From the Guidelines
For knee flexion contractures, the most effective exercise approach involves a combination of static stretching, progressive heel props, and strengthening of the quadriceps, as supported by the 2018 EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis 1.
Key Exercise Components
- Static stretching: Hold for 30-60 seconds and repeat 3-5 times daily, as recommended for improving joint range of motion 1.
- Progressive heel props: Use a rolled towel under the ankle for 10-15 minutes, 2-3 times daily, to allow gravity to gradually stretch the knee into extension.
- Quadriceps strengthening: Utilize straight leg raises to maintain the gained range of motion.
Exercise Considerations
- Start gently and increase duration rather than intensity to avoid pain and muscle guarding that can counteract progress.
- Low-load, prolonged stretching is beneficial for elongating connective tissue without triggering protective muscle contractions.
- As mobility improves, incorporate active-assisted exercises like seated knee extensions with the opposite leg to achieve full extension.
Additional Recommendations
- Consider individualized exercise programs that are progressively overloaded with frequency, duration, and intensity, consistent with the patient’s preference and capability, as suggested by recent clinical practice guidelines for osteoarthritis care 2.
- While there is no consensus on the type of exercise that elicits the greatest benefit, a combination of strengthening, aerobic exercise, and tai chi exercise therapy may be beneficial for managing knee osteoarthritis 2.
From the Research
Knee Flexion Contracture Exercises
The following exercises have been studied for the treatment of knee flexion contractures:
- Continuous passive motion (CPM) machines: A case study found that the use of CPM machines resulted in a 55-degree reduction in knee flexion contractures 3.
- Static progressive splint: A study found that the use of a static progressive splint resulted in significant improvements in knee extension, with an average increase of 38.6 degrees 4.
- Low-load, prolonged stretch: A study found that the use of low-load, prolonged stretch (using a splint) did not result in significant improvements in knee range of motion compared to traditional passive range of motion exercises 5.
- Knee flexion with quadriceps cocontraction: A study found that this exercise can yield considerable levels of quadriceps activation while preventing excessive strain on the healing tissue, making it a potential therapeutic exercise for the early stage of ACL rehabilitation 6.
- Continuous passive motion after total knee arthroplasty: A study found that the use of CPM after total knee arthroplasty resulted in significant improvements in knee flexion and functional outcomes, particularly when applied with initial high flexion and rapid progress 7.
Key Findings
- CPM machines and static progressive splints have been shown to be effective in reducing knee flexion contractures.
- Low-load, prolonged stretch may not be more effective than traditional passive range of motion exercises.
- Knee flexion with quadriceps cocontraction is a potential therapeutic exercise for the early stage of ACL rehabilitation.
- CPM after total knee arthroplasty can improve knee flexion and functional outcomes.