sedigheh kahrizi

Chronic low back pain (CLBP) is a global burden with an unknown etiology. Reorganization of the cortical representation of paraspinal muscles in the primary motor cortex (M1) may be related to the pathology. Single-pulse transcranial magnetic stimulation (TMS), commonly used to map the functional organization of M1, is not potent enough to stimulate the cortical maps of paraspinal muscles in M1 in CLBP patients with reduced corticospinal excitability (CSE) with intensities even as high as maximum stimulator output (100% MSO). This makes TMS mapping impractical for these patients. The aim of this study was to increase the practicality of TMS mapping for people with CLBP.

This study included eight men and ten women who had CLBP for over three months. A biphasic paired-pulse TMS paradigm, conjunct anticipatory postural adjustment (APA), and maximal voluntary activation of paraspinal muscles (MVC) were used to facilitate TMS mapping. 

TMS mapping was possible in all CLBP participants, with TMS intensities <50% of the MSO. Reorganization in terms of an anterior and lateral shift of the center of gravity (COG) of the cortical maps of paraspinal muscles was observed in all participants with CLBP, and a reduced number of discrete peaks was found in 33%.

The facilitation of the CSE to paraspinal muscles makes TMS mapping more practical and tolerable in people with CLBP, lowering the risk of seizure and discomfort associated with high-intensity TMS pulses.

Research has shown that there are some risk factors for creating and developing low back pain with prolonged standing. For attempt to recognition of predisposing factors to development of LBP during prolonged standing, the purpose of this study was to investigate to maximal voluntary contraction (MVC) at selected groups of muscles and some of the psychological aspects in back-healthy subjects who developed LBP during prolonged standing.

In this cross sectional study, 25 back-healthy subjects and 14 chronic nonspecific LBP completed anxiety inventory (STAI), Tampa Scale for kinesiophobia (TSK) and pain catastrophizing scale (PCS) questionnaires. Dynamometer was used to assess MVC of the selected groups of muscles. Finally back-healthy subjects get tested for 2 h prolonged standing protocol and based on a visual analog scale (VAS) were categorized as pain developers (PD) or non-pain developers (NPD).

Ten subjects (% 40) with developing pain were categorized as PD. There were no significant difference at psychological aspects between three groups of PD, NPD and LBP had. But analysis of MVC showed PD and LBP groups had less MVC at the left plantar flexors than left plantar flexors of the NPD group. Also PD and LBP groups had significantly more between two sides asymmetry at MVC at the plantar flexors compared to NPD group.

This preliminary data suggests less MVC and asymmetry of MVC at plantar flexor muscles maybe related to development of the LBP during prolonged standing in the back-healthy peoples. Future study is needed to investigate other function of plantar flexors and their probably relations to development of LBP during prolonged standing.

This study aimed to investigate the efficacy of educational intervention on sitting posture in female student studying in high school in Izeh, Iran.

Current study was performed in two schools in Izeh city of Iran. Ethical approval and informed consent was obtained from the participants. One hundred and forty six (N=146) participants from these schools were randomly allocated to an intervention (n = 73) or control group (n = 73). The intervention included two group-based sessions. The control group received usual educational. Data collection was conducted by Nordic questionnaire and a researcher– made questionnaire. Data were analyzed by SPSS 16 software, using independent t-test and Chi-square test.

The mean age of participants in this study in the intervention and control groups were 16.15 ± 0.88 and 15.95 ± 0.81 years respectively. The intervention group had significant improvements compared with the control group. In intervention group significant differences were found in score of knowledge, attitude and sitting behavior before and after of intervention (P<0.05).

This study showed that educational intervention was effective in improving proper sitting and maintaining the status of the spine.

