Quantitative Electroencephalography and Surface Electromyography Correlations upon Predictable and Unpredictable Perturbation in Older Adults.

Background: Quantitative Electroencephalography (qEEG) is a non-invasive method used to quantify electrical activity over the cortex. QEEG provides an accurate temporal resolution of the brain activity, making it a useful tool for assessing cortical function during challenging tasks. Objective: This study aimed to investigate postural adjustments in older adults in response to an external perturbation. Material and Methods: In this observational study, nineteen healthy older adults were involved. A 32-channel qEEG was employed to track alterations in beta power on the electrodes over the two sensory-motor areas. Integrated electromyographic activity (IntEMG) of the leg muscles was evaluated in response to perturbations under predictable and unpredictable conditions. Results: The results indicated higher beta power during late-phase in the Cz electrode in both conditions. IntEMG was significantly greater in the tibialis anterior muscle during both conditions in the CPA epoch. In predictable condition, a positive correlation was found between the beta power over C4 (r = 0.560, p = 0.013) and C3 (r = 0.458, p = 0.048) electrodes and tibialis anterior muscle amplitude, and between beta power in C4 and gastrocnemius amplitude (r = 0.525, p = 0.021). In unpredictable condition, there was a positive correlation between beta power over the C4 and the tibialis anterior amplitude (r = 0.580, p = 0.009) and also it over the C3 and the tibialis anterior amplitude (r = 0.452, p = 0.049). Conclusion: Our findings demonstrate that sensorimotor processing occurs in the brain during response to perturbation. Furthermore, cortical activity appeared to be greatest during the recruitment of the muscles upon late-phase in older adults.

Cortical Activity During Postural Recovery in Response to Predictable and Unpredictable Perturbations in Healthy Young and Older Adults: A Quantitative EEG Assessment.

INTRODUCTION: To investigate the effects of predictable and unpredictable external perturbations on cortical activity in healthy young and older adults. METHODS: Twenty healthy older and 19 healthy young adults were exposed to predictable and unpredictable external perturbations, and their cortical activity upon postural recovery was measured using a 32-channel quantitative encephalography. The absolute spectral power and coherence z-scores of cortical waves were analyzed through a 3-way mixed ANOVA. RESULTS: During postural recovery from predictable perturbations, older adults exhibited higher frontoparietal beta power and higher alpha and beta coherence during the late-phase recovery than the young individuals. After unpredictable perturbations, the older group showed lower alpha power in the early phase and higher beta power in the late phase as compared to the young group. Results for the group × time and group × location interactions in the older group showed a higher alpha and beta coherence over the late phase, a higher alpha coherence in F3-P3 and F4-P4 regions, and a higher beta coherence in the F4-P4 region compared to the younger group. CONCLUSION: Our results revealed that the cortical activation after external perturbations increases with aging, particularly in frontoparietal areas. A shift from automatic (subcortical level) to attentional (cortical level) processing may reflect the contribution of attentional resources for postural recovery from an external threat in older individuals.

Relationship Between Hamstring Flexibility and Extensor Muscle Activity During a Trunk Flexion Task.

OBJECTIVE: The purpose of this study was to investigate the relationship between hamstring flexibility and electromyography (EMG) muscle parameters in back and lower limb extensor muscles during a trunk flexion task. METHODS: Thirty healthy women aged 18 to 30 years with normal hip movement were recruited for this study. Hamstring muscle flexibility was measured with the 90-90 active straight leg raise test. Surface EMG activities were simultaneously recorded from the lumbar erector spinae, gluteus maximus, biceps femoris, semitendinosus, lateral gastrocnemius, and medial gastrocnemius muscles during forward bending. Muscle activity onset and offset, amplitude, and duration were calculated with technical computer software (MATLAB, version 1.6.0). Linear regression analysis was used to investigate the relationships between hamstring flexibility test results and EMG parameters during trunk flexion. In addition, the Friedman test was used to determine the recruitment activity pattern in women with low versus normal hamstring flexibility. RESULTS: During flexion, the back extensor muscles in individuals with lower hamstring flexibility test scores were activated and deactivated later, which can lead to delayed flexion-relaxation. Regression analysis did not disclose any significant correlations between hamstring flexibility and other EMG parameters (duration and amplitude) in back extensor muscles. Activation and deactivation recruitment patterns differed between the groups with normal and low hamstring flexibility. CONCLUSION: The findings of this study suggest that hamstring flexibility plays an important role in the patterns of trunk and lower limb muscle activity onset, offset, and recruitment.

Head and neck extension more than 30° may disturb standing balance in healthy older adults.

