Background:It is believed that ultrasound-guided imaging of activation/contraction of the deep abdominal muscles (such as transervsus abdominis) is useful for assisting deep muscle re-education, which is often dysfunctional in non-specific low back pain (NSLBP). Thus, this pilot study aimed to evaluate the use of real-time ultrasound (US) as a feedback device for transverse abdominis (TrA) activation/contraction during an exercise program in chronic NSLBP patients.Methods:Twenty-three chronic NSLBP patients were recruited and randomly assigned to a US-guided (n= 12, 8 women, 47.6 ± 2.55 years) or control group (n= 11, 9 women, 46.9 ± 4.29 years). The same motor control-based exercise program was applied to both groups. All patients received physiotherapy twice per week for seven weeks. Outcome measures, tested at baseline and post-intervention, included Numeric Pain Rating Scale, TrA activation level (measured through a pressure biofeedback unit-based developed protocol), seven established motor control tests, Roland-Morris Disability Questionnaire and Hospital Anxiety and Depression Scale.Results:For each group, all outcome variables yielded statistical differences post-intervention (p< 0.05), indicating significant improvements. However, there were no significant group x time interactions for any of the outcomes (p> 0.05), thus, indicating no superiority of the US-guided group over the control.Conclusions:The addition of US as a visual feedback device for TrA re-education during a motor control exercise program was not proven superior to traditional physiotherapy.