Abstract
Background: The phenomenon of fear of movement is called kinesiophobia. Kinesiophobia is a significant factor that complicates the treatment process. Fear of movement and physical activity is a risk factor for the transformation of acute pain into chronic pain. Therefore, the assessment of the level of kinesiophobia is a prognostic factor for disability and mental stress, thus having a significant impact on the quality of life of people with lower back pain. One of the psychometric diagnostic tools for assessing the level of kinesiophobia is the Kinesiophobia Causes Scale (KCS). The aim of the study was to assess the reliability of the KCS test used in people suffering from chronic nonspecific lower back pain (nsLBP). Methods: The study included a group of 112 people suffering from chronic nsLBP. The subjects completed the same Polish version of the KCS questionnaire 4 weeks apart. Results: Good internal consistency was recorded for both domains-the biological and psychological one-as well as the general KCS index (Cronbach's alpha index α from 0.8 to 0.9). Reliability was excellent for both domains (95% CI of ICC(3.1) biological domain: 0.86-0.93 and for psychological domain: 0.92-0.96) and for the total score of the Kinesiophobia Causes Scale (95% CI of ICC(3.1): 0.91-0.93). Conclusions: These results indicate very good measurement reliability of the Polish version of the KCS questionnaire among people suffering from chronic nsLBP.