An interventional study of Recumbent-Cycle Aerobic Exercise and Lower-Limb Strengthening Exercise in Osteoarthritis of Knee, sponsored by Bahçeşehir University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 45 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by Bahçeşehir University · Not applicable, Interventional, and Treatment
Knee osteoarthritis can cause pain, reduced muscle strength, and difficulty with daily activities. Exercise is commonly used to manage knee osteoarthritis, but the effects of different exercise programs on muscle oxygenation are not fully understood.
This study will compare three 6-week exercise programs in adults with knee osteoarthritis: aerobic exercise on a recumbent bicycle, lower-limb strengthening exercise, and a program combining aerobic and strengthening exercise. Participants will be randomly assigned to one of the three groups. Each group will attend three supervised exercise sessions weekly for 6 weeks. All participants will also receive a home stretching program. Participants will be assessed before the program, at weeks 3 and 6, and again at week 10, after a 4-week period without supervised exercise.
The study will examine whether the exercise programs improve muscle oxygenation and whether changes in muscle oxygenation are associated with changes in muscle strength, pain, and physical function. The investigators expect muscle oxygenation to improve after the exercise programs and expect these changes to be associated with improvements in clinical measures.
This is a single-center, parallel-group randomized clinical study planned at the laboratories of the Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Istanbul University-Cerrahpaşa, Türkiye. The planned enrollment is 60 participants, with 20 participants in each group. Participants will be randomly assigned to an aerobic exercise group, a strengthening exercise group, or a combined aerobic and strengthening exercise group using an online randomization program.
The supervised intervention will last 6 weeks, with three sessions per week, for a total of 18 sessions. Study assessments will take place at baseline and at weeks 3, 6, and 10. No supervised exercise intervention is planned between weeks 6 and 10. All participants will receive the same home flexibility program, consisting of bilateral hamstring and quadriceps stretches and gastrocnemius stretches with a towel or sheet. Participants will be advised to perform the home exercises 3 to 5 days per week.
The aerobic exercise group will train on a recumbent cycle ergometer. Sessions will include a 5-minute warm-up and a 5-minute cool-down. At the beginning of the program, the main exercise period will last approximately 20 to 30 minutes at 40% to 50% of age-predicted maximum heart rate. Exercise duration and intensity will be progressed according to participant tolerance, with a target of approximately 40 to 45 minutes at 60% to 70% of maximum heart rate by week 6. Cadence will be maintained at approximately 60 to 80 revolutions per minute. Heart rate and perceived exertion will be monitored during exercise.
The strengthening exercise group will perform lower-limb exercises, including isometric knee extension, hip flexion, extension, abduction and adduction, clamshell exercise, and knee flexion and extension using ankle weights. Exercises will be performed bilaterally. The program will use 1 to 3 sets of 8 to 12 repetitions, with 90 to 120 seconds of rest between sets. Resistance will begin at approximately 30% of one-repetition maximum and may be progressed toward 60%, depending on participant tolerance. One-repetition maximum will be reassessed every 2 weeks to update exercise loads.
The combined group will perform aerobic and strengthening exercise consecutively during the same session. Exercise progression in all groups will be guided by participant tolerance and pain. Progression will be considered when exercise pain is no greater than 4 on a 0-to-10 scale and there is no persistent increase in pain or symptom exacerbation during the following 24 to 48 hours. Exercise duration or intensity will be reduced if the participant cannot tolerate the prescribed exercise.
The same assessment procedures will be used at each scheduled assessment visit. Muscle oxygenation will be assessed using near-infrared spectroscopy, alongside clinical and physical-function assessments specified in the study record.
3,407 studies on the registry are indexed under Osteoarthritis, Knee; 638 are open to participants now.
This study's planned enrollment of 60 is below the median of 69 across 2,822 interventional studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →Bahçeşehir University is the lead sponsor of 124 studies on the registry; 24 are open to participants now.
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Participants will complete supervised aerobic exercise on a recumbent cycle ergometer three times per week for 6 weeks (18 sessions). Each session will include a warm-up, cycling, and a cool-down. Exercise intensity and duration will be individually adjusted and progressed according to participant tolerance and pain response, with heart rate and perceived exertion monitored during exercise. Participants will also receive the common home stretching program.
Other: Recumbent-Cycle Aerobic Exercise · Other: Home Flexibility Exercise Program
Participants will complete supervised bilateral lower-limb strengthening exercises three times per week for 6 weeks (18 sessions). Exercises will include isometric knee extension, hip flexion, extension, abduction and adduction, clamshell exercise, and knee flexion and extension using ankle weights. The program will use 1 to 3 sets of 8 to 12 repetitions, with resistance progressed according to tolerance and pain response. Participants will also receive the common home stretching program.
