Welcome to the last part of the “Prosthetic Foot Alignment” series, where we help you become more familiar with the importance of proper prosthetic foot alignment, how it affects your walking, and how it can cause discomfort in the joints above your foot.
The toe-in and toe-out movements of your prosthetic foot are referred to as foot rotation. And rotational changes can negatively affect how your prosthetic foot functions right before your leg goes into swing phase of walking when you’re on the “toe.” (This group of orchestrated movements is referred to as the late stance phase of gait.)
When your prosthetic foot is rotated too far outward, you're losing the toe function of your prosthetic foot. This becomes apparent when you take a step, and it feels as if you just stepped into a hole. Too often, this is caused by an outwardly rotated foot. So, having your prosthetist turn your foot in a few degrees—preferably to match your other leg—can bring back the toe resistance.
A prosthetic foot is engineered to accommodate an appropriate degree of rotation. So, when you find yourself struggling to overcome your foot when taking a step, the issue can be your prosthetic foot has too little toe out.
Some amputees with an excessive toe-in claim it feels as if you're walking uphill. Others complain about pain in their knee from the constant backward force caused by too much toe resistance.
Typically, during initial prosthetic alignment, your prosthetist aligns your foot rotation to match your sound side leg. But what about those prosthetic users that wear a prosthesis on both legs? What rotational baseline does your prosthetist follow when you're a bilateral amputee?
To find out the baseline, start by bisecting your socket when viewing from the front. Next, take a plumb bob and have the midpoint of your socket fall between the big toe and the second toe of your prosthesis. The rotation created using this method is a great starting point for bilateral amputees. Rotation can be further refined when you walk and evaluate your foot's toe resistance.
If you’re in doubt, ask a family member or friend to take a video of you walking head-on. Then, watch the video on loop and compare the movements of your prosthetic foot and your sound side. If you’re a bilateral amputee, compare both prosthetic feet. If your prosthetic foot is not identical to your sound side, or both prosthetic feet don’t match, schedule a visit to your prosthetist for a fast and easy fix.This concludes our three-part prosthetic foot alignment series. Let us know what you thought about this prosthetic alignment series so we can improve and provide you with content that interests you. Thank you!