Median Frequency Values Research Articles

The impact of positive-pressure breathing apparatus on muscle fatigue of volunteer firefighter.

Muscle fatigue is one of the leading causes that contributes tremendously to injuries among volunteer firefighters in the workplace. The purpose of this study was to investigate the impact of positive-pressure breathing apparatus on muscle fatigue in the shoulder, back, and legs of volunteer firefighters. A total of 60 volunteer firefighters were recruited to perform a running task on a motorized treadmill in a controlled laboratory environment. Surface electromyography and rating of perceived exertion scores were collected from all participants every 60 seconds during the running task. Results show that the median frequency values for all measured muscle groups were significantly lower, and the rating of perceived exertion score was significantly higher after running with the positive-pressure breathing apparatus. Meanwhile, there were no significant differences in the median frequency values for the upper trapezius, erector spinae, and biceps femoris between the initial and final periods of running task without load. However, the median frequency values with load for gastrocnemius, rectus femoris, and tibialis anterior exhibited a greater downward trend compared to those without load. Additionally, using a breathing apparatus can cause asymmetric muscle fatigue in bilateral upper trapezius, erector spinae, gastrocnemius, and tibialis anterior muscles. The decreased performance due to muscle fatigue increases the risk of accidents, thereby posing a threat to the safety of volunteer firefighters. This study offers valuable insights into the effects of positive-pressure breathing apparatus on muscle fatigue among volunteer firefighters. These results may serve as a reference for developing improved fatigue management strategies and optimizing the design features of breathing apparatus.

Effect of physical activity education on shoulder girdle pain and muscle strength in participants with fibromyalgia: a pilot experimental study.

In patients with fibromyalgia, exercise and education are recommended to decrease pain level and improve pain management. The latest scientific evidence recommends to focus interventions on the upper limb. The aim of this pilot study was to compare the immediate effect of physical activity education vs. a control group on pain and muscle capacity in fibromyalgia patients. Fifty-six participants with fibromyalgia were randomized into an experimental group and a control group. The intervention consisted in watching a five-minute video that provided information about fibromyalgia, pain, kinesiophobia and physical activity. The control group watched a neutral five-minute video about beavers in Quebec. Following the video, participants performed a muscular fatigue task consisting of a repeated unilateral shoulder abduction task. At baseline and following the muscular fatigue task, maximal voluntary contraction (MVC) in shoulder abduction was assessed as well as pain level and pressure pain threshold (PPT) in the upper limb. Electromyographic activity was also assessed for upper trapezius and middle deltoid muscles. Two-way repeated measures analysis of variance was used to compare the MVC, PPT, and pain level before and after the muscular fatigue task between groups. The experimental group showed a significantly lower increase in pain than the control group in the middle deltoid muscle (p = 0.002) when assessed by verbal pain rating scale. No significant interaction or main effect of Group and Time were observed for the pain level at the upper trapezius and elbow extensor muscles nor for any of the PPT measures. According to electromyographic data, the median frequency values indicate that neither group experienced muscle fatigue during the repeated contraction task. The preliminary results suggest that a short physical activity education video positively influenced middle deltoid pain following repeated abduction in participants with fibromyalgia. Electromyographic analysis showed no evidence of objective muscle fatigue, suggesting that there might be a partial disconnection between the perception of muscle fatigue and the physiological biomarkers associated with muscle fatigue.

Spectral characterization of human leg EMG signals from an open access dataset for the development of computational models.

