What Causes Balance Issues in Lower Limb Amputees?
Maintaining good balance has been studied in many different people over the years. However, researchers have not thoroughly looked into all the possible reasons why lower limb amputees, in particular, have trouble balancing after losing a leg until a team of researchers reviewed the existing research. If you or someone you know has had problems with balance after limb loss, it’s important to find out what might be causing it.
The comprehensive review
In a comprehensive review, researchers studied 23 papers and found that most of them reported increased postural sway—the small, unconscious movements that help us stay balanced when we’re standing still—in people with lower limb loss.
The studies looked at people of different ages and checked their ability to stay balanced while standing. The goal of the review was to give an overview of the current research on balance in people with lower limb loss. Understanding what causes balance problems is crucial for helping these individuals improve their posture and get better through rehabilitation.
Balance factors
Besides the apparent asymmetry in body weight, which is mainly distributed in the sound side leg, the studies point to various factors. Below are the major factors that contribute to balance issues in lower-limb amputees.
Load distribution pattern
Seven studies examined how weight is distributed in the body. Four found that the side of the body with the intact leg carries more weight than the side with the prosthetic limb.
They also found that people new to using a prosthetic limb had more uneven weight distribution than those who were experienced. This suggests that using a prosthetic limb more often leads to better results.
The studies also found that people with below-knee limb loss carry the most weight through the ankle of the sound side leg. In contrast, people without amputations evenly distribute their weight between their ankles and hips.
Sensory perception
In most of the studies reviewed, researchers examined the effects of visual input (what we see) and somatosensory input (sensations like pressure, pain, or warmth). These studies have shown that people with lower limb loss tend to sway more when they close their eyes. This is especially noticeable in the front-to-back movement when standing on the side without the prosthetic leg.
Interestingly, when the study participants open their eyes, this front-to-back swaying reduces, but there’s no significant difference in side-to-side swaying with eyes open or closed.
Another study found that people’s balance improved when they could use their vision and sense of touch.
Residual limb length
In addition to studying the impact of vision and sense of touch, researchers also looked at how the length of the residual limb affects balance. They found that people with shorter residual limbs tended to sway more than those with medium-length residual limbs.
Limitations
The 23 papers reviewed by the researchers had several limitations. First, the review was restricted to English-based publications and only utilized five databases.
Second, the inclusion criteria were limited to standing still, which excluded studies focusing on gait analysis and gait balance intervention.
Third, the selected studies did not take into consideration the cause of amputation. This limited information collection may have resulted in the omission of some balance-related factors from the review.
Finally, none of the studies examined the participants' confidence levels (fear of falling) and sleep quality, both of which are significant factors in maintaining balance.
The bottom line
Understanding the impact of load distribution, sensory perception, and residual limb length can significantly inform rehabilitation strategies for individuals with lower limb loss.
Improving prosthetic limb use and optimizing weight distribution between the sound side leg and the prosthetic leg are crucial steps in addressing balance issues. By considering these factors, individuals and healthcare professionals can work together to enhance balance and overall quality of life for lower limb amputees.
