Restructuring of emergent grain boundaries at free surfaces – an interplay between core stabilization and elastic stress generation

Scanning tunneling microscopy and numerical calculations are used to study the structure and relaxation of grain boundaries at the surface of planar nanocrystalline copper (111) films and bicrystals. We show that the strong energetic preference for boundary cores to lie along close-packed planes introduces a restructuring that rotates adjoining grains and generates elastic stresses in the triple junction region. The interplay of this stress field and the core stabilization determines the length scale of the restructuring and controls the shape and magnitude of the displacement field around the triple junction. Depending on the in-plane angle, restructured boundaries can extend to depths of ~ 15 nm with the associated elastic stress fields extending to even greater depths. These results point to a new mechanism of boundary relaxation at surfaces that is expected to play an important role in grain coalescence and stress evolution in growing films.

CLINICAL AND PHYSICAL EFFICIENCY OF VIRTUAL REALITY GAMES IN SOCCER PLAYERS WITH LOW BACK PAIN

ABSTRACT Introduction: Virtual reality training (VRT) is an advanced technology that creates virtual games by a computer through specific software. It is a type of rehabilitation training commonly used in balance problems to treat musculoskeletal conditions. Objective: To determine and compare the effects of virtual reality games with those of core stabilization training on physical efficiency in soccer players with chronic low back pain. Methods: A randomized, double-blinded, controlled study was conducted on 60 LBP participants at a university hospital. The first group (n=20) received virtual reality (VR) training; the second group (n=20) received core stabilization (CS) training; and the third group (n=20) received conventional training exercises for four weeks. Scores of clinical and sports performance were measured at baseline, and after 4 weeks, 8 weeks and 6 months. Results: The baseline demographic and clinical characters did not show any significant differences (p>0.05) in the statistical analysis, which shows a homogenous population. Four weeks following the training, the VR training group showed more significant changes in clinical scores than the CS training and control groups (p≤0.001). The scores for sports performance also showed more significant improvement in the VR training group than in the other two groups (p≤0.001). The same improved clinical and sports performance changes were seen at 8 weeks and 6 months of follow-up in the VR training group, when compared to the other two groups (p≤0.001). Conclusion: This study suggests that training through virtual reality games results in long-term improvement in clinical and sports performance compared to other forms of training in soccer players with chronic low back pain.Level of evidence I b; Therapeutic studies – Investigation of treatment results.

Effects of core stabilization exercise and strengthening exercise on proprioception, balance, muscle thickness and pain related outcomes in patients with subacute nonspecific low back pain: a randomized controlled trial

Background Therapeutic exercises are used in clinical practice for patients with low back pain (LBP). Core stabilization exercises can retrain the important function of local trunk muscles and increase the accuracy of the sensory integration process for stability of the spine in individuals with LBP. The aim of this study was to compare the effects of two different exercise regimes, Core stabilization exercises (CSE) and Strengthening exercise (STE), on proprioception, balance, muscle thickness and pain-related outcomes in patients with subacute non-specific low back pain (NSLBP). Methods Thirty-six subacute NSLBP patients, [mean age, 34.78 ± 9.07 years; BMI, 24.03 ± 3.20 Kg/m2; and duration of current pain, 8.22 ± 1.61 weeks], were included in this study. They were randomly allocated into either CSE (n = 18) or STE groups (n = 18). Exercise training was given for 30 min, three times per week, for up to 4 weeks. Proprioception, standing balance, muscle thickness of transversus abdominis (TrA) and lumbar multifidus (LM), and pain-related outcomes, comprising pain, functional disability and fear of movement, were assessed at baseline and after 4 weeks of intervention. Results The CSE group demonstrated significantly more improvement than the STE group after 4 weeks of intervention. Improvements were in: proprioception [mean difference (95% CI): − 0.295 (− 0.37 to − 0.2), effect size: 1.38, (p < 0.001)], balance: single leg standing with eyes open and eyes closed on both stable and unstable surfaces (p < 0.05), and percentage change of muscle thickness of TrA and LM (p < 0.01). Although both exercise groups gained relief from pain, the CSE group demonstrated greater reduction of functional disability [effect size: 0.61, (p < 0.05)] and fear of movement [effect size: 0.80, (p < 0.01)]. There were no significant adverse effects in either type of exercise program. Conclusion Despite both core stabilization and strengthening exercises reducing pain, core stabilization exercise is superior to strengthening exercise. It is effective in improving proprioception, balance, and percentage change of muscle thickness of TrA and LM, and reducing functional disability and fear of movement in patients with subacute NSLBP. Trial registration Thai Clinical Trial Registry (TCTR20180822001; August 21, 2018).

