Table 3 Rotated component matrix with extraction method of Principal Component Analysis and Varimax rotation method

Q1

I feel like my back is going to “give way” or “give out” on me

Q2

I feel the need to frequently pop my back

Q3

I have frequent bouts or episodes of symptoms

Q4

In the past my back catches or locks when I twist or bend my spine

Q5

I experience pain when I change positions (e.g., sit to stand or stand to sit)

Q6

When I bend forward it hurts, but returning to standing is usually worse

Q7

My pain increases with quick, unexpected, or mild movements

Q8

I have difficulty sitting without a back support (such as a chair) and feel better with a supportive backrest

Q9

My pain is usually worse with prolonged or static positions

Q10

It seems like my condition is getting worse over time (e.g., shorter intervals between bouts)

Q11

I have had this problem for a long time

Q12

I get temporary pain relief with a back brace or corset

Q13

I have many occasions when I get muscle spasms in the back

Q14

I am sometimes fearful to move because of my pain

Q15

I have had a back injury or trauma in the past

Eigenvalue

% of Variance