55 years old male, known smoker complains of pain in calf on walking. pain still persists on continuing walk, but can walk with effort. which grade of claudication does this patient fall under

Boyd's classification of claudication : Grade I : Pian on walking, that improves with further walking. Grade II : pain on walking, but patient continues to walk with pain. Grade III : Pain on walking, that compels patient to take rest. Grade IV : Rest pain.