What can indicate a loss of ambulation in less than two years for children with Duchenne Muscular Dystrophy?

The correct answer is the indication of a 10-meter walk test time over 9 seconds. This measurement is a critical indicator of motor function and mobility in children diagnosed with Duchenne Muscular Dystrophy (DMD). In this context, a longer time on the test suggests decreased muscle strength and endurance, leading to a higher likelihood of loss of ambulation.

In children with DMD, the progression of the disease results in weakening of the muscles, impacting their ability to walk and perform other movements. If a child's performance on the 10-meter walk test exceeds 9 seconds, it suggests significant motor deficits and often correlates with an impending loss of the ability to walk independently within a short timeframe.

Other options, while they may indicate difficulties or functional impairments, do not provide the same quantifiable measure that is predictive of loss of ambulation as the 10-meter walk test result. Climbing stairs or swinging arms may be affected later in the disease process, but the timing of the walk test is typically a more immediate predictor of ambulation status. Therefore, the 10-meter walk test serves as a vital tool in assessing the progression of DMD and planning appropriate interventions.