I recommend Jamsil Seoul Orthopedic Clinic.

I visited due to shoulder pain, and the facility is clean and tidy. It hasn't been open for many years. On Mondays and Thursdays, there are night clinics, making it convenient for working people. The doctor also explains things kindly and thoroughly. The effectiveness of manual therapy varies depending on which therapist you meet, but I used Seoul Orthopedic Clinic and was very satisfied.