Large-scale neuromusculoskeletal models have been used for predicting mechanisms underlying neuromuscular functions in humans. Simulations of such models provide several types of signals of practical interest, such as surface electromyographic signals (EMG), which are compared with experimental data for interpretations of neurophysiological phenomena under study. Specifically, realistic characterization of spectral properties of simulated EMG signals is important for achieving powerful inferences, whereas considerations should be taken for myoelectric signals of different muscles. In this study, we characterized spectral properties of surface interference pattern EMG signals and motor unit action potentials (MUAP) acquired from three plantar flexor muscles: Soleus (SO), Medial Gastrocnemius (MG), and Lateral Gastrocnemius (LG); and one dorsiflexor muscle: Tibialis Anterior (TA). Surface EMG signals were acquired from 20 participants using the same convention for electrode placement. Specifically, interference pattern EMG signals were obtained during isometric constant force contractions at 5%, 10% and 20% of maximum voluntary contraction (MVC), whereas surface MUAPs were decomposed from surface EMG signals obtained at low contraction forces. We compared the spectrum median frequency (MDF) estimated from interference pattern EMG signals across muscles and contraction intensities. Additionally, we compared MDF and durations of MUAPs between muscles. Our results showed that MDF of interference pattern EMG signals acquired from TA were higher compared to SO, MG, and LG for all contraction intensities i.e., 5%, 10%, and 20% MVC. Consistently, MUAPs acquired from TA also had higher MDF values and shorter durations compared to the other leg muscles. We provide herein a dataset with the surface MUAPs waveforms and interference pattern EMG signals obtained for this study, which should be useful for implementing and validating the simulation of myoelectrical signals of leg muscles. Importantly, these results indicate that spectral properties of myoelectrical signals should be considered for improving EMG modeling in large-scale neuromusculoskeletal models.

Effect of expiratory muscle training on respiratory muscle fatigue in healthy adults: a randomized controlled trial.

[Purpose] This study examined the effects of expiratory muscle training on fatigue in individual respiratory muscles. [Participants and Methods] Healthy adult males (n=31) were randomly assigned to two groups: expiratory muscle training (n=15) and normal controls (n=16). In the expiratory muscle training group, training was performed once for 15 min at 50% load of the maximum expiratory mouth pressure twice daily for 4 weeks. Respiratory muscle fatigue indicators were measured using surface electromyography as the median power frequency of each respiratory muscle at the time of measuring the maximum inspiratory mouth pressure during 20 min of inspiratory muscle loading and maximum expiratory mouth pressure. [Results] In the expiratory muscle training group, the median power frequency values of the sternocleidomastoid, rectus abdominis, and internal oblique/external oblique before expiratory muscle training significantly decreased during inspiratory muscle loading. However, no difference was observed in the median power frequency values measured before and during inspiratory muscle loading after the expiratory muscle training. In the normal controls, the median power frequency values of the sternocleidomastoid and rectus abdominis significantly decreased during inspiratory muscle loading. [Conclusion] Expiratory muscle training increased fatigue tolerance of the sternocleidomastoid, rectus abdominis, and internal and external oblique muscles in healthy individuals.

Effect of continuous and intermittent blood flow restriction deep-squat training on thigh muscle activation and fatigue levels in male handball players

We aimed to investigate acute changes before and after low-intensity continuous and intermittent blood flow restriction (BFR) deep-squat training on thigh muscle activation characteristics and fatigue level under suitable individual arterial occlusion pressure (AOP). Twelve elite male handball players were recruited. Continuous (Program 1) and intermittent (Program 2) BFR deep-squat training was performed with 30% one-repetition maximum load. Program 1 did not include decompression during the intervals, while Program 2 contained decompression during each interval. Electromyography (EMG) was performed before and after two BFR training programs in each period. EMG signals of the quadriceps femoris, posterior femoral muscles, and gluteus maximus, including the root mean square (RMS) and normalized RMS and median frequency (MF) values of each muscle group under maximum voluntary contraction (MVC), before and after training were calculated. The RMS value under MVC (RMSMVC) of the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), and gluteus maximus (GM) decreased after continuous and intermittent BFR training programs, and those of the biceps femoris (BF) and semitendinosus (SEM) increased; The RMS standard values of the VL, BF, and SEM were significantly increased after continuous and intermittent BFR training (P < 0.05), The RMS value of GM significantly decreased after cuff inflating (P < 0.05). The MF values of RF, VM, VL, and GM decreased significantly after continuous BFR training (P < 0.05). Continuous BFR deep-squat training applied at 50% AOP was more effective than the intermittent BFR training program. Continuous application of BFR induces greater levels of acute fatigue than intermittent BFR that may translate into greater muscular training adaptations over time.

