Have you or someone you know suffered from knee instability, sudden knee weakness, knee osteoarthritis, or other common symptoms of knee problems?
Or, have you ever wondered how an ACL tear/ACL injury, PCL tear, or other knee injures end up being so devastating to athletes?
This post will describe the function and anatomy of the knee, how you can strengthen weak knees with some of the best exercises, and reduce knee pain.
These positive lifestyle changes can be used by people of all ages.
Your knee is a highly important and vulnerable complex joint in your body. We use our knees every day, and sometimes put much pressure on the body part(1).
Anatomy of The Knee
Let me explain the anatomy of the knee joint briefly.
Your knee is a hinge joint that is able to bend forward and backward to complete these movements and acts as a shock absorber.
They are made up of many parts including bones, leg muscles, tendons, ligaments, nerves, cartilage, and blood vessels (2).
The bones of the knee include the tibia, fibula, patella (kneecap), and femur(thighbone).
If we do not take special care of them, we run the risk of developing medical conditions such as rheumatoid arthritis, osteoarthritis, swelling, inflammation, and femoral neuropathy.
Taking special care of our knees can prevent these issues and also common symptoms such as tight muscles and muscle soreness.
Before You Start
You would be surprised to find out how common knee injuries are to Americans. Research has found that:
- Nearly 1/3 of Americans suffer from the sensation of chronic pain
- Knee injuries is of the highest potential causes of said chronic pain.
- 15-20% of adult men report knee pain, with even more women suffering from the sensation of pain.
- Most knee injuries are caused by either a heavier weight on the knee joint, or improper technique during activity (3).
As you can see, knee pain is common to many Americans. With proper training and care, you can prevent knee pain, develop strong muscles, and reduce the chance of injury over the long term.
Below, you will find 10 exercises to strengthen knees that will help prevent injuries and sensation of pain in the best way.
Before you employ these exercises, be sure to seek professional medical advice from a physician, personal trainer, or physical therapy program.
Medical clearance is highly advised especially if you are concerned about any underlying cause that may put your knee health at risk.
They can work to assess and test your knee status and provide physical activity guidelines on how to use these exercises safely.
Exercise Program for Weak Knees
When you begin any new exercise program, keep these training guidelines in mind:
- Start slowly: give yourself some time to learn the exercise technique and increase to a heavier weight resistance. Proper technique can provide the ability to perform higher number of exercise repetitions at heavier weight.
- Do not ignore the sensation of acute pain: exercise should not feel painful. We should feel some discomfort when exercising, but you should not feel a sensation of sharp pains. You can feel sharp pain in the kneecap, shinbone, hamstrings, front of the thigh, glutes, and calves. When pain occurs, stop the exercise altogether or find a modification that does not hurt to prevent potential further injury. Seek professional medical advice if the pain persists.
- Do not overdo your workouts: That is how injuries occur. Take time and use the correct form and appropriate number of exercise repetitions and sets. Knee injuries from overuse and heavier weight happen quite often. Muscle soreness and tight muscles that reduce your performance would be signs you are overworking your thigh muscles and other body parts.
- Ask questions: When in doubt, ask an expert. You will be much better off learning how to do an exercise correctly from knee specialists or physical therapists than doing an exercise incorrectly all along on your own. Always seek medical advice when you have any doubt about an knee strengthening exercise (4).
The Best Exercises to Strengthen Your Knees
As described above, your knees are important and complex joints that require careful care and training to stay healthy.
There are many exercises that work your knees and surrounding ligaments, cartilage, and other structures.
For you to achieve the strongest knees possible, it is critical to employ a variety of weight lifting, body weight, cardiovascular, and stretching techniques to keep your knee joint strong all around.
This is not an exhaustive list. Many knee and leg exercises are out there.
These exercises are easy to learn and have an effective way of keeping your knees safe and healthy.
Using these movements will achieve several important concepts: stronger muscles and bones, reduced instability, and more flexible muscles.
Weight lifting and bodyweight exercises will strengthen the muscles surrounding the knee joint.
These exercises also strengthen the bones that make up the leg. Stretching exercises will improve the stability and flexibility of your knees.
When completing these kinds of exercises, your knee can increase its range of motion and help prevent strains and injuries that come from constant use.