One of unhealthy behaviours that can be leading to musculoskeletal pain and discomfort in students is keeping inappropriate posture of the vertebra column, posture of sitting on bench or behind computer, and also improper carrying of backpacks. Therefore, the aim of this study was to evaluate the status of musculoskeletal pains and disorders of female students in the schools of izeh ,Ahvaze , Iran. In this descriptive-analytical study, 146 female students from two schools at this city were selected through simple random sampling. In order to evaluate musculoskeletal discomforts and pains, a Nordic Musculiskeletal Questionnaire (NMQ) was used and a also body map was used to determine the location of pain. Data analysis was performed, using SPSS software. totally, 146 female students were examined. According the results, the majority of the students felt pain in their back ( 27.40%) and shoulder (26.03%) respectively. However, least rate of feeling torment was related with elbow (5.48%). Musculoskeletal Disorders (MSD) are clearly seen in female students . This study recommended doing more studies regarding the causes of these disorders . Furthermore, designing appropriate clinical/ educational intervention regarding keeping right posture of vertebra column is garanteed.

Proprioception, or joint position sense, probably plays an important role in joint function. A number of studies have shown that proper joint position sense can decrease the risk of injuries in sports. It is not very clear how patellofemoral pain syndrome (PFPS) can affect athletes joint position sense (JPS). Regarding the importance of proper joint position sense for movement performance and injury prevention in athletes, the aim of this study was to evaluate knee JPS in athletes with PFPS and compare it with asymptomatic individuals under non-weight bearing (sitting) conditions.
The study design was comparative in which 15 patients and 15 healthy athletes participated. JPS was evaluated by active and passive replication of knee angles for 30, 45 and 60° of knee flexion target angle while visual cues were eliminated. Each test was repeated three times. By subtracting the test angle from the replicated angle, the absolute error was calculated as a dependent variable. T-statistical test was used to compare data between two groups and P value of 0.05 was considered as the level of statistical significance.
No significant difference (P According to results, both groups had the same JPS ability, it seems PFPS does not affect the knee JPS at least in athlete cases. It would be possible that deficiency of JPS compensated for the physical activity or on the other hand, maybe pain intensity was not high enough to interfere with JPS accuracy. According to our results, PFPS doesn’t reduce IPS but further investigation is needed to disclose if other factors such as skill level, intensity of pain or joint pathology are effective on JPS accuracy or not.

According to the importance of the back extensor muscle strength in postmenopausal women, this study aimed to determine the relationship between strength and changes in the thickness of back extensor muscles during isometric contraction in healthy and osteoporotic postmenopausal women.
Material and 42 volunteer postmenopausal women according to their Bone Mineral Density divided into two groups “healthy” and “osteoporosis.” Strength and thickness of the muscles were measured, respectively, using a handheld dynamometer and ultrasonography. The interclass correlation was used to evaluate the relative reliability dynamometer and ultrasonography. In addition, the Pearson’s correlation coefficient was used to analyze the relationship between the strength and thickness.
The results indicated a high reproducibility dynamometer test and ultrasonography. There was a good significant positive correlation between strength and the thickness change of the muscles during isometric contractions in the healthy group (P In postmenopausal women with osteoporosis, due to the low quality of muscles (muscular component of strength), changes of the muscle thickness is not in line with muscle strength during isometric contraction, so it is necessary special back muscle training for these subjects besides of other treat intervention from the point of rehabilitation

anterior cruciate ligament injury (ACL) has destructive effects on the postural stability and muscle strength of the knee and cause to impair the neuromuscular control. Patients with ACL injury divided to Coper and Noncoper groups. The purpose of this study has been to compare the muscle strength and postural stability of the two groups of the patients with the ACL- injury: Coper and Noncoper In this case control study, 23 athletic individuals with ACL rupture (11 coper, 12 noncoper) and 12 healthy athletic control ones, completely matched with case groups as demographic parameters, have participated. The Strength and postural stability have been evaluated. Postural control has been evaluated through the Biodex Stability System in two levels (4 & 8). The muscle strength has been evaluated by Isokinetic dynamometer and parameters are set at angular velocity of 60°/s and concentric form. Both groups of coper and noncoper of the patients with ACL injury have less postural stability compared to the control subjects, so that the Coper group have the greatest changes in the postural stability of the individuals(p<0.05). Also, the quadriceps muscle strength of the noncoper group is less than healthy group (p=0.00). The coper group with regarding the muscle strength and noncoper group with regarding the postural stability act so similar to the control subjects.

