Are you having pain behind your knee? Are you a competitive athlete or weekend warrior? You may have injured your popliteus.
Pain at the back of your knee can be caused by an injury to the hamstring muscles in the back of your thigh, by an injury to the gastrocnemius muscle in your calf, or by swelling from your knee joint (a popliteal cyst/Baker’s cyst).
However, there is another cause that is less common and sometimes overlooked. A popliteus muscle strain or popliteal tendinopathy. The popliteus is a small triangular muscle located at the back of your knee. It originates from your outer thigh bone (femur) and your meniscus and attaches to the back of your lower leg bone (tibia). Though it’s small in size, it has a huge role in knee function!
The popliteus: 1) ‘unlocks’ the knee to allow it to bend from a fully straightened position, by rotating the tibia inwards, 2) pulls the meniscus backwards when your knee is bending, to help prevent it from getting pinched, 3) is a very weak contributor towards helping the knee to bend, 4) helps to stabilize the knee.
The popliteus is most frequently injured during sports activities, such as running and downhill skiing.
Popliteus Strain and/or Tendinopathy Symptoms
People with popliteal issues often have pain in the back and outer areas of the knee. There is often pain when straightening the knee fully, or when bending the knee against resistance. Pain is usually worse when walking downhill, with stairs and when running. The area behind the knee is often swollen and tender to the touch, and there may be a crackling sound with movement if the tendon is involved. If an athlete continues to overload the knee with this injury symptoms will worsen, delaying healing.
Popliteus Strain and/or Tendinopathy Causes
Popliteus strains and tendinopathies most commonly occur in downhill skiers, and in runners and triathletes who compete on hills or uneven surfaces. The typical cause of injury is a direct blow to the inside of the knee, or a sudden forceful overextension/over straightening of the knee. Muscle weakness and poor dynamic stability can increase the risk of an injury during training.
Popliteus Strain and/or Tendinopathy Treatment
In the early stages of healing, after a new popliteus injury, treatment often includes rest from aggravating activities, icing the knee for 10 to 15 minutes every few hours, a compression wrap to help decrease swelling, and laser or ultrasound to help to decrease pain and inflammation. An assessment of movement patterns and dynamic stability at the feet, ankles, knees, and hips should be performed, to determine factors predisposing the athlete to injury. As healing progresses, a gentle soft tissue massage of the popliteus, graded loading of the musculotendinous unit, and a combination of soft tissue release, contract, relax, stretching techniques and strengthening exercises to correct imbalances will help to decrease pain, and speed return to play. Patients should not run or ski until the knee is pain-free and should limit sports activities for at least the first 6 weeks. Once you are pain-free, a gradual return to play can begin.
Written by Aislinn Braun – Registered Physiotherapist at Burlington Sports Therapy
LaPrade R et al., Analysis of the static function of the popliteus tendon in evaluation of an anatomic reconstruction: “the fifth ligament of the knee”. American Journal of Sports Medicine. 2010: 38(3); 543-549.
Nyland J et al. Anatomy, Function, and Rehabilitation of the Popliteus Musculotendinous Complex. Journal of Orthopaedic & Sports Physical Therapy. 2005: 35(3); 165-179.
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