The main symptom of Duchenne muscular dystrophy, a progressive neuromuscular disorder, is muscle weakness associated with muscle wasting with the voluntary muscles being first affected, especially affecting the muscles of the hips, pelvic area, thighs, shoulders, and calf muscles. Muscle weakness also occurs in the arms, neck, and other areas, but not as early as in the lower half of the body. Calves are often enlarged. Symptoms usually appear before age 6 and may appear as early as infancy. The other physical symptoms are:
* Awkward manner of walking, stepping, or running. (patients tend to walk on their forefeet, because of an increased calf tonus. Also, toe walking is a compensatory adaptation to knee extensor weakness.)
* Frequent falls
* Difficulty with motor skills (running, hopping, jumping)
* Increased Lumbar lordosis, leading to shortening of the hip-flexor muscles. This has an effect on overall posture and a manner of walking, stepping, or running.
* Muscle contractures of achilles tendon and hamstrings impair functionality because the muscle fibers shorten and fibrosis occurs in connective tissue
* Progressive difficulty walking
* Muscle fibre deformities
* Pseudohypertrophy(enlarging) of tongue and calf muscles. The enlarged muscle tissue is eventually replaced by fat and connective tissue, hence the term pseudohypertrophy.
* Higher risk of behavior and learning difficulties, due to adjustment problems and muscular fatigue.
* Eventual loss of ability to walk (usually by the age of 12)
* Skeletal deformities (including scoliosis in some cases)