Despite the widespread use of whole body vibration (WBV),especiallyin recent years, its neurophysiological mechanism is still unclear and the results about the facilitatory or inhibitory effects of WBV widely vary in different studies. The aim of this study was to compare between immediate (one session) and short term (12 sessions) effects of WBV on the spinal motor neurons excitability in healthy young men. Ten voluntary non-athlete healthy young-men (mean age:26.1±2.23) were participated in this study.In the sham sessions subjects stood on the turned off vibration plate while were maintaining the semi-squat position and then after 2 weeks wash-out, vibration training sessions were done on the same position with frequency of 30 HZ and peak to peak amplitude of 3 mm training sessions (sham & vibration) consisted of 12 sessions (3 sessions per week) and 4 set in each of them, weekly one set added to the training protocol. H reflex recruitment curve of soleus muscle was recorded before and after first and also 12th sessions in both sham and vibration training protocol. Ascending slope of recruitment curve, threshold and peak amplitudes and related intensities, amplitude of Mh and Hmax/Mmax ratio were determined. Immediate effects of vibration training 12th session caused a significant decrease of threshold amplitude and an increase of peak intensity (p=0.05 and p=0.05 respectively). Short term WBV training significantly decreased the threshold intensity of soleus recruitment curve (p=0.01). The results suggest the inhibitory effect of acute WBV training on the spinal motor neurons excitability. It seems that short term WBV training may be effective to facilitate the motor neurons excitability or increase the muscle spindle sensitivity.

Electromyography (EMG) response of muscles to Whole Body Vibration (WBV) has most studied acutely in areas close to the vibration platform. While، chronic effects of WBV on EMG response of muscles in far areas from vibration plate and with therapeutic perspective has been neglected. This study aimed to investigate the EMG response of muscles in areas far from vibration plate and important from orthopedic view in osteoporotic fractures and at risk population like women. Twelve nonathletic healthy young women (mean age ± SD; 25. 66 ± 2. 71 years) were participated in the one-blind controlled trial study design. They all enrolled to the WBV (static semi squat training + vibration) (vertical vibration، 30 Hz، 3mm) and placebo (static semi squat training) groups، randomly. Training protocol was similar in both groups except of WBV machine set as off in placebo group. EMG tests of muscles (lumbar erector spine (ES)، Gluteous maximus (G. max)، Rectus femoris (RF)) were carried out before and after twelve sessions of training and root mean square and median frequency were extracted for statistical analysis. WBV effects on RMS of ES (P = 0. 017) and G. max (P = 0. 014)، as well as median frequency of ES (P = 0. 020) increased than before training. The net effect of WBV compared with placebo increased statistically only in RMS of G. max muscle (P < 0. 001) and this increase was more than other two muscles، significantly (P = 0. 001). The results indicate the positive net effect of twelve sessions of WBV training on amplitude of muscle activity in G. max. This muscle is far from vibration plate and its strengthening can impose physiologic loading on the greater trochanter، cause likely to strengthen it and prevent osteoporotic fractures in this area. However، the relevance of this finding has to be further investigated in other studies and population like the postmenopausal women.

The primary aim of the present study was to study the reliability of postural stability measures during whole body dynamic conditions، so they can be used in postural stability evaluations، investigations of injury mechanisms and assessments of treatment efficacy. Twelve healthy volunteers and 12 low back pain patients performed repeated trunk bending motions in eight different conditions of high and low speed، in symmetric and asymmetric planes and with or without external load. All measurements were repeated on a second session، 7-10 days later. Center of pressure (COP) data were used to calculate the standard deviation of amplitude and that of velocity in anterior-posterior and medial-lateral directions، the mean total velocity and the path length. Relative reliability was assessed using the intra class correlation coefficient (ICC) and absolute reliability using the standard error measurement، minimum detectable change and coefficient of variation. Results in both low back pain and healthy subjects revealed that the mean total velocity showed good to excellent reliability، with ICC ranging from 0. 6 to 0. 91. In the healthy group other parameters such as standard deviation of amplitude and standard deviation of velocity in the anterior-posterior direction showed good to excellent reliability (range: 0. 66-0. 97). In the low back pain group standard deviation of amplitude in the anterior-posterior direction in symmetric test conditions (range: 0. 61-0. 75) and standard deviation of amplitude in the medio-lateral direction in asymmetric test conditions (range: 0. 62-0. 81) were good or excellent. Mean total velocity is suggested as a good parameter for evaluation of postural stability in dynamic situations such as lifting and complex trunk movement and also for identifying low back pain patients from healthy subjects.

