Background. Osteoarthritis (OA) of the knee is defined as a progressive disease of the synovial joints and is characterized by wear and tear of the cartilage and underlying bone. This study aimed to determine the short-term effects of the lower limb rehabilitation protocol (LLRP) on pain, stiffness, physical function, and body mass index (BMI) among knee OA participants who were overweight or obese. Methodology. A single-blinded randomized controlled trial of one-month duration was conducted at Rehmatul-Lil-Alameen Postgraduate Institute, Lahore, Pakistan. Fifty overweight or obese participants with knee OA were randomly divided into two groups by a computer-generated number. Participants in the rehabilitation protocol group (RPG) were provided with leaflets explaining the strengthening exercises of the LLRP and instruction of daily care (IDC), while the participants in the control group (CG) were provided with leaflets explaining the IDC only for a duration of four weeks. The primary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores for pain, stiffness, and physical function. The secondary outcome measures were BMI, exercise adherence, and patients’ satisfaction assessed by using the numeric rating scale ranging from 0 to 10. The paired-sample t-test was used to analyze the differences within groups from baseline to posttest evaluations. The analysis of variance 2 × 2 factor was used to analyze the differences in BMI, knee pain, stiffness, and physical function between the groups. Results. Participants in the RPG and CG reported a statistically significant reduction in knee pain and stiffness () within the group. The reduction in the scores of knee pain was higher in participants in the RPG than that in participants in the CG (). Additionally, participants in the RPG reported greater satisfaction () and higher self-reported exercise adherence () and coordinator-reported exercise adherence () than the participants in the CG. Conclusion. Short-term effects of the LLRP appear to reduce knee pain and stiffness only, but not physical function and BMI.
The knee joint is a complex synovial joint in the human body where the femur, tibia, fibula, and patella articulate . Articulation is supported by structures that include the muscles, ligaments, tendons, articular cartilage, synovial membrane, synovial capsule, meniscus, and fat pad . The synovial fluid and articular cartilage lubricate the knee allowing low-friction joint movement . The articular cartilage protects the subchondral bone from local stresses because of its strong reported excessive joint load in knee osteoarthritis (OA) . A study provides evidence on the fact that excessive joint load in knee osteoarthritis (OA) patients can lead to an increased inflammatory response, joint pain, and swelling . A recent study compared the body mass index (BMI) of obese and nonobese knee OA elderly individuals and reported that obesity resulted in less functional mobility, slower gait speed, higher pain intensity, and difficulty in performing daily living activities than nonobese individuals . It was reported that obesity increases the joint load in knee OA patients, resulting in lowering functional mobility and increasing pain intensity. Over the past decade, the prevalence rate of overweight and obesity has increased in the United States of America (USA), Canada, Mexico, France, and Switzerland . However, the prevalence of obesity solely among men and women of the USA population was 37.9 and 41.1%, respectively . A recent retrospective study investigated the physical and functional characteristics of 320 patients with knee OA, reporting that obesity and advanced age were associated with an increased risk of knee OA . Yet another study in the perspective under discussion reached the conclusion that overweight and obesity had a negative impact on increasing pain perception among patients with OA .
A study suggested that the reduced weight may be related to less demand on the proximal muscles and the internal medial rotator muscle of the knee, to provide stability at the toe‐off during excessive rearfoot motion . A recent exposition led to the fact that by acquiring the habit of regular exercise, knee OA patients can reduce pain and improve the quality of life and physical activity. One of the defense mechanisms of the knee, such as body weight control, is useful for healthy aging . All international clinical practice guidelines recommend patients with knee OA, who are overweight or obese, to lose their weight. Adherence may refer to different things and can be used to evaluate the attendance, technique, or accuracy of exercise protocols in supervised appointments . Research in the context of adherence refers to the accomplishment of self-reported and coordinator-reported adherence by the intervention groups.
