It is a form of myotonia where the distal muscles, particularly the hands and feet, fail to relax immediately after voluntary contraction.
To better understand this, is this for a general overview, or acromyotonia
The affected area can feel like a solid, immovable piece, similar to a spasm. It is often a symptom of underlying neuromuscular disorders rather than a disease on its own. It is a form of myotonia where the
Symptoms are often worsened by cold temperatures or repetitive movement, leading to a "locked" or "solid" feel in the hands. particularly the hands and feet