[A new dynamic index in the clinical evaluation of muscle efficiency].

A dynamic index for the clinical evaluation of muscle performance is proposed. It takes account of Gowers time, supine time and the ability of the subject to hold up his neck and lower extremities. Its experimentation in 98 healthy subjects and 99 myopathic patients divided into four age groups showed it to be useful, particularly in the follow-up of patients subjected to pharmacological and/or physical management.