Inside Knee Pain: What Is It and How To Fix It

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With so many places to feel pain in the body, inside knee pain is one of the most common places for you to hurt. The lower body is a complicated structure of muscles, ligaments, tendons, nerves, and more, all intertwined either directly or indirectly.

As you may guess, if one piece of this elaborate puzzle doesn’t fit, the whole picture is incomplete, resulting in pain at a specific point in our body — in this case, the inside of our knee.

To make matters more confusing, the knee is a complex joint, and can be affected by the joints above and below it — the hip and the ankle.

Luckily, there can be straight-forward answers for seemingly tough questions. Let’s take a look at types of pain, study the knee, and talk about how to eliminate the pain for good!

Insidious vs. Event Pain

Insidious pain refers to pain that shows up randomly — you can’t quite put your finger on why things are hurting, but something is definitely wrong. 

Event pain is when the pain comes on due to something specific — maybe you were getting up from the couch or playing an intense game of football, and you twisted your knee, heard a pop or had someone fall on you — there was a specific event when the pain came on.

The reason that it’s important to know if the pain came on randomly or with a specific event is that we can often rule out things like ligament and meniscus damage in the knee when there is no specific injury that occurred.

The good news is, whether insidious or not, you can often fix the problem with conservative treatment, usually in the form of exercises that include strengthening, mobility, and stability work.

But first, let’s check out the knee’s anatomy, so that we can pinpoint where the issue actually is, and guide our treatment accordingly. 

Anatomy 101

The knee is a bi-condylar synovial joint, which means that it mainly bends and straightens (flexion and extension), with a small degree of rotation. 

Moving past its capabilities can cause irritation/injury of different structures surrounding the knee — which there a lot of, so let’s take a crash course on the ones specific to inside knee pain.

Ligaments

Ligaments attach bone to bone. 

The ligament by the inside of the knee is the medial collateral ligament (MCL).

The MCL begins from the inside of the thigh-bone (femur) and attaches to the inside of your shinbone (tibia). About halfway down the MCL, it attaches to the medial meniscus (more on that guy later). 

It works to protect the knee by resisting valgus forces, which is when your knee caves inwards due to forces on the outside of the knee. 

It also protects the knee from lateral rotation, which is where your tibia twists outwards. 

Muscles

The main muscles affecting the inside of the knee are:

The hamstring: this is the big muscle at the back of your thigh. It works to bend your knee and extend your hips. It has three parts to it, all beginning at the ischial tuberosity:

1. the biceps femoris — attaches to the fibula (outside knee)
2. the semimembranosus — attaches to your tibia (inside knee) 
3. the semitendinosus — pretty much goes hand-in-hand with the semimembranosus

The hamstring has an important function in acting as an antagonist muscle to the quadriceps, which means that it stops your leg from over-extending during running or walking. 

The quadriceps: these are the front-thigh muscles, AKA the ones most often skipped in the gym. 

As the name implies, the quads are made up of 4 muscles, all acting to extend (straighten) the knee. Additionally, the rectus femoris flexes the hip.

All the quad muscles come together at the knee to attach to the kneecap (AKA patella) via the quadriceps tendon, which then attaches to the tibia via the patellar tendon. Here’s a closer look:

1. the rectus femoris — begins at the ilium (part of the hip bone), above your hip joint
2. the vastus lateralis — begins at the outside of the femur at the hip joint 
3. the vastus medialis — the “teardrop” muscle at the inner thigh, attaches from the inner femur near the hip
4. the vastus intermedius — it basically runs underneath the rectus femoris, but only begins below the hip joint

These muscles have an important role when it comes to stabilizing the knee, and work hard during things such as jumping, getting up from a chair, running, and climbing stairs.

The calf muscles: when we think of our calves, we often think of the visible gastrocnemius, but forget about the hidden soleus. These two muscles propel us forward through our feet, acting as powerful plantarflexors. 