Also, cardiorespiratory exercises strengthen your heart and lungs. In effect, your endurance and ability to handle stress will improve.
Let’s begin with some weight lifting examples.
The squat is the epitome of lower body exercises. They’re one of the best exercises for knee pain.
It is an effective way to strengthen your entire lower body including your glutes, hips, quads (the front of your thigh), and hamstrings (the muscle in the back of your thigh).
When it comes to strengthening your knees and completing exercises, safety will always be of the utmost importance.
For you to complete this exercise:
- Starting position: Load weight (barbell/dumbbell/kettlebell) safety onto your shoulder blades or in your hands
- With your chest up and knees shoulder length apart, sit back into your hips and drop your body into a squat position while keeping your lower back neutral and your upper body straight.
- When your knees are parallel to the floor, push through your feet and return to your starting position
- Complete 3-4 sets of 8-12 repetitions to failure for maximum results
Using this exercise over time can help improve your balance and reduce instability.
This knee strengthening exercise has many variations and can be used by any skill level.
Consider these several variations/modifications:
- Body Weight: just you and no equipment
- Back Barbell: setting a barbell with plates securely on your shoulders
- Goblet: holding a dumbbell as if you are holding a heavy goblet
- Kettlebell: holding a kettlebell by your knees by the handle
- With a resistance band
The next exercise that helps strengthen your knees would be the Lunge.
This exercise focuses on forward and backward motion.
It works your abdominal muscles, buttocks, hips, and thighs. This exercise can be completed going forwards or in reverse.
There are many variations/modifications to the lunge as well:
- Forward with your body Weight
- Reverse with your body Weight
- While supporting a barbell on your back
- While holding dumbbells
- To complete this exercise correctly, follow these steps:
- Begin in a standing position with your feet together
- With a straight back and engaged spine, take a large step forward (or backward) with your right leg
- Firmly push off with your right foot and return to your starting position
- Complete 8-12 repetition then switch sides to your left leg; repeat for 3-4 sets
3. Leg Press
The next exercise that helps strengthen your knees would be the Leg Press.
This exercise is much like the squat but changes the position of the weight load.
Therefore, it engages the muscles in a different way. You could either do this exercise with both legs or a single leg.
For you to complete a leg press:
- Seat yourself in a leg press machine with your back flat and tailbone against the back rest and feet flat on the resistance plate
- Adjust the machine so that your knee bend is at a 90-degree angle with your heels
- While engaging your abdominals, push your feet away from you until your knees extend out
- After pausing momentarily, flex your knees back to the starting position in a slow, controlled movement.
- Depending on your weight load, complete 3-4 sets of 4-12 repetitions to failure for maximum results
- Completing this exercise correctly will keep your knees safe and free of injury. Be sure to keep all points of contact flat against the machine. Do not extend or flex your legs too far beyond what feels comfortable.
4. Step Ups
Another quality exercise for stronger knees would include the Step Up. This movement replicates you climbing a stair.
Therefore, we call it a functional exercise. It works the muscles around your knees and hips, strengthening your lower body.
You will need a flat bench for this exercise:
- Starting position: stand with your feet hip-width in front of a flat bench
- Step onto the bench securely with your leading foot and plant it flat onto the bench
- Push off with your other (trailing) foot and lift it until your thigh is parallel to the ground
- At the top of your step, pause momentarily, then transfer your weight to the foot secured on the bench. Step back with the trailing foot that is in mid air
- Step down with your leading foot to the starting position
- Complete 10-12 repetitions then switch sides; complete 3-4 sets
5. Leg Extension and Flexion Exercises
The next two knee strengthening exercises are mirror images of each other.
Both the Leg Extension and Hamstring Curl will strengthen your quadriceps and hamstring muscles, which make up your thigh muscles.
Both of these are normally performed on specific machines. The hamstring curl machine can be either seated or lying down.
To complete these exercises:
- Seat (or lay) your body into the machine. Adjust your position so that you feel comfortable and your legs hit the recommended contact points (most machines will have diagrams to guide you).
- Choose the desired resistance of the machine
- Extend (or flex) at your knee with a smooth motion. Do not hyperextend or flex your knees.
