Coherence in muscle activity of the biceps brachii at middle, proximal and distal tendon region among the arm wrestling contestants (original) (raw)
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Analysis of Electromyography (EMG) signals generated by individuals is part of human musculoskeletal system research and signals are always influenced by the electrode placement in the muscle. This characteristic is also obvious at Biceps Brachii (BB) muscles during the movement of elbow at different angles. The purpose of this study was to monitor and determine the BB muscle function in 3 conditions: (i) electrodes were placed at 3 locations on the BB, (ii) elbow was fixed at the two angles (90° and 150°) and (iii) isometric contractions were performed to record EMG data. EMG data were obtained from six healthy subjects (n = 6, mean±SD age = 24.4±3.1 years, body mass = 68±6.3 kg, height = 164±4.1 cm, BMI = 21.2±2.3, right arm dominated). A Bluetooth-enabled laptop, wireless EMG sensors, digital dynamometer and angle meter were used for data recording. EMG data were calculated and analyzed by average value, standard deviation, Root Mean Square (RMS) and highest peak of the signal during maximum voluntary contraction. All the dependent variables were calculated using repeated measures Analysis of Variance (ANOVA). The results from the research showed that (i) according to the calculation of average RMS and the maximum peaks of EMG signals, there was a significant difference between 2 angles (p = 0.047, i.e., p<0.05), but no interaction at the same angles when overall average EMG and standard deviation value are considered and (ii) majority of the outcomes showed that EMG activity is higher in the order of middle, upper and lower BB muscle. It is therefore important that electrical signals generated upon different electrode placements and angles on the BB muscle are used for biceps rehabilitation and other physiological measurements on upper arm.
Electromyographic Activity of the Upper Limb Muscleduring Specific Salat’s Position and Exercise
International Journal of Applied Physics and Mathematics, 2013
This study investigated the muscle activity of the neck extensors (NE), sternocleidomastoideus (SCM) and biceps brachii (BB) muscles in healthy subjects during salat and specified exercises using surface electromyography (EMG). A group of undergraduates aged between 19 to 25 years voluntarily participated in this study. For the assessment of the NE and SCM, the subjects were asked to perform salat (salam's position) and exercise [neck rotation exercise (NRE)]. Subjects were asked to perform takbir's position and biceps dumbbell curl (BDC) to access BB. The EMG and the motion signals of the muscles were recorded. The findings indicate that there were contractions of the muscles during the salat and exercise with difference EMG level. For NE and SCM, Wilcoxon's Rank Sum Test showed a statistically no significant difference between salat and exercise for NE (p = 0.482) and SCM (p=0.161). For the BB, Wilcoxon's Rank Sum Test showed a statistically significant difference between salat and exercise (p<0.05) with differences 18.48% MVC. However, BB showed the EMG level with mild contraction. Therefore, salat may be useful in warm up exercise or in rehabilitation programs. This pilot study can be as initial research about other biomechanical response of human muscle with other position in salat.
EMG frequency during isometric, submaximal activity: a statistical model for biceps brachii
The purpose of this study was to develop a statistical model to describe the electromyography (EMG) signal frequency changes during a submaximal isometric contraction. Thirty subjects performed a 30-second isometric contraction of the biceps brachii muscle at 80% of the maximal voluntary isometric force. Surface EMG electrodes recorded electrical activity of the biceps brachii. Zero-Crossing-Rate was calculated to identify EMG frequency shifts. The mean frequencies for every one-second period were used to calculate a linear relationship between frequency and time. A significant relationship ( p < 0.05) between slope and initial frequency value was identified. The model described EMG frequency changes during submaximal effort of biceps brachii up to 15 seconds. The prediction error was 9.8%. Modifying this equation to initial values of frequency of each participant decreased prediction error to 7.2%. These results demonstrate that despite individual differences between subjects it is possible to derive single equation that describes EMG alterations during submaximal, isometric contractions across a homogeneous group of people.
Journal of Physical Therapy Science, 2013
Purpose] In some earlier studies of electromyography (EMG) of the upper arm biceps brachii (BB), researchers preferred to place the electrodes on the middle of the biceps muscle to analyze its function. This study investigated the BB muscle activity between the region of the endplate and distal tendon insertion (electrode placed on lower part of the BB muscle belly). [Subjects and Methods] Six right-arm dominant Asian subjects (n=6, 3 males and 3 females), age range 20-30 years, who were free from any musculoskeletal disorder in BB, participated in this study. EMG signals were recorded from 12 BB muscles (6 subjects × 2 arms) during two types of muscle contraction (concentric and eccentric). Mean ± SD was calculated and analysis of variance (ANOVA) was performed. [Results] The results indicate that, the dominant right arm (R) of both males (M) and females (F) showed significantly higher activity than non-dominant left arm (L). In addition, there were interactions between M(L) and M(R), F(L) and F(R), M(L) and F(L), M(R) and F(R), and both male BB and both female BB; but, no interactions were found between M(L) and F(R), and M(R) and F(L). We also discovered that eccentric contraction generates higher EMG signals than the concentric contraction of that muscle region.
