Lumbar Erector Spinae Activity During Anterior Trunk Flexion of People Who Use the Computer for More Than 30 h a Week

College communities engage in more mental than physical activities, working for more than 30 h per week in sitting postures in front of computers, and it can lead to low back pain (LBP). The aim of this work was to study the LES (longissimus and multifidus) muscle activity during anterior flexion of the trunk of people involved in higher education activities who use the computer for more than 30 h a week. The lumbar muscle electromyographic activity during anterior flexion of the trunk was evaluated in 41 subjects (22 with LBP/19 without LBP) that work at the UNAM Campus Juriquilla. As results, the Flexion-relaxation phenomena was not observed in healthy participants, and myoelectric silence was not present in the multifidus muscle of LBP group. Multifidus FRR was lower than average in both groups and lower than longissimus FRR. The muscles at L4-L5 vertebrae are at higher risk of asymptomatic muscle disorders and perhaps passive structures damage as well.