1. The gastrocnemius is the two-headed muscle that we can see when we look at our calves. It attaches to the heel from the achilles tendon and runs up past the knee, attaching to both the inside and outside parts of our femur. Because of it attaching past the knee, the gastrocnemius helps with knee flexion. 
2. The soleus, also called the “workhorse” muscle, attaches from the achilles tendon, but only runs up to about the top 3rd of the tibia and fibula — therefore, it doesn’t act on the knee.

The last muscle I want to talk about is an important one, and yet it doesn’t attach anywhere near the knee. 

So why does this muscle matter?

Great question. The answer is because this muscle, the gluteus medius, is heavily involved in stabilizing the knee. 

Decreased stability = risk of pain. 

It mainly acts to abduct your leg and sits on the outside of your hip, spanning from your ilium to your femur. 

8/10 people that I see in the clinic with knee pain have a weak gluteus medius — and while that doesn’t automatically make it the main problem, it has a heavy influence on the matter.

Tendons

Tendons attach muscles to bones, which is how they differ from ligaments. 

Tendons can become irritated separately from the muscles even though they are directly connected, and it’s important to understand that they have a separate function and therefore may have separate treatment options (we’ll cover that soon). 

Bursas/Plica

Bursas are small fluid-filled sacs that sit between some bones and tendons to reduce friction.

Plica are small folds in the joint lining, with the medial plica covering your inside knee.

Meniscus

Finally, the last part of this anatomy lesson.

The menisci are 2 crescent-shaped pieces of cartilage that sit on top of the tibia, both laterally and medially, creating the lateral and medial menisci. 

The medial meniscus is the one we’re most concerned about. It acts as a shock absorber for the knee, and can be irritated/injured especially with sudden twists in your knee.

Symptoms

Let’s take a quick look at some of the symptoms that you may be experiencing.

The first one, obviously, is inside knee pain. It can present as a dull ache or a sharp pain, and can be constant or only with activity. 

The second symptom is your knee giving out/laxity, which means that you feel like your knee will collapse underneath you randomly, and seems to have more movement in it than it should. This symptom often points to a ligament injury. 

Third is clicking/cracking in the knee. Now, this isn’t always something to worry about unless it’s accompanied by pain. It may indicate cartilage damage, joint degeneration, or some tight tendons.

The fourth symptom is locking. If your knee locks, it’s often because something is getting stuck in the joint — often indicating a meniscus injury or torn cartilage. 

Finally, there is tenderness to the touch/swelling. Swelling can indicate several different things, including joint irritation or some sort of injury to a ligament/tendon. Tenderness to the touch often indicates the same thing, or bursitis. 

Causes

With so much going on in the knee, you’re right to think that there are many potential causes for inside knee pain. Luckily, there are a handful that are the most common culprits. Let’s check them out.

MCL Injury

This is a likely one if you had something hit you from the outside of your knee, causing your knee to bend inwards. It can also happen when changing directions quickly or twisting hard. This can cause tearing of the ligament, and is often accompanied by swelling, a popping sound at time of injury, pain to the touch, and unstable walking. 

Medial Meniscus Injury

Like an MCL injury, you can injure your medial meniscus if you twist your knee too hard or have a strong impact on it. There are different grades of injury, and may present with swelling, locking/giving out of the knee, tenderness when pushing at the inside of your knee, and stiffness/pain when bending/twisting your knee.

Arthritis/Degeneration

This is one that usually hits you when you’re over 60, but may affect you before that. Osteorathritis causes degeneration in your knee cartilage, allowing your femur and tibia to rub together. As you may imagine, that can be very irritating!

Pain often comes on when you put pressure on your knee, like with walking and climbing stairs.

Tendinopathy/Strains

Physical activity or repetitive use can cause a strain/irritation in a muscle or tendon — you can think of this as pulling too hard on a rubber band, leaving it over-stretched. This can cause inflammation and pain in the muscle/tendon, especially with heavier activity. Sometimes, light activity actually makes this feel better. 

Muscle Weakness

Muscle weakness is a common cause for inside knee pain. As I mentioned before, the gluteus medius is often underdeveloped and therefore not able to provide enough stability for the knee. There can also be weakness in the quads, hamstrings, or calves, causing decreased function in the knee joint. 

