The stationary bicycle is a recommended, low-impact exercise following total knee replacement (TKR) surgery. This activity provides a safe, controlled method to restore the knee’s range of motion (ROM) without placing excessive strain on the new joint. Consistent, gentle cycling helps to strengthen the surrounding musculature, particularly the quadriceps, which are often weakened immediately following the procedure. While this guide offers general parameters, clearance from a surgeon or physical therapist is always required before starting any exercise program.
Timing the Initial Ride
The appropriate time to begin using a stationary bike is individualized, but generally falls within the first few weeks. Most patients can safely start this activity around two to four weeks, though some may be cleared as early as one week. Starting the bike requires sufficient initial healing; the surgical wound should be clean, dry, and free from excessive swelling.
Achieving a minimum level of knee flexion is a prerequisite for cycling. To complete a full rotation, the knee typically needs to bend to at least 90 degrees. If the knee cannot yet achieve this angle, initial sessions will involve a rocking motion rather than full revolutions. The physical therapist will monitor this progress, ensuring the knee is ready for the repetitive motion of cycling.
Setting Up the Bike for Safety
Proper adjustment of the stationary bike is critical to ensure the movement does not cause undue stress on the recovering knee. The seat height must be set correctly to prevent the knee from bending too much at the bottom of the pedal stroke. Using the heel-to-pedal technique, when the heel of the operated leg rests on the pedal at its lowest point, the knee should be nearly straight, maintaining only a very slight bend.
This high seat position reduces the degree of knee flexion required, making the initial movements more comfortable and manageable. A recumbent bike is often preferred in the early stages as it reduces pressure on the knee joint and offers a more secure seated position. If an upright bike is used, the patient may find it easier to start by pedaling backward first, as this sometimes requires less initial knee flexion than a forward motion.
To initiate the movement, especially if the operated leg is still weak, the patient should place their non-operated leg on the pedal first. This stronger leg can then drive the first few rotations, assisting the surgical leg through the range of motion. This approach allows the recovering knee to move passively through the early, stiff phase, gently increasing flexibility. The resistance level must be set to zero or the absolute minimum to ensure the movement remains focused on range of motion rather than strength training.
Duration and Frequency Guidelines
The initial prescription for stationary cycling focuses on gentle, repetitive motion for a short duration, prioritizing consistency over intensity. Patients should begin with sessions aiming for just 5 to 10 minutes. This short duration minimizes the risk of increasing post-exercise swelling or pain in the new joint.
These brief sessions should be performed frequently, typically one to three times per day. The goal is to gently warm the joint and surrounding tissues, encouraging improved flexibility throughout the day. Resistance must be maintained at the lowest possible setting, making the activity feel effortless.
If a patient experiences pain that is more than a mild, temporary ache during the ride, they should immediately reduce the duration or stop the session. This exercise is not meant to be a strenuous workout but rather a controlled, rhythmic movement to restore function. The focus during these early weeks is building tolerance and comfort with the motion itself.
Monitoring and Progression
Progression should occur gradually after the initial duration and frequency goals are comfortably achieved without adverse reaction. Once a patient can consistently complete a 10-minute session with minimal pain or increased swelling, they can begin to incrementally increase the duration. A safe progression involves adding one to two minutes per week.
Resistance should be introduced after the patient has achieved a comfortable duration, often 20 to 30 minutes, and has a pain-free, smooth pedal stroke. When resistance is added, it must be done in the smallest possible increments, ensuring the focus remains on smooth motion rather than muscle strain. The physical therapist will guide this process, determining the appropriate time to transition from range-of-motion work to strengthening.
Patients must watch for signs of overexertion, such as a noticeable increase in knee swelling or pain that persists for more than two hours after the exercise session. If these symptoms occur, it indicates that the last increase in duration or resistance was too aggressive, and the patient should return to the previous, well-tolerated level. Regular communication with the physical therapy team ensures that the progression is safe and aligns with the body’s healing timeline.