Your knee is the largest joint in your body and is very vulnerable to injuries. As a result, the structures that support the joint — the muscles, ligaments and tendons — can become weak and loose, making your knee unstable. Sports injuries or accidents aren’t the only causes of knee instability 1. Lack of exercise and some health conditions such as arthritis can also be contributing factors. Strengthening exercises build muscle that supports the knees and strengthens the ligaments and tendons to increase stability.
These isometric exercises allow you to strengthen the quadriceps muscle at the front of the thigh without placing weight on your knee or requiring too much movement of the joint. Begin by sitting down with the leg of your affected knee outstretched in front of you. Keep your other leg bent. Slowly contract your quadriceps muscle as much as you can. The exercise will pull your kneecap upward. Hold for 5 to 10 seconds, then relax. Repeat 8 to 12 times, then switch legs. If you find it more comfortable, you can place a rolled towel under your knee.
- These isometric exercises allow you to strengthen the quadriceps muscle at the front of the thigh without placing weight on your knee or requiring too much movement of the joint.
Stretching Exercises for ACL Injuries
The squat is a common knee rehabilitation exercise — and it’s also versatile. For instance, you can do it against a wall or without support, or you can do it with one or both legs on the ground. If you’re just starting to strengthen your knee, try the wall squat. Stand up and lean back against a wall with your feet about two feet away from the wall. Slowly lower yourself into a squat. Don’t let your knees bend beyond 90 degrees or protrude over your toes. Hold for 5 to 10 seconds.
- The squat is a common knee rehabilitation exercise — and it’s also versatile.
- For instance, you can do it against a wall or without support, or you can do it with one or both legs on the ground.
Prone Hamstring Curls
You can perform hamstring curls standing, but you might find them easier to do while lying on your abdomen. Fold your arms and rest your head on them. Begin with both legs outstretched. Slowly curl your right leg toward your buttocks until your knee reaches about 90 degrees — no further. Hold the contraction for three to five seconds, then lower your leg. Repeat 8 to 12 times, then switch legs.
- You can perform hamstring curls standing, but you might find them easier to do while lying on your abdomen.
- Hold the contraction for three to five seconds, then lower your leg.
Exercises for the Sagittal Plane
Always warm up before performing strengthening exercises for your knee. For instance, walk or bicycle at a leisurely pace for 5 to 10 minutes. Perform each exercise in a slow, controlled motion. Stop if you experience sharp, stabbing pain during any of the exercises. Do a few gentle stretches after your strengthening routine to relax the muscles and reduce soreness and your risk of further injury.
- Always warm up before performing strengthening exercises for your knee.
Stretching Exercises for ACL Injuries
Exercises for the Sagittal Plane
Therapist's Exercises for Knock Knee
How to Strengthen the Patella Tendon
Knee Injuries & Sprinting
Seated Calf Stretches
Tensor Fasciae Latae Muscle Stretches
The Best Exercises to Lose Weight in Your Hips
How To Stretch the Gastrocnemius & Soleus Muscles
Muscles Used in Hip Extension
- American Academy of Orthopaedic Surgeons: Common Knee Injuries
- Lespasio MJ, Piuzzi NS, Husni ME, Muschler GF, Guarino A, Mont MA. Knee Osteoarthritis: A Primer. Perm J. 2017;21:16-183. doi:10.7812/TPP/16-183
- Kiapour AM, Murray MM. Basic science of anterior cruciate ligament injury and repair. Bone Joint Res. 2014;3(2):20-31. doi:10.1302/2046-3758.32.2000241
- Doral MN, Bilge O, Huri G, Turhan E, Verdonk R. Modern treatment of meniscal tears. EFORT Open Rev. 2018;3(5):260-268. doi:10.1302/2058-5241.3.170067
- Reinking MF. CURRENT CONCEPTS IN THE TREATMENT OF PATELLAR TENDINOPATHY. Int J Sports Phys Ther. 2016;11(6):854-866.