Sex differences in torque steadiness, accuracy and activation of the shoulder girdle muscles during isometric shoulder scaption

Females present more neck/shoulder musculoskeletal disorders and have different activation strategies of the shoulder girdle muscles than males. However, the sensorimotor performance and potential sex differences are still largely unexplored. The aim of this study was to investigate sex differences in torque steadiness and accuracy during isometric shoulder scaption. We also examined the amplitude and variability of the activation of the trapezius, serratus anterior (SA), and anterior deltoid muscles during torque output evaluation. Thirty-four asymptomatic adults (17 females) participated. Torque steadiness and accuracy were evaluated during submaximal contractions at 20 % and 35 % of peak torque (PT). There was no sex difference in torque coefficient of variation, but females had significantly lower torque standard deviation (SD) values than males at the two intensities evaluated (p < 0.001) and lower torque median frequency values compared to males, regardless of intensity (p < 0.01). Females had significantly lower absolute error values than males for torque output at 35 %PT (p < 0.01) and lower constant error values compared to males, regardless of intensity (p = 0.01). Females had significantly higher muscle amplitude values than males, except for SA (p = 0.10) and in general, females showed higher muscle activation SD values compared to males (p < 0.05). Females may require more complex muscle activation patterns to achieve a more stable and accurate torque output. Therefore, these sex differences may reflect control mechanisms that may also be at play when explaining the greater risk of neck/shoulder musculoskeletal disorders in females than males.

Evaluation of Posturographic and Neuromuscular Parameters during Upright Stance and Hand Standing: A Pilot Study

Upright bipedal posture is the physiological human posture; however, it is not the only possible form of human standing; indeed, an inverted position, a handstand, is required during gymnastics or other sports. Thus, this study aimed to understand the differences between the two standing strategies from a postural and neuromuscular perspective. Thirteen gymnasts with at least three years of sports experience underwent a baropodometric assessment and a surface electromyography (sEMG) examination in a standard upright bipodalic stance and during a handstand. The sEMG examination was performed on the gastrocnemius during an upright stance and on the flexor carpi radialis during the handstand. Limb weight distribution presented differences between the two vertical stances (p < 0.01). During the handstand, the weight ratio was prevalently observed on the palm of the hand for both hands with a significant difference between the front and rear aspect of the hand compared to the standing tasks (p < 0.01). Normalized sEMG amplitude showed significant differences during bipedal standing and hand standing; however, over a 5 s period, the normalized median frequency (MDF) value was similar for the two tasks. Both standing tasks presented similar postural weight managing patterns when analysed on the frontal plane, but they were different on the sagittal plane. In addition, the neuromuscular patterns during a 5 s window differ in amplitude but not for the frequency domain.

CRP versus Alvarado Score in Appendicitis Diagnosis

Objective:To evaluate whether C-reactive protein (CRP) level results on admission could aid the diagnostic accuracy of Alvarado score in patients with suspected appendicitis. Study Type: cross sectional study. Study Place and Duration: January to December 2019 in the Surgical Unit, Nishtar Hospital, Multan. Material and methods: Total 230 patients participated in the study with suspected acute appendicitis. Patient’s Alvarado score, age of the patients, sex, length of period of complaint for abdominal pain and level of CPR were recorded on the time of admission. Descriptive statistics for study data included mean, median, standard deviation, minimum and maximum frequency and ratio values. Quantitative data was examined using Mann-Whitney U test. On the other hand a receiver operating characteristic curve was used for effects and cut-off values. Results: The mean C-reactive protein of AA complicated and AA uncomplicated patients was 40.61±9.59 mg/L and 38.25±9.08 mg/L, respectively. The difference was statistically insignificant, (p=0.905). The mean Alvarado score of AA complicated and AA uncomplicated patients was 7.51±1.72 and 7.75±2.08, respectively. The difference was statistically insignificant, (p=0.248). Conclusion: Serum levels of C-reactive protein when assessed alone are not adequate enough in making a diagnosis of acute appendicitis. When combined with Alvarado score, they increase the overall diagnostic value. Moreover these levels in serum also help in differentiation of uncomplicated and complicated acute appendicitis.

