Neck musculoskeletal dysfunction in patients with chronic primary headaches.

OBJECTIVE: To compare cervical musculoskeletal findings in chronic forms of migraine, tension-type headache, cluster headache, and healthy controls and identify which variables were most strongly associated with headache frequency, neck disability and impact in each headache group. METHODS: Single-blinded cross-sectional study with a non-probabilistic sample. A blinded physiotherapist assessed 129 participants: chronic migraine (n = 35), chronic tension-type headache (n = 30), chronic cluster headache (n = 34) and headache-free controls (n = 30). Psychosocial and cervical musculoskeletal variables (head posture, total cervical active range of motion, flexion-rotation test, motor control, symptom reproduction and resolution) were compared. Backward linear regression analyses were performed to explore associations between cervical variables and headache frequency. neck disability and headache-related impact. RESULTS: Compared to controls, chronic cluster headache showed reduced total cervical active range of motion [F(3,128) = 8.8; p = 0.001, d = 0.75], retraction [F(3,128) = 4.66; p = 0.007, d = 0.70], protraction [F(3,128) = 7.77; p = 0.017, d = 0.73] and flexion-rotation [F(3,128) = 3.68; p = 0.014, d = 0.72]. While sex confounded total active range of motion (p = 0.009); neither variable influenced protraction or retraction (all p ≥ 0.26). Familiar head pain was evoked more in chronic migraine (68.6%) and tension-type headache (72.4%) than controls (23.3%) [χ²(1) = 20.85; p = 0.008; χ²(1) = 29.99; p = 0.0003]. Erector spinae activity was negatively associated with cluster headache frequency (Adjusted R²=0.25; β=-0.65; p = 0.02), cervical retraction was negatively associated with migraine frequency (Adjusted R²=0.11; β=-1.58; p = 0.03), and no significant associations were found for tension-type headache. CONCLUSION: This study provides the first comprehensive assessment of cervical musculoskeletal function in chronic cluster headache and directly compares it with the main chronic primary headaches and free-headache control group. Chronic cluster headache showed reduced cervical range of motion and impaired flexion-rotation versus controls; Although some differences between headache groups were observed, cervical musculoskeletal impairments were broadly present across chronic headache populations, without a clearly distinctive disorder-specific pattern. Neck musculoskeletal findings were not associated with headache frequency or impact.