Table 1.

Intervention group: Multimodal Rehabilitation Program, description of the treatment

Graded Exposure module	OR	Combination module (Graded exposure and physical training)
Phase 1 Intake and PHODA-Youth (60 min) • Information about cognitive, behavioral and psychophysiological aspects of pain complaints • Description of family system and situation • Identification of activities that are being avoided, and accompanying cognitions Phase 2 Education (60 min) • Explanation of treatment rationale • Explanation of treatment • Alternative explanation for persistence of pain complaints • Personal fear avoidance model Phase 3 Graded Exposure treatment sessions (12 × 60 min) • Systematic exposure to fear provoking activities and movements • Behavioral experiments • Generalization and relapse prevention		Phase 1 Intake, PHODA-Youth, and physical examination (60 min) • Information about cognitive, behavioral and psychophysiological aspects of pain complaints • Description of family system and situation • Identification of activities that are being avoided, and accompanying cognitions • Physical examination of strength, balance and propriocepsis. Phase 2 Education Graded Exposure and training (60 min) • Explanation of treatment rationale • Explanation of treatment: Training and graded exposure sessions • Alternative explanation for persistence of pain problems • Explanation of physical training • Personal fear avoidance model Phase 3 Training (16x120 min) • Training (hydrotherapy if possible), focusing on aerobic capacity, muscle strength, core stability, propriocepsis • Homework (training exercises) Phase 4 Graded Exposure treatment sessions (6x 60 min) • If necessary: repetition of treatment rationale • Systematic exposure to fear provoking activities and movements • Behavioral experiments • Generalization and relapse prevention
	AND
Parent module Phase 1 Medical education and treatment rationale • Explanation of treatment rationale • Explanation of treatment • Alternative explanation for persistence of pain complaints • Personal fear avoidance model for their child Phase 2 The role of pain within the family system • Explanation of the influence of pain on the family system and interaction between parents and child • Tools to support the child in creating and maintaining behavioral change Phase 3 Generalization and relapse prevention • Identifying and recognizing risky situations that can trigger relapse • Preventing relapse by making plans