Low back pain is one of the most common work-related musculoskeletal disorders. Healthcare workers are prone to low back pain because of the nature of their profession. Low back pain may be related to lumbar multifidi atrophy or instability and poor core stability. Core stability can be assessed using the unilateral hip bridge endurance test. This cross-sectional study aims to determine the correlation between unilateral hip bridge endurance (UHBE) and sonologic characteristics of the bilateral L4-L5 lumbar multifidus muscles of physically active allied healthcare professionals.

Forty (40) physically active healthcare professionals (mean age = 31.3 ± 6.39 years, mean height = 161.17 ± 8.45 cm, mean weight = 61.88 ± 13.58 kg, mean BMI = 23.61 ± 3.68 kg/m2) were recruited via purposive sampling. The participants answered online versions of the Global Physical Activity Questionnaire (GPAQ) and Oswestry Disability Index. They subsequently underwent the UHBE test and ultrasound assessment of the L4-L5 multifidi. Multiplied anteroposterior (AP) and lateral linear (L) measurements were used to estimate L4-L5 multifidi size. The Pearson test was used to test for correlation between the primary outcomes of the study.

There was no statistically significant correlation between Lumbar Multifidi CSA and UHBE Scores (r = -0.172, p > 0.05), and between Lumbar Multifidi CSA% Difference and UHBE Scores (r = -0.140, p > 0.05). However, results showed a very weak negative correlation between the Lumbar Multifidi CSA% Difference and UHBE Scores.

There is no definite evidence showing a correlation between core stability tests such as the unilateral hip bridge test scores and sonologic characteristics of the lumbar multifidi. However, lumbar multifidi symmetry may have a role with core stability. The correlation between core stability tests and lumbar multifidus morphology should be further investigated.