SEMG-based fighter pilot muscle fatigue analysis and operation performance research

Fatigue has a tremendously adverse impact on pilot performance. This study aims to explore the Biceps Brachii (BB), Rectus Femoris (RF), Flexor Carpi Radialis (FCR), and Tibialis Anterior (TA) activities of fighter pilots in the early and late combat stages, and the target hitting time. A total of 13 volunteers were recruited to conduct simulated combats inside a real fighter cockpit. The surface Electromyography (sEMG) was collected from all volunteers in the initial and final 20s of flight, and the target hitting time during three simulated combats was recorded. The root mean square (RMS) values of right BB and TA were significantly higher than the left side values (p ​< ​0.001), while insignificant differences were found in the RMS values between the bilateral RF and FCR. Compared to the early flight period, the median frequency (MF) values of BB and TA were significantly lower during the late flight period, and the RMS values were significantly higher (p ​< ​0.047). Contrastively, the RMS values of FCR and RF differed insignificantly during the late flight period. Regarding the target hitting time, a significant difference was noted between task 1 and rask3. Subjects exhibit varying levels of muscle fatigue for different muscle groups before and after the flight. The muscle fatigue levels are asymmetrical on the left and right sides. Muscle fatigue might reduce the pilots' operational ability. This study provides a reference for fighter pilot fatigue protection and treatment.

Workers’ subjective discomfort, muscle fatigue, and kinematics during a manual packaging task

Due to the prevalence and increased demand for manual packaging tasks, the concern for worker health and safety has grown. This study aims to assess the effects of gender and work postures on subjective discomfort, muscle fatigue, and kinematics during a manual packaging task. Twenty participants, including 10 males and 10 females, were recruited to perform a 60-minute manual packaging task in sitting and standing postures. Discomfort was evidenced by increased the rating of perceived exertion (RPE) values (sit: from 6 to 14.55; stand: from 6 to 17.15) and muscle fatigue was supported by decreased median power frequency (MPF) values for right brachioradialis (RB) (sit: -23.68%; stand: -16.20%), right upper trapezius (RUT) (sit: -20.14%; stand: 11.79%), and right erector spinae (RES) (sit: 8.64%; stand: 11.21%) muscles. Women were more likely to bend forward in a relaxed upper body position, especially while sitting, which may increase the risk of low back pain and women also reported greater discomfort than men, but not in the hands and back. Compared with sitting, the back showed greater muscle fatigue in standing, while muscle fatigue for the shoulders and hands was the opposite. These findings suggest that work posture should be considered to prevent fatigue in manual packaging tasks. Given the impact of gender on muscle fatigue, work performed by women and men should both be considered. The results can help to develop action strategies and work posture design to prevent musculoskeletal disorders in the manual packaging industry.

Investigation of muscle fatigue of the archer’s during endurance shooting

Endurance of Drawing-Aim-Release (DAR) during the shooting process in archery will be causing the muscles to fatigue. Besides, the archer's inability to use the right muscles for DAR will lead to a muscle injury as well as dropping the performance. This study aims to monitor the localized muscle fatigue of an archer during the repetitive DAR and its effect to the archer’s performance. Wet electrode sensors were placed on the specific muscles that are heavily involved in DAR such as Muscle Extensor Digitorum (MED) on the archer's bow arm and the Supraspinatus muscle at the shoulder. In order to induce fatigue, the archer has shot 72 arrows continously in 2 rounds of set. The surface electromyography (sEMG) signals of the muscle contraction are recorded during the shooting for the post-processing analysis. Each score of the shooting was also recorded to correlate with the effect of muscle fatigue to the archer’s performance. The finding of this study is that the MED and Supraspinatus begin to fatigue toward the end of each shooting round. The Root Mean Square (RMS) and Median Frequency (MDF) values for both targeted muscles increased significantly during the 6th end compare to the 1st end. It is also found that there is no correlation between muscle fatigue on MED and Supraspinatus to the score obtained by the archer where the F value is lower than F-critical while Draw (1.9339), Aim (1.3754) and Release (0.6515) phases. In conclusion, this experiment benefits archers and coaches to identify which muscles are vigorously used during the DAR process and allows for precaution and prevention procedures.

