Between open kinetic chain exercises and closed kinetic chain exercises, which exercise group is more effective in improving physical function, balance and quality of life of patients with moderate knee osteoarthritis?

1. Study area / setting The department of physiotherapy, Teaching hospital, Anuradhapura.

   1. Randomization - Patients will be randomized into two groups (close-chain and open-chain exercises groups) using the one-to-one randomization method by allocating one patient to the study group and the other patient to the control group one by one according to their order in the hospital register.

Patients in both groups will be acknowledged about knee osteoarthritis and protective recommendations, updated details on current practices for the knee OA,

1. Then exercises will be demonstrated separately to each group at the hospital by the principal investigator, and advice to continue for 8 weeks, for a duration of 30 minutes, 2 times a day, (every other day) 3 times a week at home.

OPEN KINETIC CHAIN EXERCISES Brisk walking for 5 minutes followed by active stretching for 5 minutes. STRAIGHT LEG RAISES- Participants in the supine position isometric ally contracted their quadriceps and lift the lower extremity up to achieve about 45° of hip flexion while maintaining the knee in extension. They held the position to a count of 10, and then lowered the limb; repeating the exercise 10 times STATIC BIKE CYCLING EXERCISE (without resistance) KNEE EXTENSION EXERCISE - Participants in a high sitting position a towel roll will be used for protection of the popliteal space and lift the limb slowly through the range of 90° knee flexion to 0° of knee extension. The position will be held for a count of 5 then lower the limb HIP ABDUCTION EXERCISE HIP ADDUCTION EXERCISE - Side lying on the bed raising lower limb on top up to 450 and lowering back on to bed. TERMINAL KNEE EXTENSIONsupporting the knee keeping a folded towel under the popliteal region and ask patient to press against it lifting leg up with ankle dorsiflexion and holdthepositinfor5 seconds and release. 8. Slow walking for 5 minutes followed by stretching

CLOSED KINETIC CHAIN EXERCISES Brisk walking for 5 minutes followed by active stretching for 5 minutes. STANDING WITH FEET TOGETHER IN EYES-CLOSED. a. On hard ground b. On soft ground (on a mat) SINGLE LEG STANCEStanding on one extremity for 30 second (repeated in both extremities), leaning forward, backward, and to the sides on one extremity (eyes open), leaning forward, backward, and to the sides on one extremity (eyes closed) STAIR-UP AND -DOWN Regular 3 steps staircase (17 cm high and 23 cm wide) EXERCISE WITH WOBBLE BED WALL SLIDE- Sliding against the wall bending bilateral knee joints up to 150 holding the rubber ball in between thighs with straight back and upper limbs.2 feet should be kept apart at shoulder width. STEP UP EXERCISE - Step-up and step-down Participants performed forward, backward and lateral step-ups and step-downs using a 5cm – high sturdy wooden box. Patients are instructed to keep their trunk upright and to ensure that their heel is the last to leave the floor and the last to return in order to emphasize the activities of the quadriceps muscle. Slow walking for 5 minutes followed by stretching

To monitor the proper understanding and adherence to the home-based exercises program, maintaining an exercise diary will be advised to each participant from both open kinetic chain exercises and closed kinetic chain exercises groups and also asking patients to bring a video on exercising sessions to the department during their weekly visits will be done. Similarly, participant’s family educations sessions will be conducted separately for each group. Additionally, a telephone call or a message will be given to remind hospital visit days, weekly visits, throughout the 8-week intervention period to encourage the participants to adhere to their exercise program at home and to keep track of any adverse effects.

Medical conditions - Male and female patients who are medically diagnosed with moderate bilateral osteoarthritis attending to the department of physiotherapy, Teaching hospital, Anuradhapura.

Moderate bilateral osteoarthritis will be diagnosed using Kellgren-Lawrence Scale – grade 3, by the consultant rheumatologist of Teaching Hospital Anuradhapura

Age - Above 40 years of age.

1. Patients with comorbid neurological conditions - Alzheimer's disease, Amyotrophic lateral sclerosis (ALS) or Lou Gehrig's disease, Brain cancer, Cerebral palsy, Epilepsy, Multiple sclerosis (MS), Parkinson's disease, Stroke,Traumatic brain injury.

2. Patients with severe systemic diseases - refer to conditions affecting the entire body, rather than a single organ or body part. Diabetes, Gout, Lupus, Scleroderma,Dermatomyositis, Malaria,, Lymphogranuloma venereum (LGV) , Chronic fatigue syndrome, Heart disease, Stroke, HIV, Asthma, Crohn's disease, and Muscular dystrophy.

3. Patients who cannot walk independently

4. Patients who have undergone knee/hip or ankle surgeries.

5. Patients with congenital abnormalities.

6. Patients who cannot provide with informed written consent.