What muscles could cause behind the knee pain?

Muscles that may contribute to behind the knee pain include popliteus, gastrocnemius, plantaris, biceps femoris, semimembranosus, semitendinosus. Trigger points, strains, or weakness in these muscles can refer pain to this area.

Lower Leg

Behind the Knee

Q: What causes pain in the behind the knee?

Common causes of behind the knee pain include baker's cyst (popliteal cyst) from excess joint fluid, hamstring tendinopathy at the knee insertion, popliteus strain from twisting or pivoting, posterior meniscal tear, deep vein thrombosis in the popliteal vein. The specific cause depends on the nature of the pain, how it started, and which movements aggravate it.

Pain behind the knee involves the popliteus, gastrocnemius, hamstring tendons, and the popliteal fossa. It can result from a Baker's cyst, hamstring tendinopathy, or popliteus strain, and may be worsened by deep knee bending.

Medical Disclaimer

This information is for educational purposes only and does not constitute medical advice. Consult a qualified healthcare provider for proper diagnosis and treatment of any pain or medical condition.

Common Causes

Baker's cyst (popliteal cyst) from excess joint fluid

Hamstring tendinopathy at the knee insertion

Popliteus strain from twisting or pivoting

Posterior meniscal tear

Deep vein thrombosis in the popliteal vein

Muscles in This Area

Lower Leg

popliteus

The popliteus is a small knee muscle behind the joint that 'unlocks' the knee from full extension for flexion. Crucial for downhill running and pivoting in sports. Prevents knee hyperextension.

Popliteus tendinopathyPosterolateral corner injury

Lower Leg

gastrocnemius

The gastrocnemius forms the visible calf bulge, crossing knee and ankle for explosive plantarflexion. Key for sprinting, jumping, and calf raises. Two heads make it powerful for athletic propulsion.

Gastrocnemius strainAchilles tendinopathyTear (tennis leg)

Lower Leg

plantaris

The plantaris is a thin, vestigial calf muscle aiding knee flexion and plantarflexion, like a minor gas pedal muscle. Often ruptured without issue due to redundancy. Useful for explosive calf power in jumping.

Plantaris rupturePlantaris tendinopathy

Thigh

biceps femoris

The biceps femoris is the lateral hamstring on the back of the thigh, with long and short heads forming a thick band from hip to knee. It flexes the knee, extends the hip, and rotates the leg outward, vital for running, jumping, and deadlifts. Key for posterior chain power and injury prevention.

Biceps femoris strainHamstring tendinopathyProximal hamstring avulsion

Thigh

semimembranosus

The semimembranosus is a posterior thigh hamstring forming the teardrop at knee back, flexing knee and extending hip. Powers deadlifts, lunges, and deceleration in sports. Prevents ACL strains by stabilizing.

Hamstring strainSemimembranosus tendinopathyBaker's cyst

Thigh

semitendinosus

Semitendinosus is the slender medial hamstring with a long tendon, flexing knee and extending hip. Aids in medial knee stability for cutting sports. Complements semimembranosus for balanced posterior chain.

Semitendinosus strainPes anserine tendinopathy

Stretches That May Help

Popliteus figure-four stretch

Kneeling knee bend

Posterior knee glide

Wall calf stretch straight knee

Downward dog

Foam roll calf

Calf wall stretch

Plantaris-specific toe point

Seated hamstring stretch

Forward fold with knee straight

Lying hamstring stretch with strap

Hamstring forward fold

Seated reach

Lunge hamstring stretch

Good morning stretch

Figure four hamstring

Recommended Exercises

When to See a Doctor

Seek immediate medical attention if you have sudden calf swelling with warmth and redness (may indicate DVT), a locked knee that cannot straighten, or severe pain with visible swelling behind the knee.