Other: Lower-Limb Strengthening Exercise · Other: Home Flexibility Exercise Program
Participants will complete supervised aerobic exercise on a recumbent cycle ergometer and lower-limb strengthening exercises consecutively during each session, three times per week for 6 weeks (18 sessions). Exercise intensity, duration, and resistance will be adjusted according to the participant's tolerance and pain response. Participants will also receive the common home stretching program.
Other: Recumbent-Cycle Aerobic Exercise · Other: Lower-Limb Strengthening Exercise · Other: Home Flexibility Exercise Program
Supervised aerobic exercise on a recumbent cycle ergometer, three times per week for 6 weeks (18 sessions). Each session includes a 5-minute warm-up and a 5-minute cool-down. At the beginning of the program, the main cycling will be at 40% to 50% of age-predicted maximum heart rate. Duration and intensity are progressed according to participant tolerance, with a target at 60% to 70% of maximum heart rate by week 6. Cadence is 60 to 80 revolutions per minute. Heart rate and perceived exertion are monitored during exercise.
Supervised bilateral lower-limb strengthening exercise, three times per week for 6 weeks (18 sessions). Exercises include isometric knee extension, hip flexion, extension, abduction and adduction, clamshell exercise, and knee flexion and extension using ankle weights. Participants perform 1 to 3 sets of 8 to 12 repetitions, with 90 to 120 seconds of rest between sets. Resistance starts at approximately 30% of one-repetition maximum and may progress toward 60%, according to tolerance and pain response. One-repetition maximum is reassessed every 2 weeks.
Home flexibility exercises provided to participants in all three arms. The program includes bilateral standing hamstring and quadriceps stretches and a towel-assisted gastrocnemius stretch. Each stretch is held at the point of tension for 20 to 30 seconds. Participants are asked to perform the exercises 3 to 5 days per week.
Muscle Oxygenation
1. Resting VMO Muscle Oxygen Saturation (SmO₂): Mean muscle oxygen saturation (SmO₂, %) recorded over 60 seconds after 10 minutes of seated rest, measured over the vastus medialis oblique using near-infrared spectroscopy. 2. Minimum VMO SmO₂ During Mini-Squat Exercise: Minimum muscle oxygen saturation (SmO₂, %) recorded over the vastus medialis oblique during one set of 20 mini-squats performed at approximately 30 degrees of knee flexion, with a 3- to 4-second hold per repetition and isometric hip adduction. 3. Post-Exercise VMO SmO₂ Recovery Time: Time in seconds from completion of the mini-squat set until SmO₂ returns to the pre-exercise resting baseline, measured over the vastus medialis oblique.
Time frame: Baseline, week 3, week 6, week 10
Knee Pain
Participant-rated knee pain at rest using a 0-to-10 Numerical Rating Scale (NRS), where 0 indicates no pain and 10 indicates the worst pain imaginable.
Time frame: Baseline, week 3, week 6, week 10
WOMAC Score
The Turkish version of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) will assess pain, stiffness, and physical function. The total score will be normalized to a 0-to-100 scale using (raw total score × 100) / 96; higher scores indicate worse symptoms and function.
Time frame: Baseline, week 3, week 6, week 10
SF-36 Health-Related Quality of Life
The Turkish version of the 36-Item Short Form Health Survey (SF-36) will be scored across its eight domains on a 0-to-100 scale. Higher scores indicate better health-related quality of life.
Time frame: Baseline, week 3, week 6, week 10
Active Knee Flexion Range of Motion
Active knee flexion range of motion, measured in degrees with a universal goniometer. Three measurements will be taken and the mean will be used.
Time frame: Baseline, week 3, week 6, week 10
Maximal Isometric Knee Extension Torque
Maximal isometric knee extension torque, measured in Newton-meters using an isokinetic dynamometer at 15 degrees of knee flexion. Three contractions will be performed and the mean torque will be used.
Time frame: Baseline and weeks 3, 6, and 10.
30-Second Sit-to-Stand Test
Number of complete sit-to-stand repetitions performed in 30 seconds from a chair with a seat height of 44 cm, with arms crossed over the chest.
Time frame: Baseline and weeks 3, 6, and 10.
2-Minute Walk Test
Distance walked in meters during a 2-minute walk test on a 30-meter corridor.
Time frame: Baseline and weeks 3, 6, and 10.
Started Oct 2026 (actual). Primary completion is estimated for Oct 2027, 12 months after the start.
Of 1,149 non-industry interventional studies with no phase under Osteoarthritis, Knee, half reached primary completion within 17 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 36. This study's planned 12 months is below that.
Counting every sponsor, half of 1,292 studies reached it within 17 months; a quarter within 8 and three quarters within 36.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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