Segment angle. The general motion was similar between the two trials, however, a greater flexion of trunk segment occurred in the platform shoe trial. The maximum forward angle was 7 degrees in the flat-soled shoe trial and 10 degrees in the platform shoes. Maximum backward rotation of the trunk was the same with both shoes (-8 deg). The range of motion for the flat-soled shoe trial was 15 degrees, in comparison to the 18 degree range of motion found in the platform shoe.
|
|
|
|
Figure 3. Trunk segment angle during the flat-soled shoe (left) and the platform shoe (right). The trunk angle is calculated from the vertical axis about the hip joint. Anatomical position corresponds to zero degrees, which is at the origin. Increasing values represent clockwise rotation. | |
Joint angle 1. The motion of the joint angle was similar between the two movements, but the knee displayed greater variations in movement while wearing the platform shoe. The maximum extension angle in the flat-soled shoe trial was 180 degrees and 184 degrees for the platform shoe. Maximum flexion angle was 114 degrees resulting in a range of motion of 66 degrees for the flat-soled shoe. The maximum flexion angle was 120 deg resulting in a range of motion for the platform shoe trial of 64 degrees.
|
|
|
|
Knee joint angle of the flat-soled shoe trial (left) and the platform shoe trial (right). Knee joint angle is calculated as the angle between the thigh and the leg. Anatomical position corresponds to 180 degrees. Increasing values represent extension. | |
Joint angle 2. The movements were almost identical. The range of motion of the flat-soled shoe trial was 51 degrees, while the range of motion for the platform shoe trial was 42 degrees. Maximum plantar flexion values were 262 and 257 degrees, for the flat-soled and platform shoes respectively. In the flat-soled shoe trial, the maximum dorsiflexion was 211 degrees, while it was 215 degrees in the platform shoes.
|
|
|
|
Figure 5. Ankle joint angle during the flat-soled shoe trial (left) and the platform shoe trial (right). Ankle joint angle is calculated as the angle between the leg and foot. Anatomical position corresponds to 180 degrees. Increasing values represent dorsiflexion. | |
Joint velocity. There were differences in the dorsiflexion and plantarflexion velocities of the ankle joint graphs. There was a difference of 96 deg/sec between the maximum dorsiflexion velocities with the flat-soled (-356 deg/sec) and platform (-260 deg/sec) shoes. The maximum plantar flexion velocities were 296 deg/sec (flat-soled) and 347 deg/sec (platform), which is a difference of 51deg/sec.
|
|
|
|
Figure 6. Ankle joint angular velocity in the flat-soled shoe trial (left) and the platform shoe trial(right). Positive values represent plantarflexion velocity. | |
Angle-Angle Plot. The two movements were not coordinated in a similar fashion. The flat-soled shoe trial had a decoupled coordination, approaching no relationship and a rounded trajectory. The decoupled coordination was shown in the graph by large horizontal changes combined with small vertical changes in the first part of the stance phase, while there were large vertical changes paired with small horizontal changes. On the other hand, the platform shoe trial exhibited a coupled coordination, demonstrated by a more linear relationship between the vertical and horizontal changes , so that the reversals of motion were not simultaneous.
|
|
|
|
Figure 7. Coordination of knee joint angle and ankle joint angle in the flat-soled shoe (left) and platform shoe (right). | |
