Final answer:
Lateral wall collapse in calcaneus fractures can cause a flatfoot deformity, leading to decreased arch height, pain, and impaired foot function.
Step-by-step explanation:
Lateral wall collapse in calcaneus fractures can lead to a condition known as a flatfoot deformity. When the lateral wall of the calcaneus collapses, it can cause the height of the foot arch to decrease, resulting in a flattening of the foot arch. This affects the biomechanics of the foot and can lead to difficulties in walking, pain, and altered gait. The calcaneus is a crucial bone for maintaining the normal arch of the foot, and its impairment can have significant consequences for foot function.