Segment angle. The angle of the lower leg segment was analyzed for both the level walking (left) and incline walking (right). There was a larger range of motion during level walking than in incline walking. In level walking, the range of motion was 77 degrees which was found by determining the difference between the two angles. In incline walking, the range of motion was 63 degrees.
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Figure 3. Lower leg segment angle during the level walking (left) and incline walking (right). The angle was calculated from the vertical (y)- axis through the knee joint. The knee is measured at 180 degrees when the body is in anatomical position. For both graphs, the angle is calculated clockwise. Increasing values indicate movement in the clockwise direction; decreasing values indicate movement in the counterclockwise direction. | |
Joint angle 1. The knee joint angle was analyzed for both level walking (left) and incline walking (right). There was a larger range of motion in level walking than in incline walking. In level walking, the range of motion was 66 degrees. In incline walking, the range of motion was 52 degrees. Minimum peak flexion occurred during the middle of the swing phase. Maximum extension for level walking occurred just following right heel strike. The maximum peak for incline walking occurred just following right toe off.
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Figure 4. Knee joint angle in level walking (left) and incline walking (right). Joint angle is the thigh and lower leg segments with respect to the vertical axis in the sagittal plane. Anatomical position for the knee is 180 degrees. Positive slope represents flexion and negative slope represents extension. | |
Joint angle 2. The hip joint angle was analyzed for both level walking (left) and incline walking (right.) There was a larger range of motion in incline walking than in level walking. In level walking maximum extension was 191 degrees and the maximum flexion was 160 degrees. The range of motion during level walking was 31 degrees. In incline walking maximum extension was 188 degrees and the maximum flexion was 150 degrees. The range of motion during incline walking was 38 degrees. The calculations show that the hip was more flexed during incline walking. The maximum peak angles for both level and incline walking occurred at toe off. The minimum peak angles for both level and incline walking occurred during the middle of the swing phase.
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Figure 5. Hip joint angle in level walking (left) and incline walking (right). Joint angle is calculated between the trunk and thigh segments with respect to the vertical axis in the sagittal plane. Anatomical position is 180 degrees. Positive slope represents flexion and negative slope represents extension. | |
Joint velocity. The angular velocity of the knee during level walking (left) and incline walking (right) was analyzed. The extension velocity for level walking was 349 degrees/sec and the flexion velocity was -291 degrees/sec. The extension velocity for incline walking was 287 degrees/sec and the flexion velocity was -281 degrees/sec.
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Figure 6. Knee angular velocity in the level walking (left) and incline walking (right). In level and in incline walking, the swing phase is from the beginning of movement (toe-off) until the knee is in full extension (heel strike). Heel strike begins when velocity equals zero and it indicates the beginning of the stance phase which lasts until the next toe-off. For both movements, negative values indicate knee extension and positive values indicate knee flexion. | |
Angle-Angle Plot. During the swing phase in level walking, beginning with toe- off, the hip and knee flex. As the right foot approaches the toe-off position in level walking, hip and knee extend. During the swing phase in incline walking, beginning with toe-off, the hip angle and the knee angle simultaneously decrease until the heel strike phase. Here, the knee angle increases as hip angle stays relatively constant due to the change in inclination, compared to level walking. Eventually, the hip angle increases along with the knee angle as toe-off position is reached.
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Figure 7. Coordination of knee angle and hip angle in level walking (left) and in incline walking (right). The head of the arrows are pointed in the direction of the movement, starting at the point of the first frame. | |
