Lumbar erector spinae and sacral multifidus contractile properties in healthy females and males as determined by laser displacement mechanomyography

Contractile properties of the lumbosacral spine appear predominantly homogeneous, with no difference between sides (Tc, ½Tr, Ts). However, muscle displacement (Dmax) and contraction velocities (Vc, ½Vr) did vary between cephalic and caudal vertebral levels. This may be attributed to the difference in muscular CSA between the segments. As a preliminary analysis, gender appears to have no effect but requires future investigation.