Electromyography Registration Research Articles

Short‐time effect of the kangaroo position on electromyographic activity of premature infants: a randomized clinical trial

ObjectiveTo verify the short‐term influence of the kangaroo position (KP) on the electromyography activity of preterm newborns. MethodA clinical study was conducted in a kangaroo unit sector (secondary and tertiary care) in the city of Recife, Brazil, with 44 preterm infants randomized to intervention (n = 21) and control (n = 23) groups. The KP was performed through a band that supports the newborn against the adult's thorax, in a prone and vertical position, and infants were dressed with few pieces of clothes, thus keeping skin‐to‐skin contact with the mother. Surface electromyography was used to investigate the muscle activity of the biceps brachii and hamstrings. The randomization of the groups was performed by the program R® (v. 3.3.1). The electromyography registrations were made at three different times: before the KP and after one and two hours of KP. In the control group, the registrations were performed at the times corresponding to those of the intervention group. The mean values of the electromyography activity among the times were analyzed by ANOVA for repeated measures and the Kruskal‐Wallis test. The clinical trial was recorded in ClinicalTrials.gov (NCT02849665 ‐ 07/28/2016). ResultsIn the intervention group (n = 21), there was a variation of the electromyography activity values between the three recording moments for both the biceps brachii and hamstrings. In the control group (n = 23), there was no statistical difference between the recording moments for both. ConclusionsThe KP increases the short‐term electromyographic activity of the biceps brachii and hamstrings.

Short-time effect of the kangaroo position on electromyographic activity of premature infants: a randomized clinical trial

ObjectiveTo verify the short-term influence of the kangaroo position (KP) on the electromyography activity of preterm newborns. MethodA clinical study was conducted in a kangaroo unit sector (secondary and tertiary care) in the city of Recife, Brazil, with 44 preterm infants randomized to intervention (n=21) and control (n=23) groups. The KP was performed through a band that supports the newborn against the adult's thorax, in a prone and vertical position, and infants were dressed with few pieces of clothes, thus keeping skin-to-skin contact with the mother. Surface electromyography was used to investigate the muscle activity of the biceps brachii and hamstrings. The randomization of the groups was performed by the program R® (v. 3.3.1). The electromyography registrations were made at three different times: before the KP and after one and two hours of KP. In the control group, the registrations were performed at the times corresponding to those of the intervention group. The mean values of the electromyography activity among the times were analyzed by ANOVA for repeated measures and the Kruskal–Wallis test. The clinical trial was recorded in ClinicalTrials.gov (NCT02849665 - 07/28/2016). ResultsIn the intervention group (n=21), there was a variation of the electromyography activity values between the three recording moments for both the biceps brachii and hamstrings. In the control group (n=23), there was no statistical difference between the recording moments for both. ConclusionsThe KP increases the short-term electromyographic activity of the biceps brachii and hamstrings.

Comparison of selected muscular activity of trunk and lower extremities in young women's walking on supinated, pronated and normal foot

Changes in anatomical structure of the foot reduce the foot ability for normal performance. This study aimed to compare selected muscles of trunk and lower extremities during walking in individuals with different foot types. Forty-five female students were categorized into three groups depending on their foot structures namely, pronated, supinated and normal feet. Foot types defined by foot posture index and X-ray under the specialist physician. Electromyography activities were recorded from muscles of tibialis anterior, peroneus longus, medial gastrocnemius, biceps femoris, gluteus medius, external oblique and erector spinae in three groups while walking in determined path with self-selected gait speed. Each effort simultaneous with electromyography registration was recorded with camera. One-way ANOVA test was used to compare the groups at significance level of 0.05. The activity of muscle of tibialis anterior and medial gastrocnemius was greater in pronated foot group than that in supinated and normal groups during heel contact phase of gait (p=0.001). Supinated foot group exhibited a greater peroneus longus activation than the other groups (p=0.001). No significant differences were observed for remaining four muscles (p>0.05). During midstance phase, peroneus longus, supinated foot group exhibited a greater activity compared to other groups while pronated foot group exhibited a greater muscle activity for gluteus medius than others (p=0.001). There was a significant difference between normal and pronated foot groups for external oblique (p=0.001). Regarding the findings of this study, the muscular performance changes in pronated and supinated foot groups are more noticeable than that in normal foot type.

