Segment angle. The upper arm segment motion was similar between both movements, with the exception of the range of motion. In the shoulder press with the barbell, the maximum and minimum angles of the upper arm segment were 140 degrees and 28 degrees, respectively. In the shoulder press with the dumbbells, the maximum and minimum angles of the upper arm segment were 152 degrees and 2 degrees, respectively. The range of motion of the upper arm segment in the shoulder press with the barbell was 112 degrees, while the range of motion of the upper arm segment in the shoulder press with the dumbbells was 150 degrees. The average angle of the upper arm segment in the shoulder press with the barbell was 85 degrees, while the average angle of the upper arm segment in the shoulder press with the dumbbells was 77 degrees. All angles are in the clockwise direction.
|
|
|
|
Figure 3. Left upper arm segment angle during the shoulder press with barbell (left) and the shoulder press with dumbbells (right). The left upper arm segment angle is calculated from the vertical axis about the shoulder joint. Anatomical position corresponds to zero degrees. Increasing values represent clockwise rotation | |
Joint angle 1. The left elbow joint motion was very similar between both movements. In the shoulder press with the barbell, the maximum and minimum angles of the elbow joint were 312 degrees and 182 degrees, respectively. In the shoulder press with the dumbbells, the maximum and minimum angles of the elbow joint were 311 degrees and 176 degrees, respectively. The range of motion of the elbow joint in the shoulder press with the barbell was 130 degrees, while the range of motion of the elbow joint in the shoulder press with the dumbbells was 135 degrees. The average angle of the elbow joint in the shoulder press with the barbell was 258 degrees, while the average angle of the elbow joint in the shoulder press with the dumbbells was 253 degrees. All angles are in the counterclockwise direction.
|
|
|
|
Figure 4. Left elbow joint angle during the shoulder press with barbell (left) and the shoulder press with dumbbells (right). Left elbow joint angle is calculated as the angle between the left forearm and the left upper arm. Anatomical position corresponds to 180 degrees. Increasing values represent flexion. | |
Joint angle 2. The left shoulder joint motion was very similar between both movements. In the shoulder press with the barbell, the maximum and minimum angles of the shoulder joint were 258 degrees and 141 degrees, respectively. In the shoulder press with the dumbbells, the maximum and minimum angles of the shoulder joint were 264 degrees and 133 degrees, respectively. The range of motion of the shoulder joint in the shoulder press with the barbell was 117 degrees, while the range of motion of the shoulder joint in the shoulder press with the dumbbells was 131 degrees. The average angle of the shoulder joint in the shoulder press with the barbell was 195 degrees, while the average angle of the shoulder joint in the shoulder press with the dumbbells was 199 degrees. All angles are in the counterclockwise direction.
|
|
|
|
Figure 5. Left shoulder joint angle during the shoulder press with barbell (left) and the shoulder press with dumbbells (right). Left shoulder joint angle is calculated as the angle between the left upper arm and the left shoulder segment. Anatomical position corresponds to 270 degrees. Increasing values represent abduction. | |
Joint velocity. The velocities of both movements were similar. During flexion, the maximum and minimum angular velocities of the elbow joint in the shoulder press with the barbell were 404 degrees per second and 2 degrees per second, respectively, while the maximum and minimum values for this same movement with dumbbells were 341 degrees per second and 1 degree per second, respectively. The average angular velocity for the entire movement of the elbow joint in the shoulder press with the barbell was 1 degree per second, while the average angular velocity of the elbow joint in the shoulder press with the dumbbells was -1 degree per second.
|
|
|
|
Figure 6. Left elbow joint angular velocity in the shoulder press with barbell (left) and the shoulder press with dumbbells (right). Positive values represent flexor velocity. | |
Angle-Angle Plot. The angles in both movements were coordinated in a similar fashion. As the shoulder joint angle decreased (adduction), the elbow joint increased (flexion). This negative slope demonstrated that the joint angles are moving out of phase. The diagonally aligned segment indicated coupled coordination between the shoulder and elbow joint.
|
|
|
|
Figure 7. Coordination of the elbow angle and shoulder angle in the shoulder press with barbell (left) and shoulder press with dumbbells (right). | |
