discussion
Based on the findings from this study, the data did not support the proposed hypothesis that increased speed would result in a larger separation of the center of mass and the center of pressure. The data also did not show an increased separation from the ground to the curb. Quite on the contrary, the data revealed only one significant change that occurred in the excursion of the ground heel strike and the curb strike in the y direction. These data showed that the separation of the center of mass and center of pressure was smaller on the curb than it was on the ground from the front to the back. This contradicts our hypothesis, but is very significant. What this could possibly tell us is that when healthy people walk up a curb, they compensate for the curb by taking a shorter step. The center of mass and the center of pressure may have been further apart on the ground because the subjects were striding further. When they reached the curb however, they may have taken a shorter and more conservative step, which resulted in their center of pressure and center of mass being closer together. Given that the center of pressure and center of mass were closer together, the person would experience better stability.
The results of this study do correlate well with the findings of the study by Shirley Rietdyk and Chris Rhea. Like Rietdyk and Rhea found when they obstructed subjects’ vision, the subjects compensated for the object more than they needed to when they had less vision input. For example, the toe clearance and lead stride length both increased when the test subjects were wearing goggles. A similar occurrence can be seen in this study. The objects know the curb is ahead, so they subconsciously step a shorter distance onto the curb than on the ground. When the subjects knew there was an obstacle, they compensated for it.
Based on the findings in this study, the center of mass and center of pressure separation do not vary significantly at different walking speeds or from the ground to a curb, except in the heel strikes. This information is not particularly helpful in understanding why falls occur. If this data were compared to one with people who have impairments or are elderly, a greater separation of the center of mass and center of pressure may be able to be seen and explain their instability. In future research, the results of this study could be compared to one with a railing to see if the railing provided more stability.
It is also important to note the limitations of this study. Only healthy adults participated in this study, and there was no way to regulate speed. Each of the subjects were told to walk at a self-selected comfortable pace and a fast pace that was still comfortable but not running. Each of these speeds were personal, so there was no way to keep a constant speed or control that variable any more than was already done. The subjects were also advised to try and step on each force plate individually but nothing was done to regulate that other than perform multiple trials until that was the outcome. In future trials, a set location could be marked where the participants would have to step in the same place each time. The limitations to this are that each individual person has a different stride length, so the data could be scued if people with different strides all had to step the same distance.
The results of this study do correlate well with the findings of the study by Shirley Rietdyk and Chris Rhea. Like Rietdyk and Rhea found when they obstructed subjects’ vision, the subjects compensated for the object more than they needed to when they had less vision input. For example, the toe clearance and lead stride length both increased when the test subjects were wearing goggles. A similar occurrence can be seen in this study. The objects know the curb is ahead, so they subconsciously step a shorter distance onto the curb than on the ground. When the subjects knew there was an obstacle, they compensated for it.
Based on the findings in this study, the center of mass and center of pressure separation do not vary significantly at different walking speeds or from the ground to a curb, except in the heel strikes. This information is not particularly helpful in understanding why falls occur. If this data were compared to one with people who have impairments or are elderly, a greater separation of the center of mass and center of pressure may be able to be seen and explain their instability. In future research, the results of this study could be compared to one with a railing to see if the railing provided more stability.
It is also important to note the limitations of this study. Only healthy adults participated in this study, and there was no way to regulate speed. Each of the subjects were told to walk at a self-selected comfortable pace and a fast pace that was still comfortable but not running. Each of these speeds were personal, so there was no way to keep a constant speed or control that variable any more than was already done. The subjects were also advised to try and step on each force plate individually but nothing was done to regulate that other than perform multiple trials until that was the outcome. In future trials, a set location could be marked where the participants would have to step in the same place each time. The limitations to this are that each individual person has a different stride length, so the data could be scued if people with different strides all had to step the same distance.