Impact of Combined Skin Sparing Mastectomy and Immediate Subpectoral Prosthetic Reconstruction on the Pectoralis Major Muscle Function

We assessed the subjective and objective functional loss induced by detachment of the pectoralis major muscle and whether synergistic function of adjacent muscles compensates for such loss. A preoperative to postoperative comparison of the Disability of the Arm, Shoulder and Hand score, 3-dimensional video-analysis of the range of motion, and dynamometric force assessment with electromyography registration were prospectively conducted in 22 women who underwent bilateral preventive breast surgery. Although the statistically significant postoperative increase of the Disability of the Arm, Shoulder and Hand score (P = < 0.01) was indicative of more subjective disability, this difference is irrelevant for activities of daily life. This is in line with the observed postoperative lack of restrictions of range of motion of the shoulder. The mean postoperative maximum force measured in 4 directions reflective of the pectoralis major muscle function was 7.13 N, or 3.8%, lower than the preoperative force (P = 0.079). The mean postoperative maximum force in the 2 contramovement directions was 15.5 N, or 14%, higher than the preoperative force (P = 0.04). Electromyographically, both parts of the deltoid muscle preoperatively and postoperatively showed the same peaks in the 6 directions. Contrastingly, the clavicular part of the pectoralis major muscle postoperatively showed a statistically significant increase of peak of muscle activity in 3 of 4 directions reflective of pectoralis major function and in both contramovement directions, indicating compensatory activity. Daily life consequences of partial detachment of the pectoralis major muscle were acceptable in our patients.

Chronic Testicular Pain as a Symptom of Pelvic Floor Dysfunction

We determined whether chronic testicular pain is related to pelvic floor overactivity after ruling out other disease pathology. A total of 41 patients with chronic testicular pain evaluated at our Pelvic Floor Department at a tertiary academic center were included in this retrospective study. All patients underwent standard pelvic floor investigation, including history using a standardized questionnaire and electromyography registration of the pelvic floor. In the questionnaire patients were asked about complaints in 3 domains (micturition, defecation and sexual function) suggestive of pelvic floor dysfunction. Electromyography registration of the pelvic floor was performed. The resting tone of the pelvic floor was considered increased at 3 muV or greater. Mean patient age was 48 years. Of the patients 93% had at least 1 symptom suspicious of pelvic floor dysfunction. A total of 22% had complaints in 1 of the domains of micturition, defecation or sexual function, 24% had complaints in 2 domains and 49% had complaints in all 3 domains. On electromyography registration of the pelvic floor 88% of patients appeared to have an increased resting tone of the pelvic floor muscles at a mean of 6.7 muV (normal less than 3). The patients with a normal pelvic floor resting tone were significantly older than those with an increased resting tone (65.6 vs 45.6, p = 0.0001). Chronic testicular pain can be a symptom of pelvic floor overactivity, especially in younger patients. A diagnostic evaluation should be performed when no pathophysiology can be found.

THE COMPARISON OF EMG ACTIVITIES BETWEEN KINAESTHETICS AND NORMAL METHODS DURING PATIENT-HANDLIMG TASKS IN HEALTH CARE WORKERS

INTRODUCTION A high prevalence rate of low-back pain (LBP) is found among health care workers (HCW). Compared to other jobs with heavy lifting tasks and a high prevalence rate of LBP. This may indicate that the risk in connection with a single personal handling situation is higher than the risk in connection with lifting. Several of these risk factors are present in patient-handling tasks. Biomechanical studies have estimated the load on the low back in several patient-handling tasks. Recently, the kinaesthetics method was developed in Germany. This method can reduce the mechanical load of HCW in patient-handling task. Becouse it was the result of our application of the research findings of the science of Feedback Control Theory to problems of human functions. The purpose of present study was to investigate the activities of muscles during kinaesthetics or normal method patient-handling tasks in HCW using electromyography (EMG). METHODS Twelve female subjects volunteered to participate in the laboratory experiments. The mean values ± SD of their heights, weights, and ages were 1.72 ± 0.05 m, 65.2 ± 8.9 kg, 23.2 ± 7.8 yrs., respectively. They received an explanation of the experimental protocol and provided informed consent prior to testing. None of the subjects experienced low-back pain on the experimental day. In a laboratory set-up they performed two different patient-handling tasks in randomized order. The electromyography (EMG) system (WEB-5000, Nihon Kohden, Japan) was used to collect muscle activities from the biceps brachii (BB), triceps brachii (TB), rectus abdominis (RA), erector spinae (ES), hamstrings (HA), vastus lateralis (VL), gastrocnemius (GA). and tibialis anterior. The EMG signals were amplified and recorded by a computer via A/D converter. Before carrying out the tasks, EMG was measured when the subjects performed three different isotonic contractions for arm curl, dead lift and squat. The highest obtained EMG value during these contractions, IEMGmean, was used to normalise the EMG registrations during the tasks. Immediately after completion of each patient-handling task, the subject was asked to rate her perceived physical exertion (RPE) on the low back by answering the question ‘how did you perceive the exertion on the low back’. The Borg CR10 scale (Borg, 1990), where 0 implies ‘nothing at all’ and 10 implies ‘extremely strong’ perceptual intensity, was used for the rating. All values are expressed as means ± SEM. A Student’s paired t-test was used to determination differences between the kinematic variables when using either the kinaesthetics and normal methd. Probability values of p < 0.05 were accepted as being statistically significant. RESULTS AND DISCUSSION Figure 1 shows the change of IEMGmean when the subjects performed kinaesthetics and normal method on patient-handling tasks in randomized order. IEMGmean, in BB, TB, ES, HA, GA and TA were significant difference in kinaesthetics method lower than normal one during patient-handling tasks in HCW. The decrease of the muscular activity of ES could be contributed to the LBP prevention of the nurse. Figure 2 shows change of the Borg CR10 scale when the subjects performed kinaesthetics and normal method on patient-handling tasks in randomized order. The Borg CR10 scale was significantly er kinaesthetics method than normal one. These results indicated that the patient-handling tasks in HCW affect lifting method. The kinaesthetics was a method for contributing to the reduction in the body of the HCW. CONCLUSIONS The kinaesthetics method was decreased EMG activity and muscle fatigue during patients lifting in bed. Thus, in this study kinaesthetics method may be reduced LBP in patient-handling tasks in HCW.

