What are some good physical exercises for people stuck in wheelchairs?

Sitting exercises. Traditional yoga encourages positive physical and mental health, according to the national center on physical activity and disability (ncpad). Hatha yoga, the most popular yoga form in western cultures, emphasizes physical poses called asanas that stretch, tone and strengthen muscles, along with focused breathing that can help alleviate anxiety, stress and depression. This can be done sitting.
Upper extremity. If one is unable to use their lower extremities for whatever reason , i would concentrate on upper extremity and core exercises i would use dumbells to work on arm exercises which are helpful for transfers also some isometric core exercise should be done if possible which also will help transfers.