Context: Individuals must change the way they perform activities in response to chronic pain. In the literature, three activity patterns are commonly described: avoidance, pacing, and persistence. Many studies have explored these activity patterns. However, little research has delved into the factors that lead people to adopt a particular activity behaviour. This study aimed to explore the relationship that people with chronic musculoskeletal pain have with activity and highlight the factors underlying their practices. Methods: The qualitative study was conducted by researchers in the social sciences, physiotherapy, psychology, and rehabilitation medicine. Observations of vocational workshops and semi-structured interviews were conducted with 33 persons undergoing rehabilitation for chronic musculoskeletal pain after an accident. Results: Patients' declarations and actions show that any one patient will alternate between activity patterns: the same person may adopt a strategy of avoidance, pacing or persistence depending on the context, the importance of the activity, personal objectives, and representations of self, pain, and activity. The decision to engage in a particular behaviour is based on a process of self-negotiation weighted by the circumstances, the nature of the activity, the importance attached to it, and the individual's perceived ability. Conclusion: Our study emphasized the complexity of physical, social, and contextual factors that intervene in the relationship toward activity. Rather than favouring pacing, the therapist's role in rehabilitation might be to reinforce the reflexive process and the patient's adaptability in approaching the activity, to foster the capacity to find flexible solutions. Significance: Patients choose an activity pattern (avoidance, pacing, persistence) according to the challenges they face in their daily lives. Context, representations of self and activity, as well as goals sought influence these choices. Some patients report having learned to adapt their activity management strategies. Therefore, therapeutic approaches in the rehabilitation context could focus on these adaptive capacities to offer patients optimal pain and activity management and develop their ability to use different strategies according to the circumstance.