Massage.
MuscleLegdeepBeyond Cert IVDraft

PopliteusMusculus popliteus

Small, flat, triangular muscle deep behind the knee that rotates the tibia or femur to "unlock" the straightened knee so it can bend.

No image yet
LatinMusculus popliteus
Origin
  • Groove on the lateral surface of the lateral condyle of the femur (by a short, strong tendon)
  • Oblique popliteal ligament of the knee joint (a few fibres)
Insertion
  • Posterior surface of the tibia, on the triangular area above the soleal line
Action
  • Leg free (sitting): medially rotates the tibia on the femur
  • Foot on the ground (standing): laterally rotates the femur on the tibia, unlocking the fully straightened knee
  • Assists flexion of the knee, especially at the start of bending
  • Helps stop the femur sliding forward on the tibia when crouching
NerveTibial nerve (L4–S1)
NameLatin poples, 'the ham (back) of the knee' — the muscle forms the floor of the hollow behind the knee.

Palpation

  1. Client prone with a small bolster under the ankle so the knee is slightly bent and the calf is relaxed.
  2. Find the back of the upper tibia just below the knee crease, on the inner (medial) side of the calf.
  3. Work slowly and gently in, between the two heads of the gastrocnemius, towards the back of the tibia; the popliteus is deep and hard to feel clearly.
  4. With the knee bent, ask the client to turn the toes inwards against light resistance (medial rotation of the tibia) and feel for a faint firming under your fingers.

Landmarks: Patella

The popliteus lies in the floor of the hollow behind the knee (the popliteal fossa), under the two heads of Gastrocnemius and the popliteal blood vessels and tibial nerve. Because those structures are sensitive, the back of the knee is treated as an area of caution in massage: use broad, light pressure here and never press hard into the centre of the hollow. Deeper, specific work on popliteus belongs to remedial training.

Its job is small but important. A fully straightened knee is “locked” by a slight twist; popliteus undoes that twist so the knee can start to bend. For this reason it is often called the key that unlocks the knee. Clients who stand for long periods, walk downhill or squat a lot sometimes report tenderness at the back of the knee.

Popliteus is not a calf muscle in the usual sense: it acts only on the knee and does not reach the Achilles (calcaneal) tendon at the heel, unlike its neighbours Gastrocnemius and Soleus.

Source notes. Nerve roots differ between sources: Gray’s Anatomy (1918) gives L4, L5 and S1, while Wikipedia gives L5 and S1. Wikipedia also describes a variable attachment to the lateral meniscus of the knee, which Gray does not mention.

Techniques

  • Compression — Pressing straight down into a muscle with the palm, fist or forearm, holding briefly, then releasing and moving on.
  • Positional release — A gentle, indirect method where a tender point is monitored with a fingertip while the body part is moved into a comfortable, shortened position that eases the tenderness, held for about 90 seconds.
  • Trigger point pressure release — Sustained thumb or finger pressure on a tender spot within a taut band of muscle, held until the client reports the discomfort easing, then slowly released.

Works with

  • Hamstrings — Group of three muscles on the back of the thigh, running from the sitting bone to below the knee, that bend the knee and extend the hip.
  • Gastrocnemius — Two-headed superficial calf muscle that runs from above the knee to the heel and points the foot and helps bend the knee.

Opposes

  • Quadriceps — Group of four large muscles on the front of the thigh that join into one tendon over the kneecap and are the only muscles that straighten the knee.

Sources

  1. Wikipedia: Popliteus muscle
  2. Wikipedia: Tibial nerve
  3. Gray's Anatomy of the Human Body (1918), Myology 8c: The Muscles and Fasciae of the Leg (archived Bartleby page) (Public domain. Used for attachments, actions and nerve roots. Gray gives L4, L5 and S1; Wikipedia gives L5 and S1.)