Core Stabilization Exercise on the Lumbar Lordosis and Pelvic Inclination Among Chronic Nonspecific Low Back Pain Patients

Introduction: Chronic low back pain (CLBP) is one of the most common musculoskeletal disorders and it is documented that >90% of the cases have no defined cause for pain, called nonspecific low back pain (NSLBP). Alteration in the joint position, abnormal posture, and impaired muscle recruitment may result in recurrent CLBP. Lumbar lordosis (LL) provides strength against the compressive forces of gravity and it also protects the posterior spinal ligament and acts as a shock absorber for vertical forces. Increased LL is considered as a reason for radiculopathy, facet pain, and postural pain. Spinal posture and pelvic position were analyzed and documented as altered in CLBP patients. Anatomically, the anterior and posterior tilt of the back and pelvis by the force of different muscles can alter the spinal curvature. Posterior pelvic tilt in a standing position can decrease the LL. The pelvic inclination is related to the lumbar curve, and both are related to the performance and length of the back and abdominal muscles. Therefore, in this study, we aimed to evaluate the effect of core stabilization exercise on pain intensity, functional disability, LL, and pelvic inclination in NSLBP. Methodology: A total of 63 patients aged between 20 and 60 years who met the selection criteria were included. All participants gave their written consent to participate in this study. Demographic data such as age, weight, height, and duration of the back pain were documented. Patients were asked to report their pain using the Visual Analogue Scale (VAS) and Disability in Roland Morris Disability Questionnaire (RMDQ). Exclusion criteria were participants with musculoskeletal disorders (osteoarthritis and rheumatoid arthritis) and a history of previous fractures and systemic diseases. DIERS Formetric 4D spine and posture analyzer were used to assess spinal alignment using the light-optical scanning method on the back of patient in standing position. Angle of LL: the angle formed by the apex of LL and the T12 and L5 spinous processes. Pelvic tilt is the orientation of the pelvis in respect to the thighbones and the rest of the body. Core stabilization exercises were given for 30 min, five days a week, for 12 sessions. Pre- and posttest values were documented and analyzed. Result: In this experimental study, we used Pearson’s correlation coefficient to find the correlation between LL and pelvic inclination angle and found a strong positive correlation (r = 0.76; P = 0.001). The study showed that core stabilization exercise for 12 weeks’ duration had statistically significant reduction in the pain intensity (p < 0.01), functional disability (p < 0.002), LL (p < 0.05), and pelvic inclination angle (p < 0.05) among patients with chronic NSLBP. Conclusion: From this research, we conclude that core stabilization exercises decrease the pain intensity, functional disability, LL, and pelvic inclination angle in patients with chronic NSLBP. Thus, evaluation of the lumbar curvature and pelvic inclination, and designing the appropriate exercise is recommended in the management of NSLBP.