Clinical guidelines recommend exercise therapy as the primary nonpharmacologic treatment for knee OA . Because of remarkable evidence demonstrating the beneficial effects of physical exercise among patients with OA, exercise is often indicated as one of the main components in the rehabilitation process [14, 15]. Among the several types of physical exercise programs, muscle strengthening is important because of the relationship between muscle weakness, pain, and malfunction [16, 17]. A current systematic review on nonpharmacological interventions for treating symptoms of knee OA in overweight or obese patients resulted that the most effective intervention that showed improvement of knee pain and function was strengthening exercise. Similarly, it also reported that the combination of diet and exercise was found effective in reducing weight and improving knee pain . A study explained that progressive resistance strength training increases the load gradually over the training course to strengthen the major muscle groups and has been recommended to prevent or reduce late-life disability for older adults . The effectiveness of rehabilitation in non-weight-bearing positions as well as strengthening exercises of major muscle groups of the lower limbs may provide more objective data than the standard rehabilitation approaches we are using today to treat overweight and obese knee OA patients. However, there is a gap in knowledge regarding whether strengthening exercises of major muscle groups of lower limbs in non-weight-bearing positions can improve the effects of rehabilitation among overweight or obese knee OA participants. Hence, the current randomized controlled trial aimed to determine the short-term effects of strengthening exercise of the lower limb rehabilitation protocol (LLRP) in non-weight-bearing positions on knee pain, stiffness, physical function, BMI, patients’ satisfaction, and exercise adherence in overweight or obese knee OA participants.
The current study aimed to determine the short-term effects of strengthening exercises of LLRP in non-weight-bearing positions on pain, stiffness, physical function, BMI, patients’ satisfaction, and exercise adherence in overweight or obese knee OA participants.
2.1. Design and Setting
This is a single-blinded randomized controlled trial that involved participants diagnosed with knee OA who are overweight or obese. Participants were randomized into the rehabilitation protocol group (RPG) and the control group (CG) using a computer-generated simple randomization technique. The study was conducted at the teaching bay of Rehmatul-Lil-Alameen Postgraduate Institute of Cardiology (RAIC), Punjab Employees Social Security Institution (PESSI), Lahore, Pakistan. All participants were asked to complete the clinical research form (CRF) following randomization. The CRF gathered sociodemographic information, symptoms of knee pain and stiffness, physical function scores, and BMI. The participants’ satisfaction and exercise adherence were collected after four weeks of intervention.
Participants in each treatment group were provided with necessary details about their intervention protocol after randomization. Making explanation of the purpose and constraints of the study, the participants were asked to provide written informed consent for their participation in the study. All participants were also given a diary and asked to record the attendance of completion of their interventions based on leaflets. The current study was approved by the ethical committee of Rehmatul-Lil-Alameen Postgraduate Institute of Cardiology, Punjab Employees Social Security Institution, with reference number RAIC PESSI/Estt/2020/36 on 20-05-2020, and the trial was registered in the Iranian Registry of Clinical Trials with reference number https://trialsearch.who.int/?TrialID=IRCT20191221045846N2 on 28-06-2020.
2.2. Study Participants, Recruitment, and Selection
Participants with knee OA who were overweight or obese from the urban community of Punjab, Lahore, Pakistan, were screened. The sample included males and females with OA on one or both knees as confirmed by a medical specialist according to the Kellgren and Lawrence radiographic scale for the assessment of OA . Plain radiography was performed to obtain anteroposterior and lateral views of the affected knee/knees in the standing position at the Al-Rehmat Trust Hospital, Lahore.