Although there is clinical evidence of postural instability at extreme angles of head extension, the effects of lower angles on balance have been not investigated. This study aimed to investigate the effects of different head and neck extension angles on standing balance in older adults, and to determine the critical angle of instability. Twenty-eight healthy older adults were tested at 0°, 20°, 30° and 40° head and neck extension. The center of pressure (COP) parameters were recorded with a force plate. Significant differences were observed between 30° and 40° compared to 0° in anteroposterior and mediolateral COP displacement and total COP velocity, and between 40° and 0° in mediolateral COP velocity. Head and neck extension at 30° was the critical angle associated with the appearance of instability, and this value should be considered in the ergonomic design of work and living spaces, exercise programming and daily activities in older adults.

Evaluating the Cross-Cultural Adaptation, Reliability, and Validity of the Persian Versions of the Copenhagen Neck Function Disability Scale and Neck Bournemouth Questionnaire.

STUDY DESIGN: A cross-sectional study. OBJECTIVE: To evaluate cross-cultural adaptation and psychometric properties of the Copenhagen Neck Function Disability Scale (CNFDS) and Neck Bournemouth Questionnaire (NBQ) in patients with chronic nonspecific neck pain. SUMMARY OF BACKGROUND DATA: CNFDS and NBQ are among the most popular scales to investigate aspects of life in patients with chronic neck pain. To date, the Persian versions of these scales have not been validated. METHODS: Following the translation process, the questionnaires were given to 106 patients with chronic nonspecific neck pain. To evaluate reliability, Cronbach alpha and test-retest reliability were evaluated. To investigate construct validity, the Neck Disability Index (NDI) and Neck Pain Disability Scale (NPDS) were used. Internal consistency of the scales was evaluated with exploratory factor analysis. RESULTS: No missing data were observed for the NBQ, and missing data affected 0% to 3% of the CNFDS items. There were no floor or ceiling effects. Cronbach alpha was 0.92 for the CNFDS and 0.95 for the NBQ. Test-retest reliability was estimated as 0.86 for the CNFDS and 0.91 for the NBQ. The CNFDS correlated very well with the NDI pain subscale, and the NPDS. The NBQ correlated very well with the NPDS and NDI, and correlated well with the CNFDS and its subscales. Exploratory factor analysis detected three dimensions for the CNFDS and confirmed unidimensionality of the NBQ. CONCLUSION: The Persian versions of the CNFDS and NBQ have acceptable validity and reliability for use with Persian-speaking patients with chronic nonspecific neck pain. LEVEL OF EVIDENCE: 2.

Trunk postural control during unstable sitting differs between patients with patellofemoral pain syndrome and healthy people: A cross-sectional study.

BACKGROUND: Patellofemoral pain syndrome (PFPS) is a common orthopedic problem with a high prevalence among young women. Patients with PFPS have altered trunk muscle activity, impaired postural control and greater displacement of the center of pressure (COP) while standing. Training in unstable sitting, by putting more emphasis on trunk sensory receptors, may improve trunk proprioception by minimizing the role of the lower extremities. The aim of this study was to compare trunk postural control in healthy persons and in patients with PFPS. METHODS: Twenty-one women diagnosed with PFPS and 21 healthy women volunteered to participate in this cross-sectional study. The participants were asked to maintain trunk postural balance on an unstable sitting device, and COP indices of trunk postural control were compared between groups. RESULTS: All COP indices (e.g., mean anterior-posterior and lateral COP displacement, mean COP velocity and mean area of COP displacement) were significantly increased in participants with PFPS in comparison to healthy controls (P < 0.001). The effect sizes of all the indices were greater than 0.80. CONCLUSIONS: Trunk postural control is impaired in patients with PFPS, and this finding has clinical implications for rehabilitation in patients with PFPS. Adding seated postural control training to conventional physical therapy management in patients with PFPS may have beneficial effects by emphasizing trunk proprioception while minimizing the role of the lower extremities.

Effects of Integrated Neuromuscular Inhibition Technique on pain threshold and pain intensity in patients with upper trapezius trigger points.

