muscle exercise. MAIN MEASURES: Both Oswestry Disability Index (ODI) and visual analogue scale (VAS) were recorded preoperatively and postoperatively at three-day, one-month, six-month, one-year and two-year follow-up. RESULTS: From January 2006 to January 2009, a total of 82 patients were assessed for eligibility, 60 patients were enrolled and randomized into two groups. Forty-two (70%) patients (20 of 30 in Group A and 22 of 30 in Group B) were successfully followed-up for two years. Systematic back muscle exercises resulted in a significant advantage in both measurements. The ODI of Group B was significantly better than Group A at the six-month, one-year and two-year follow-ups (P < 0.05). The pain level of Group B was significantly lower than in Group A at the one- and two-year follow-ups (P < 0.05). At the end of our study, the mean (SD) of the ODI in Groups A and B were 39.1 (9.14) and 23.4 (5.62); the mean (SD) of the VAS in Groups A and B were 3.4 (1.15) and 2.1 (0.84), respectively. CONCLUSIONS: Our findings suggest that the benefit of the exercises required at least six months to be observed; however, the favourable effects could last for two years. Therefore, systematic back muscle exercise should be recommended as one of the treatment guidelines for postpercutaneous vertebroplasty patients.

Protective effects of early hypoxic post-conditioning in cultured cortical neurons.

PRIMARY OBJECTIVE: Recent evidence suggests that delayed hypoxic post-conditioning is neuroprotective. The aim of the present study was to test whether early post-conditioning applied immediately after hypoxia could protect cultured neurons from hypoxia/reoxygenation (H/R)-induced injuries. METHODS: Primary cortical neuronal culture depleted of microglia was exposed to H/R. Post-conditioning started immediately after hypoxia and consisted of three cycles of 15-minutes of reoxygenation and 15-minutes of hypoxia. Cell viability assay was performed using Cell Counting Kit-8 (CCK-8). Apoptosis was evaluated by Hoechst 33258 staining, FITC-Annexin V/PI double staining and Western blot assay (testing the cleaved caspase-3 expression). Reactive oxygen species (ROS), intracellular Ca(2+) and mitochondrial membrane potential (MMP) were examined using confocal laser-scanning microscopy. MAIN RESULTS: H/R significantly reduced cell viability and increased neuronal apoptosis and necrosis. Furthermore, the expression of cleaved caspase-3, ROS production and intracellular Ca(2+) were increased. MMP was attenuated. Injuries induced by H/R were substantially attenuated by early hypoxic post-conditioning. Changes in cleaved caspase-3 expression, ROS production, intracellular Ca(2+) level and MMP in response to H/R were significantly decreased by the post-conditioning. CONCLUSIONS: The findings demonstrated that early hypoxic post-conditioning could protect neurons against H/R-induced injuries independent of microglial cells, possibly by inhibiting ROS over-production and intracellular Ca(2+) accumulation and maintaining MMP.

NMDA receptors are involved in upstream of the spinal JNK activation in morphine antinociceptive tolerance.

N-methyl-d-aspartate (NMDA) receptors and c-Jun N-terminal kinase (JNK) have been shown to be involved in morphine antinociceptive tolerance. However, whether chronic morphine-induced activation of the spinal JNK is NMDA receptor-dependent is unknown. The present study investigated the link between the spinal NMDA receptor NR2B subunit and the JNK activation during morphine antinociceptive tolerance in rats. Our results showed that chronic morphine treatment induced upregulation of the NR2B expression and activation of JNK in the spinal cord. Moreover, the increased NR2B-immunoreactivity (IR) and phosphorylated JNK-IR were observed mainly at the superficial dorsal horn laminae of the spinal cord; the spinal p-JNK was mainly expressed in astrocytes and NR2B in neurons. SP600125, a selective inhibitor of JNK, significantly attenuated morphine tolerance. MK-801, a noncompetitive NMDA receptor antagonist, not only suppressed morphine antinociceptive tolerance and the increase in NR2B, but also reduced the spinal JNK activation induced by chronic morphine treatment. These findings demonstrated for the first time that NMDA receptor-dependent activation of the spinal JNK contributes to morphine antinociceptive tolerance and that MK-801 attenuates morphine tolerance partly due to its inhibition on the spinal JNK activation.