Bursitis/plica irritation

Bursitis usually happens with repetitive knee movements or with a direct blow to the inside of your knee, where your pes anserine bursa is located. This causes the bursa to become inflamed and irritated. Your medial plica can be affected the same way, where overuse may cause thickening of the plica and result in it getting stuck between your femur and tibia.

How To Fix Inside Knee Pain

There are 3 components we want to make sure we include in our rehab program: strength, stability, and mobility.

Hitting the pain from a couple of different angles often works great, as we can focus on a couple potential problems with only a few exercises.

IMPORTANT: we don’t want to aggravate the knee more with these exercises. Begin with a comfortable range of motion, and find the amount of reps and sets that is tolerable. A good “pain level” to stay below is 3-4/10. 

Using heat, ice, and braces to help calm the pain down can also be helpful, but one of the key points is to limit irritating movements — you don’t have to completely stop moving, just respect the movements that cause you pain until you’re able to tolerate them better.

That being said, let’s dive in.

Strengthening Exercises

Exercise 1: VMO Leg Extension

Sit down in a chair, grab a deflated soccer ball or fold a pillow in half — anything squishy — and place it between your knees, squeezing them together. Now, slowly straighten your legs with your feet pointed straight, not rotating inwards or outwards. Hold for a second at the top, then slowly bend your knees again.

Repeat 8-12 times for 2-3 sets.

Exercise 2: Eccentric Step Down

Start by standing with one foot on a low surface, such as a step (increase the height of the object you’re standing on as you get stronger). Keep your belt-line level with the ground, and slowly bend your hips and knee as your squat down towards the ground with one foot in the air. Keep your bending knee lined up with the centre of your planted foot.

Lower for 3-4 seconds before touching the ground, 5-10 times for 2 sets. 

Mobility Exercises

Exercise 1: Active Hamstring Stretch

Lying on your back, grab behind one of your thighs with both hands, bringing your leg closer to your chest. Bend your ankle upwards, and slowly extend your knee until you feel a stretch in the back of your leg. Hold for 2 seconds, slowly bend your knee back down, and repeat.

8-12 reps for 2 sets.

Exercise 2: Loaded Calf Stretch

This is essentially a calf raise on a step, but hold the stretch at the bottom for 5 seconds, do the calf raise, then slowly lower into another stretched hold for 5 seconds.

Repeat 8-10 times for 2 sets. 

Enjoy the burn.

If you want another underrated mobility method to decrease knee pain, check out our article on improving squatting mobility to help reduce pain and bulletproof your knees.  

Stability Exercises

Exercise 1: Single Leg Balance

Exactly what the name implies. Stand on one leg, and look straight in front of you. The goal is to stay upright for 60 seconds without holding onto anything. If you need, begin by holding on to something stable, and slowly decrease your hold on it over time. To make it harder, stand on a pillow.

2 sets, up to 60 seconds each. 

Exercise 2: Monster Walk

You’ll need an exercise band for this. Loop it around either your ankles or above your knees, get into a partial-squat position, spread your legs apart, and take small steps out to the side, keeping your belt-line level with the ground. 

10 steps each direction for 2 sets.

Some Notes

Remember, start with a level that you are comfortable with. It’s always best to slowly progress, rather than start too intense and have to back off. There is wisdom in starting slow!

Once things feel stronger, try this bodyweight hamstring workout to help build even more strength from home, or this calisthenics leg workout to build muscle and further reduce the risk of injury.

Recap

Let’s go over what we learned today:

1. Inside knee pain may come from many different things, but can often be improved with exercises
2. If the pain came on randomly, it’s often due to muscle weakness, arthritis, tendinopathy, or bursitis
3. If the pain came on with an event, it’s often due to muscle strains or meniscus and ligament injuries
4. Using ice/heat/braces may help decrease the pain, and it’s important to respect movements that aggravate the knee until tolerance is built back up

Strength takes time to build, so stay patient and keep at it! Find your baseline of how much work you can do before your knee starts bugging you, and slowly build up from there. 

Then, you’re well on your way to making your inner knee pain non-existent!