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Muscle Fatigue in the Three Heads of the Triceps Brachii During a Controlled Forceful Hand Grip Task with Full Elbow Extension Using Surface Electromyography.

Ali A, Sundaraj K, Badlishah Ahmad R, Ahamed NU, Islam A, Sundaraj S - J Hum Kinet (2015)

Bottom Line: The root mean square values were then analysed to determine the fatiguing condition for the heads of triceps brachii muscle.The highest fatiguing rate was observed in the long head (slope = -2.863), followed by the medial head (slope = -2.412) and the lateral head (slope = -1.877) of the triceps brachii muscle.The results of the present study concurs with previous findings that the three heads of the triceps brachii muscle do not work as a single unit, and the fiber type/composition is different among the three heads.

View Article: PubMed Central - PubMed

Affiliation: AI-Rehab Research Group, Universiti Malaysia Perlis (UniMAP), Kampus Pauh Putra, Perlis, Malaysia.

ABSTRACT
The objective of the present study was to investigate the time to fatigue and compare the fatiguing condition among the three heads of the triceps brachii muscle using surface electromyography during an isometric contraction of a controlled forceful hand grip task with full elbow extension. Eighteen healthy subjects concurrently performed a single 90 s isometric contraction of a controlled forceful hand grip task and full elbow extension. Surface electromyographic signals from the lateral, long and medial heads of the triceps brachii muscle were recorded during the task for each subject. The changes in muscle activity among the three heads of triceps brachii were measured by the root mean square values for every 5 s period throughout the total contraction period. The root mean square values were then analysed to determine the fatiguing condition for the heads of triceps brachii muscle. Muscle fatigue in the long, lateral, and medial heads of the triceps brachii started at 40 s, 50 s, and 65 s during the prolonged contraction, respectively. The highest fatiguing rate was observed in the long head (slope = -2.863), followed by the medial head (slope = -2.412) and the lateral head (slope = -1.877) of the triceps brachii muscle. The results of the present study concurs with previous findings that the three heads of the triceps brachii muscle do not work as a single unit, and the fiber type/composition is different among the three heads.

No MeSH data available.


Related in: MedlinePlus

Electrode placement on the three heads of TB muscle (A=Lateral head, B=Long head, C=Medial head, D=Proximal head of ulna, E=Distal head of ulna, F=Hand grip dynamometer)
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f1-jhk-46-69: Electrode placement on the three heads of TB muscle (A=Lateral head, B=Long head, C=Medial head, D=Proximal head of ulna, E=Distal head of ulna, F=Hand grip dynamometer)

Mentions: For the sEMG signal recording, we used two PowerLab systems (Model 4/25T by ADInstruments Pty. Ltd., Bella Vista, NSW, Australia) where each system consists of two channels with a common isolated ground. These two PowerLab systems were interfaced to a computer using the LabChart® (Version 7 by ADInstruments Pty. Ltd., Bella Vista, NSW, Australia) software for Windows®. Appropriate skin areas of the TB were shaved, cleaned with alcohol, and abraded with emery paper. We placed and aligned the disposable pregelled bipolar Ag/AgCl surface electrodes (Kendall MeditraceTM 100 Tyco Healthcare Group LP, Mansfield, MA, USA) to the muscle fibre direction in the lateral, long, and medial heads of the TB, where the inter-electrode distance was 2.5 cm. The references electrodes were placed to the proximal head of ulna, and the distal head of ulna of the same arm. Electrodes placements are anatomically indicated in Figure 1. All muscle identification and electrode placement were observed and validated by a medical personnel present during the experimentation. The sEMG signals were recorded at a bandwidth of 10 to 500 Hz, using a differential amplifier (BioAmp, ADInstruments, Australia), A/D converted at 1000 Hz (16 bit resolution) and stored in a computer for further analysis. Once the sEMG amplitudes (in mV) from the three heads of the TB were recorded, sEMG data were digitally filtered (bandpassed between 20 to 250 Hz) to reduce motion and electrocardiopraphic artefacts. Before the actual trial, the MVC – RMS was calculated from the average of the RMS values taken during the three MVC trials. During the actual trials, the RMS values were then calculated for every 5 s throughout the isometric contraction of 90 s for each subject (1 value per 5 s segment per subject per head of TB). The RMS value for each 5 s segment of sEMG signals was then normalized with respect to the MVC – RMS value for each subject and expressed as a percentage.


