The comparative assessment of paraspinal tissue compliance in asymptomatic female and male subjects in both prone and standing positions.

Segmental bilateral paraspinal tissue compliance measures were obtained from 50 male and 50 female asymptomatic subjects (vertebral segments C7-L5). Interexaminer concordance for the taking of the measure was found to be extremely high (r greater than .90). Additionally, test-retest measures obtained from the same subjects initially, and again 15 min or 2 wk later indicated fairly low short-term as well as long-term temporal variabilities for the measure. The greatest levels of variability were encountered at lumbar segments, particularly with 2 wk intervals between assessments, and when measures were obtained with subjects in the standing, rather than prone, position. Data generated by this study suggest that tissue compliance assessments may provide useful information with respect to the contractile state of the paraspinal musculature at various regions or segmental levels.