Most common causes of knee pains

Most common causes of knee pains

Knee pain is one of the most common sources of pain and it can affect us at any age.

I’m sure you know someone, or perhaps you are suffering from knee pain yourself, and would like to learn how to get rid of knee pain.

The purpose of this article is not to help self-diagnose knee pain, since there are many causes and varieties of knee pain (which we will briefly cover). Even if you currently do not have knee pain, we believe functional training will help improve the function of the knee and prevent some of the common instances of knee pain.

Thus, this article will cover the most common types of knee pain, and how you can consider functional training as a form of prehab to bulletproof your knees.

If you are currently suffering from knee pain, we recommend you to have your knee assessed by a physiotherapist or medical specialist first.

Let’s first take a look at the knee joint itself:

As you can see from the knee illustration, the knee joint comprises several structures that are attached to it. You have:

  • Muscles – which connect to bones via tendons to generate movement
  •  Tendons – which attach muscles to bone, providing movement and function as shock absorbers,
  • Ligaments – which attach bone to bone to form joints and provide stability to the joint
  • Cartilage – which coats areas of bone that contact with each other to allow for smooth movement and also function as joint shock absorbers.

Together, these structures work together as a team to allow us to walk, run and jump efficiently.

However, sometimes this efficiency can be compromised, either due to an accident or from imbalances between different team members.

Here are some of the most common causes and types of knee pain we often see at Retrofit:

Most common causes and types of knee pain

1. Sudden stopping/ change of direction – ligament injuries, e.g. ACL

Changing directions or decelerating suddenly is a common source of knee injuries, especially in sports such as soccer. Out of the 4 ligaments connecting our thigh bone (femur) to our shin bone (tibia), the Anterior Cruciate Ligament (ACL) is the most commonly injured when it comes to sharp change of directions.

2. Trauma by external forces – bone fractures, dislocations

Suddenly external forces caused by falls or accidents can cause bone fractures and dislocations. Knee joint dislocations occur when the thigh bone and shin bone become misaligned. Kneecap, or patella dislocation, refers to the misalignment of the patella on the groove of the femur, aka the trochlear groove.

3. Overuse injuries – tendinitis

When running, our knee joints are loaded with 3-4 times our body weight with each step. With jumping, that loading can go up to 9 times our body weight! While our muscles and tendons are in charge of absorbing that impact, they require nutrients and time to recover and adapt to the load.

Picking up an intensive new sport, a lack of progressive increases in running distance or not allowing your body to rest can result in overuse injuries. When tendons are not given enough time to recover and adapt to loads, they can get inflamed and cause knee pain.

4. Wear and tear – Osteoarthritis, meniscus injuries

As mentioned earlier, our muscles and tendons are the main shock absorbers in our body. If they lack the strength and endurance to absorb load properly, the remaining load will go to the joint itself. This will eventually wear out the cartilage between bones, causing osteoarthritis. For those involved in sports, this process can occur at a much quicker rate and result in knee pain at a younger age.

The meniscus, a thick cartilage that lies between our thigh bone and shin bone, can become worn out gradually or as a result of a sudden twisting of the knee.

As the cartilage gets worn down, bones will start to grind against each other during movement and cause knee pain.

Understanding the muscles that act on the knee

Now that you know the common ways in which knee pain can occur, it’s time we look at how we can improve our knee health.

Let’s start by exploring which key muscles act on the knee directly and indirectly and how training them correctly can improve knee health.

The quadriceps are a group of four muscles that are located on the front of the thigh. Their role is to straighten the knee, which makes them one of the main muscle groups needed to walk, run, climb stairs, jump and pretty much perform any sport.

Another benefit of having strong quads will help keep the knee stable when running, jumping, and climbing stairs.

These four muscles attach to the kneecap(patella) at different angles and help guide the kneecap during motion. Insufficient strength or an imbalance in each of these four quadriceps muscles can lead to the maltracking of the kneecap. During maltracking of the kneecap, it will begin to grind on the sides of your thigh bone, causing inflammation and knee pain. If left unaddressed, this can result in permanent cartilage damage and osteoarthritis.

Another activity where strong quadriceps are needed to prevent knee pain is going downhill or climbing down stairs. During each step, the quadriceps in each have to be able to sustain our entire body weight when bending the knee under control. A lack of strength during this movement will result in the load going to the joint itself, which can become a source of pain.

Here’s an exercise from our exercise specialist that will strengthen the quadriceps when going downstairs:

Single leg step down

1) Stand on top of a step and use a wall beside you for support.

2) Point one leg about 45deg forwards and hold it there. This leg will act as a counter-balance.

3) Bend your hips and your back knee slightly, keeping your weight on your back leg.

4) Imagine you are trying to sit down on an invisible chair beneath you and continue to bend your hips and back knee. You should feel the quadriceps of your back leg working hard to control the weight.
(Ensure that both the knee and foot of your back leg are pointed forwards as you lower yourself to maintain proper joint alignment)

5) Lower until the heel of the front foot lightly taps the floor. Push down through your back foot to extend back to the starting position.

