How to Strengthen the Popliteus Muscle

Strengthening the popliteus muscle comes down to loading it through the two movements it controls: knee flexion and internal rotation of the tibia. Because it is a small, deep muscle buried behind the knee joint, you cannot isolate it the way you would a quadriceps or hamstring. But research on its mechanics shows that specific positions and exercises recruit it heavily, especially weight-bearing activities performed with a relatively straight knee. The real challenge is less about finding the right exercise and more about understanding when and how the popliteus is most active so you can bias your training toward it.

What the Popliteus Actually Does

The popliteus sits at the back of the knee, running from the outer side of the femur (thighbone) down to the inner side of the tibia (shinbone). Its most famous job is “unlocking” the knee: when your leg is fully straight and you start to bend it, the popliteus internally rotates the tibia a few degrees so the joint surfaces can glide past each other. Without that rotation, the knee would stay locked in extension like a stuck hinge.

But the muscle does far more than unlock the knee. It acts as a dynamic guidance system that monitors and controls subtle rotational and side-to-side movements at the knee joint, assists with three-dimensional postural stability during single-leg stance, helps prevent the femur from sliding forward on the tibia when you stand with bent knees, and makes fine postural adjustments during quiet standing.¹ It also retracts the back part of the lateral meniscus during knee flexion, pulling the cartilage out of the way so it does not get pinched between the bones.² This meniscus-protection role is one reason a weak or dysfunctional popliteus can contribute to lateral knee pain and cartilage problems over time.

The Positions Where It Works Hardest

A 2021 ultrasound study that measured popliteus stiffness in real time gave some of the clearest guidance on when the muscle is most active. The researchers found that popliteus force increases with weight bearing and decreases as the knee bends more deeply during single-leg standing. Muscle stiffness was significantly greater at full knee extension (zero degrees of flexion) compared to 30 degrees of flexion during one-leg stance. The muscle was also highly active during isometric knee flexion combined with internal rotation, and when the knee was passively held at full extension with 20 degrees of external rotation.³

This tells you several practical things. First, the popliteus works harder when you are standing on one leg than when you are seated. Second, it is most engaged when the knee is close to full extension, not deeply bent. And third, combining knee flexion effort with an inward-rotation component creates the ideal loading pattern. These findings shape every exercise worth doing for this muscle.

Open-Chain Exercises for Targeted Recruitment

Open-chain exercises are those where your foot is free rather than planted on the ground. They are the closest you can get to isolating the popliteus, though you will always recruit some hamstring and calf tissue alongside it.

Seated tibial internal rotation: Sit on a chair or bench with your knee bent to about 90 degrees and your foot off the floor. Without moving your thigh, slowly rotate your shin inward (turning your toes toward the midline) against light resistance from a band looped around your foot. This directly loads the popliteus through one of its primary actions. Keep the motion controlled and the resistance light; this is a small muscle producing a small range of motion.
Prone knee flexion with rotation: Lie face down and bend your knee to roughly 20-30 degrees while simultaneously rotating the lower leg inward. You can add a light ankle weight. The combination of flexion and internal rotation mirrors what the research identifies as the loading pattern that raises popliteus activity most.³
Isometric internal rotation at near-extension: Sit with your knee almost fully straight, foot on the floor, and press the inside of your foot against an immovable object (a wall, a table leg) as though you are trying to rotate your shin inward. Hold for 5-10 seconds. This isometric version is especially useful early in rehabilitation when movement may be painful.

With all of these, start with very low resistance. The popliteus is roughly the size of your thumb; it does not need the loading volume of a squat or deadlift. Two to three sets of 10-15 repetitions, performed slowly, is a reasonable starting point.

Closed-Chain and Weight-Bearing Progressions

Because popliteus force increases with weight bearing, closed-chain exercises (where your foot is planted) tend to challenge the muscle more functionally than open-chain drills alone. Rehabilitation protocols following popliteus tendon injuries typically introduce controlled closed kinetic chain exercises and proprioceptive retraining as early as weeks two through six, alongside low-resistance cycling and neuromuscular re-education to maintain joint coordination.⁴

For someone without an acute injury who simply wants to build popliteus strength and resilience, closed-chain work can be more aggressive. Good options include:

Shallow single-leg squats: Stand on one leg and perform a partial squat, bending only to about 20-30 degrees. Remember that the popliteus works hardest near full extension and loses mechanical advantage in deep flexion. So rather than squatting deep, focus on controlling the first 30 degrees of the bend and pausing at the bottom. Try to keep your tibia from rotating outward, which forces the popliteus to actively stabilize the joint.
Step-downs from a low box: Stand on a 4- to 6-inch step on one leg. Slowly lower the opposite foot toward the floor, controlling the descent. This is essentially a slow eccentric single-leg squat in the exact range where popliteus recruitment peaks. It also demands rotational knee control, since the knee will try to collapse inward or the tibia will try to rotate outward under load.
Low-resistance cycling: Pedaling on a stationary bike at low resistance works the popliteus through repeated flexion-extension cycles while keeping load modest. It is a staple in early rehab but also a useful warm-up before more demanding exercises.

