The objective was to analyze the effect of a back education programme on the spinal shapes of the sagittal plane. A total of 80 primary schoolchildren were divided into three groups (1 control and 2 experimental groups). The experimental groups carried out the back education programme in their Physical Education classes for a full school year (9 months), two sessions per week (31 weeks, 62 sessions of physical education). The programme covered awareness, abdominal and lumbar strengthening, and hamstring stretching exercises,.. 17 minutes of each Physical Education session was used to teach it. The control group followed the standard programme of Physical Education classes. Before and after the implementation of the programme the sagittal plane of the spine was evaluated with an ISOMED-95 inclinometer in three positions: standing, forward flexion, and seated. The results show improvements in both experimental groups in all measurements, although they are only significant in the forward flexion and seated positions. For the control group, there were no improvements in any parameter, but rather they worsened in both the static sagittal position (standing) and the dynamic positions (forward flexion and seated). Conclusions. The implementation of a back education programme in Physical Education classes improves the sagittal plane in primary schoolchildren.<\/p>\n\n