This pilot study will test the testing and exercise training protocols for a larger study that is in the desing phase and may be modified based on the findings of this study. Two exercise groups will be compared; one is a stadard treatment group using leg strength exercises that are commonly employed in therapy clinics. The other group will do balance and agility type exercises, but no specific strength exercises. These "KBA" exercises are increasingly common in therapy clinics, but very little research has been conducted on their effectiveness in treating knee osteoarthritis symptoms. Participants in this study will complete three short paper and pencil tests at the beginning and end of the study (8 weeks of exercise) as well as a leg strength test, a leg endurance test, two short walking tests, and a stair climb/descend test. One of the paper and pencil tests will be taken every two weeks in an effort to see how quickly changes to symptoms might occur. The exercise programs will be conducted 3 afternoons per week (Mon-Wed-Fri) and will be lead by an ACSM certified instructor.

Radiographic knee OA is present in an estimated 37% of Americans over the age of 60, representing more than 13 million people. Current medical, non-surgical knee OA treatments focus primarily on symptomatic relief and have met with limited, temporary success. Various therapeutic exercise prescriptions have been used to help ameliorate knee OA symptoms and improve function. Leg strength training is most commonly used. However, recent evidence suggests that shorter programs of kinesthesia, balance and agility (KBA) techniques may result in more rapid symptom relief and functional improvements in comparison to traditional therapeutic exercise. These early benefits could potentially lead to greater long term exercise adherence.

In a case study of an elderly female patient with dynamic knee instability related to OA, physical therapists reported success with a combination of KBA training and traditional therapeutic exercise. These findings need to be verified in a controlled clinical trial. This pilot study will help determine the proper testing and exercise training methods for a larger clinical trial, and will indicate if KBA training done without concurrent strength training is a viable intervention.

Research Hypothesis: Among men and women age 50 and over with Kellgren and Lawrence (1957) Grade 2 or higher symptomatic tibiofemoral OA in one or both knees, an 8-week, 3-day per week kinesthesia, balance & agility (KBA) exercise program - designed to increase dynamic neuromuscular knee stability - safely and effectively changes physical function more effectively than standard leg strength training

Inclusion Criteria:

• Aged 50 years or over of either gender
• Radiographic tibiofemoral OA grade 2 or higher, unilateral or bilateral
• Demonstrated knee OA related dysfunction per WOMAC score
• Not engaged in a regular exercise program for minimum of 6 months

Exclusion Criteria:

• Inability to obtain physician release for exercise

• High risk health status:

  e.g., uncontrolled medical conditions such as hypertension, diabetes, heart disease, pulmonary disease, high cholesterol, anginal type pain, dizziness or syncope, orthopnea or paroxysmal nocturnal dyspnea, ankle edema, heart palpitations or tachycardia, intermittent claudication, known heart murmur, unusual fatigue or shortness of breath with usual activities.

• Unresolved balance disorder
• Unresolved neurological disorder
• History of knee surgery or major knee trauma injury
• Hip or ankle instability, excessive weakness, surgery or major trauma injury
• Intra-articular joint injection within 4 weeks of the study