Validity of long-term electromyography in the quantification of tremor.

We previously developed a method of tremor quantification using long-term electromyography registration of antagonistic forearm muscles that is reliable, sensitive, and specific for pathologic tremors. The present study demonstrates that tremor occurrence as measured by this method correlates well with clinical parameters of tremor in idiopathic Parkinson's disease (PD) and essential tremor (ET) (subscores of the Unified Parkinson's Disease Rating Scale for PD, tremor rating according to Bain et al. for ET). We conclude that the method is a valid and objective means of tremor quantification in PD and ET.

Muscle Activity Patterns of Elite Downhill Ski Racers during Landing

The purpose of this study was to examine motion and muscle activity in downhill skiing in order to estimate muscular involvement during the landing phase and its potential effect on ACL injury. Specially developed 8-channel portable electromyo-graphy registration was conducted during three jumps on the Russi jump of the 1994 Olympic downhill slope, and six control jumps were carried out in the laboratory. The results reveal that the skier adapts to the expected loading of the knee, possibly by using a learned motor control pattern. It is still not clear, however, how important muscular adaptation to expected forces is. The complex functional EMG pattern that skiers use while landing indicates that ACL rupture caused during a backward fall in downhill skiing might be due to a combination of the boot-top-induced anterior shear, the force generated in the ACL by forceful knee hyperflexion supported by the high bending moment generated by a stiff spoiler, and the possible absence of a significant protecting hamstrings force during maximum loading.

Contraction of knee flexors and extensors in skiing related to the backward fall mechanism of injury to the anterior cruciate ligament

The purpose of this study was to examine the motion pattern and muscle activity during jumping and landing in downhill skiing to estimate the muscular involvement during the jump-landing-backward fall-anterior cruciate ligament (ACL) injury. A digitized 2-D video motion analysis and a synchronous 8-channel electromyography registration was performed over a jump on a downhill slope during 3 runs by 2 skiers and during 6 control jumps in the laboratory. The knee flexors (lateral gastrocnemius and biceps femoris) were recruited before touchdown and mean 60 ms earlier than the extensors (vastus lateralis and rectus femoris). Extensors and flexors reached peak activity simultaneously at the instant of landing. The knee flexion angle at the instant of landing was mean 36 degrees. As the landing was stabilized, the extensor activity persisted during eccentric work at increasing knee flexion as a corresponding flexor relaxation took place. The control jump in the laboratory showed a similar order of recruitment and timing of muscle contraction. The gastrocnemius was recruited mean 96 ms earlier and the biceps femoris mean 63 ms earlier than the extensors. This recruitment pattern during the landing movement suggest a learned motor program engaging the kinetic chain of the lower extremity to intercept the landing energy. The results also indicate that the knee flexor activity may protect the ACL at the instant of landing but that it is minimal shortly thereafter and probably not able to protect the ACL when a backward fall occurs. The knee was flexed substantially as the extensors became the dominating muscles. Thus, their ability to apply any anterior drawer force able to rupture the ACL is questioned.

Partial superior laryngeal nerve (SLN) lesions before and after thyroid surgery.

AbstractThe incidence of superior laryngeal nerve (SLN) lesions and their consequences in terms of voice quality was studied in 20 patients undergoing thyroid surgery, performed by surgeons who were not specialists in endocrine surgery. The SLN function was examined by electromyography (EMG) of the cricothyroid muscles before and after surgery. Voice analysis was performed through the registration of the average pitch and range of the speaking voice and the upper pitch limit. The perceptual voice quality was judged by a panel of listeners. Voice problems were registered through a questionnaire. The larynx status was examined by indirect laryngoscopy before and after surgery. Three patients who had not previously been operated on in the neck had partial SLN lesions before surgery. According to the EMG, no SLN at risk developed a complete lesion, but 58% of the SLN's developed partial lesions which persisted 1 year after surgery in all but 1 of the examined patients. Seven of 10 patients with isolated SLN lesions had postoperative voice problems, which had disappeared after 1 year in 4 of them. Standard indirect laryngoscopy failed to diagnose an isolated partial SLN paresis. A significant correlation was found between SLN lesion and a reduction in the average pitch of the speaking voice (p &lt; 0.05). Partial SLN lesions cannot be diagnosed exclusively on voice symptoms and standard indirect laryngoscopy. EMG registrations make a definite diagnosis possible. Measurements of the average pitch of the voice could be used as a noninvasive screening procedure.