Why might progressive ankle and foot deformities be observed?

Why might progressive ankle and foot deformities be observed?

• A. Development of spasticity and motor strength loss associated with cord tethering
• B. Improved neuromuscular control
• C. Decreased muscle tone with increased balance
• D. Increased bone density

Answer: (A)

Progressive ankle and foot deformities in individuals with spina bifida are often tied to changing neurologic status from cord tethering. When the spinal cord becomes tethered as a child grows, it experiences increasing traction, which can worsen neurologic symptoms over time. This often manifests as heightened spasticity and selective motor weakness in the legs. The result is an imbalance in muscle forces around the ankle and foot: some muscles become overactive and pull the foot into abnormal positions, while others weaken and fail to counteract that pull. Over months and years, this imbalance leads to contractures and progressively deformed positional patterns such as equinus (tiptoe posture) or other malalignments of the foot and ankle. Explaining why the other ideas don’t fit helps reinforce the concept. If neuromuscular control were improving, deformities would be less likely to progress. A decrease in muscle tone would not typically drive progressive deformities driven by spasticity and unequal muscle strength. Increased bone density is not related to the development of these deformities and doesn’t explain the evolving motor imbalance seen with tethered cord.

Progressive ankle and foot deformities in individuals with spina bifida are often tied to changing neurologic status from cord tethering. When the spinal cord becomes tethered as a child grows, it experiences increasing traction, which can worsen neurologic symptoms over time. This often manifests as heightened spasticity and selective motor weakness in the legs. The result is an imbalance in muscle forces around the ankle and foot: some muscles become overactive and pull the foot into abnormal positions, while others weaken and fail to counteract that pull. Over months and years, this imbalance leads to contractures and progressively deformed positional patterns such as equinus (tiptoe posture) or other malalignments of the foot and ankle.

Explaining why the other ideas don’t fit helps reinforce the concept. If neuromuscular control were improving, deformities would be less likely to progress. A decrease in muscle tone would not typically drive progressive deformities driven by spasticity and unequal muscle strength. Increased bone density is not related to the development of these deformities and doesn’t explain the evolving motor imbalance seen with tethered cord.