In participants with knee symptoms, few activity limitations at baseline, non-western or Indonesian ethnicity, low educational level, bilateral hip pain, high comorbidity count, high BMI, pain on palpation of the joint line, high bodily pain and poor general health perception were associated with a two-year increase in activity limitations. In participants with hip symptoms, few activity limitations at baseline, low educational level, bilateral hip pain, high comorbidity count, no paid employment, few physical activity during leisure, restricted active hip flexion, poor general health perception, and frequent use of the pain coping strategy transformation were associated with a two-year increase in activity limitations. Conclusion: After two years of follow-up large between subject variation was observed in the course of activity limitations. Risk factors for an unfavorable course of activity limitations are identifiable already at an early stage of the disease. Medically unexplained symptoms (MUS) are an economic and humanitarian burden. Amongst them, pain complaints without organic pathology are the most prevalent. Theoretically, activated illness-related memory may cause reporting of symptoms by changing perception and interpretation of bodily signals. In the current study, we used a subliminal priming technique to test whether activating memory related to illness without conscious awareness leads to increased reporting of pain. The subliminal priming task consisted of a simple computer task during which words were shown for a short duration (34 ms). Participants were divided over four different conditions, with prime words describing either (a) health complaints, to activate an illnessrelated memory, or three control categories: (b) neutral words, (c) words describing bodily sensations and (d) negative valence words. The latter two conditions were added to test whether reduced pain tolerance would already be observed after the semantic activation of these two components or correlates of health complaints. For pain stimulation, we used a cold pressor task (CPT). We hypothesized that participants primed with health complaint words would show less pain tolerance (PT) compared to participants primed with neutral words. Participants were healthy students (n=66; mean age=21.57 years, SD=3.45; 84.8% female). Participants primed with health complaint words (n=15; mean PT=77.9 s, SD=79.7) showed reduced pain tolerance compared to participants primed with neutral words (n=17; mean PT=127.2 s, SD=92.5), t(30)=-1.963, p=.027 (one-tailed). Participants primed with either sensation words (n=17; mean PT=95.9 s, SD=75.3) or negative valence words (n=17; mean PT=95.4 s, SD=77.8) did not significantly differ in pain tolerance from participants primed with neutral words, respectively t(32)=-0.581, p=.282 (one-tailed) & t(32)=-0.859, p=.197 (one-tailed). Thus, pain complaints can be involuntary produced by activated illness-related memory. This memory is thought to be chronically over-activated in MUS patients. This would explain why they have complaints without observable bodily pathology and thus without a medical explanation.