effects of external focus and motor control training in comparison with motor control training alone on pain, thickness of trunk muscles and function of patients with recurrent low back pain: a single blinded, randomized controlled trial

Background: recurrent low back pain (rlbp) affects different structures in the lumbar spine. exercise therapy is highly recommended as one of the first-line treatments. one crucial variable introduced to enhance rlbp is the external focus. the present study aimed to investigate the effects of external focus training on pain, the thickness of transverse abdominis (tra), internal oblique (io), external oblique (eo), and lumbar multifidus (lm) muscles, kinesiophobia, fearavoidance beliefs, and disability of people with rlbp. methods: this randomized-controlled trial consisted of 38 rlbp patients. patients were randomly divided into two groups the treatment group (n=19) that received external focus training in addition to motor control training and the control group (n=19) that received motor control training alone. the primary outcome was pain intensity, and secondary outcomes were the thickness of tra, io, eo, lm muscles, kinesiophobia, fear-avoidance beliefs, and disability that were measured at the baseline and after 16 sessions of interventions. the interventions were performed three sessions weekly. results: reduction in pain intensity was more significant in the intervention group than in the control group (p<0.001, cohen’s d=-1.47). the thickness of tra muscle in the contraction condition of the intervention group was significantly more on the left side (p<0.001, cohen’s d=1.05) than on the right side (p=0.03, cohen’s d=0.44). other outcomes showed no significant differences. however, the cohen’s d effect size for the left io (cohen’s d=0.57) and tks (cohen’s d=-0.53) were moderate. conclusion: in rlbp patients, external focus and motor control training could effectively reduce the pain. although this intervention could increase the thickness of the tra muscle of rlbp, it has no significant effect on the thickness of io, eo, and lm muscles. in addition, the obtained results indicated that this intervention has no significant effect on kinesiophobia, fear-avoidance beliefs, and disability.