Although the effects of whole body vibration (WBV) on the electromyographic (EMG) response of some muscles have been investigated in different studies، the effect of WBV on different types of motor units is not clear yet. The aim of the present study was to assess the different effects of a short-term WBV training on different motor units. Soleus (SOL) and gastrocnemius lateralis (GL) muscles were selected as the representatives of slow- and fast-twitch muscles، respectively. Twelve healthy young women (mean age 25. 66 ± 2. 71 years; mean height 161 ± 5. 6 cm; mean weight 66. 5 ± 5. 42 kg) were randomly allocated into the sham (n = 6) and WBV (n = 6) groups. The maximal isometric voluntary contraction (MIVC) of SOL and GL muscles was recorded before the initiation and after the termination of 12 training sessions. The training program was composed of the isometric squatting in both study groups such that in the sham group، the WBV machine set as off and in the WBV group، isometric squatting was offered in combination with whole body vibration (frequency of 30 Hz and peak to peak amplitude of 3 mm). The root mean square of EMG of soleous and gastrocnemius muscles was not statistically different between the two groups before training (P > 0. 05). The 12 sessions of training did not induce any statistically significant change in the muscle activity (EMGrms) of the SOL and GL muscles in either group (P > 0. 05). Although the RMS response of lateral gastrocnemius showed increasing behavior from the sham to the WBV groups، there was no significant difference in EMGrms values of these two groups (P > 0. 05). The difference value of EMGrms for soleus muscle did not also show any significant difference between these two groups (P > 0. 05). Despite the fact that EMGrms increases in soleus and gastrocnemius muscles were not statistically significant after WBV training، monitoring the response pattern in these two muscles between the sham and WBV groups is indicative of a positive effect of WBV on the lateral gastrocnemius motor units as a fast-twitch muscle.

Low back pain after load- holding and carrying can result in significant functional disability and financial disadvantage. Dynamic load-holding imposes varying torque on intervertebral joints and endangers the balance. The goal of the present study was to study the reliability of the postural stability during holding dynamic load for more accurate evaluation of lumbar spine injury.

Participants in this study were 12 healthy men and 12 male patients with low back pain (LBP), subjects were assessed 3 times in 8 conditions while they held dynamic loads in neutral and flexed trunk positions. Center of pressure (COP) data including displacement, velocity, path length and their respective standard deviations (SD) in anterior-posterior (AP) and medial-lateral (ML) directions were assessed. Relative reliability was measured using intra class correlation coefficient (ICC) while absolute reliability was obtained via standard error measurement (SEM) and minimal metrically detectable change (MMDC).

Healthy subjects’ velocity in ML direction (0.8-0.9), LBP patients’ velocity and its SD in AP direction (0.7-0.9) had the highest reliability among the parameters of interest. Reliability of displacement in ML direction and its respective SD yielded similar results in both groups (0.6-0.9). Reliability of displacement and its SD in ML direction and path length in healthy subjects were more than those of LBP patients.

Velocity of center of pressure in both AP and ML directions are suggested as appropriate parameters for evaluation postural stability during dynamic load- holding in subjects with and without non specific low back pain.

