Background and Purpose: There is a high prevalence of self reported back pain in the adolescent population. A randomised controlled trial (RCT) was undertaken to determine the effects of a high density foam seating wedge on back pain intensity.

Methods: The study took part in a large predominantly rural county in Eastern England. 185 students with back pain were recruited from 12 schools. Randomisation was stratified by school, and resulted in 92 students in the control and 93 in the intervention groups, respectively. The primary outcome measure was pain intensity (numerical rating 0–10 scale) recorded in pain diaries over 4 weeks. Following a one week baseline at the beginning of week 2, the intervention group were given a wedge to use on their school chairs. Linear effects models were used to analyse the pain intensity data.

Results: 97 students (46 control, 51 intervention) completed the RCT. For the intervention group, pain intensity was significantly reduced during the 3 weeks when the wedge was used (0.013 point reduction per half day, 95%CI −0.025 to −0.001, p=0.04). Evening pain was significantly less for the intervention group (0.324 reduction, 95%CI −0.543 to −0.104, p≤0.01).

Conclusion: The introduction of the wedge significantly reduced back pain intensity especially in the evenings. Despite its benefits some students found carrying the wedge a nuisance. It is therefore only suitable to relieve back pain in the short term. The results suggest that further research into the longer-term effect of alternative, permanent, seating on pain intensity in adolescents should be completed.