Onset of Trunk muscles in landing in healthy subjects

Activity of trunk muscles is essential for the stability of lumbar spine because of the unstable structure of that portion of the spine. Also stabilization of the core and pelvis are necessary for all movements of the extremities. In order to investigate how function of the central nervous system in landing on trunk muscles. With this situation the timing component of the muscles of trunk were evaluated during landing. In this quasi-experimental study to examine onset of trunk muscles 15 male subjects with no history of low back pain studied. Surface EMG of gluteus medius، Erector spine and Internal Oblique was recorded and EMG onset was assessed during landing. The time of foot contact was assessed by a sensitive surface during landing. Findings of this study indicated that lumbar muscles activity occurring prior to touch of foot with ground. Result suggest that the central nervous system deal with stabilization of the spine by contraction of the core muscle in anticipation of perturbation produced by touch of foot with ground.