Participant inclusion criteria were as follows:(i)Aged between 45 and 60 years(ii)Having minimum qualification of matriculation(iii)History of knee pain for more than three months(iv)Overweight (BMI ≥ 25 kg/m²) or obese (BMI > 30 kg/m²) (v)Diagnosed with mild or moderate knee OA according to the Kellgren and Lawrence radiographic scale 
Participant exclusion criteria were as follows:(i)Diagnosed with rheumatoid arthritis, systemic lupus erythematosus, flat foot/feet, or spinal deformities(ii)History of metabolic, hormonal, orthopaedic, or cardiovascular disease(iii)Previous surgery of the knee/s (iv)Inability to walk independently(v)Injection of knee/s for the last six months 
All information related to inclusion and exclusion criteria was gathered from the predefined questionnaire.The researcher recruited the participants by using active recruitment strategies such as urban political and welfare organizations via word of mouth by the convenience sampling technique. The list of participants with knee OA in the studied area was obtained from the welfare organization by explaining the benefits of study participation. Two study coordinators prepared the list of potential participants with knee OA in the recruitment area. After obtaining the list of potential participants with knee OA, the researcher arranged a meeting with the knee OA participants by calling them on the phone. The meeting was held at the teaching bay of RAIC, PESSI, Lahore, Pakistan, in the presence of a medical specialist. Participants were screened for eligibility to participate in the study. Only participants fulfilling the inclusion criteria of the study were invited to participate in this study.
2.3. Sample Size
Sample size estimation was performed using the G∗ Power 3.1.3 software. By assuming the medium effect size f = 0.70 and setting α = 0.05, power (1 − B) = 0.80, number of groups = 2, and number of measurements = 2, the total sample size estimated was 33 participants. After considering the apprehension of dropout or mortality during the research period, the sample size of 50 participants for the two groups was decided.
2.4. Blinding and Allocation
The principle investigator was not blinded in the study. The participants receiving the intervention were kept blinded by simply not informing them of their treatment allocation. The coordinators collecting data were independent individuals from the trials and were unaware of the group allocation. There were different coordinators at the baseline and posttest evaluation. Individuals performing the statistical analysis were kept blinded by labelling the groups with nonidentifying terms (such as X and Y).
2.5. Study Randomization
After completing the screening of knee OA participants, the researcher allocated 50 selected participants into two groups, namely, RPG and CG, by using a computer-generated number. Each group consisted of 25 participants. The participants receiving the intervention were blinded by their treatment allocation. The participants in the RPG followed the strengthening exercise of the LLRP and followed the instructions of daily care (IDC) for a duration of 4 weeks. The participants in the CG were not involved in the rehabilitation protocols, but these participants only followed the IDC for a duration of 4 weeks.
2.6. Research Procedures
2.6.1. Research Procedure of the RPG
The researcher taught the strengthening exercises of the LLRP and IDC to the RPG for a duration of four weeks. Participants were advised to continue performing the strengthening exercises of the LLRP three times a week for four weeks at home. These training sessions included strengthening exercises for the lower limbs in non-weight-bearing, sitting, or lying positions. Each training session started with 10 minutes of warm-up, 45–60 minutes of lower limb resistance training, and 10 minutes of cooldown at the end of the training protocol.A cooldown period is essential after a training session and should last approximately 5–10 minutes [23, 24]. When static stretching is used as a part of warm-up immediately prior to exercise, it causes harm to muscle strength . The participants in the RPG performed the strengthening exercises of the LLRP and followed the IDC at home for four weeks. The contents of the IDC are explained in a recent randomized controlled trial .
The sequence of the training program started with 10 minutes of warm-up with whole body range of motion (ROM) and dynamic stretching exercises (Table 1). The participants performed 10 repetitions of ROM exercises for each muscle group and five repetitions of dynamic stretching exercises for each muscle group as a part of warm-up. After the warm-up, the participants performed the strengthening exercises of the LLRP for the stipulated weeks as stated in Table 2. After completing the strengthening exercises, the participants performed the 10-minute cooldown with whole body ROM and static stretching exercises (Table 1). The participants performed 10 repetitions of ROM exercises for each muscle group and three repetitions of static stretching exercises for each muscle group as a part of cooldown.
Flexion and extension, side flexion to the right and then to the left, and neck rotation to the right and then to the left
Shoulder flexion and extension, shoulder abduction and adduction, and shoulder rotation
Elbow flexion and extension
Wrist flexion and extension
Spine flexion and extension and spine rotation to the right and then to the left
Hip abduction and adduction and hip flexion and extension
Knee flexion and extension
Ankle dorsiflexion and plantar flexion
10 repetitions of each muscle group’s ROM exercises will be performed before and after the intervention period
ROM, range of motion.