Background: A few studies have noted that paraspinal muscle training is important to reduce pain for patients with lumbar disc herniation (LDH). However, little is known about the exact signs for necessary training of lumbar multifidus muscles (LMM).
Objective: The study aimed to analyze the relationship between the straight leg-raising test (SLR) and the area of fat infiltration in LMM for patients with LDH.
Method: One hundred and fourteen LDH patients were involved in this study. Clinical data were collected from a medical record system. On the MRI images, the cross-sectional areas (CSA) of bilateral fat infiltration in LMM were measured by picture archiving and communication system (PACS).
Result: For 61 patients with inclusive LDH, the positive side of SLR was positively correlated with the side of the larger total CSA of fat infiltration in LMM of L2-S1 (r= 0.75, pï¼ 0.01), and the CSA of fat infiltration on the side of SLR with a positive result was significantly larger than that on the side of SLR with a negative result only at L3-4 and L4-5 levels (pï¼ 0.01).
Conclusion: SLR may be used as an important sign for dysfunction of LMM and can identify the more severe side.
Keywords: Multifidus muscle; disc herniation; fat infiltration; straight leg-raising test.