The Relationship Between Core Stabilization and Balance in The Curling Athletes

Objective: The aim of this study is to the relationship between core stabilization and balance in the national curling athletes. Materials and Methods: 38 curling player, 19 men and 19 women, whose average of age was 19.67±2.90 were included in the study. İn the study, Body composition were measured to use TANİTA TBF 300 device. To Measure Core stabilization levels were used Sit-Up Test, Biering Sorenson Test and Sport-Specific Core Muscle Strength & Stability Plank Test. Balance were measured with SPORKAT 4000 Dynamic and Static Balance Device.The analysis of acquired datas from study is doneusing SPSS (version 24) for Windows Statistical Programme.Independent t-test was used for the comparison of paired groups while Pearson correlation was used for the control of the association between variables. Significance for statistical datas was selected being p<0.05. Results: Sit-up Test average were 44.31± 7.59 in men and 30.84±6.13- in women, Biering Sorenson Test average were 226.78±74.60 in men and 289.10±111.10 women, Sport-Spesific Core muscle strength & stability plan test average 280.26±113.14 in men and 176.05±47.128 women. Dynamic Balance Test average were 7677.26±1467.12 in men and 5207.94±1436.02 in women. The Static balance average were definitely 7759±1554.98 in men and 5477.63±2004.06 in women. Conclusion: As a result of the study, it is found that there wasn’t a significant relation between back endurance and static, dynamic balance, that there was a significant relation between sit up and static, dynamic balance. There was significantly relation between plank time and dynamic balance. However between Plank time and Static balance was not significantly relation. Keywords: Balance; Body composition; Core; Curling

Comparison of core stabilization techniques on ultrasound imaging of the diaphragm, and core muscle thickness and external abdominal oblique muscle electromyography activity

BACKGROUND: To restore core stability, abdominal drawing-in maneuver (ADIM), abdominal bracing (AB), and dynamic neuromuscular stabilization (DNS) have been employed but outcome measures varied and one intervention was not superior over another. OBJECTIVE: The purpose of this study was to compare the differential effects of ADIM, AB, and DNS on diaphragm movement, abdominal muscle thickness difference, and external abdominal oblique (EO) electromyography (EMG) amplitude. METHODS: Forty-one participants with core instability participated in this study. The subjects performed ADIM, AB, and DNS in random order. A Simi Aktisys and Pressure Biofeedback Unit (PBU) were utilized to measure core stability, an ultrasound was utilized to measure diaphragm movement and measure abdominal muscles thickness and EMG was utilized to measure EO amplitude. Analysis of variance (ANOVA) was conducted at P< 0.05. RESULTS: Diaphragm descending movement and transverse abdominis (TrA) and internal abdominal oblique (IO) thickness differences were significantly increased in DNS compared to ADIM and AB (P< 0.05). EO amplitude was significantly increased in AB compared to ADIM, and DNS. CONCLUSIONS: DNS was the best technique to provide balanced co-activation of the diaphragm and TrA with relatively less contraction of EO and subsequently producing motor control for efficient core stabilization.

NEUROMUSCULAR MECHANISMS AND EFFECTS OF CORE STABILIZATIONS ON TRUNK AND HIP MUSCLE ACTIVITY DURING LIFTING MOVEMENT

While the presence of lumbopelvic-hip stabilization has been provided as an importance component of the intra-abdominal pressure and dynamic spinal stabilization prior to movement, no previous study has investigated the effects in nonsymptomatic adults. This study investigated neuromuscular mechanisms and effects by comparing the natural core stabilization (NCS), abdominal bracing stabilization (ABS), and coordinated core stabilization (CCS) techniques in nonsymptomatic adults during lifting movement. A convenience sample of 40 nonsymptomatic adults (mean [Formula: see text] standard deviation, [Formula: see text]; 27 males, 13 females) were randomized into the NCS, ABS, and CCS techniques during lifting movement. The clinical outcomes included the deep and local (transverse abdominis (TrA), internal oblique (IO), and gluteus maximus (Gmax)) and superficial and global muscle (thoracic erector spinae (TES), lumbar erector spinae (LES), and external oblique (EO)) activation and balance ratios (IO/LES and Gmax/LES) and onset time co-activation ratios (IO/LES and Gmax/LES). One-way repeated-measures analysis of variance (ANOVA) and Bonferroni correction revealed that the IO/LES and Gmax/LES balance and activation ratios were greater in CCS than in NCS and ABS. The onset time co-activation ratio was improved in CCS as compared with NCS and ABS, and ABS dropped equally inversely to NCS. Our results provide novel therapeutic evidence that CCS-based lifting movement is more balanced or coordinated in terms of neuromuscular control than the other techniques and may be used as an alternative exercise for core stabilization.