Non-specific chronic low back pain (CLBP) is a prevalent multifactorial condition causing great economic costs. Numerous symptoms and dysfunctions are associated with CLBP including limited sagittal range of motion (ROM). Pain can also intensify in the extremes of ROM. This study examined whether progressive lumbar extension resistance exercise through a limited ROM can produce full ROM strength changes. An RCT of three groups was performed; FullROM, LimROM and Control. Participants (n=15 males, n=12 females) were randomised to the study groups (n=11 FullROM, n=8 LimROM, n=8 Control) and demographics recorded (Age 44.4+14.2yrs, Stature 175.8+6.8cm, Body Mass 80.4+13.8kg, BMI 25.8+3.0, Symptom Duration 14.0+11.7yrs). Pre/post full ROM strength testing was measured on a MedX Lumbar Extension Machine. Pre/post schobers tests of flexion and extension, visual analogue pain scale (VAS) and Oswestry questionnaire were completed. Intervention was 12 weeks progressive resistance exercise of the isolated lumbar extensors (1 set, 8-12 reps to momentary muscular failure). FullROM trained through 100% of their ROM, LimROM trained through the mid 50% of their ROM, the Control group did not train. One way ANOVA and Tukey post hoc tests compared between group relative changes (mean+SD). Strength data was averaged over quarters of ROM (i.e. Q1, Q2, Q3, and Q4). Groups did not differ (p>0.05) in age, stature, body mass, BMI, symptom duration, strength, VAS or attendance (84.6+21.8%). ANOVA on initial preliminary data (n=8 FullROM, n=5 LimROM, and n=6 Control; Full data set to be presented at conference) show significant changes in VAS (p=0.002) and Oswestry (p=0.004). No changes were seen in schobers test measures. Trends toward improvement in lumbar extension strength at each quarter (Q1 p=0.058; Q2 p=0.081; Q3 p=0.057; Q4 p=0.051) were found. Post hoc tukey show between Controls and FullROM significant improvement in VAS (p= 0.003, -59.0+36.8%), Oswestry (p=0.01, -46.7+19.9%) and significant strength changes in Q3 and Q4 (Q3 p=0.049, 44.5+53.8%; Q4 p=0.043, 31.4+27.3%;) but improvements failed to achieve significance in Q1 or Q2. Between Controls and LimROM were significant changes in VAS (p=0.007, -61.7+18.8%) and Oswestry (p=0.008, -56.4+24.3%), but not in any of the strength variables (Q1-4). No significant differences between training groups were found in any variables. Initial data suggest limited ROM lumbar extension exercise may produce full ROM strength changes as indicated by the absence of difference between training groups, with pain and disability improvement also. This may have important application to the rehabilitation of CLBP as many suffer from end ROM pain increases. Avoiding these positions in exercise may still be effective and may also provide less pain during exercise for participants.