Incongruity of Geometric and Spectral Markers in the Assessment of Body Sway.

Different measurements of body oscillations in the time or frequency domain are being employed as markers of gait and balance abnormalities. This study investigates basic relationships within and between geometric and spectral measures in a population of young adult subjects. Twenty healthy subjects stood with parallel feet on a force platform with and without a foam pad. Adaptation effects to prolonged stance were assessed by comparing the first and last of a series of eight successive trials. Centre of Foot Pressure (CoP) excursions were recorded with Eyes Closed (EC) and Open (EO) for 90s. Geometric measures (Sway Area, Path Length), standard deviation (SD) of the excursions, and spectral measure (mean power Spectrum Level and Median Frequency), along the medio-lateral (ML) and antero-posterior (AP) direction were computed. Sway Area was more strongly associated than Path Length with CoP SD and, consequently, with mean Spectrum Level for both ML and AP, and both visual and surface conditions. The squared-SD directly specified the mean power Spectrum Level of CoP excursions (ML and AP) in all conditions. Median Frequency was hardly related to Spectrum Level. Adaptation had a confounding effect, whereby equal values of Sway Area, Path Length, and Spectrum Level corresponded to different Median Frequency values. Mean Spectrum Level and SDs of the time series of CoP ML and AP excursions convey the same meaning and bear an acceptable correspondence with Sway Area values. Shifts in Median Frequency values represent important indications of neuromuscular control of stance and of the effects of vision, support conditions, and adaptation. The Romberg Quotient EC/EO for a given variable is contingent on the compliance of the base of support and adaptation, and different between Sway Area and Path Length, but similar between Sway Area and Spectrum Level (AP and ML). These measures must be taken with caution in clinical studies, and considered together in order to get a reliable indication of overall body sway, of modifications by sensory and standing condition, and of changes with ageing, medical conditions and rehabilitation treatment. However, distinct measures shed light on the discrete mechanisms and complex processes underpinning the maintenance of stance.

Core stability training combined with acupuncture in treatment of chronic nonspecific low back pain: a prospective randomized controlled trial

To investigate the clinical effect of core stability training combined with acupuncture in the treatment of chronic nonspecific low back pain (CLBP). Seventy-five CLBP patients were randomly divided into experimental group (n=38) and control group (n=37) according to a random number table. Patients in the control group were required to perform core stability training, whereas those in the experimental group received core stability training combined with fire needle acupuncture, once every two days, three times per week, for four successive weeks. The Oswestry disability index (ODI), visual analogue scale (VAS), lumbar muscular endurance index, clinical efficacy, as well as average electromyographic (AEMG), root mean square (RMS), median frequency (MF), and average median frequency (AMF) values during multifidus muscle contraction in the two groups before and after the treatment were compared. After treatment, ODI, VAS, MF, and AMF of the two groups were lower than those before the treatment (P<0.01), while the lumbar static and dynamic muscular endurance, AEMG, and RMS values were higher (P<0.01). The ODI, VAS, MF, and AMF of the experimental group significantly declined as compared with those of the control group (P<0.01), whereas the lumbar static and dynamic muscular endurance, AEMG, and RMS values were elevated (P<0.01). The total effective rate of the experimental group was 97.14%(34/35), higher than 85.71%(30/35) of the control group(P<0.01). Core stability training combined with acupuncture effectively enhances lumbar muscular endurance, improves electromyographic signals of multifidus muscle and lumbar function, and relieves pain, implying the good efficacy of such combined therapy in treating CLBP.

