A study of the stress wave factor technique for nondestructive evaluation of composite materials

The acousto-ultrasonic method of nondestructive evaluation is an extremely sensitive means of assessing material response. Efforts continue to complete the understanding of this method. In order to achieve the full sensitivity of the technique, extreme care must be taken in its performance. This report provides an update of the efforts to advance the understanding of this method and to increase its application to the nondestructive evaluation of composite materials. Included are descriptions of a novel optical system that is capable of measuring in-plane and out-of-plane displacements, an IBM PC-based data acquisition system, an extensive data analysis software package, the azimuthal variation of acousto-ultrasonic behavior in graphite/epoxy laminates, and preliminary examination of processing variation in graphite-aluminum tubes

Changes in postural and trunk muscles responses in patients with chronic nonspecific low back pain during sudden upper limb loading

Background: Alterations in the neuromuscular control of the spine were found in patients with chronic low back pain (CLBP). Sudden loading of the spine is assumed to be the cause of approximately 12 of lower back injuries. However, some aspects of this problem, such as alterations in the sensory-motor control of the spine, remain questionable. This study investigated postural and neuro- motor changes in trunk muscles during sudden upper limb loading in patients with CLBP. Methods: Electromyography of the erector spinae (ES) and transverses abdominis/internal oblique (TrA/IO) and external oblique (EOA) muscles were recorded in 20 patients with CLBP and 20 asymptomatic individuals with eyes open (EO) and eyes closed (EC) conditions. Moreover, measurements of the center of pressure (COP) and vertical ground reaction force (GRF) or Fz were recorded using a force plate. Data were analyzed using paired t-test and independent t-test at the significance level of 0.05. Results: In patients with CLBP, decreased electrical activity of the ES muscle was observed under both the EO and EC conditions and that of the TrA/IO muscle was observed under the EO condition (p < 0.05). Other findings included a shorter peak latency of the ES muscle in the EO condition and a greater increase in the peak latency of the ES muscle following the EC condition (p < 0.05). No significant differences were observed in COP and GRF measurements between the groups. Conclusion: Electrical muscle activity may indicate less stiffening or preparatory muscle activity in the trunk muscle of patients with CLBP. Altered latency of the muscle may lead to microtrauma of lumbar structures and CLBP

The effects of arm movement on reaction time in patients with latent and active upper trapezius myofascial trigger point

Background: Myofascial pain syndrome is a significant source of mechanical pain. The aim of this study was to investigate the effects of arm movement on reaction time in females with latent and active upper trapezius myofascial trigger point. Methods: In this interventional study, a convenience sample of fifteen women with one active MTP, fifteen women with one latent MTP in the upper trapezius, and fifteen normal healthy women were participated. Participants were asked to stand for 10 seconds in an erect standing position. Muscle reaction times were recorded including anterior deltoid (AD), cervical paraspinal (CP) lumbar paraspinal (LP), both of upper trapezius (UT), sternocleidomastoid (SCM) and medial head of gastrocnemius (GcM). Participants were asked to flex their arms in response to a sound stimulus preceded by a warning sound stimulus. Data were analyzed using one-way ANOVA Test. Results: There was significant differences in motor time and reaction time between active and control groups (p<0.05) except for GcM. There was no significant difference in motor time between active and passive groups except for UT without MTP and SCM (p<0.05). Also, there were no significant differences in motor times between latent MTP and control groups. Furthermore, there was no significant difference in premotor times between the three groups. Conclusion: The present study shows that patients with active MTP need more time to react to stimulus, but patients with latent MTP are similar to healthy subjects in the reaction time. Patients with active MTP had less compatibility with environmental stimulations, and they responded to a specific stimulation with variability in Surface Electromyography (SEMG)

Circadian rhythms and sleep regulation in seasonal affective disorder

Seasonal affective disorder (SAD) is characterised by recurrent episodes in autumn and winter of depression, hypersomnia, augmented appetite with carbohydrate craving, and weight gain, and can be successfully treated with bright light. Circadian rhythm hypotheses (summarized in) have stimulated research into the pathophysiology of SAD, postulating that: 1.The illness is a consequence of delayed phase position, 2.It is correlated with diminished circadian amplitude, or 3.It results from changes in the nocturnal duration between dusk and dawn e.g. of low core body temperature or melatonin secretion. Light is considered to act directly on the circadian pacemaker (‘Process C') and not on sleep dependent processes (‘Process S'). Thus successful treatment of SAD must act via mechanisms within known retinohypothalamic pathways. Conversely, emergence of SAD symptoms may reflect inappropriate neurobiological response to decreasing daylengt

