With Coach Alexa, Online Running Coach and in-person coaching in South Oxfordshire
Meet Your Knees – The Basics
Talking about knees now – knees are basically hinge joints. I’m going to give you an overview of the complicated anatomy, but it’s all built around supporting that simple hinge movement.
You can see in this scan the thigh bone coming down from the top, the larger tibia bone and the smaller fibula coming up from the bottom, and the kneecap floating at the front. All of that works together to act like a hinge joint.
Unlike the ankle and the hip, which have much more complex ranges of motion, the knee just bends and straightens. That’s all it’s really designed to do. It does not particularly like sideways or rotational movements – that’s what the hip and ankle are built for.
We’ll now take a closer look at the anatomy and see how it all fits together.
The Muscles and Tendons Supporting the Knee
In the diagram on the left-hand side, we’re looking at the front of the leg. You can see the kneecap as a point of reference. Around it are the large quad muscles – ‘quad’ because there are four of them. These all merge into a tendon with the kneecap embedded in the middle, which attaches at the top of the shin bone.
There are also other muscles wrapping around the knee – muscles from the front and sides of the shin, covered in my lower leg anatomy video, curve around and help provide stability.
You can also see the white band on the outside – that’s your IT band. It attaches just below the knee and helps stabilise it. Smaller muscles also run around the inside and back of the leg. On the rear view, you’ll spot the hamstrings coming down the back and attaching below the knee.
The biggest quad muscle also attaches underneath, overlapping with the hamstrings. All these big muscles cross over the knee joint, giving it strength – it’s like building your own knee brace.
That’s why leg strength is absolutely key. It keeps the knees aligned, pointing forwards, and doing their job – bending and straightening – without twisting or wobbling.
Under the Surface – Deeper Layers of Knee Anatomy
As with most muscular diagrams, there’s always another layer. Once you remove the top muscle layer, you begin to see the structures within the knee joint itself.
Between the thigh and shin bones, there’s a gap containing key stabilising structures. This is where the deeper complexity of the knee becomes clear.
Further diagrams reveal even more – though this still isn’t the full picture. Looking at the outside of the knee, you can see the IT band again attaching to the top of the tibia. Around the knee are many different muscles and tendons, as well as cartilage and internal structures.
Ligaments and tendons attach in various places to provide the knee with critical support. Some diagrams show the outside ligaments, while others depict the more well-known ones like the ACL and PCL – the cruciate ligaments – that cross inside the joint.
These inner and outer structures combine to stabilise the knee and hold the joint capsule together. It’s a brilliantly complicated design.
Knee Pain and Strength – What to Keep in Mind
Given how complex the knee is, pain could come from any of these structures. But remember – the knee is built to bend and straighten. It does not like excessive sideways or twisting forces.
The best way to protect your knees? Build strength in the big muscles – the quads, hamstrings and calves – that cross the joint. This creates natural stability, almost like a built-in brace.
Also, work on hip and ankle strength and stability. It puts the knee in a better position to function properly.
Is Running Bad for Your Knees?
Let’s finish on a myth buster: no, running isn’t bad for your knees. In fact, recent studies show that running is good for your joints. It loads your cartilage and bones in a way that can actually benefit them – provided it’s managed sensibly.
Running is a high-impact activity, so it’s important not to overdo it. Follow a structured plan, include rest days, and combine it with strength training.
Running alongside strength work is one of the best things you can do for your knees.
I hope that’s useful – happy running!
