Mun is a physiotherapist by profession. As a community-based physiotherapist, she is a pioneer of integrating rehabilitation in aged care in Hong Kong. Her expertise lies in preventive care, rehabilitation and wellness. Mun is Head of Allied Health of The Hong Kong Society for Rehabilitation, responsible for various rehabilitation services and projects for persons with disabilities and chronic diseases, as well as the elderly. She leads the multidisciplinary team to build the service model of stroke rehabilitation in HKSR. Apart from this, she serves currently as Secretary of Community-based Rehabilitation and Primary Health Care Working Group and Treasurer of Aquatic Physiotherapy Working Group in Hong Kong Physiotherapy Association. She is also a Committee Member of Exercise Is Medicine-HK (EIM-HK) Advisory Board.