The Averaged EMGs Recorded from the Arm Muscles During Bimanual “Rowing” Movements
Frontiers in Physiology, 2015
The main purpose was to analyze quantitatively the the average surface EMGs of the muscles that function around the elbow and shoulder joints of both arms in bimanual "rowing" movements, which were produced under identical elastic loads applied to the levers ("oars"). The muscles of PM group ("pulling" muscles: elbow flexors, shoulder extensors) generated noticeable velocity-dependent dynamic EMG components during the pulling and returning phases of movement and supported a steady-state activity during the hold phase. The muscles of RM group ("returning" muscles: elbow extensors, shoulder flexors) co-contracted with PM group during the movement phases and decreased activity during the hold phase. The dynamic components of the EMGs strongly depended on the velocity factor in both muscle groups, whereas the side and load factors and combinations of various factors acted only in PM group. Various subjects demonstrated diverse patterns of activity redistribution among muscles. We assume that central commands to the same muscles in two arms may be essentially different during execution of similar movement programs. Extent of the diversity in the EMG patterns of such muscles may reflect the subject's skilling in motor performance; on the other hand, the diversity can be connected with redistribution of activity between synergic muscles, thus providing a mechanism directed against development of the muscle fatigue.
Investigation of the EMG-angle relationship in the upper-limb muscles during isometric contraction
2017
Purpose: The relationship between EMG and elbow angle was investigated to identify the signal characteristics of upper-limb muscles during isometric contraction. The study would improve the current understanding of electrophysiological activities of the human upper limbs, which would aid the development of prosthetic arms for rehabilitation research. Subjects and Methods: Ten subjects aged 22.4(±1.5) years participated in this study. The electromyography signals from the biceps brachii muscle were recorded during isometric contraction. The root mean square and mean absolute value of the EMG signals were calculated and evaluated to assess the relationship between the signals and elbow angles. In addition, the force exerted by the upper limb was recorded using a dynamometer to identify more features of the relationship. Results: The results revealed that both the RMS and MAV of the EMG signals are not significantly related with the elbow angle (r2=0.70 and 0.21; p=0.075 and 0.43, resp...
Age-Related EMG Responses Of The Biceps Brachii Muscle Of Young Adults
Biomedical Research-tokyo, 2016
Although the effect of an Electromyographic (EMG) signal on the Biceps Brachii (BB) muscle is at the forefront of human movement analysis, there is limited information regarding the importance of the differences in the age-related EMG responses during contraction. The present study aimed to compare the BB muscle activity of three different groups of young adults divided based on age and to find a relationship between surface EMG and endurance time during isometric contraction. The EMG signal was recorded in 30 healthy right-arm-dominant young male subjects during a handgrip force task. The subjects were rationally divided into one of the three age groups (ten in each group): adolescents (‘A’; aged 17.3 ± 1.4 years), vicenarians (‘V’; 24.6 ± 2.1 years), and tricenarians (‘T’; 33.2 ± 1.1 years). The muscle activation during contraction was determined as the root mean square (RMS) EMG signal normalised to the peak RMS EMG signal during a 10-s isometric contraction. The statistical anal...
European Journal of Applied Physiology, 2006
The aim of the present study was to investigate the extent to which work-related muscular disorders of the upper trapezius affect the activity of other pain-free muscles, in particular in the biceps brachii. Two groups of female subjects (age >43 years) participated in the study: seven affected subjects with self-reported disorders in the shoulder/neck region (cases) and nine healthy subjects (control group). Multi-channel electromyography (EMG) and force were recorded during maximum voluntary contractions (MVC) and during 6 min sustained contractions (at 30% MVC) of the upper trapezius and biceps brachii on the dominant side. From the EMG signals, the root mean square (RMS), median frequency (MDF) and single motor unit (MU) conduction velocity (CV) were estimated. From the force signal, the coefficient of variation was calculated. All data are presented as mean values and standard deviation. Differences between the cases and controls were found in the MVC force of the upper trapezius, which was lower in cases [253 (70) N] than in controls [357 (75) N], while the coefficient of variation of force during the sustained contraction was increased [cases 5.5 (2.2); controls 4.1 (1.9)]. The RMS (normalized to the RMS at MVC) during the 6 min sustained contractions was significantly lower in the cases than in the controls for both the upper trapezius and the biceps brachii. A tendency towards a smaller increase in the RMS with fatigue was only found in the trapezius muscle [slope: cases 6.5 (14.1) %/min, controls 10.2 (12.9) %/min]. No differences were found between the two subject groups with respect to the MDF and single MU CV in both muscles. While the lower RMS for the trapezius muscles of the cases may reflect changes at the local level, as well as in motor control, the lower biceps activity indicates a change in the central control strategies of the primarily unaffected muscle. Indications for a changed fatigability of the muscle were only found in the trapezius.