Short-term Effects of Sling Exercise Combined with Massage on the Treatment of Neck Type Cervical Spondylopathy

<bold>Objective:</bold> To observe the effects of sling exercise combined with massage in patients with neck type cervical spondylopathy (NTCS) by using surface electromyography (sEMG), and to explore the short-term effects on neck pain, neck disabilities and muscle fatigue. <sec><title>Methods</title> A total of ninety-three patients with neck type cervical spondylopathy who met the inclusion criteria were divided into three groups according to the random number table: massage group, sling exercise group and sling exercise combined with massage group, with 31 cases in each group. The three groups were treated with massage, sling exercise, sling exercise combined with massage therapy respectively, 30 minutes per time, once a day, 5 days per week, for a total of one week. Before and after treatment, the McGill Pain Questionnaire (MPQ) and the Neck Disability Index (NDI) were used to evaluate the cervical function and quality of life of patients, and the median frequency (MF) of the upper trapezius muscle was measured by electromyography biofeedback instrument. </sec><sec><title>Results</title> Before treatment, the MPQ scores, NDI scores and MF value of the three groups were not statistically different (<italic>P</italic>>0.05). After treatment, the MPQ scores, NDI scores and MF value of the three groups were all improved (<italic>P</italic><0.05); the MPQ scores and NDI scores of the three groups all decreased, and those of the massage group, sling exercise group and sling exercise combined with massage group were (16.68±2.52) scores, (17.06±1.71) scores, (15.03±1.66) scores, and (15.35±4.77) scores, (15.29±4.38) scores, (13.71±4.61) scores respectively; the MF value increased, the value on the left was (69.73±6.47) Hz, (70.05±7.40) Hz and (73.34±5.21) Hz respectively, and the value on the right was (63.29±8.66) Hz, (63.51±9.76) Hz and (65.85±8.21) Hz respectively, the differences were statistically significant (<italic>P</italic><0.05); the short-term effects of sling exercise combined with massage group on neck pain, dysfunction and neck muscle fatigue were better than those of the massage group and the sling exercise group respectively (<italic>P</italic><0.05), but there were no significant differences between the massage group and the sling exercise group (<italic>P</italic>>0.05). Further correlation analysis showed that the MPQ scores was negatively correlated with MF value (left: <italic>r</italic>=-0.626, <italic>P</italic><0.05; right: <italic>r</italic>=-0.695, <italic>P</italic><0.05); besides the NDI scores decreased with the increase of MF value (left: <italic>r</italic>=-0.692, <italic>P</italic><0.05; right: <italic>r</italic>=-0.491, <italic>P</italic><0.05), and the average MF value on the right was lower than that on the left. </sec><sec><title>Conclusion</title> Sling exercise combined with massage can significantly reduce the patients pain, activate and strengthen the neck muscles, improve the neck function of patients. At the same time, the sEMG can objectively reflect that sling exercise combined with massage has better short-term effects on the upper trapezius muscle. </sec>

Non-obstructive monitoring of muscle fatigue for low intensity dynamic exercise with infrared thermography technique.

Surface electromyography (sEMG) has been widely used in evaluating muscle fatigue among athletes where electrodes are attached on the skin during the activity. Recently, infrared thermography technique (IRT) has gain popularity and shown to be another preferred method in monitoring and predicting muscle fatigue non-obstructively. This paper investigates the correlation between surface temperature and muscle activation parameters obtained using both IRT and sEMG methods simultaneously. Twenty healthy subjects were required to perform a repetitive calf raise exercise with various loads attached around their ankle for 3 min to induce fatigue on the targeted gastrocnemius muscles. Average temperature and temperature difference information were extracted from thermal images, while root mean square (RMS) and median frequency (MF) were extracted from sEMG signals. Spearman statistical analysis performed shows that there is a significant correlation between average temperature with RMS and between temperature difference with MF values at p<0.05. While ANOVA test conducted shows that there is significant impact of loads on RMS and MF where F=12.61 and 3.59, respectively, at p< 0.05. This study suggested that skin surface temperature can be utilized in monitoring and predicting muscle fatigue in low intensity dynamic exercise and can be extended to other dynamic exercises.