Muscle Fatigue in the Three Heads of the Triceps Brachii During a Controlled Forceful Hand Grip Task with Full Elbow Extension Using Surface Electromyography.

Ali A, Sundaraj K, Badlishah Ahmad R, Ahamed NU, Islam A, Sundaraj S - J Hum Kinet (2015)

Electrode placement on the three heads of TB muscle (A=Lateral head, B=Long head, C=Medial head, D=Proximal head of ulna, E=Distal head of ulna, F=Hand grip dynamometer)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519223&req=5

f1-jhk-46-69: Electrode placement on the three heads of TB muscle (A=Lateral head, B=Long head, C=Medial head, D=Proximal head of ulna, E=Distal head of ulna, F=Hand grip dynamometer)
Mentions: For the sEMG signal recording, we used two PowerLab systems (Model 4/25T by ADInstruments Pty. Ltd., Bella Vista, NSW, Australia) where each system consists of two channels with a common isolated ground. These two PowerLab systems were interfaced to a computer using the LabChart® (Version 7 by ADInstruments Pty. Ltd., Bella Vista, NSW, Australia) software for Windows®. Appropriate skin areas of the TB were shaved, cleaned with alcohol, and abraded with emery paper. We placed and aligned the disposable pregelled bipolar Ag/AgCl surface electrodes (Kendall MeditraceTM 100 Tyco Healthcare Group LP, Mansfield, MA, USA) to the muscle fibre direction in the lateral, long, and medial heads of the TB, where the inter-electrode distance was 2.5 cm. The references electrodes were placed to the proximal head of ulna, and the distal head of ulna of the same arm. Electrodes placements are anatomically indicated in Figure 1. All muscle identification and electrode placement were observed and validated by a medical personnel present during the experimentation. The sEMG signals were recorded at a bandwidth of 10 to 500 Hz, using a differential amplifier (BioAmp, ADInstruments, Australia), A/D converted at 1000 Hz (16 bit resolution) and stored in a computer for further analysis. Once the sEMG amplitudes (in mV) from the three heads of the TB were recorded, sEMG data were digitally filtered (bandpassed between 20 to 250 Hz) to reduce motion and electrocardiopraphic artefacts. Before the actual trial, the MVC – RMS was calculated from the average of the RMS values taken during the three MVC trials. During the actual trials, the RMS values were then calculated for every 5 s throughout the isometric contraction of 90 s for each subject (1 value per 5 s segment per subject per head of TB). The RMS value for each 5 s segment of sEMG signals was then normalized with respect to the MVC – RMS value for each subject and expressed as a percentage.

Bottom Line: The root mean square values were then analysed to determine the fatiguing condition for the heads of triceps brachii muscle.The highest fatiguing rate was observed in the long head (slope = -2.863), followed by the medial head (slope = -2.412) and the lateral head (slope = -1.877) of the triceps brachii muscle.The results of the present study concurs with previous findings that the three heads of the triceps brachii muscle do not work as a single unit, and the fiber type/composition is different among the three heads.

View Article: PubMed Central - PubMed

Affiliation: AI-Rehab Research Group, Universiti Malaysia Perlis (UniMAP), Kampus Pauh Putra, Perlis, Malaysia.

ABSTRACT
The objective of the present study was to investigate the time to fatigue and compare the fatiguing condition among the three heads of the triceps brachii muscle using surface electromyography during an isometric contraction of a controlled forceful hand grip task with full elbow extension. Eighteen healthy subjects concurrently performed a single 90 s isometric contraction of a controlled forceful hand grip task and full elbow extension. Surface electromyographic signals from the lateral, long and medial heads of the triceps brachii muscle were recorded during the task for each subject. The changes in muscle activity among the three heads of triceps brachii were measured by the root mean square values for every 5 s period throughout the total contraction period. The root mean square values were then analysed to determine the fatiguing condition for the heads of triceps brachii muscle. Muscle fatigue in the long, lateral, and medial heads of the triceps brachii started at 40 s, 50 s, and 65 s during the prolonged contraction, respectively. The highest fatiguing rate was observed in the long head (slope = -2.863), followed by the medial head (slope = -2.412) and the lateral head (slope = -1.877) of the triceps brachii muscle. The results of the present study concurs with previous findings that the three heads of the triceps brachii muscle do not work as a single unit, and the fiber type/composition is different among the three heads.

No MeSH data available.


Related in: MedlinePlus