How to Decrease Knee Instability

Imagine you’re at home, watching your grandchildren play in the backyard. Since you are active and love interacting with them, you reach down, pick up one of your grandkids, and start to lift them into their air as they squeal with laughter. That sound, the joy you feel, you’re just beaming, and your heart is full of love.

Until, you hear that pop, or feel that sudden buckle in your knee. Suddenly, your heart drops. You feel like you’re going to fall and now you’re going to drop your grandchild in the process.

Whether you’ve had this exact experience or just experience that knee buckling sensation, you know the fear created by knee instability. That feeling of not knowing if you’re going to have the strength and stability to keep yourself from ending up on the floor, and it’s terrible!

Feeling “weak at the knees” may seem cute if you’re a teenager in love, but it creates a whole different set of butterflies if you’re an older adult wanting to avoid an injury.

This article will address possible causes of knee instability and what can be done to help prevent/decrease knee instability from causing falls, injury, and pain.

Anatomy of the Knee

The knee is a hinge joint, which means that it only allows for movement in two directions- flexion (bending the knee) or extension (straightening the knee).

What keeps the knee stable is the configuration of the bones, along with the connective tissue surrounding the bones (ligaments and menisci), and the muscles surrounding the knee joint as well.

Before explaining the components that make up this joint, it’s helpful to understand the directional terms often used in medicine to describe locations of bony prominences, ligaments, and muscles.

These directions are based on the position the bone/joint/ligament/muscle is in if you were looking at someone standing in front of you with their arms down by their sides and palms facing forwards.

• Anterior: Front surface
• Posterior: Back surface
• Medial: Side closer to midline
• Lateral: Side further from midline
• Proximal: Close to attachment point
• Distal: Further from attachment point

The Bone of the Knee Joint

• Femur– The femur is the long bone in the thigh. It has two round surfaces, called condyles, on the distal end that sit in grooves located on the tibia
• Tibia– The tibia is the bone that makes up the majority of your shin. It has grooves on the proximal surface of the bone, also called condyles, that the menisci (collagen tissue) sit in to provide shock absorption between the femur and the tibia

The connective tissues that support the knee joint:

• Anterior Cruciate Ligament (ACL)– Attaches from the anterior surface of the tibia to the posterior surface of the femur, prevents the knee from sliding too far forward
• Posterior Cruciate Ligament (PCL)– Attaches from the posterior surface of the tibia to the posterior surface of the femur, prevents the knee from sliding too far backward
• Medial Collateral Ligament (MCL)– Attaches from the medial surface of the tibia to the medial surface of the femur, prevents the knee from sliding too far inwards
• Lateral Collateral Ligament (LCL)– Attaches from the lateral surface of the tibia to the lateral surface of the femur, prevents the knee from sliding too far outwards
• Medial Meniscus– C-shaped band of collagen that sits on the medial condyle of the tibia, while provides shock absorption and stability to the knee
• Lateral Meniscus– O-shaped band of collagen that sits on the lateral condyle of the tibia, while provides shock absorption and stability to the knee

The Muscles that Support the Knee Joint:

• Quadriceps– four muscles (names listed below) located on the anterior surface of the femur that are responsible for knee extension (straightening), and also help control knee flexion (bending)
  • Rectus femoris
  • Vastus medialis
  • Vastus lateralis
  • Vastus intermedius

• Hamstrings– three muscles (names listed below)located on the posterior surface of the femur that are responsible for knee flexion (bending), and also help control knee extension (straightening)
  • Biceps femoris
  • Semimembranosus
  • Semitendinosus

Why Do Older Adults Experience Knee Instability?

Knee instability can be caused by a variety of factors. Generally speaking, it is likely due to either injury to a ligament or weakness of the muscles surrounding the knee.¹

Studies have also found that those who have osteoarthritis (OA) in the knee can experience knee buckling. Even though OA is a degeneration of the smooth surface of the bone, the muscles that support the joint help maintain the joint space. That space is crucial for proper blood flow and lessening pain.

Therefore, not having adequate strength in those muscles may lead to increased pain, or contribute to balance issues which can cause feelings of instability or knee buckling.¹

How Do You Know What’s Causing Your Knee Instability?

An injury to a ligament usually is caused by force that causes the knee to twist or buckle in an uncomfortable way.

Oftentimes, the foot is planted and the knee takes on all of the force in the twist, which causes the ligament to be overstretched/torn.

Let’s say you’re right handed and you’re playing Pickleball. Your opponent just hit a ball to your left side that’s a little out of reach, and you make a sudden cut to the left. You may hear a pop or just feel sudden instability in your knee. In this case, it is possible that you injured a ligament.

Ligamentous injuries commonly occur in sports. However, they may also occur doing more every day activities like twisting your leg to get out of a car or booth at a restaurant, changing directions quickly to avoid stepping on something, landing from a fall on a bent knee, or your dog unexpectedly running into the side of your knee.

Usually injuries to the ligaments result in pain, swelling, and/or feelings of instability in the knee.²

A physical therapist can perform tests to help identify laxity in each of the ligaments. However, X-rays may be needed to rule out any additional injury, such as fracture, so it’s important to see your healthcare provider if you experience an injury like this.²

If you have not experienced a traumatic injury to the knee, it’s possible that strength deficits are causing your knee instability.

Is Surgery Required for a Ligament Tear?

The short answer: it depends.

Typically, complete tears won’t heal on their own, and surgery may be required in order to restore the stability in the joint.

However, smaller tears can respond well to physical therapy and strengthening, which will help restore stability and decrease pain within the joint.³

6 Exercises to Decrease Knee Instability

Click Here for a video of Dr. Katie performing all of the following exercises.

