The crutch-gait movement began with a right heel strike and ended with the subsequent right heel strike. The cycle for the Hope-crutch gait took 1.33 seconds compared to 1.43 seconds for the Standard-crutch gait. The movement consisted of two phases: first, the stance phase which includes heel strike, rollover, and toe off; and second, the swing phase which is the period of the crutch-gait while the foot is off the ground. For the Hope crutches, the stance phase was completed in 0.83 seconds (62.5% of the total movement time); thus, the swing phase was completed in 0.50 seconds (37.5% of the total movement time). For the Standard crutches, the stance phase was completed in 0.93 seconds (65.1% of the total movement time); thus, the swing phase was completed in 0.50 seconds (34.9% of the total movement time). In addition, a major component of the movement was the time that the crutch was in contact with the ground. This component overlaps with both the stance and swing phase of the mobile leg. The crutches were in contact with the ground for 0.70 seconds (52.5% of the total movement time) for the Hope crutches and 0.80 seconds (55.8 % of the total movement time) for the Standard crutches.
One crutch-gait cycle for each set of crutches was selected for analysis. At the beginning of the stance phase the right hip was flexed, the knee was extended, and the ankle was dorsiflexed. Throughout the stance phase the hip extended, the ankle plantarflexed, and the knee remained extended until the heel began to come off the ground at which time it began to flex. When the foot left the ground and the swing phase began, hip motion changed from extension to flexion, the ankle motion changed from plantarflexion to dorsiflexion, and the knee changed from flexion to extension at approximately midway through the swing phase.
|
|
|
|
Figure 2. Body motion during Hope-crutch gait (left) and Standard-crutch gait (right). Body segments include the lower leg, thigh, trunk, upper arm, and forearm. There is also a segment indicating the motion of the crutch with respect to the shoulder. The arrows denote the direction of the movement and the squares represent the reference markers on the ground. The reference markers were 2.8 meters apart. | |
