Activities of daily living (ADL) are various functional activities that may range from basic ones, such as walking or bending, to more complex activities (also called instrumental activities of daily living, IADL), such as cooking, bathing or getting dressed, in other words activities which enable independent living [
14,
15]. There seems to be a consensus across studies that LBP is associated with problems in ADL. An Austrian study in the general population aged 65 years and over found a clear association between LBP and problems in ADL with an odds ratio (OR) 2.01 (95% confidence interval, CI 1.57–2.57) and IADL with OR 2.17 (95% CI 1.82–2.59), adjusted for sociodemographic, lifestyle and health-related parameters. Another Austrian cross-sectional study of older adults with and without osteoporosis, osteoarthritis and chronic back pain using a nationally representative dataset reported that doing heavy housework, bending or kneeling, climbing stairs up and down without walking aids and walking 500 m without a walking aid were the most problematic ADLs in all groups [
16]. Interestingly, people with chronic LBP reported a much larger number of problematic ADLs compared to those with other musculoskeletal diseases or without them [
16].
A Thail cohort study (
N = 42,785; 80% aged between 30 and 50 years) showed that 30% of the cohort participants reported LBP, where approximately 6% of the cohort reported difficulties in bending, 3.1% had difficulties in walking a 100 m, 2.2% could not climb stairs, and a further 2.9% had problems when dressing. This longitudinal cohort study reported a time-dependent increasing gradient in the functional limitation across all activities [
17]. This study provided interesting results not only due to its longitudinal design but also gave insights into the LBP problems occurring in middle income level countries, which are seldom presented in research [
4]. As mentioned in the introduction, the high prevalence of LBP is a known public health issue in industrialized countries [
3]; however, longitudinal studies investigating LBP as a disability factor are rare. Some studies however, showed that LBP is an independent factor that worsens the self-reported disability level and makes ADL much harder for people who are already living with disabilities. For example, results from the Women’s Health and Aging Study (
n = 1002) showed that 42% of older women with disability reported LBP. After multivariate adjustments, women with severe back pain were 3–4 times more likely to report difficulties with light housework or shopping as well as having an increased likelihood of issues with various mobility tasks [
18]. Results of this study need to be interpreted in the light of the study participants, namely older women (30% of participants older than 85 years) who were already living with a serious disability. Similar results came from a cohort of patients living with rheumatoid arthritis (RA). In a study population of 281 patients with RA, 53.4% reported LBP over a 6-month period. Those patients who reported experiencing LBP presented with significantly higher disability in ADL compared to RA patients without LBP. This study found a moderate effect of LBP, which was enough to demonstrate a clinical relevance of LBP comorbidity in this patient group [
19]. Some studies looked into patient groups with an objectively confirmed etiology of reported LPB. A Turkish study investigated differences in ADL in patients with LBP resulting from lumbar disc herniation between those who received conservative treatment and those who underwent surgery. Prior to treatment they found that patients in both groups reported similar issues, mostly problems with prolonged standing, lifting weights and socializing. At follow-up (3 months following treatment) there seemed to be no differences in ADL that the patients had problems with; however, it is important to note that the patients who received conservative treatment reported worsening in terms of experienced pain [
20]. These results need to be interpreted with caution as the study did not report on surgical or conservative treatment protocols, post-surgery complications, physiotherapy or occupational therapy that the study patients underwent.
Studies of both the general population as well as populations of patients with other chronic illnesses or disabilities reach a consensus that LBP causes problems in functional capacity and performing ADL [
21‐
23]. The reason for this association may be in the deconditioning syndrome (complex process of physiological changes due to periods of inactivity [
24]), which has been reported in substantial numbers of patients with chronic LBP issues [
25‐
27]. Furthermore, LBP and ADL deficits do not only occur together very often. If chronic pain and ADL deficits coincide, they work synergistically towards an adverse outcome. Subjects affected by both ADL deficits and chronic pain showed a strong synergistic effect towards health care utilization. This means that healthcare utilization was much higher than could be expected from the mere addition of the health care utilization due to ADL deficits plus health care utilization due to chronic pain [
28].