Do patients with low back pain and central sensitization have differences in physical fitness?

Low back pain is one of the main musculoskeletal complaints, and may be associated with central sensitization (CS). The physical capacity of patients with low back pain and CS is not very clear.

A cross-sectional study, with 92 patients divided into two groups according to their risk of CS. The patient's physical capacity ability was assessed using 6-min walking test (6MWT); timed up and go test (TUG); sit-to-stand test (STS); and trunk flexor, extensor and side-bridge endurance tests. In addition, participants completed questionnaires regarding disability, kinesiophobia, catastrophization and quality of life.

The group with a higher risk of CS had worst performance in the 6MWT (U = 1248; p < 0.001), STS (t(83) = 3.63; p < 0.001) and TUG (t(83) = -4.46; p < 0.001). Similarly, endurance in the right (U = 1453,5; p = 0,002) and left (U = 1467; p = 0,003) side-bridge tests, and the trunk extensor test (U = 1546; p = 0,003) was worse. Disability (U = 1272; p < 0.001), physical capacity kinesiophobia (t(83) = -2.21; p = 0.03) work kinesiophobia (U = 1452; p < 0.001), and pain catastrophization (t(77.57) = -5.03; p < 0.001), were also higher in the group with a higher risk of CS. Quality of life indicators were worse in the higher risk group for all domains of the EQ-5D-3L: Mobility (X²(1) = 12.92; p < 0.001), self-care (X²(1) = 16,3; p = 0,012), usual activities (X²(2) = 14.14; p = 0.001), pain (X²(2) = 27.79; p < 0.001), anxiety and depression (X²(2) = 15.05; p = 0.001).

Patients with low back pain and higher risks of CS appear to show lower performance in physical capacity tests, higher rates of disability, kinesiophobia, pain catastrophization, and lower quality of life compared to those with lower risks of CS.