Effect of abdominal penetrating moxibustion on function of core muscle group in stroke patients based on surface electromyography

To observe the effect of abdominal penetrating moxibustion on strength and endurance of core muscle group in patients with stroke. Sixty-two patients with stroke were randomly divided into an observation group (31 cases, 2 cases dropped off) and a control group (31 cases, 2 cases dropped off). The patients in the control group were treated with routine basic treatment, acupuncture treatment and rehabilitation training; based on the treatment of the control group, the patients in the observation group were treated with abdominal penetrating moxibustion, approximately 50 min each time, once a day. The treatments in the two groups were given 5 times a week for 4 weeks. The root mean square (RMS) and median frequency (MF) of bilateral transverse abdominis and multifidus of performing sitting-standing and making steps were measured by surface electromyography before and after treatment. The postural assessment scale for stroke (PASS), Berg balance scale (BBS) and lower-limb Fugl-Meyer motor assessment (FMA) scores were observed before treatment, 2 weeks into treatment and 4 weeks into treatment. Compared before treatment, when performing different postures, the RMS and MF of bilateral transversus abdominis and multifidus in the two groups were increased after treatment (P<0.01, P<0.05). The RMS of affected-side transversus abdominis and multifidus and the MF value of bilateral transverse abdominis and multifidus in the observation group were higher than those in the control group (P<0.05). Compared before treatment, the PASS, BBS and FMA scores were increased 4 weeks into treatment in the two groups (P<0.01), and those in the observation group were higher than the control group (P<0.01). The abdominal penetrating moxibustion could effectively improve the strength and endurance of core muscle group, improve the posture control, balance ability and lower-limb motor function in patients with stroke.

Electromyographic Evaluation of the Shoulder Muscle after a Fatiguing Isokinetic Protocol in Recreational Overhead Athletes.

The goal of our study was to examine the muscle activity of the shoulder girdle after isokinetic fatigue, which may simulate muscle activities commonly occurring during specific sport-related activities in recreational overhead asymptomatic athletes. We hypothesized that exercise-induced fatigue, reported after isokinetic protocols, may cause a decrease in the median frequency (MF) of the upper trapezius (UT), infraspinatus (IS), and deltoid muscles. Twenty-four male overhead volleyball (n = 8), handball (n = 8), and tennis (n = 8) athletes participated in this study. All subjects were without shoulder injury history. The surface electromyography (SEMG) was collected on the right (dominant) side of the shoulder girdle muscles in the following order: UT, IS and anterior (DA), and posterior deltoideus (DP). The fatigue protocol consisted of three sets of 32 maximum isokinetic concentric contractions while performing shoulder internal and external rotation at an isokinetic speed of 120 o/s. The resultant difference in median frequency (ΔMF) values consistently dropped after the fatiguing tasks across all recorded muscles, in terms of the initial MF (MFINI = 65.1 ± 1.1 Hz) and final MF (MFFIN = 57.9 ± 0.9 Hz), and the main effect of time was significant (F(1,22) = 43.15, p < 0.001). MF values decreased mostly for IS (ΔMFIS = −9.9 ± 1.6 Hz) and DP (ΔMFPD = −9.5 ± 1.9 Hz) muscles, while DA and UT showed smaller changes (ΔMFDA = −6.9 ± 1.5 Hz) and (ΔMFUT = −3.2 ± 1.3 Hz). The results of our study show a meaningful contribution in determining increased fatigue of the shoulder girdle muscles during repeated isokinetic internal-external rotation protocols. We have also demonstrated a significant decrease in MF in all examined muscles, especially IS and DA.

