Often runners and cyclists can present with issues in the back part of the knee that they find gets worse with the kilometres that they endure into an event or training run/ride. It can also be a pain that presents itself upon jumping or extension of the leg. It’s not necessarily a pain that will make you wince or clutch at your leg in pain, but it sits there niggling and causing discomfort. It can also be a pain that presents itself when stretching and that uncomfortable ‘locked knee’ position where bending from a straight position requires just that little bit of bravery to execute the move.
Posterior knee pain can often be a warning sign for ligamentous damage and stability of the knee joint in flexion and can be a sinister omen of issues with the knee joint itself. However, it can also be a smaller issue related to a muscular tightness that is involved directly in knee flexion and that isn’t part of the hamstring group – the popliteus.
This small triangular shaped muscle lies just at the back portion of the knee joint, deep to the larger hamstring group and gastrocnemius muscles. It has a small insertion point on the lateral (outside) femur (thigh bone) and inserts in a broad section that runs along the inside bone of the lower leg, the tibia at the topmost section of the bone. The broad insertion makes this muscle a powerful initiator of movement of the knee flexing, indeed it is often referred to as the ‘unlocker of the knee’ from the extended or ‘straight’ position. It helps to support the posterior ligaments of the knee and stabilises in knee flexion particularly during walking. It is important for the poplitues to be active to medially rotate the lower leg so as to help with aligning the bony protuberances of the tibia and allow the knee joint to flex without crushing the meniscus between the two bones involved in the action. This slight rotation is vital to normal function.
Often the muscle can become shortened and/or weak, especially where there is an imbalance between the medial and lateral hamstrings which can often occur, particularly in bike riders as they maintain a strong medial rotation in their cycling action as well as with a medial or ‘turned in’ position when clipped into their cleats. A slight dominance of one hamstring over the other and repeated reinforcement of this alignment can bring about pain or weakness in the posterior knee compartment and can also be a target for imbalance of the hamstrings. Runners who have an internal rotation of the knee or pronated stride can often experience this niggle. The reinforced internal rotation really can overwork the popliteus. You can often find this with novice runners who are training for their first 10km run or deciding that they are going to take up running as a training option. It’s not a debilitating issue but it can and does put a dampener in your stride and make it uncomfortable to complete a training session or event.
A weak popliteus can result in hyperextension of the knee and this is particularly indicated in jumping actions or where sudden movements stress the knee joint in a straightened position, such as field and court sports. Particular sports where quick, sharp rotation (tennis, soccer, volleyball, basketball, squash etc) is required can place a lot of strain on the posterior cruciate ligaments and in turn the popliteus. It is also very important in the action of full knee flexion, such as in crouching or going into a ‘full squat’ position in a yoga class or sitting in a full squat. A healthy popliteus helps to prevent the forward movement of the femur on the tibia as does the cruciate ligament. Thus it is an important muscle to be aware of and to maintain particularly if you are coming out of a knee dislocation or are post surgery after such an event or a reconstruction.
Working as a soft tissue therapist, the popliteus is important for assisting with full knee flexion as well as ensuring an efficient balance between the hamstrings group and also the gastrocnemius. Often atheletes misdiagnose themselves with hamstring pain in this instance and will spend time stretching and stretching their hamstrings with no benefit. Indeed the prolonged extension of the knee in this instance may not actually do much for the injury at all. Cross fibre work to the area is an easily effective technique that can help to influence tone and length of the area and the flexion of the knee.
Like so many smaller muscles, it is difficult to target or ‘train’ and can also fall prey to an overactive or stimulated hamstring or gastrocnemius. Combining internal rotation of the leg with knee flexion is the best way to target the popliteus and ensure it works in cohesion with the medial and lateral hamstrings. Touching your heel to your opposite butt cheek (or gluteal muscles to be more PC) is one such activity to help ensure this muscle is active in the right way.
So if you are finding that your runs or weekend games of tennis or soccer are leaving you pulling up with that niggling soreness directly behind the knee, you don’t necessarily need to start looking into knee replacement surgery or contemplating benching yourself just yet. It can be as easily rectified with a little extra encouragement from your Remedial Massage Therapist. With a smiling face and happy countenance of course.