Home Program for Patellar Instability

What you are treating

When the kneecap slips to the outside, the ligament on the inside of the knee that tethers it (the MPFL) is torn, and the muscles that pull the kneecap toward the middle are switched off by pain and swelling. This program rebuilds the two things that keep the kneecap in its groove without surgery: a strong inner thigh muscle (the part of the quadriceps just above the inside of the kneecap, the VMO) and strong hip muscles that keep the knee from collapsing inward when you land, squat, or cut. Those hip muscles matter more than most people expect.

The same program is the rehabilitation after an MPFL reconstruction, on a slower timeline that I set with your therapist.

Two rules:

• Do not force deep bending in the first weeks. The kneecap is most likely to slip between straight and about 30 degrees of bend, and it is pushed hardest into the groove in deep bending, which hurts the bruised cartilage.
• Keep the knee in line with the second toe in every standing exercise. If the knee drifts inward, the exercise is too hard. Make it easier until the line is clean.

Phase 1: protect and wake up (weeks 0 to 2)

• A knee brace or immobilizer for comfort for the first week or two, walking with crutches only as long as needed to walk without a limp.
• Ice for 15 minutes, several times a day, with the leg up, until the swelling is down.
• Quad sets. Sit with the leg straight, press the back of the knee into the floor and tighten the thigh. Hold 5 seconds, 20 times, several times a day. Put a hand on the inner thigh just above the kneecap and feel that muscle work.
• Straight-leg raises. Lying on your back with the other knee bent, tighten the thigh and lift the straight leg a foot off the floor. 3 sets of 10. Turn the foot slightly outward to bias the inner thigh.
• Heel slides. Slide the heel toward the buttock to bend the knee as far as comfortable, then straighten. 10 slow repeats, 3 times a day. The goal is 90 degrees by two weeks.
• Ankle pumps and calf stretches, as for any injured leg.

Phase 2: build the inner thigh and the hips (weeks 2 to 6)

Four days a week.

• Terminal knee extension with a band. Loop a band behind the knee, anchored in front. Stand and straighten the knee against the band from slightly bent to fully straight, squeezing the inner thigh at the top. 3 sets of 15.
• Mini squats, feet shoulder width, to about 45 degrees, knees over the second toes. 3 sets of 10. Progress to a wall sit, 30 seconds, 3 rounds.
• Clamshells with a band around the knees. 3 sets of 15 each side.
• Side-lying leg raises, toes pointing forward. 3 sets of 12 each side.
• Bridges, then single-leg bridges. 3 sets of 10.
• Monster walks: a band around the knees or ankles, slight squat, 10 steps sideways each way, 3 rounds.
• Stationary bike at an easy resistance once the knee bends enough, 10 to 20 minutes.
• Stretching: quadriceps, hamstrings, calves, and the outer thigh (IT band) with a foam roller, 20 seconds each, 3 rounds, daily. A tight outer thigh pulls the kneecap outward.
• A kneecap brace with a lateral buttress for walking and, later, sport, for the first three months.

Phase 3: control the knee under load (weeks 6 to 10)

Begin when the knee is not swollen, bends fully, and the single-leg bridge and monster walks are easy.

• Step-downs. Stand on a low step on the injured leg and slowly lower the other heel toward the floor, keeping the knee over the second toe and the pelvis level. 3 sets of 10. Raise the step as it gets easier. This is the single most useful exercise in the program.
• Single-leg squats to a chair, 3 sets of 8.
• Lateral step-ups, 3 sets of 10.
• Romanian deadlifts on one leg, 3 sets of 8.
• Landing practice: step off a low box and land on both feet with a soft, quiet landing, knees over the toes, then on one foot. 2 sets of 10.
• Balance: single-leg stand on a pillow, 30 seconds, 3 rounds, adding a ball toss.

Phase 4: return to sport (weeks 10 and beyond)

• Jogging in a straight line first, then cutting at half speed, then full speed, then sport drills.
• Return to practice when hopping on one leg for distance is within 90 percent of the other side and the knee stays in line on landing. Return to games a week or two after a full practice without symptoms.
• Keep the step-downs, clamshells, and monster walks as a twice-weekly habit for the rest of the season.
• If the kneecap slips again despite all of this, that is the point at which I usually recommend a ligament reconstruction. The program is not wasted: it is the rehabilitation afterward.

Notes for the physical therapist

• Quadriceps (VMO-biased) and hip abductor and external rotator strengthening, with neuromuscular control of dynamic valgus as the central goal.
• Limit loaded flexion beyond 60 degrees for the first 4 to 6 weeks; avoid open-chain knee extension in the 0 to 30 degree arc early.
• Patellar taping or a buttress brace for comfort and confidence in phases 2 and 3.
• Address foot pronation with an insole if it is contributing to the valgus.
• Return-to-sport criteria: full motion, no effusion, limb symmetry over 90 percent on hop tests, and clean landing mechanics on a step-down and drop-jump screen.
• After an MPFL reconstruction: brace locked in extension for walking the first 2 weeks, motion 0 to 90 by week 4, no cutting before month 4, return to sport at months 5 to 6.

When to call

• The kneecap slips again, or the knee locks or will not straighten.
• Swelling that increases rather than decreases, or a hot, red knee.
• Giving way with ordinary walking after the first two weeks.

Learn more

OrthoInfo (AAOS), Unstable Kneecap: orthoinfo.aaos.org (opens in a new tab)

My guides to lateral patellar instability, and the quadriceps and IT band stretching printouts.

More for families

OrthoKids · POSNA

POSNA's OrthoKids: illustrated, family-friendly information on this condition.

Open on OrthoKids (opens in a new tab)

Scan for the OrthoKids page

This program is a starting place and a set of suggestions for your physical therapist, not a prescription. Your therapist will adjust it to your child's exam and scans. Stop and call us if the kneecap slips again, if the knee locks, or if swelling increases.