1. Squats

Squats are a great way to increase the strength in the quadriceps and gluteus muscles. I personally love doing this with a physioball against a wall, but if you don’t have one of those handy, you can place a chair behind you to help with your form.

Using a Physioball:

1. Stand in front of a wall with a physioball between your mid-back and the wall.
2. Place your feet shoulder-width apart, with toes slightly turned out.
3. Imagine you’re trying to wrap your low back and bum around the ball as you bend your knees (no lower than 90 degrees).
4. Straighten your knees to stand.
5. Repeat steps 3-4 10x.
6. Rest for 1-3 minutes.
7. Repeat for a total of 3 sets.

Without a Physioball:

1. Stand with your back to a stable chair.
2. Place your feet shoulder-width apart, with toes slightly turned out.
3. Imagine you’re going to sit in that chair as you bend your knees (no lower than 90 degrees).
4. Straighten your knees to stand.
5. Repeat steps 3-4 10x.
6. Rest for 1-3 minutes.
7. Repeat for a total of 3 sets.

2. Hamstring curls with physioball

This is my favorite hamstring exercise! If you don’t have a physioball, you can do standing hamstring curls, but they aren’t quite as effective.

With a Physioball:

1. Lie down on your back on a mat with legs straight, and a physioball under your heels.
2. Lift your hips off of the mat.
3. Dig your heels into the physioball as your bend your knees, bringing the physioball towards your bottom.
4. Straighten your legs, rolling the ball away from you.
5. Repeat steps 3-4 8x.
6. Lower your hips and rest for 1-3 minutes.
7. Repeat for a total of 3 sets.

Without a Physioball (if you have an ankle weight, you can use it with these curls):

1. Stand with your hands on a countertop/stable surface, with feet hip-distance apart.
2. Without allowing your left hip to drop, lift your right foot off the floor as you bend your knee.
3. Your knees don’t have to be touching, but you want them to be level (only the lower leg is moving).
4. Straighten your right leg, without letting the right foot rest on the floor.
5. Complete 15 curls on right side, then repeat steps 2-4 on left side.
6. Complete 3 sets total.

3. Sidelying hip abduction

Strengthening the hip muscles is essential for knee stability as well. If the hips aren’t strong, the knee has to take on more of the load than it is intended to.

1. Lay on your left side.
2. Bend your bottom knee.
3. Keep your top leg straight.
4. Lift your top leg about 6 inches off of the floor/mat/bed (focus on lifting from your glutes. You should feel your glutes working! This movement is not very big).
5. Lower your leg to starting position.
6. Repeat 10x.
7. Rest for 30 seconds.
8. Perform 3 sets.
9. Repeat on other side.

4. Deadlifts

Once again, focusing on working the back of the legs and the glutes to help balance the muscles surrounding the knee joint. The deadlift is a very functional movement- think picking a laundry basket off the floor.

For this reason, it’s important to work up to deadlifting with some weight as we need to be able to do this in daily life. You can use a kettlebell or dumbbell, or your detergent or laundry basket. Starting with no weight to get form and build your strength up is advised!

1. Stand with your feet hip-width apart. (If you’re using a kettlebell, stand with one foot on each side of the weight)
2. Bend your knees slightly.
3. Keeping a flat back, hinge forward at the hip as you reach towards the floor to grab your weight (if using weight).
4. Keeping a flat back will require your abdominals to turn on to support your back.
5. Maintaining your flat back with the help of your abs, use your hamstrings and glutes to bring you back up to standing.
6. Repeat 8x.
7. Rest for 1-3 minutes.
8. Complete 3 sets total.

5. Lunges

Many people avoid lunges because they report knee pain. However, many people aren’t instructed on how to lunge properly. Lunges are a great exercise (when done correctly) to strengthen the front and back of the legs.

1. Stand with a countertop/stable surface on your right side.
2. Place your right hand on the countertop/stable surface for stability.
3. Take a step back with your left leg (don’t step straight back, step back and to the left- this will help create more stability).
4. Bend both knees as you lower straight down (think about lowering 6 inches, not all the way to the floor).
5. Straighten both knees to stand.
6. Repeat 10x.
7. Repeat steps 1-5 with right leg.
8. Complete 3 sets total.

6. Heel Raises

Most people use heel raises to strengthen the muscles of the calf. While this will help strengthen those muscles as well, these heel raises are going to focus on strengthening the glutes. Once again, this will help with proper muscle balance to prevent the knee from taking on excessive load/strain.

1. Stand facing a countertop/stable surface with feet hip-width apart.
2. Lift your heels and swing them in towards each other so heels are touching and toes are slightly turned out (if your heels can’t come together, you can place a pillow or towel roll between your heels and squeeze the pillow/towel roll)
3. Squeeze your heels together as you raise them off the floor.
4. Your weight should be on the ball of the foot, with a focus on feeling the weight in the ball of the first and second toe (you don’t want to have most of your weight on your pinkie toe).
5. Lower your heels to the ground.
6. Repeat steps 3-5 10x.
7. Rest for 1-3 minutes.
8. Complete 3 sets total.

Have the Strength to Live Life to the Fullest!

Sources:

1. https://www.webmd.com/healthy-aging/news/20160211/weakened-knees-a-big-cause-of-falls-for-older-people-study
2. https://canberraorthopaedic.com.au/orthopaedics-act-conditions-treated/knee-conditions-and-procedures,ligament-injuries/ligament-injury-causes-symptoms-treatment/
3. https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/knee-ligament-repair
4. All photos created on Canva.com