Abstract :The purpose of this study was to assess the temporal and spatial Electromyography (EMG) parameters from Lumbar paraspinal (LP) muscles during walking gait after induced tensionrelaxation of the lumbar spinal tissues. Ten healthy participants (22.4 ± 3.9 yrs, 1.80 ± 0.09 m, 83.3 ± 11.2 kg) volunteered for this experiment. A passive cyclic trunk flexion-extension loading protocol was performed for 10 mins. Prior to (pre-loading) and immediately after (post-loading) this loading protocol, each participant performed five walking trials across a walkway. Repeated measures ANOVAs were used to compare LP EMG and trunk and lower extremity kinematics between conditions. LP EMG timing significantly shifted from pre (13.0 ± 24.7 ms after heel contact) to post (70.0 ± 23.9 ms prior to heel contact) loading walking conditions (p< 0.05). There was no significant EMG amplitude modifications observed. Transverse trunk angle at heel contact was the only significant kinematics difference between walking conditions (p< 0.05). Passive loading of the viscoelastic passive lumbar tissues significantly modified LP muscle activity and may contribute to a neuromuscular compensatory mechanism to attenuate shock at foot contact when the low back tissues stiffness is reduced. The results from this work may assist in progressing the understanding of mechanisms of low back pain.