Hamstrings - Key in sprinting and shock absorber when jumping

Our hamstrings consist of three muscles located on the back of our thigh bone. They cross our hip and knee joints and are responsible for bending our knees and pulling them behind our body when walking and running.

The hamstrings are usually under trained as compared to other muscle groups, such as the quadriceps and glutes. This creates a functional strength imbalance between the two main muscle groups that act directly on the knee: the quadriceps and hamstrings.

As a result, hamstring injuries are extremely common in sports.

A systematic review of 26 studies involving hamstring injuries in sports found that the most common hamstring injury occurs in sprinting in late swing phase – when the leg is at its maximum swing in front of the body.

Therefore, improving hamstring flexibility and eccentric strength (the muscles’ ability to lengthen under control) can prevent hamstring injuries and improve sprinting performance.

Strong hamstring control can also reduce the risk of ACL injuries by preventing excessive forward movement of the shin bone during movement which is the main mechanism of injury to the ACL.

Here’s an exercise that will strengthen the hamstrings’ in walking/ running:

Lying hip extension
with resistance band/ cable machine

1) Lie on your back with a cable/ resistance band attached to one ankle and anchored around waist-height behind you.

2) Keep your leg straight as you raise it with control, resisting the external tension of the cable/ band.

3) Stop when you can feel the maximum stretch in the hamstrings, and then drive your heel back down to the starting position.

4) Repeat for 3 sets of 8-10 repetitions per side

Video: Supine Hip Extension w/ Band ( – YouTube

Gluteus maximus - Generating power
when running, jumping, climbing stairs

The gluteus maximus is the biggest of three muscles in the bum that we casually refer to as ‘glutes’. The gluteus maximus’ main function is to drive the leg behind the hip, and works with the quadriceps as a prime mover in running, jumping, or climbing stairs.

Due to this synergistic relationship, a lack of gluteus maximus strength can cause the quadriceps to overwork, resulting in pain around the knee joint.

Apart from generating power, the gluteus maximus also plays an important role in absorbing impact when landing from a jump.

Here’s an exercise that will strengthen the gluteus maximus for climbing stairs/ running:

The Step-up

1) Place on foot on an elevated step/ box in front of you.

2) Lean your body forwards until you feel the weight of your body on the front leg. You should feel both your quadriceps and your gluteus maximus working.

3) Drive your front foot straight into the step to bring your hip and body up and over your front knee.

4) Slowly lower yourself back down in reverse by keeping the weight of your body on the front foot.

5) Repeat for 3 sets of 8-10 repetitions per side


Gluteus medius - maintaining hip stability,
esp in changing direction

The gluteus medius is the second of the three gluteus muscles and is a key hip stabiliser. 

In walking and running, the gluteus medius helps keep the pelvis level when one leg is lifted. This ensures proper hip-knee-ankle joint alignment, reducing the risk of compensations from our lower back and knees which may cause pain.

Therefore, if someone is suffering from lower back or knee pain during walking, running, or climbing stairs, gluteus medius weakness is something we will assess.

Proper hip-knee-ankle joint alignment is important because it allows our body weight to be managed evenly through the knee. If the knee caves inwards/ outwards, it causes an imbalance of load between the inner and outer sides of the knee. This places a higher risk of injury during sports and wearing down the cartilage on the side bearing more weight.

The gluteus medius plays such a pivotal role in hip stability, which has cascading effects on knee and ankle stability during movement. Apart from walking and running, the gluteus medius also helps to maintain hip stability when changing directions quickly in sports and has been linked to increasing jump performance.

Ultimately, a stable pelvis allows muscles in the hips (e.g. the gluteus maximus) and legs (e.g. quadriceps, hamstrings) to work optimally in most movements and sports!

Here’s a simple gluteus medius exercise that will help you to appreciate its role in maintaining pelvic stability:

Hip hitching

1) Stand on one leg with the opposite leg bent.

2) Keeping your supporting leg straight, allow the opposite hip to drop.

3) Drive through the heel of your supporting leg to lift the opposite hip until it’s level.

4) You should feel the muscles in the side bum of your supporting leg working.

5) Repeat for 3 sets of 8-10 repetitions per side

Exercise Guide – Hip Hitch – YouTube
Alt source: Gluteus Medius Exercises – Posture Direct

How functional training can
improve your knee health

As you can see from the four key muscle groups described today, the structures in our body work as a team to help us move.

While knee pain can sometimes be due to direct injury to the knee, it often times can also be a result of poor biomechanics in the way we move.

At Retrofit, we use a series of movement assessments to find out potential imbalances and muscle weakness, and then provide exercises targeted at addressing those issues.

When you think about cars, you will understand the importance of having regular maintenance checks to find and fix potential problems before they occur. This is because waiting for problems to surface can be costly and very dangerous. We believe in looking at our body the same way as a vehicle and believe that preventing injuries is simpler than treating them.

If you’d like to learn more about how you can bulletproof your knees, feel free to for a consultation today!

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