Total knee replacement (TKR) is a common and highly effective surgical procedure used to treat severe knee arthritis by replacing damaged joint surfaces with prosthetic components. Preparation is a significant factor in determining the speed and success of recovery for individuals facing this operation. The period leading up to surgery offers a unique opportunity to condition the muscles surrounding the joint. This article provides foundational, low-impact exercises designed to prepare the knee and surrounding musculature for the demands of the upcoming surgery.
The Value of Prehabilitation Before Surgery
Engaging in a structured exercise routine before TKR, often referred to as prehabilitation, establishes a stronger muscular baseline that can withstand the trauma of surgery and facilitate an easier recovery. By strengthening the quadriceps, hamstrings, and hip muscles, patients enter the operating room in better physical condition, which minimizes the amount of strength lost immediately following the procedure. This proactive conditioning often translates into measurable clinical benefits, including a potential reduction in the length of the hospital stay.
A stronger pre-operative state makes the initial post-operative physical therapy less challenging, as the muscles are already accustomed to controlled activation and movement. Patients who participate in prehabilitation programs often report better range of motion and overall function in the months immediately after the operation. Becoming familiar with these movements beforehand also builds confidence, allowing individuals to approach the rehabilitation process with greater preparedness.
Six Essential Exercises for Knee Strength and Flexibility
Quad Sets
Lie flat on your back with your legs extended straight out on a firm surface. Actively tighten the muscles on the front of your thigh (the quadriceps) by pushing the back of your knee down toward the surface below. Hold this contraction for six to ten seconds, feeling the thigh muscle fully engage without lifting the heel. Slowly relax the muscle and repeat the sequence, focusing on achieving a complete contraction.
Straight Leg Raises (SLR)
Begin by lying on your back with the non-surgical knee bent, planting the foot flat on the surface for support and stability. Keep the surgical leg straight, tighten the quadriceps muscle, and slowly lift the entire straight leg about 6 to 12 inches off the ground. The height should align with the bent knee, ensuring that the movement originates from the hip and not the lower back. Hold the leg suspended for a few seconds before lowering it slowly and with control back to the starting position.
Heel Slides (Hamstring Slides)
Lying on your back, start with both legs extended straight out, keeping your feet relaxed. Slowly bend the knee by sliding the heel of the surgical leg up along the surface toward your buttocks. Only pull the heel back as far as comfortable, stopping immediately if you feel a sharp increase in knee pain. Gently slide the heel back down until the leg is fully extended again, repeating the motion to improve flexion range.
Ankle Pumps
This exercise is performed while sitting or lying down and focuses on circulation, which helps reduce swelling and prevent blood clots. With your legs extended, slowly pull your feet and toes up toward your body as far as you can, flexing the ankle. Next, slowly point your feet and toes away from your body, extending the ankle as fully as possible. Continue this gentle, rhythmic pumping motion for several minutes, aiming for a consistent, controlled pace.
Bridging (Gluteal Sets)
Lie on your back with both knees bent and your feet placed hip-width apart on the floor or bed. Engage your abdominal and gluteal muscles to gently lift your hips off the surface until your body forms a straight line from your shoulders to your knees. Hold this elevated position briefly, maintaining a neutral spine and avoiding excessive arching of the lower back. Slowly lower your hips back down to the starting position with control.
Mini-Squats
Stand upright, facing a sturdy countertop or chair back for balance and support, with your feet shoulder-width apart. Slowly bend your knees and lower your hips only a short distance, as if you were just starting to sit in a chair. This partial movement should be shallow, involving no more than 30 degrees of knee bend to minimize stress on the joint. Hold the position for a moment before slowly pushing back up to a standing position, using the support only as needed for stability.
Important Safety Guidelines and When to Stop
Before initiating any exercise program, consult with your surgeon or a physical therapist to ensure the exercises are appropriate for your specific condition and to provide guidance tailored to your degree of arthritis and overall fitness level. The guiding principle for pre-operative exercise is consistency, not intensity; aim to perform your exercises daily, but always prioritize correct form over increasing the number of repetitions.
You should never push through sharp, stabbing, or persistent pain during any of these movements. If an exercise causes a sudden increase in joint discomfort, significant swelling, or a feeling of instability in the knee, the activity should be stopped immediately. A mild, aching soreness in the working muscles is often normal, but any pain felt directly within the joint space indicates that the exercise is placing too much stress on the damaged cartilage.