Neck-specific strengthening exercise compared with sham ultrasound when added to home-stretching exercise in patients with migraine: study protocol of a two-armed, parallel-groups randomized controlled trial - Benatto, Mariana Tedeschi; Florencio, Lidiane Lima; Bragatto, Marcela Mendes; Dach, Fabiola; Fernández-de-las-Peñas, César; Bevilaqua-Grossi, Débora (Chiropractic & Manual Therapies, 2020)