Responsiveness of the Bridge tests in Symptomatic Lumbar Spondylolisthesis.

BACKGROUND AND OBJECTIVE: Bridging maneuvers, also called Bridge tests (BTs), were proposed to detect abdominal and spinal muscles stabilization endurance. They were also used to train lumbar muscles in patients with low back pain (LBP). To date no study was made on the responsiveness of BTs in subjects with LBP and Spondylolisthesis (SPL) submitted to a physical therapy program. The aim of this study was to examine the ability of BTs to be responsive in detecting clinical changes after conservative treatments in subjects with symptomatic lumbar spondylolisthesis. MATERIALS AND METHODS: This prospective cohort observational study involved two Outpatient Physical Therapy Clinics. 120 adults with symptomatic SPL were included. Patients received physical therapy treatments targeted to the symptomatic SPL including the performance of supervised exercises and the teaching of home exercises program to improve the lumbar stability. Two expert Orthopaedic Physical Therapists collected the measurements and administered the treatments. At the beginning and immediately after the treatment, the participants completed a booklet containing the Oswestry Disability Index – Italian version (ODI-I), a Numerical Rating Scale (NRS), and performed the Supine Bridge Test (SBT) and the Prone Bridge Test (PBT). The global perception of effectiveness was measured with a 7-point Likert scale (GPE). RESULTS: The mean post-treatment change of PBT was 18.2 (14.5; 21.9) and the effect size -0.62 (P<0.001); the SBT results were 43.9 (35.1; 52.8) and -0.75 (P<0.001), respectively. All other outcome measures (NRS and ODI-I) showed statistically significant improvements after the period of treatment. DISCUSSION: Our results showed a relevant effect of the treatment on the BTs scores. The changes in BTs scores appeared also significantly related to the amount of perceived improvement and were coherent with the changes in the other outcome measures (NRS and ODI-I). Most part of patients in our sample referred a much better or better condition on GPE, so we cannot comment about the responsiveness of BTs in subjects who did not change or worsened their state. CONCLUSIONS: Bridge maneuvers proved to be responsive and may be suggested to detect clinical changes after conservative treatment in subjects with symptomatic SPL.