- Petersen W, Rembitzki I, Liebau C. Patellofemoral pain in athletes. Open Access J Sports Med. 2017;8:143-154. doi:10.2147/OAJSM.S133406
- Frush TJ, Noyes FR. Baker's Cyst: Diagnostic and Surgical Considerations. Sports Health. 2015;7(4):359-65. doi:10.1177/1941738113520130
- Huang YC, Yeh WL. Endoscopic treatment of prepatellar bursitis. Int Orthop. 2011;35(3):355-8. doi:10.1007/s00264-010-1033-5
- Beals C, Flanigan D. A Review of Treatments for Iliotibial Band Syndrome in the Athletic Population. J Sports Med (Hindawi Publ Corp). 2013;2013:367169. doi:10.1155/2013/367169
- Tsai CH, Hsu CJ, Hung CH, Hsu HC. Primary traumatic patellar dislocation. J Orthop Surg Res. 2012;7:21. doi:10.1186/1749-799X-7-21
- Ragab G, Elshahaly M, Bardin T. Gout: An old disease in new perspective - A review. J Adv Res. 2017;8(5):495-511. doi:10.1016/j.jare.2017.04.008
- Lee PYF, Nixion A, Chandratreya A, Murray JM. Synovial Plica Syndrome of the Knee: A Commonly Overlooked Cause of Anterior Knee Pain. Surg J (N Y). 2017;3(1):e9-e16. doi:10.1055/s-0037-1598047
- Vaishya R, Azizi AT, Agarwal AK, Vijay V. Apophysitis of the Tibial Tuberosity (Osgood-Schlatter Disease): A Review. Cureus. 2016;8(9):e780. doi:10.7759/cureus.780
- Zanon G, Di vico G, Marullo M. Osteochondritis dissecans of the knee. Joints. 2014;2(1):29-36.
- Hindle P, Davidson E, Biant LC. Septic arthritis of the knee: the use and effect of antibiotics prior to diagnostic aspiration. Ann R Coll Surg Engl. 2012;94(5):351-5. doi:10.1308/003588412X13171221591015
- Gwinner C, Märdian S, Schwabe P, Schaser KD, Krapohl BD, Jung TM. Current concepts review: Fractures of the patella. GMS Interdiscip Plast Reconstr Surg DGPW. 2016;5:Doc01. doi:10.3205/iprs000080
- Voskuil R, Evenski AJ, Montgomery C, Emory CL. Malignant Bone Tumors of the Knee: How to Identify and Treat. J Knee Surg. 2019;32(4):305-314. doi:10.1055/s-0038-1675828
- Gupte C, St mart JP. The acute swollen knee: diagnosis and management. J R Soc Med. 2013;106(7):259-68. doi:10.1177/0141076813482831
- American Academy of Orthopedic Surgeons. Unstable Kneecap.
- Bhatia D, Bejarano T, Novo M. Current interventions in the management of knee osteoarthritis. Journal of Pharmacy & Bioallied Sciences 2013 Jan-Mar;5(1):30-38. doi:%2010.4103/0975-7406.106561
- Bronstein RD, Schaffer JC. Physical Examination of the Knee: Meniscus, Cartilage, and Patellofemoral Conditions. J Am Acad Orthop Surg. 2017 May;25(5):365-374.
- Browne K, Kurtz CA. How to perform a comprehensive examination of the knee. JAAPA. 2009 Jun;22(6):20-25.
- Hergenroeder AC, Harvey BS. (2017). Osteochondritis dissecans (OCD): Clinical manifestations and diagnosis. Bachur RG, ed. UpToDate. Waltham, MA: UpToDate Inc.
Kay Uzoma has been writing professionally since 1999. Her work has appeared in "Reader’s Digest," "Balance," pharmaceutical and natural health newsletters and on websites such as QualityHealth.com. She is a former editor for a national Canadian magazine and holds a Bachelor of Arts in political science from York University.