Segment angle. Lower leg motion was similar during cycling in the standard and aero positions. In the standard cycling position the lower leg segment angle reached a maximum of -7 degrees and a minimum of -47 degrees with the total range of motion equaling 40 degrees. The maximum segment angle of the lower leg segment during the aero cycling position was -8 degrees while the minimum angle corresponded to -53 degrees making the overall range of motion for the aero position 45 degrees.
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Figure 3. Lower leg segment angle during the standard (left) and aero (right) positions. The lower leg segment angle is calculated from the vertical axis. Anatomical position is viewed in the sagittal plane with the left lower leg at an angle of 0 degrees. Increasing values represent the clockwise direction of movement. | |
Joint angle 1. No significant differences in range of motion of the knee joint were found between the standard and aero cycling movements. Peak extension during the standard cycling position was 140 degrees and occurred at the beginning of the cycle. Peak flexion during the standard cycling position was 72 degrees and occurred 0.7 seconds from the onset of the movement. The overall range of motion for the knee joint in the standard position was 68 degrees. Peak extension during the aero position was 148 degrees and occurred at 0 seconds. Peak flexion during the aero cycling position was 75 degrees and occurred 0.8 seconds from the onset of the movement. The overall range of motion for the knee joint in the aero position was 73 degrees.
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Figure 4. Knee joint in the standard (left) and aero (right) positions. The knee joint angle is calculated as the angle between the thigh and lower leg segments with the anatomical position corresponding to a knee angle of 180 degrees in the sagittal plane. Increasing knee angles represent extension and decreasing knee angle represent flexion. | |
Joint angle 2. The hip joint was more extended throughout the standard cycling movement in comparison to the aero cycling movement. Peak hip extension during the standard cycling position was 100 degrees and occurred at the beginning of the cycle. Peak hip flexion during the standard cycling position was 58 degrees and occurred 0.9 seconds from the onset of the movement. The overall range of motion for the hip joint in the standard position was 42 degrees. Peak hip extension during the aero position was 80 degrees and occurred at 0.1 seconds. Peak hip flexion during the aero cycling position was 36 degrees and occurred 0.9 seconds from the onset of the movement. The overall range of motion for the hip joint in the aero position was 44 degrees.
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Figure 5. Hip joint angle in the standard (left) and aero (right) positions. The hip joint angle is calculated as the angle between the trunk and thigh segments. Anatomical position is represented by a hip angle of 180 degrees in the sagittal plane. Increasing angles correspond to hip flexion and decreasing angles correspond to hip extension. | |
Joint velocity. The peak knee joint angular velocity was higher in the aero position when compared to the standard position. The peak extension angular velocity of the knee joint in the standard position was 157 degrees per second. The peak flexion angular velocity of the knee joint in the standard position was -137 degrees per second. The peak extension angular velocity of the knee joint in the aero position was 178 degrees per second. The peak flexion angular velocity of the knee joint in the aero position was -171 degrees per second.
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Figure 6. Knee joint angular velocity in the standard (left) and aero (right) positions. Negative angular velocity values represent flexion of the knee joint while positive angular velocity values represent extension of the knee joint. | |
Angle-Angle Plot. Both the hip and knee joints were found to be tightly coordinated in phase, as can be seen in the diagonal portion of the graphs, except during the period of peak flexion where a delay in coupling occurred. The knee and hip were coupled more closely at peak extension than during peak flexion in both the standard and aero positions due to tighter corners of the graph which represent peak extension. The higher placement of the graph in the standard position indicates that the hip joint was more extended through the duration of the movement relative to the aero position.
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Figure 7. Coordination of knee and hip joint angles in the standard (left) and aero (right) cycling positions. Arrows represent counter-clockwise direction of movement. Movement initiates at the tails of the arrows. | |
