Segment angle. Upon analysis of the upper arm segment angle, it was determined that the range of motion in the dumbbell bench press was significantly greater than the range of motion for the upper arm segment in the barbell bench press. For the dumbbell bench press, the upper arm moved trough a range of 110 degrees, while the upper arm segment in the barbell bench press passed through 87 degrees of rotation. The maximum angle created during the dumbbell bench press was 117 degrees compared to a maximum segment angle of 108 degrees that was achieved during the barbell bench press. Minimum values for the barbell and dumbbell bench presses were 21 degrees and 7 degrees, respectively with both minimum angles occurring at the end of the movement. It must also be noted that the segment angle was an absolute measurement therefore the negative sign was not considered when the data was analyzed.
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Figure 3. Segment angle during the barbell bench press (left) and the dumbbell bench press (right). The angle of the left upper arm segment angle is measured in relation to a line running perpendicular to the ground through the shoulder. Increasing the angle (in the negative direction) represents counterclockwise rotation and a decrease in the segment angle (towards 0) corresponds to clockwise rotation. | |
Joint angle 1. During the barbell bench press the elbow joint reached a peak extension angle of 178 degrees, and a peak flexion angle of 63 degrees. The complete range of motion for the movement was 115 degrees. Peak flexion for the barbell movement occurred 1.1 seconds into the exercise, while peak extension was reached at 2.0 seconds. In contrast, the dumbbell bench press attained a peak extension of 175 degrees, and a peak flexion of 55 degrees. The range of motion for this exercise was 120 degrees, with peak flexion occurring at 1.5 seconds and maximal extension at 2.6 seconds.
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Figure 4. Elbow angles of the flat barbell bench press (left) and the dumbbell bench press (right). The joint angle is measured by the angle created by the upper arm segment and the forearm segment. Thus elbow flexion corresponds to a decrease in the joint angle while extension at the elbow results in an increase in the angle. | |
Joint angle 2. During the barbell motion for the shoulder joint angle peak horizontal adduction, 77 degrees, was attained at the beginning of the exercise. Peak horizontal abduction reached 152 degrees at 1.2 seconds into the motion. The range of motion for this exercise was 75 degrees. For the dumbbell bench press, peak horizontal adduction occurred at the end of the exercise and was 82 degrees. Peak horizontal abduction occurred 1.5 seconds into the motion reaching 167 degrees. The range of motion for the dumbbell bench press was 80 degrees.
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Figure 5. Shoulder angles in the barbell bench press (left) and the dumbbell bench press (right). The joint angle is calculated by the angle created by the upper arm segment and the clavicle segment. An increase in joint angle indicates horizontal abduction and a decrease in joint angle indicates horizontal adduction. | |
Joint velocity. During the barbell bench press peak flexion velocity for the elbow was 144 degrees per second, while peak extension velocity was -279 degrees per second. For the dumbbell bench press, elbow angular velocity had a peak flexion velocity was 236 degrees per second, while peak extension velocity was -283 degrees per second. For both of these movements, velocity at peak flexion and peak extension was approximately 0 degrees per second due to the reversing and finishing of the movement.
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Figure 6. Elbow joint angular velocity in the barbell bench press (left) and the dumbbell bench press (right). A positive angular velocity corresponds to flexion at the elbow while a negative angular velocity indicates elbow extension. | |
Angle-Angle Plot. Coordination between the shoulder and elbow joints were coupled during the barbell as well as the dumbbell bench press exercises. In both movements, flexion at the elbow and horizontal abduction at the shoulder (indicated by the arrows) occurred simultaneously to lower the weight towards the chest. Conversely, ascension of the weight coupled extension at the elbow and horizontal adduction at the shoulder. In the barbell bench press, the range of motion at the shoulder joint seen at the shoulder (73 degrees) was less than the range of motion observed at the shoulder during the dumbbell bench press (81 degrees). Meanwhile, the elbow joint went through ranges of motion of 115 degrees and 117 degrees during the barbell and dumbbell bench presses, respectively.
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Figure 7. Coordination of the elbow and shoulder joint angles in the barbell bench press (left) and the dumbbell bench press (right). Flexion at the elbows and horizontal abduction occur as the graph moves down and to the right in the direction of the arrows. | |
