Segment angle. The trunk segment motion was different between the bicep curl with a heavy weight and the bicep curl with the light weight. The maximum trunk angle during the bicep curl with a heavy weight was fifteen degrees in the counterclockwise direction. The maximum trunk angle during the bicep curl with a light weight was only five degrees in the counterclockwise direction. The minimum trunk angle for the bicep curl with the heavy and light weight was twenty degrees and seven degrees in the clockwise direction respectively. The range of motion for the first movement was 35 degrees while the range of motion for the second movement was only twelve degrees.
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Figure 3. Trunk angle during the bicep curl with a heavy weight (left) and the bicep curl with a light weight (right). The trunk angle is calculated from the vertical axis about the hip joint. Anatomical position corresponds to trunk angle of zero degrees. Increasing values represent clockwise rotation. | |
Joint angle 1. The elbow angle during the bicep curl of a heavy weight and the bicep curl of the light weight was very similar. The maximum joint angles between the arm and forearm (extension angle) for the bicep curl of the heavy weight was 168 degrees and 175 degrees for the bicep curl of the light weight. The minimum joint angles between the arm and forearm (flexion angle) for the bicep curl of the heavy weight was 12 degrees and 18 degrees for the bicep curl of the light weight. For the bicep curl with the heavy weight, the range of motion from extension to flexion was 156 degrees. The range of motion from extension to flexion for the bicep curl with the light weight was 157 degrees.
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Figure 4. Elbow angle during the bicep curl with a heavy weight (left) and the bicep curl with a light weight (right). Elbow angle is calculated as the angle between the arm and the forearm. Anatomical position corresponds to the elbow angle at 180 degrees. Increasing values represent extension. | |
Joint angle 2. The motion of the hip angle is different between the bicep curl with a heavy weight and the bicep curl with a light weight. There is much more angular displacement in the hip angle during the bicep curl with the heavy weight than the bicep curl with the light weight. The maximum flexion angle and the maximum extension angle of the hip during the bicep curl with the heavy weight were 155 degrees of flexion and 198 degrees of extension. The maximum flexion angle and the maximum extension angle of the hip during the bicep curl with a light weight were 174 degrees of flexion and 189 degrees of extension. The range of motion in the hip during the bicep curl with a heavy weight was 43 degrees between maximum flexion and extension, whereas the range of motion for the hip during the bicep curl with a light weight was only 15 degrees between maximum flexion and extension.
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Figure 5. Hip angle during the bicep curl with a heavy weight (left) and the bicep curl with a light weight (right). Hip angle is calculated as the angle between the trunk and the thigh. Anatomical position corresponds to the hip angle at 180 degrees. Increasing values represent extension. | |
Joint velocity. The data on the angular velocity of the hip in the bicep curl with heavy and light weights show some difference. The maximum hip angular velocity (extension velocity) of the bicep curl with heavy weights was 262 degrees per second, while the maximum hip angular velocity of the bicep curl with light weights was 109 degrees per second, a difference of 153 degrees per second. The minimum hip angular velocity (flexion velocity) of the bicep curl with heavy weights was &endash; 140 degrees per second, while the minimum hip angular velocity of the bicep curl with light weights was &endash;69 degrees per second, a difference of &endash;71 degrees per second.
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Figure 6. Hip angular velocity in the bicep curl with a heavy weight (left) and the bicep curl with a light weight (right). Positive values represent extensor velocity. | |
Angle-Angle Plot. The elbow and hip angles of the bicep curl with heavy weights were less coordinated than the bicep curl with the light weights. In the graph of the bicep curl with the heavy weight, there was a region between 48 and 95 degrees of the elbow angle that showed decoupled coordination. Near the completion of the bicep curl with the heavy weight, coordination resumed. In the graph of the bicep curl with the light weight, the elbow and hip angles maintained coordination throughout the movement. In the bicep curl with the heavy weight, the elbow angle increased while the hip angle remained constant for the first 90 degrees of flexion. In the remainder of the movement with the heavy weight, the hip angle decreased as the elbow angle increased. In the bicep curl with the light weight, as the elbow angle increased the hip angle did not change.
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Figure 7. Coordination of elbow angle and hip angle in the bicep curl with a heavy weight (left) and bicep curl with a light weight (right). | |
