Fig. 1.

Intraoperative measurement of dramatic sarcomere length increases in muscle contractures. A: intraoperative view of the anterior elbow of a person with an elbow contracture secondary to brain damage from prenatal cytomegalovirus infection. This image shows the gap created by surgical release (transection of the anterior fascia of the brachialis muscle and intramuscular tendon bundles and the biceps brachii distal tendon) before stair step lengthening. These releases allow passive elbow extension and, thus, basic activity of daily living functions such as self-care, feeding, and wheelchair driving. Intraoperative sarcomere length was measured by laser diffraction (17, 38) in upper extremity muscles from children with cerebral palsy (CP) or typically developing (TD) children or radial nerve injury patients: flexor carpi ulnaris muscle (B), soleus muscle (C), gracilis muscle (D), and semitendinosus muscle (E). (Data replotted from Refs. 35, 46, and 66.) Data represent means ± SE, n = 6–10 subjects/group. No error bars are provided for TD sarcomere lengths in D or E since these were single sarcomere length estimates based on a mathematical model.