INTRODUCTION: Upper trapezius trigger points are among the most common causes of neck pain. This study aimed to investigate the effects of integrated Neuromuscular Inhibition Technique (INIT) on pain intensity and threshold. MATERIALS & METHODS: Thirty two female participants with upper trapezius trigger points were recruited in this study. The participants were assigned to control (n = 16) or intervention (n = 16). The intervention group received INIT in one session, consisted of muscle energy technique, ischemic compression and strain-counter strain. Pain threshold and intensity were measured using Pressure Pain Threshold (PPT) and Numerical Pain Scale (NPS). These measurements were performed at baseline, immediately after treatment and 24 h after treatment. FINDINGS: The results showed that pain intensity significantly decreased in the intervention group immediately after treatment (P = .01) and 24 h after treatment (P = .009) in comparison with the control group. There were no significant differences in pressure pain threshold between both groups. CONCLUSION: It seems that Integrated Neuromuscular Inhibition Technique can reduce pain intensity in patients with upper trapezius trigger points.

Clinical Evaluation of Scapular Positioning in Patients With Nonspecific Chronic Low Back Pain: A Case-Control Study.

OBJECTIVE: The purpose of this study was to investigate the position of scapula in patients with nonspecific chronic low back pain. METHODS: A total of 17 participants with a history of nonspecific chronic low back pain and 17 healthy participants in the same age, sex, and weight range were enrolled in this case-control study. Lateral scapular slide test and Lennie test were used for clinical evaluation of scapular position in the frontal plane using a tape measure. The data were analyzed using an independent t test. RESULTS: The results of lateral scapular slide test indicated that there were significant differences between patients with nonspecific chronic low back pain and healthy individuals in both left and right sides in 2 positions: shoulder in neutral position and shoulder at 40°-45° abduction. Also, in the Lennie test, there was only a significant difference between groups when we measured the distances from thoracic spinous process to the inferior angle of the scapula in both left and right sides. CONCLUSION: This study indicated that upward rotation of the scapula can be seen in patients with nonspecific chronic low back pain.

Effectiveness of treadmill training on balance control in elderly people: a randomized controlled clinical trial.

UNLABELLED: Physical exercise would improve postural stability, which is an essential factor in preventing accidental fall among the elderly population. The aim of this study is to examine the effectiveness of treadmill walking on balance improvement among the elderly people. A total of 30 community dwelling older adults with a Berg Balance Scale score of 36-48 and the ability to walk without aid were considered and divided into control (n=15) and experimental (n=15) groups. Individuals in the experimental group participated in 30 minutes of forward and backward treadmill training based on three times a week interval for a period of four weeks. Individuals in the control group were instructed to continue with their daily routine activity. Before and after training, gait speed was measured by six-minute walk test and balance ability was evaluated by Fullerton Advanced Balance Scale (FABS) and Berg Balance Scale (BBS) tests. Postural sway items such as the Center of Pressure (COP), average displacement and velocity were evaluated by using a force platform system. Data were collected in quiet standing, tandem position and standing on foam pads before and after intervention. After intervention, balance variables in the experimental group indicated a significant improvement in quiet standing on firm and foam surfaces, but no considerable improvement was shown in tandem position. A between-group comparison showed a significant reduction in COP velocity in the sagittal plane (P=0.030) during quiet standing and in the frontal plane (P=0.001) during standing on foam, whereas no significant reduction in COP parameters during tandem position was found. It is recommended that twelve sessions of forward and backward treadmill walk are effective in balance improvement in elderly people. TRIAL REGISTRATION NUMBER: IRCT201209199440N2.

Is Abdominal Muscle Activity Different from Lumbar Muscle Activity during Four-Point Kneeling?

BACKGROUND: Stabilization exercises can improve the performance of trunk and back muscles, which are effective in the prevention and treatment of low back pain. The four-point kneeling exercise is one of the most common types of stabilization exercises. This quasi-experimental study aimed to evaluate and compare the level of activation between abdominal and lumbar muscles in the different stages of the four-point kneeling exercise. METHODS: The present study was conducted on 30 healthy women between 20 and 30 years old. Muscle activity was recorded bilaterally from transversus abdominis, internal oblique, and multifidus muscles with an electromyography (EMG) device during the different stages of the four-point kneeling exercise. All the collected EMG data were normalized to the percentage of maximum voluntary isometric contraction. The repeated measures ANOVA and paired t-test were used for the statistical analysis of the data. RESULTS: A comparison between mean muscle activation in right arm extension and left leg extension showed that left internal oblique and left transverse abdominis muscles produced greater activation during left leg extension (P<0.05). The comparison of mean muscle activation between right arm extension and the bird-dog position showed that, except for the right internal oblique, all the muscles produced higher activation in the bird-dog stage (P<0.05). In comparison to the bird-dog stage, the left multifidus showed high activation during left leg extension (P<0.05). CONCLUSION: The results of this study showed that the activity of all the above-mentioned muscles during quadruped exercise can provide stability, coordination, and smoothness of movements.

