DMD progression is best described as which of the following?

• A. Slow progression with stability into adulthood
• B. Rapid decline with loss of functional mobility by adolescence
• C. Immediate improvement with physical therapy
• D. No progression over time

Answer: (B)

DMD progresses with a pattern of rapid decline in muscle strength during childhood, leading to loss of independent mobility by adolescence. The disease is caused by a lack of dystrophin, which makes muscle fibers tear more easily with use, so weakness worsens over time, especially in proximal leg and hip muscles. Children may start walking but typically lose the ability to walk within the early to mid-teens. Physical therapy helps maintain function and prevent contractures but does not reverse or halt the underlying progression. Cardiorespiratory involvement later contributes to morbidity and affects life expectancy. This description matches the option describing a rapid decline with loss of functional mobility by adolescence. The other ideas—slow, stable progress into adulthood; immediate improvement with therapy; or no progression—do not fit the typical course of Duchenne muscular dystrophy.