[Study of copper metabolism and liver damage in TX Mice-an animal model for liver disease].

OBJECTIVE: To provide right time points in selection of right aged animals and the normal physiological data of TX mice. METHODS: 7-12 months old TX and DL mice were studied, each group contained 3 female and 3 male mice of TX or DL mice. The concentration of copper in the serum, dry tissues (liver, brain and kidney), together with copper biochemistry indexes were measured. The liver histopathology was observed under light microscopy and electron microscope. RESULTS: Transaminase increased significantly only in 10 and 11-month- old (AST(TX10) = 218.3 U/L, AST(TX11) = 197.5 U/L, AST(DL10) = 171.5 U/L, AST(DL11) = 165.0 U/L, P(10) less than 0.001, P(11) = 0.022), but the copper concentration of liver, brain and kidney was significantly increased during 7-12 month old (the average concentration of copper, Liver(TX) = (750.0 +/- 85.5) mg/kg, Brain(TX) = (39.7 +/- 2.2)mg/kg, Kidney(TX) = (29.8 +/- 5.0) mg/kg, Liver(DL) = (11.6 +/- 1.5) mg/kg, Brain(DL) = (16.8 +/- 0.9) mg/kg, Kidney(DL) = (14.2 +/- 1.0) mg/kg, t = 21.16, 23.60, 7.47, for all these organs P less than 0.05). CONCLUSION: TX mice is a suitable model of liver disease with natural recovery, so selecting animal model of suitable time point is very important.

Electroacupuncture treatment of chronic insomniacs.

BACKGROUND: Due to the quick rhythm of life and work pressure, more and more people suffer from sleep quality problems. In this study, we investigated the effect of electroacupuncture on sleep quality of chronic insomniacs and the safety of electroacupuncture therapy. METHODS: Four courses of electroacupuncture treatment were applied to 47 patients. With pre-treatment and post-treatment self-control statistical method, Pittsburgh sleep quality index (PSQI) scores were used for evaluating sleep quality. Polysomnogram was used for detecting insomniacs' changes in sleep architecture. The safety of electroacupuncture was evaluated by monitoring the self-designed adverse events and side effects during treatment and post-treatment. RESULTS: Electroacupuncture considerably improved insomniacs' sleep quality and social function during the daytime. Electroacupuncture had certain repairing effect on the disruption in sleep architecture. At the same time, electroacupuncture prolonged slow wave sleep (SWS) time and relatively rapid eye movement sleep (REM sleep) time. There was no hangover, addiction or decrements in vigilance during the daytime (incidence rate was 0). However, insomnia rebound rate was about 23% within one month. CONCLUSIONS: These results suggest that electroacupuncture has beneficial effect on sleep quality improvement in the patients with chronic insomnia, which may be associated with repairing sleep architecture, reconstructing sleep continuity, as well as prolonging SWS time and REM sleep time. Electroacupuncture treatment for chronic insomnia is safe. Therefore, electroacupuncture therapy could be a promising avenue of treatment for chronic insomnia.

Inhibition of neuronal nitric oxide synthase antagonizes morphine antinociceptive tolerance by decreasing activation of p38 MAPK in the spinal microglia.

We have demonstrated that the activation of p38 mitogen-activated protein kinase (MAPK) in the spinal microglia played an essential role in the development of morphine antinociceptive tolerance. The aim of this study was to investigate whether inhibition of neuronal nitric oxide synthase (nNOS) attenuated tolerance to morphine analgesia by modulating p38 activation in the spinal microglia. It was shown that the selective inhibitor of nNOS, 7-NINA (7-Nitroindazole, sodium salt) (25 microg, i.t.) attenuated not only the development of morphine antinociceptive tolerance, but also the activation of p38 MAPK in the spinal microglia induced by chronic intrathecal administration of morphine. Our results suggest that neuronal NO signals to microglia, leading to the upregulation of microglial phospho-p38 MAPK. Such p38 MAPK activation in microglia is consistent with a potential role in the development of morphine antinociceptive tolerance. We demonstrated for the first time that the inhibition of nNOS attenuated morphine antinociceptive tolerance by reducing p38 MAPK activation in the spinal microglia.