- At the top/bottom of the repetition, pause momentarily, then return to the starting position with a slow, controlled motion
- Depending on the resistance you choose, complete 3-4 sets with 4-12 repetitions to failure for maximum results
More Knee Strengthening Exercises
Believe it or not, I would include walking on this list of knee strengthening exercises.
Walking is usually easier on the knees and is another functional exercise.
Plus, we could all do it! Walking not only strengthens your bones when your feet impact the ground, but it also works your heart and lungs in an effective way.
For maximum results, walk at least 20 minutes at a moderate pace. You can even change the intensity of walks by:
- Wearing a weighted backpack
- Changing the pace of your walk
- Going up and down inclines and declines
We not only want to strengthen our knees, but also we want to reduce the risk factors of injuring them. In order to reduce the risk of knee problems, we can keep our tendons and ligaments loose.
These exercises will reduce stiffness and increase your range of motion.
Gentle stretching loosens the muscles up and increases their flexibility so that we do not strain them.
The 2 best stretches for strengthening your knees would be the Quadriceps and Hamstring Stretch (4).
In order to complete a Quadriceps Stretch:
- Hold onto the back of a chair or chair for balance
- Lift your right foot backwards and bend at your knee
- Bring your foot up to your buttocks and hold it close to your glutes with your hand
- Hold the stretch for at least 30 seconds and repeat with the left leg
- For the hamstring stretch:
- In a sitting position, extend your legs straight out in front of you
- Slide your hands forward towards your feet until you feel a comfortable stretch in the back of your thigh
- Hold the stretch for at least 30 seconds
Swimming and Biking
Lastly, to round out our top 10 exercises to strengthen our knees and reduce knee pain, we will discuss two low-impact cardiorespiratory exercises.
Much like walking, these workouts will be a low impact on your knees and work out your lungs and heart. I am speaking of both swimming and biking.
Both of these exercises are fun and accessible to anyone who would like to pursuit them.
You would need the necessary equipment to get started (ie. a bike and helmet or a swimming pool and swimsuit).
To begin, start with several minutes of low-impact activity and work your way up you can even complete these exercises alone or in a group!
Many gyms and recreation centers offer stationary bike classes and water aerobics. If you are interested, check them out!
Exercises to Avoid for Knee Pain
For some (especially older adults), certain knee exercises would be unsafe and do more harm than good.
If you suffer from chronic knee pain, dislocation, arthritis, neuropathy, osteoarthritis, a history of a motor vehicle accident, or any other knee ailment, you would want to avoid high-impact exercises such as running and jumping.
You would also want to avoid any multiple joint exercises such as leg presses or deadlifts.
When in doubt, consult your physician, physical therapist, or personal trainer for the best medical advice and treatment plan in exercising your knees safely.
Our knees are one of the most important, yet vulnerable body parts in our bodies.
They allow us to stand, sit, walk, jump and do many other actions. In order to have a high quality of life, we must take special care of our knees.
Keeping your knees strong and healthy can reduce the risk factors of developing many mechanical problems such as swelling rheumatoid arthritis, sclerosis, inflammation, femoral neuropathy, and many other ailments.
This can help prevent the use of pain medications, knee braces, and other aids. Certain exercises strengthen the bones and muscles surrounding our knee joints.
The exercises discussed offer a variety of weight lifting, bodyweight, stretching, and cardiorespiratory options.
For optimum results and healthy knees, include a variety of these examples in your exercise program, and have fun!
- “Knee Pain and Problems.” Johns Hopkins Medicine, 2021, www.hopkinsmedicine.org/health/conditions-and-diseases/knee-pain-and-problems.
- Jones, Oliver. “The Knee Joint.” TeachMeAnatomy, 15 Aug. 2020, teachmeanatomy.info/lower-limb/joints/knee-joint/.
- “Knee Pain Statistics and Causes.” Class Rehabiliation, Inc, 2021, https://www.classicrehabilitation.com/blog/knee-pain-statistics-and-causes/
- ‘Knee Exercises.” Ortho Info, February 2009, https://orthoinfo.aaos.org/en/staying-healthy/knee-exercises/
- “Exercise Database & Library.” Featured Exercises from ACE, www.acefitness.org/education-and-resources/lifestyle/exercise-library/.