Furthermore, it was evident that the cumulative loss of shorter dystrophin isoforms (Dp 140, Dp71, and Dp116) will have an effect on the natural history of DMD, where patients with mutations in the DMD gene affecting shorter dystrophin expression are more prone to having an accelerated decline in hip muscle power, knee muscle power, and NSAA activities involving the lower limbs. Here, DMD is linked to Duchenne muscular dystrophy.