Sacroiliac joint manipulation attenuates alpha-motoneuron activity in healthy women: a quasi-experimental study.

OBJECTIVE: To determine whether sacroiliac joint (SIJ) manipulation decreases α-motoneuron activity and increases the pressure pain threshold (PPT) over the posterior superior iliac spine (PSIS) in healthy women. DESIGN: Quasi-experimental study. SETTING: A university medical center. PARTICIPANTS: Healthy young women (N=20) aged 18 to 30 years were recruited from among the students of a university medical center after a request for volunteers. INTERVENTIONS: Joint manipulation consisted of the supine rotational glide manipulation for the sacroiliac region. PPT measurements from the PSIS and Hoffman-reflex (H-reflex) amplitudes from the tibial nerve on the same side were recorded before and after joint manipulation. PPT was monitored for 15 minutes and H-reflex for 20 minutes after the procedure. MAIN OUTCOME MEASURES: Changes in tibial nerve H-reflex amplitude and PPT values after SIJ manipulation. RESULTS: SIJ manipulation attenuated α-motoneuronal activity significantly (P<.05) but transiently, since the decrease was seen only for 20 seconds after the intervention. There was no positive significant difference in the PPT after SIJ manipulation at any time during postintervention follow-up. CONCLUSIONS: SIJ manipulation produced a transient attenuation of α-motoneuron excitability in healthy women. These findings demonstrate that our manipulation technique can lead to a short-term reduction in muscle tone as a result of changes in sensory discharge, predominantly in la afferents. SIJ manipulation did not significantly affect the PPT in healthy women.

The prevalence of musculoskeletal pain in male cigarette smoking students at shiraz university of medical sciences, iran.

BACKGROUND: The rising trend of smoking cigarettes, especially among the youth, has become a great concern in Iranian society. Not only does smoking cigarettes harm one financially, but also it will cause immense damage to the smoker as well as the society. This paper investigated the prevalence of musculoskeletal pain and the factors affecting it in young smokers. METHODS: The research has been conducted on 400 men smokers aged 18-30 studying at Shiraz University of Medical Sciences. Data was collected through a questionnaire containing information about age, history and amount of smoking, existence of pain and its severity according to the visual analog scale (VAS). The subjects were randomly selected while making sure the proportion of subjects from each department was appropriate. The subjects were smokers for more than two years and smoked more than five cigarettes a day. Data was analyzed by analysis of variance (ANOVA) and the least significant difference (LSD) test. FINDINGS: Among all studied subjects, 129 (32.25%) suffered from musculoskeletal pain. Most of the subjects (31.25%) had pain in their backs. The relationship between the duration of smoking and musculoskeletal pain, as well as that between the number of cigarettes smoked per day and the pain, was direct and significant. However, no significant relationship was found between age and pain. CONCLUSION: The occurrence of musculoskeletal pain in male students was relatively high. This fact can bring irrecoverable damages to the society and would put its health at risk. It also decreases the socioeconomic improvements.

Low back pain patients demonstrate increased hip extensor muscle activity during standardized submaximal rotation efforts.

STUDY DESIGN: A comparative study of trunk and hip extensor muscle recruitment patterns in 2 subject groups. OBJECTIVE: To examine for changes in recruitment of the hip and back extensor muscles during low level isometric trunk rotation efforts in chronic low back pain (CLBP) subjects by comparison with matched asymptomatic control subjects. SUMMARY OF BACKGROUND DATA: Anatomic and biomechanical models have provided evidence that muscles attaching to the thoracolumbar fascia (TLF) are important for providing stabilization to the lumbopelvic region during trunk rotation. This has guided rehabilitation programs. The muscles that link diagonally to the posterior layer of the TLF have not previously been examined individually and compared during low-level trunk rotation efforts in CLBP patients and matched controls. METHODS: Thirty CLBP patients and 30 matched controls were assessed using surface electromyography (EMG) as they performed low-level isometric rotation efforts while standing upright. Muscles studied included latissimus dorsi, erector spinae, upper and lower gluteus maximus, and biceps femoris. Subjects performed the rotation exertion with various levels of external trunk support, related to different functional tasks. RESULTS: EMG results demonstrated that subjects with CLBP had significantly higher levels of recruitment for the lower and upper gluteus maximus (P < 0.05), hamstrings (P < 0.05), and erector spinae muscles (P < 0.05) during rotation to the left compared with the control subjects. CONCLUSION: This study provided evidence of increased muscle recruitment in CLBP patients when performing a standardized trunk rotation task. These results may have implications for the design of therapeutic exercise programs for CLBP patients.