Prehab is physical therapy and exercise in the weeks before a knee or hip replacement, aimed at entering surgery as strong and mobile as the joint allows and already knowing the exercises you will do afterward. The American Academy of Orthopaedic Surgeons says you need several weeks to prepare physically and emotionally, and lists exercise among the ways to get ready. Suites at Carmel City Center open at 5 AM on weekdays, and the matching team can suggest an independent, licensed therapist to run your prehab one-on-one there.
Last reviewed By the Monon Therapy Collective editorial team
- When to start
- Several weeks before surgery (AAOS); a longer window allows more strength work
- Main targets
- Quadriceps, hip strength, knee straightening, walking aids
- Also covers
- Home setup, stairs and car transfers
- Who clears it
- Your surgeon and primary care doctor
Does prehab before a knee or hip replacement really make a difference?
For many people it makes the early recovery smoother, mainly because they arrive stronger, already know their exercises and have practiced walking with a walker, climbing stairs and getting in and out of a car. The benefit is usually described as modest and practical rather than dramatic, and it varies from person to person.
AAOS patient guidance on getting ready for joint replacement recommends preparing physically and emotionally over several weeks, including exercise. A painful arthritic joint often has weak muscles around it, because people naturally avoid loading it. Rebuilding some of that strength before surgery gives you a better starting point for the weeks afterward.
Prehab also gives you a baseline. Measuring how far the knee straightens, how many times you can stand from a chair in 30 seconds, and how far you walk before pain stops you makes it easier to see progress after surgery, when it can feel as though you are starting from zero.
What does a prehab plan in the weeks before surgery usually include?
A typical plan builds strength and joint motion first, then adds rehearsal of the skills you will need right after surgery. The table shows one way a plan can be laid out when you have about two months; with less time the same steps are compressed, and your therapist adjusts it to your joint, pain level and health.
| Weeks before surgery | Focus | Examples |
|---|---|---|
| 8 to 6 | Baseline testing and strength foundation | Chair stands, walking test, knee or hip range; quadriceps, glute and calf strengthening within comfort |
| 6 to 3 | Progressive strength and fitness | Heavier sit-to-stands, step-ups, leg press or cable work; stationary bike or pool walking |
| 3 to 1 | Rehearse post-operative skills | Walker or crutch practice, stairs with a rail, car and bed transfers, the first-week exercise routine |
| Final days | Rest and preparation | Light activity only; home setup finished; questions listed for the surgeon |
Which exercises matter most before a knee replacement versus a hip replacement?
Before a knee replacement, quadriceps strength and the ability to straighten the knee fully matter most, because both are hard to regain after surgery. Before a hip replacement, the gluteal muscles that hold the pelvis level when you stand on one leg take priority, along with comfortable hip motion.
For a knee, a therapist may use quad sets, straight leg raises, the sit-to-stand exercise, step-ups and leg press work, plus gentle work on knee extension. For a hip, side-lying and standing hip strengthening, bridges, the glute bridge and balance on each leg are common. Upper-body strength helps with both, because you will push up from chairs and lean on a walker.
In the private suites, the rack, cable system and adjustable bench let your therapist load these patterns safely even on a painful joint, for example with a box squat to a set height or a cable-assisted step-up. Suites open at 5 AM on weekdays, which suits people who want prehab before work.
- Quadriceps sets and straight leg raises
- Sit-to-stands from a progressively lower seat
- Step-ups and step-downs with a rail
- Bridges and side-lying hip work
- Ankle pumps and calf raises for circulation
- Walker practice, including turning and backing up to a chair
What does prehab rehearse for the first week home after a joint replacement?
It rehearses the movements that are hardest in the first days: standing up from a chair or toilet with a fresh incision, walking with a walker without shuffling, getting into a car, climbing a few steps, and getting in and out of bed. Practicing them before surgery, when only the arthritis hurts, makes them feel familiar later.
A therapist usually teaches the stair rule many people remember as “up with the good, down with the bad”: the non-operated leg leads going up, and the operated leg leads coming down, with the walking aid moving with it. Car transfers are practiced by backing up to the seat, sitting first, then swinging the legs in together. If you have a hip replacement coming, the therapist will rehearse these within the precautions your surgeon expects to use.
Prehab is also a chance to try a walker or crutches at the right height and to learn the exact home exercises the surgical team will give you. People who already know ankle pumps, quad sets and heel slides tend to start them sooner and with less worry. Write questions down as they come up; the first post-operative visit moves quickly.
What does the surgeon decide about prehab and the surgery plan?
Your surgeon decides the surgical approach, any movement precautions afterward, and whether anything in your health means exercise should be limited before surgery. Hip precautions in particular vary with the approach used, so ask what yours will be and practice within them during prehab.
Your primary care doctor usually completes a pre-operative check several weeks ahead. If they find something that changes your exercise plan, such as heart or blood pressure concerns, share it with your therapist. Skin problems on the operated leg, such as cuts or infections, can delay surgery, so mention any you notice.
Medicare requires a physician or other qualified provider to certify a physical therapy plan of care, and some private plans require a referral or authorization even for prehab. The therapist’s office checks this before the first visit; our cost and insurance page explains how that works.
How should you set up your home before a joint replacement?
Set up a single-level living space if possible, with a firm chair that has arms, a clear path to the bathroom, nightlights, and no loose rugs. Plan where the walker will fit, especially through bathroom doors and around the bed, and practice that route during prehab. Raise seats that are very low, put everyday items at waist height, and arrange help with driving and errands for the first weeks.
Our knee replacement checklist and our guide to preparing your home for a hip replacement cover the details. When you are ready to start, the two-minute questionnaire tells the matching team your surgery date, so they can propose a therapist who can see you before and after the operation.
Pause prehab and contact your doctor or surgeon if you notice
- Joint pain that becomes sharply worse after exercise and does not settle by the next day
- A new wound, rash or skin infection on the leg that is having surgery
- Chest pain, unusual breathlessness or dizziness during exercise (call 911 if severe)
- Calf swelling, warmth and pain on either leg
If you think it is an emergency, call 911.
