Our knee muscles are responsible for initiating and controlling movement of the knee and the kneecap.
They also work with the various buttock, thigh and calf muscles to help control the hip and foot.
When we think about the muscles of the knee, the ones that usually spring to mind are the quadriceps and the hamstrings but there are other muscles around the knee that are just as important.
Knee muscles need to have both good strength and flexibility. Any tightness or weakness in the muscles around the knee makes you prone to a whole host of knee problems.
The hamstrings and quadriceps work together, one contracting (agonist) while the other relaxes (antagonist) to allow the knee to bend and straighten.
Here we look at each of the muscles of the knee, how they work, what can go wrong and how to prevent knee muscle injuries.
The main knee muscle groups are the:
Let's have a look at each of the muscles around the knee, how they work, what activities they are important for, how they are injured and how to target them.
Location: The quads are found on the front of the thigh from the hip to the knee and are the main muscles above knee
Action: Their main action is to straighten the knee, but they also help bend the hip
Common Activities: Getting up from a chair, going upstairs, walking & running
The quadriceps are a group of four muscles found in the front of the thigh and over the knee. Their primary role is to straighten the leg.
They pass down the front of the thigh and then join together near the knee to form the quadriceps tendon.
The quads tendon flows around the patella (kneecap) before finally attaching to the tibial tuberosity at the front of the shin bone, by which time it is known as the patellar tendon.
Location: The hamstrings are found on the back of the thigh from the hip to the knee
Action: Their main action is to bend the knee, but they also help to extend the hip
Common Activities: running, twisting the knee
Common Problems: tightness, weakness, muscle tear, tendonitis
The hamstrings are made up of three muscles in the back of the knee and thigh. They are the main knee flexor muscles and their primary role is to bend the knee.
Each of the three hamstrings muscles, semimembranosus, semitendinosus and biceps femoris, originate from the bottom of the pelvis, travel down the back of the thigh and attach to the back of the knee.
The calf muscles mainly control foot and ankle movement but the do also play a small part in knee movements alongside the other muscles behind knee.
Another group of muscles not to be overlooked with knee problems is the glutes, or buttock muscles:
The glutes play a very important role in the stability of the knee and in my experience, almost everyone suffering from ongoing knee pain has weak glutes and would benefit from glute strengthening exercises and in some cases glute stretches as swell.
Popliteus is one of the small muscles in the back of the knee.
It is often overlooked when thinking about knee muscles but popliteus plays an important role in helping the knee to twist, as well as aiding stability of the knee and helping to protect the lateral meniscus.
Yes, problems in the knee muscles do cause pain! Tightness or weakness in the quadriceps, hamstrings and other muscles around the knee are often part of the cause of knee pain.
If there is muscle imbalance, it changes the way the forces go through the knee, and puts extra pressure on certain areas, leading to knee pain.
Knee muscles are also often injured. It may be that they are overstretched and tear, or that they are overused and become inflamed.
Common injuries associated with the knee muscles include:
Strengthening the muscles around the knee is one of the best ways of preventing and treating knee pain.
There are loads of great exercises that help to strengthen the various knee muscles.
Some target one muscle group at a time, others work different groups together.
People often start with open chain exercises, where the foot is free rather than fixed and progress to close chain exercises where the feet are fixed to the floor and thus there is weight going through the leg as you exercise.
You can find a whole range of strengthening exercises for the knee muscles, whatever level you are at, in the knee strengthening exercises section.
Tightness in the muscles around the knee changes how the knee moves and how the forces go through the joint which can lead to a whole host of knee problems.
Tightness in the muscles behind knee can limit knee extension and tightness in the muscles above knee can limit knee flexion.
Any tightness in the knee muscles can also affect how the knee joint functions and how the knee cap moves around which can lead to pain.
There is much debate on the best way to stretch muscles and in the knee stretches section, you can find out everything you need to know about the best way to stretch including how to check if your knee muscle are tight and how to stretch each of the muscles around the knee.
Page Last Updated: 12/01/23
Next Review Due: 12/01/25