Does Gait Symmetry Reduce Lower Back Pain?
Although gait asymmetry and lower back pain are often found together in unilateral below-knee amputees, it is still unknown whether better gait symmetry reduces lower back pain.
Researchers still haven’t found the definitive cause for lower back pain in lower-limb amputees. Still, the widely accepted hypothesis is that imbalances in muscles and movement contribute to lower back pain.
Below, we look at the causes of gait asymmetry in people with lower-limb amputations and how these are linked to incidences of lower back pain.
Movement asymmetries
Compared to non-amputees, lower-limb amputees typically find walking difficult because they depend on a prosthetic limb for bodyweight support and gait mobility. Their bodies also tend to use more energy to sustain a prosthetic limb.
These factors alter the biomechanics of an amputee’s gait, causing imbalances. And these imbalances can change the load distribution, which can lead to the development of back pain.
The scientific community widely accepts measuring stance and gait speed to determine gait symmetry and energy use.
Gait speed
Lower gait speeds are typically linked to having gait asymmetries, which is linked to a higher incidence of lower back pain. Lower-limb amputees generally have slower gait speeds than non-amputees. This is due to the altered dynamics caused by losing one or more limbs. Consequently, having altered dynamics lead to inefficient functioning of the lower limbs, resulting in reduced gait speeds.
Researchers investigated gait speed in lower-limb amputees. They found the above-knee amputees have notably slower gait speeds compared to below-knee amputees when walking at a comfortable pace.
Researchers hypothesized that lower-limb amputees reduce their gait speed to keep their energy use within normal limits. Amputees deploy this protective mechanism to sustain prolonged periods of walking and even exercise without becoming exhausted.
In contrast, faster walking speeds have been found to increase the load on the sound side limb, leading to increased asymmetry. Therefore, increased gait speed may lead to lower back pain.
Ankle
An imbalance in the ankles is also believed to lead to lower back pain. In a study of 24 participants, researchers concluded the absence of the plantar flexors affects the prosthetic limb at the ankle joint due to the decreased push-off of the prosthetic limb. Therefore, the altered kinematics and kinetics in the ankle joint could be a cause of the development of low back pain.
In another study, researchers found that powered prosthetic ankles may help improve imbalances, which can contribute to lower back pain.
The bottom line
Although more researchers are still finding conclusive evidence that gait symmetry reduces lower back pain, there is still enough evidence to support the importance of improving gait symmetry to improve lower back pain in lower-limb amputees.
So, until research shows us a better way, don’t skip that session with your physical therapist. You can also check out alternative ways to deal with lower back pain.
