Reliability and responsiveness of musculoskeletal ultrasound in subjects with and without spinal cord injury.

Rehabilitation after spinal cord injury (SCI) aims to preserve the integrity of the paralyzed musculoskeletal system. The suitability of ultrasound (US) for delineating training-related muscle/tendon adaptations after SCI is unknown. The purpose of this study was to quantify within- and between-operator reliability for US and to determine its responsiveness to post-training muscle/tendon adaptations in SCI subjects. Two novice operators and one experienced operator obtained sonographic images of the vastus lateralis, patellar tendon, soleus, and Achilles tendon from seven SCI subjects and 16 controls. For control subjects, within-operator concordance (ICC [3,1]) ranged from 0.58 to 0.95 for novice operators and exceeded 0.86 for the experienced operator. Between-operator concordance (ICC [2,1]) ranged from 0.62 to 0.74. Ultrasound detected muscle hypertrophy (p < 0.05) following electrical stimulation training in subjects with SCI (responsiveness) but did not detect differences in tendon thickness. These error estimates support the utility of US in future post-SCI training studies.