Are foot problems common?

Yes. Here are a few examples:

-High arched feet (pes cavus). High arches occur because there is more weakness in the foot muscles that extend the foot backward and flatten the arch than in the muscles that flex the foot downward.
-Shortened Achilles tendons. Achilles tendons are often short, and generally shorten further as HSP progresses.
-Jumping feet (clonus). Clonus is an uncontrollable, repetitive jerking of muscles that makes the foot jump rapidly up and down. It occurs when the foot is in a position that causes a disruption of the signals from the brain, leading to an automatic stretch reflex.
-Hammer toes or bunions. These may occur due to imbalances in the strength and tone of muscles that maintain proper alignment of joints in the feet.
-Cold feet and/or foot swelling. This is most likely caused by poor circulation. Normally, muscle contractions in the legs help pump blood from the legs back to the heart. If the muscles are weakened, or if the person is relatively inactive, the blood flow from the legs may be decreased, and fluids may accumulate. This can cause swelling, or a sensation of “cold feet”.