Comparison of cervical repositioning error in individuals with forward head posture with and without neck pain

Background and purpose: Proprioception is one of the somatic senses which is used by the nervous system for muscular control. Inappropriate posture or pain could result in impaired proprioception. One of these poor postures is forward head posture (FHP). The aim of this study was to investigate cervical repositioning error in FHP subjects with and without neck pain and normal individuals. Materials and methods: A case-control study was conducted consisting of people who had FHP without neck pain (n=31), individuals with FHP and neck pain (n=31), and healthy subjects (n=31). Cervical total range of motion (ROM) and then repositioning error in target angle (50 of full ROM in each movement(of flexion, extension, right and left lateral flexion, and right and left rotation were measured by cervical range of motion (CROM) device. Pain intensity was measured using the visual analog scale (VAS). Results: Cervical ROM in FHP subjects was significantly less than that of healthy subjects in most movement directions. The absolute repositioning error of the target angle in FHP subjects was found to be significantly more than that of healthy subjects in most movement directions (p<0.05). The mean VAS score in patients with neck pain was 4±0.68. Conclusion: FHP whether with or without pain may increase the cervical repositioning error. But presence of pain do not leads to higher rates of error. © 2016, Mazandaran University of Medical Sciences. All rights reserved

Effects of craniosacral therapy and sensorimotor training on pain, disability, depression and quality of life of patients with nonspecific chronic low back pain: a randomized clinical trial

Background: Craniosacral therapy (CST) and sensorimotor training (SMT) are two recommended interventions for nonspecific chronic low back pain (NCLBP). This study compares the effects of CST and SMT on pain, functional disability, depression and quality of life in patients with NCLBP. Methodology: A total of 31 patients with NCLBP were randomly assigned to the CST group (n=16) and SMT (n=15). The study patients received 10 sessions of interventions during 5 weeks. Visual analogue scale (VAS), Oswestry disability index (ODI), Beck depression inventory-II (BDI-II), and Short Form-36 (SF-36) questionnaires were used at baseline (before the treatment), after the treatment, and 2 months after the last intervention session. Results were compared and analyzed statistically. Results: Both groups showed significant improvement from baseline to after treatment (p < 0.05). In the CST group, this improvement continued during the follow-up period in all outcomes (p < 0.05), except role emotional domain of SF-36. In the SMT group, VAS, ODI and BDI-II increased during follow-up. Also, all domains of SF-36 decreased over this period. Results of group analysis indicate a significant difference between groups at the end of treatment phase (p < 0.05), except social functioning. Conclusions: Results of our research confirm that 10 sessions of craniosacral therapy (CST) or sensorimotor training (SMT) can significantly control pain, disability, depression, and quality of life in patients with NCLBP; but the efficacy of CST is significantly better than SMT. © 2021 Faculty of Anaesthesia, Pain and Intensive Care, AFMS. All rights reserved

Abdominal hollowing and lateral abdominal wall muscles' activity in both healthy men & women: An ultrasonic assessment in supine and standing positions

The objective of this study was to investigate the effects of Abdominal Hollowing (AH) maneuver on External Oblique (EO), Internal Oblique (IO) and Transversus Abdominis (TrA) muscles in both healthy men and women during the two postures of supine and upright standing. The study was conducted on 43 asymptomatic volunteers (22 males and 21 females) aged 19-44 (27.8 ± 6.4) years. Rehabilitative Ultrasonic Imaging (RUSI) was simultaneously performed to measure muscle thickness in both rest and during AH maneuvers while activation of the TrA during AH was controlled by Pressure Biofeedback (PBF) device. Mixed-model ANOVA with repeated measures design, and Pearson correlation tests were used to analyze the data. Muscle thickness of all muscles was significantly higher for male subjects (F> 6.2, p< 0.017). The interaction effect of gender and muscle status was significant only for IO (F= 7.458, p= 0.009) indicating that AH maneuver increased the thickness of IO in men. Interaction effect of posture and muscle status on muscular thickness indicated that changing position only affects the resting thickness of TrA (F= 5.617, p= 0.023). Standing posture significantly affected the TrA contraction ratio (t= 3.122, p= 0.003) and TrA preferential activation ratio (t= 2.76, p= 0.008). There was no relationship between age and muscle thickness (r= 0.262, p= 0.09). The PBF has been introduced as a clinical and available device for monitoring TrA activity, while RUSI showed that both TrA and IO muscles had activated after AH maneuver. We recommend performing further investigations using electromyography and RUSI simultaneously at more functional postures such as upright standing. © 2009