[Importance of the muscular system in the development of neuromuscular deformities: new diagnostic and therapeutic aspects ].

The term neuromuscular disorders covers a multitude of diagnoses which are of peculiar interest to the orthopaedic surgeon due to their impact upon the musculoskeletal system. The development of changes in muscle structure, muscle properties and muscle function carries the risk for the development of deformities and a deterioration in physical functions. Diagnostic and therapeutic measures should focus on muscular changes in particular. An interdisciplinary approach is recommended. The traditional orthopaedic management of deformity correction by muscle or tendon lengthenings always involves the risk of additional weakness. A more functional view of neuromuscular disorders should look at the 4 "M"s, i.e. muscle power, muscle excursion, muscle balance and muscle structure. Whenever possible, functionally important muscles should be preserved by correcting deformities primarily at the skeletal level. Re-establishing muscle balance reduces the risk of recurrent deformities. Contractures show different structural substrates that must be addressed individually. Orthotic treatment plays an important role in the conservative and surgical management of muscle dysfunction in neuromuscular disorders. This should include preventive as well as therapeutic splinting both for functional improvement and for postural management purposes.