Effects of Hold-Relax and Active Range of Motion on Thoracic Spine Mobility

Few studies address the use of manual muscle stretching to improve spinal active range of motion(AROM). There is evidence that' Hold-Relax'(HR) is effective for increasing ROM in the extremities, which leads the researchers to anticipate similar benefits in the spine. The purpose of this study is to investigate the effects of HR(trunk flexors) and active thoracic flexion and extension on thoracic mobility, specifically flexion and extension in healthy individuals. A convenience sample of 30 physical therapy students(22-38 years) were randomly assigned to intervention sequence 'A-B' or 'B-A', with at least 7 days between interventions. Intervention' A' consisted of HR of the ventral trunk musculature while 'B' consisted of thoracic flexion-extension AROM. Thoracic flexion and extension AROM were measured before and after each intervention using the double inclinometer method. Paired t-tests were used to compare AROM pre and post-intervention for both groups, and to test for carry-over and learning effects. There was a statistically significant increase(mean=$3^{\circ}$ ; p=0.006) in thoracic extension following HR of the trunk flexors. There were no significant changes in thoracic flexion following HR, or in flexion or extension following the AROM intervention. No carryover or learning effects were identified. HR may be an effective tool for improving AROM in the thoracic spine in pain free individuals. Further investigation is warranted with symptomatic populations and to define the minimal clinical difference(MCD) for thoracic spine mobility.