To define the dynamic organization of the neuromuscular system, we need useful tools that allow for the expression of the neuromuscular system in low dimensional term (i.e one variable), so it seems that relative phase provides a better measure of organization of the neuromuscular system. Besides, selection of a measure for research or clinical use should be motivated by several factors, including the measure reliability. To our knowledge there seems to exist no study that have ever investigated the reliability of the relative phase and deviation phase in healthy or Low back pain subjects in dynamic movement tasks. Twelve healthy volunteers and 12 low back pain patients performed repeated trunk bending motion in eight different conditions of high and low speed, in symmetric and asymmetric planes, with or without external load. All measurements were repeated on a second session, 7-10 days later. Mean absolute relative phase and deviation phase of lumbar-thorax and pelvis-lumbar were used to calculate coordination pattern and variability. Relative reliability was assessed using intra class correlation coefficient (ICC) and absolute reliability was assessed using standard error measurement, minimum detectable change and coefficient of variation. Results in healthy subjects revealed that relative phase and deviation phase showed good to excellent reliability, with ICC range of 5.3-8.4 and in low back pain group ICC range was0 /52-0/85 except in three asymmetric test conditions and one symmetric test condition. SEM values range for healthy subjects were 0/92-4/8 and for low back patients were 1/2-5/8. Relative phase and deviation phase are suggested as good parameter to use for evaluating coordination and variability in dynamic situations such as lifting and complex trunk movement and also for discrimination low back pain patients from healthy subjects.

Lumbar curvature is an important factor in posture and body movement that help us to understand low back pain problems. The aim of this study was evaluation of external load and trunk posture effect on lumbar curvature under static condition.

This study is an interventional, quasi-experimental and case-control study. Ten women with non specific chronic low back pain and ten matched without low back pain women were participated in this study. We used simple and non random method for sampling. Two clinometers sensors were used to evaluate lumbar curvature. Six static tasks while holding three levels of load (0, 6, 12 Kg) and two levels of trunk position (neutral and 30 degree of flexion) were simulated for subjects. Data were analyzed by using Kolmogroff-Smirnoff, ANOVA (Repeated Measurement) and independent T-test.

Findings revealed lumbar lordosis in patients with low back pain does not change to kyphosis while increasing external load from 0kg to 6kg and 12kg in neutral trunk position (P<0.05).

Dysfunction in passive system due to soft tissue disorder, afraid of pain, changes trunk muscles recruitment and reduction of moment arm are likely reasons for increased lumbar lordosis in patients with low back pain during loading.

The aim of this study was to determine the efficacy of three common remedial exercises and then compare them in severity of pain and disability in patients with chronic low back pain. 25 patients with same as level of physical activity and history of mechanical low back pain during 6-12 months ago invited to participate to this clinical trial. After routine physical exam, severity of pain and disability due to low back pain was evaluated with visual analog scale (VAS) and Oswestry Questionnaire (OSWQ) respectively. Patients distribute to three subgroups (stabilization exercise=10pateints, Williams exercise=8patients, McKenzie exercise=7patients). Means difference of pain score and OSWQ (disability index) in all groups wasnt significant. Patients had done exercises according to name of their group during 12 weeks. At first all groups performed a complete set of exercises every day in 6 weeks. Then second 6 weeks exercises had done every other day (3 days per week). After testing the repeat ability of the parameters, reassessment of parameters was performed at the end of every 3 weeks. Data analysis was done with SPSS software. Friedman and Willcoxon tests were used for determination and analysis of data in three groups and then Kruskal-Wallis test and Mann-Whitney was done for determination of differences between three groups. Data showed that all exercise regimens can decrease pain and disability index (P<0.000l). Though decrease of pain and OSWQ in stabilization group was faster than the other groups (P<0.05). All exercise regimens due to their strengthening properties and special affects on muscles and joints of lumbopelvic region can decrease severity of pain even acute pain. But according to the effect of pain chronocity to surrounding tissues and receptors of lumbopelvic region and also central effect of pain (reorganization of motor cortex), which exercise can more effect than the other to this parameters that can more and more affect the surrounding tissues and receptors of lumbopelvic region so in the long time stabilization exercise according to activate inhibited local stabilizing muscles and then global muscle in stable position and unstable position can more effective than the other exercise regimens.