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Muscular coordination of biceps brachii and brachioradialis in elbow flexion with respect to hand position.

Kleiber T, Kunz L, Disselhorst-Klug C - Front Physiol (2015)

Bottom Line: Normalized to MVC the sEMG amplitudes of both muscles contributing to elbow flexion movements were compared in pronated, supinated, and neutral hand position over elbow joint angle.Significant differences in the contribution of brachioradialis were found in pronated hand position compared to supinated and neutral hand position while the muscular activity of biceps brachii shows no significant changes in any hand position.In conclusion, a statistical significant dependency of the inter-muscular coordination between biceps brachii and brachioradialis during elbow flexion with respect to hand position has been observed depending on a biomechanical disadvantage of biceps brachii.

View Article: PubMed Central - PubMed

Affiliation: Department of Rehabilitation and Prevention Engineering, Institute of Applied Medical Engineering, RWTH Aachen University Aachen, Germany ; German Research School for Simulation Sciences, Joint Graduate School of RWTH Aachen University and Forschungszentrum Jülich Jülich, Germany.

ABSTRACT
Contribution of synergistic muscles toward specific movements over multi joint systems may change with varying position of distal or proximal joints. Purpose of this study is to reveal the relationship of muscular coordination of brachioradialis and biceps brachii during elbow flexion with respect to hand position and biomechanical advantages and disadvantages of biceps brachii. A group of 16 healthy subjects has been advised to perform 20 repetitions of single elbow flexion movements in different hand positions (pronated, neutral, and supinated). With a speed of 20°/s, simultaneously sEMG of biceps brachii and brachioradialis and kinematics of the movement were recorded in a motion analysis laboratory. Normalized to MVC the sEMG amplitudes of both muscles contributing to elbow flexion movements were compared in pronated, supinated, and neutral hand position over elbow joint angle. Significant differences in the contribution of brachioradialis were found in pronated hand position compared to supinated and neutral hand position while the muscular activity of biceps brachii shows no significant changes in any hand position. In conclusion, a statistical significant dependency of the inter-muscular coordination between biceps brachii and brachioradialis during elbow flexion with respect to hand position has been observed depending on a biomechanical disadvantage of biceps brachii.

No MeSH data available.


Mean (solid lines) and standard deviation (dashed lines) of the muscular activity of biceps brachii and brachioradialis from all subjects during elbow flexion in (A) neutral, (B) pronated, and (C) supinated hand position.
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Figure 2: Mean (solid lines) and standard deviation (dashed lines) of the muscular activity of biceps brachii and brachioradialis from all subjects during elbow flexion in (A) neutral, (B) pronated, and (C) supinated hand position.

Mentions: The acquired and processed sEMG data of biceps brachii and brachioradialis were assigned over measured elbow joint angles and analyzed in the range between 0 and 120° during concentric elbow flexion. The mean (solid lines) and standard deviation (dashed lines) of all subjects were calculated for both muscles in different hand positions, shown in Figure 2. Examining the muscular activity normalized to MVC, there are obvious differences in muscular coordination pattern during pronated elbow flexion in comparison to supinated and neutral hand position. As in pronated, the muscular activity of brachioradialis is constantly higher than in supinated and neutral hand position whereas the percentage activity of biceps brachii is nearly the same in all hand positions. The muscular activity of both muscles is constantly on the same level and slightly increasing with elbow joint angle in supinated and neutral hand position.


Muscular coordination of biceps brachii and brachioradialis in elbow flexion with respect to hand position.

Kleiber T, Kunz L, Disselhorst-Klug C - Front Physiol (2015)

Mean (solid lines) and standard deviation (dashed lines) of the muscular activity of biceps brachii and brachioradialis from all subjects during elbow flexion in (A) neutral, (B) pronated, and (C) supinated hand position.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526813&req=5

Figure 2: Mean (solid lines) and standard deviation (dashed lines) of the muscular activity of biceps brachii and brachioradialis from all subjects during elbow flexion in (A) neutral, (B) pronated, and (C) supinated hand position.
Mentions: The acquired and processed sEMG data of biceps brachii and brachioradialis were assigned over measured elbow joint angles and analyzed in the range between 0 and 120° during concentric elbow flexion. The mean (solid lines) and standard deviation (dashed lines) of all subjects were calculated for both muscles in different hand positions, shown in Figure 2. Examining the muscular activity normalized to MVC, there are obvious differences in muscular coordination pattern during pronated elbow flexion in comparison to supinated and neutral hand position. As in pronated, the muscular activity of brachioradialis is constantly higher than in supinated and neutral hand position whereas the percentage activity of biceps brachii is nearly the same in all hand positions. The muscular activity of both muscles is constantly on the same level and slightly increasing with elbow joint angle in supinated and neutral hand position.

Bottom Line: Normalized to MVC the sEMG amplitudes of both muscles contributing to elbow flexion movements were compared in pronated, supinated, and neutral hand position over elbow joint angle.Significant differences in the contribution of brachioradialis were found in pronated hand position compared to supinated and neutral hand position while the muscular activity of biceps brachii shows no significant changes in any hand position.In conclusion, a statistical significant dependency of the inter-muscular coordination between biceps brachii and brachioradialis during elbow flexion with respect to hand position has been observed depending on a biomechanical disadvantage of biceps brachii.

View Article: PubMed Central - PubMed

Affiliation: Department of Rehabilitation and Prevention Engineering, Institute of Applied Medical Engineering, RWTH Aachen University Aachen, Germany ; German Research School for Simulation Sciences, Joint Graduate School of RWTH Aachen University and Forschungszentrum Jülich Jülich, Germany.

ABSTRACT
Contribution of synergistic muscles toward specific movements over multi joint systems may change with varying position of distal or proximal joints. Purpose of this study is to reveal the relationship of muscular coordination of brachioradialis and biceps brachii during elbow flexion with respect to hand position and biomechanical advantages and disadvantages of biceps brachii. A group of 16 healthy subjects has been advised to perform 20 repetitions of single elbow flexion movements in different hand positions (pronated, neutral, and supinated). With a speed of 20°/s, simultaneously sEMG of biceps brachii and brachioradialis and kinematics of the movement were recorded in a motion analysis laboratory. Normalized to MVC the sEMG amplitudes of both muscles contributing to elbow flexion movements were compared in pronated, supinated, and neutral hand position over elbow joint angle. Significant differences in the contribution of brachioradialis were found in pronated hand position compared to supinated and neutral hand position while the muscular activity of biceps brachii shows no significant changes in any hand position. In conclusion, a statistical significant dependency of the inter-muscular coordination between biceps brachii and brachioradialis during elbow flexion with respect to hand position has been observed depending on a biomechanical disadvantage of biceps brachii.

No MeSH data available.