Background: Clinical recommendations suggest exercises as the core treatment for knee osteoarthritis (OA) patients. However, the biomechanical modification following exercise therapy and its influence on pain remains unclear. The purpose of the study to compare the effectiveness of two different exercise programs, open kinetic chain (CKC) and closed kinetic chain (CKC) strengthening exercises, on pain and lower limb biomechanics for people more than 50 years old with painful mild grade knee OA.

Method: 66 individuals with mild knee OA, with knee pain in the previous one week, aged 50 years and above, and who have body mass index (BMI) between 18.9kg/m2 - 29.9 kg/m2 in Kelantan, Malaysia will be recruited in this study. Participants will be randomly allocated into three different groups, either OKC, CKC, or control groups. Participants in OKC and CKC groups will perform the exercises at their home three times per week for eight weeks. The control group will receive only the patient's clinical education about clinical manifestations, risk factors, diagnosis, treatment, and nursing care for knee OA and printed materials will be given. The outcome will be measured before and after the intervention. Primary outcomes are self-reported pain, disability, and quality of life scores. Secondary outcomes include lower limb biomechanics during gait and sit-to-stand, and knee isokinetic strength.

Discussion: This study will compare the efficacy of two different home-based exercise intervention programs for people with mild grade knee OA. Findings will provide valuable information for creating an effective exercise program that could slow down the progression of OA.

The primary aim of this randomized controlled trial (RCT) is to compare the effects of two different home-based exercise programs namely OKC and CKC strengthening exercise intervention, on pain, disability, and quality of life on individuals with mild grade knee OA. Our secondary aim is to compare the effectiveness of OKC and CKC strengthening exercises on lower limb biomechanics during walking gait and sit to stand task. We hypothesize that after eight weeks of intervention OKC and CKC groups will show more improvements in pain, disability, and quality of life scores (what about the secondary outcomes) than the control group.

For the CKC and OKC exercise group, participants will perform an 8-week individualized home exercise, a minimum of three sessions in a week. Each session lasts about 30 minutes, including 5 minutes of walking as warming up session and quadriceps and hamstring stretching as the cooldown session. Daily Paracetamol 3000mg will be provided to all three groups. However, the consumption depends on each participant's needs, and the participants need to record it in the diary given. The exercise diary will be given to each participant to ensure patients' adherence to home exercise. During the intervention phase, a designated research team member will contact the participants personally to encourage them to continue their exercises.

The untreated control group received the patient's clinical education about clinical manifestations, risk factors, diagnosis, treatment, and nursing care for knee OA except the information related to exercise. The control group will not receive any home exercise guidance. Upon completing the trial, participants in the control group will receive either CKC or OKC exercises depending on their preference.

Inclusion Criteria:

• female patients
• aged above 50
• body mass index (BMI) <30 kg / m2
• diagnosed with grade I and II knee OA using Kellgren-Lawrence
• have knee pain ≥ 2 on a VAS in the past week

Exclusion Criteria:

• have neurological disorders
• have implanted electrical devices
• have non-ambulatory status
• have significant cognitive impairment
• presence of systemic inflammatory arthritis
• have history of hip or knee arthroplasty
• have history of trauma or surgical arthroscopy of either knee in the last 6 months
• involved in a previous study that includes an exercise program within the last 6 months
• received a knee intra-articular injection within the last 3 months
• receives anticoagulant therapy
• have recent or imminent surgery within the last 3 months
• have any medical co-morbidities that excluding them from participation in exercises

All forms are anonymous and will be entered into SPSS software. Only research team members can access the data. Data will be presented as grouped data and will not identify the responders individually.