Knee pain can be caused by a variety of events, and many types of minor knee pain respond well to self-treatment. But if you're experiencing minor knee pain, then unfortunately, several exercises you may be used to should be off limits during the time you have knee pain
High impact sports (basketball, soccer) and strenuous jogging should be avoided until your knee pain improves.
Low impact exercises such as aquatic exercises (swimming, water walking) and regular walking are recommended.
Stretching can improve the flexibility of the knee. These include calf, hamstring, hip, and buttocks stretches.
It is key not to cause too much discomfort during these stretches in order to avoid stressing the knee further.
Certain leg lifts and hip abductor exercises can strengthen the knee.
BUT, call a doctor if you can't bear weight on your knee, have significant swelling or are unable to fully extend and flex your knee. Your doctor can also give you more specific exercise recommendations.
Sources: www.mayoclinic.com/health/knee-pain/DS00555/DSECTION=symptoms http://familydoctor.org/online/famdocen/home/healthy/physical/injuries/479.html#ArticleParsysMiddleColumn0005 http://www.niams.nih.gov/Health_Info/Knee_Problems/#19