Effect of Mirror Feedback Therapy of Contralaterally Controlled Functional Electrical Stimulation on Hand Function of Apoplectic Hemiplegic Patients

Objective: To investigate the effects of mirror feedback therapy of contralaterally controlled functional electrical stimulation on hand function of apoplectic hemiplegic patients. Methods: A total of 60 apoplectic hemiplegic patients were randomly divided into group A, group B and group C, with 20 cases in each group. All three groups received treatment for 20 minutes each time, once a day, for 5 days a week, and for 4 weeks. On the basis of conventional rehabilitation treatment, patients in group A received mirror therapy (MT), patients in group B received contralaterally controlled functional electrical stimulation (CCFES), and patients in group C received mirror feedback therapy of CCFES. Surface electromyography (sEMG), upper extremities motor function test of Fugl-Meyer movement assessment (U-FMA), box and block test (BBT) and wrist active range of motion (AROM) were used to evaluate hand function of patients before and after treatment. Results: Before treatment, average EMG (AEMG) value, median frequency (MF) value, U-FMA scores, BBT scores and wrist AROM of all three groups showed no significant differences (P>0.05). After 4 weeks of treatment, the AEMG value, MF value, U-FMA scores, BBT scores and wrist AROM improved significantly in all three groups (P<0.05). The AEMG value, MF value, BBT scores and wrist AROM for group C were: (73.17±29.12), (95.67±26.54), (9.50±3.28), (41.75±17.19), which were better than group A: (57.33±18.47), (77.62±31.10), (7.15±3.13), (26.75±14.53), and Group B (55.61±20.17), (74.45±23.22), (6.50±3.78), (31.50±16.47). The differences were statistically significant (P<0.05). The U-FMA scores of the three groups were (25.85±8.38) in group A, (25.40±9.25) in group B and (27.20±9.21) in group C. There were no significant statistical differences in U-FMA scores in the three groups (P>0.05). Conclusion: Mirror feedback therapy of contralaterally controlled functional electrical stimulation can improve hand function of apoplectic hemiplegic patients, and is superior to the single CCFES or MT.

Physiological and electroencephalographic changes in goats subjected to transportation, lairage, and slaughter.

This preliminary trial investigated the effect of transportation and lairage periods on physiological parameters of goats subjected to slaughter. Nine male Boer cross goats aged 8-12 months were transported for 6 h and kept at lairage for 3, 6, or 16 h (n = 3). Blood samples were collected at pre- (pre-T) and post-transportation (post-T), and post-slaughter (post-S) for determination of hematological parameters, serum enzyme, protein, and cortisol concentrations. Electroencephalogram readings were taken at pre-T, post-T, pre-slaughter (pre-S), and post-S to determine the median frequency (F50 ) and total power (Ptot) values. At post-T, there were manifestations of stress leukogram; increase in hematocrit, total protein, and muscle enzyme concentrations; and decrease in Ptot (p < 0.05). The high pre-T cortisol concentration suggests that the goats were already under stress before transportation. Stress leukogram became less evident after lairage, indicating that the goats had recovered from the stress of transportation. Although the Ptot increased at post-S especially following 3 h of lairage, F50 values at post-S did not differ from pre-L, suggesting that the pre-slaughter stress may have affected the pain threshold. It is suggested that after 6 h of transportation, goats should ideally be placed in lairage for a minimum period of 3 h before slaughter.

Evaluation of vibration measurements on human face using median and maximum frequencies

There are some studies in the literature in order to make the interpretation of human tissues having different characteristics. Some of these studies focused on the evaluation of human face tissues. Vibration signals generated from vocal cords have been used in these studies about human face tissues. However, any study using the vibration signals recorded by applying the external vibration source having fixed frequency value is not available in the literature. In this study, it is aimed to investigate the frequency characteristics of the vibration signals recorded from the human face. These signals obtained from nine different regions on the faces of subjects are analysed using frequency characteristics. In the analysis stage, median and maximum frequency values are calculated and evaluated. So, the softness and hardness interpretation about these regions on the face can be made and the frequency ranges of these regions can be determined. As a result, it is observed that low-frequency signals are dominant in hard regions and high-frequency signals are dominant in soft regions.