Single-Leg Balance and Proprioceptive Training

The popliteus is not just a mover; it is a stabilizer. Its role in making fine postural equilibrium adjustments during standing means that balance training is a legitimate way to strengthen it, not merely a warm-up drill.¹ The ultrasound data confirm this: popliteus stiffness rises during single-leg stance and increases further as the knee approaches full extension.³

Single-leg standing on a firm surface is the starting point. Aim to hold 30-60 seconds without touching down, keeping the standing knee almost fully straight rather than deeply bent. Once that feels easy, progress to an unstable surface like a foam pad or balance board. The added instability forces the popliteus to make constant micro-corrections in the rotational and frontal planes. You can advance further by closing your eyes (which removes visual balance input and increases the demand on the muscles around the knee), catching and tossing a ball while balancing, or performing slow reaches with the free leg in different directions.

These drills do not feel like traditional “strengthening” because they don’t produce a burning fatigue the way a leg press does. But for a muscle whose primary function is dynamic stabilization, repeatedly demanding that stabilization under progressively harder conditions is exactly the right training stimulus.

How Neighboring Muscles Help and Hinder

The popliteus does not work in isolation. It is part of the posterolateral corner of the knee, a cluster of structures that together resist external rotation and backward sliding of the tibia. When the popliteus tendon is damaged, removing it in cadaver studies increased external tibial rotation by about 7 degrees at 30 degrees of knee flexion. When the surrounding ligaments were also cut, the rotational instability jumped dramatically.⁵ That interdependence matters for training: strengthening the popliteus alone while ignoring its neighbors is a half-measure.

On the inner side of the knee, the semimembranosus (one of the three hamstring muscles) works synergistically with the popliteus. Its tendon complex actively pulls the posterior horn of the medial meniscus during knee flexion, mirroring the popliteus’s role with the lateral meniscus.⁶ A well-rounded posterior knee program should include hamstring curls (especially with an emphasis on the medial hamstrings), calf strengthening, and hip external rotator work. This does not mean those muscles need equal attention if the popliteus is specifically weak, but neglecting them entirely can leave the knee poorly supported during activities that demand rotational control.

How to Tell if Your Popliteus Is the Problem

Before committing to a popliteus-focused program, it helps to know whether the muscle is actually the source of your trouble. Popliteus strains and tendinopathies tend to show up as posterior-lateral knee pain, which is pain behind and slightly to the outside of the knee joint. The discomfort typically worsens with downhill walking or running, where the popliteus has to work eccentrically to control tibial rotation on every step.

Clinical tests exist, though they are less standardized than tests for common knee problems like ACL tears or meniscus injuries. In one published case report on a popliteus strain in an elite soccer player, the diagnosis was supported by pain during passive knee flexion and internal rotation on a McMurray-type test, pain with the Garrick test (resisted external rotation of the tibia), and confirmatory MRI findings.⁷ A quick self-screen you can try at home: sit with your knee bent to 90 degrees and have someone resist as you try to rotate your shin inward. Pain or obvious weakness compared to the other side suggests the popliteus may be involved. This is not a diagnosis, but it can help you decide whether to seek professional evaluation.

Popliteus issues often overlap with other posterior knee complaints, including Baker’s cysts, hamstring tendinopathy, and lateral meniscus tears. Because the popliteus physically attaches to the lateral meniscus and helps retract it, damage to one structure can affect the other.⁸ If posterior knee pain persists despite several weeks of targeted strengthening, imaging is worth pursuing to rule out meniscal or ligamentous involvement.

Programming a Popliteus-Focused Routine

Putting the pieces together, a practical weekly program for popliteus strengthening might look like this:

Two to three sessions per week: The popliteus is a small muscle with a limited capacity for heavy loading. Two or three focused sessions, spread across the week with at least a day of rest between them, is sufficient.
Warm-up with cycling: Five to ten minutes of low-resistance stationary cycling warms the knee joint and begins activating the popliteus through repeated flexion-extension cycles.
Open-chain isolation work: Two sets of 12-15 repetitions of seated tibial internal rotation against a band, followed by two sets of prone knee flexion with internal rotation using a light ankle weight.
Closed-chain loading: Three sets of 8-10 repetitions of step-downs from a low box or shallow single-leg squats, emphasizing the first 20-30 degrees of flexion where the popliteus is most engaged.
Balance training: Two to three minutes of single-leg stance per side on a foam pad or balance board, with the standing knee close to full extension. Add perturbations (catching a ball, reaching with the free leg) as you improve.

Progression happens by increasing resistance on the open-chain drills, adding height to the step-down box, increasing the instability of the balance surface, or slowing the eccentric tempo on single-leg squats. Avoid progressing by going into deeper knee flexion; that shifts load away from the popliteus and toward the hamstrings and quadriceps.

Common Mistakes That Limit Results

The most frequent mistake is treating the popliteus like a big prime-mover muscle. People load up heavy resistance and perform deep squats or leg presses expecting the popliteus to benefit. While those exercises are great for overall leg strength, the popliteus is minimally loaded during deep-flexion movements. Its force production peaks near extension and drops as the knee bends further.³ Shallow, controlled, rotation-aware exercises beat heavy bilateral squats for popliteus-specific work every time.

Another common error is focusing entirely on strength while ignoring the muscle’s stabilization role. If you only do open-chain band rotations and never challenge the popliteus in standing balance tasks, you are training it for a job description it rarely performs. Most of the popliteus’s daily work involves subtle, rapid corrections during walking, stair descent, and single-leg activities. Balance and proprioceptive drills replicate that demand pattern far better than any seated exercise.

Finally, people often neglect the eccentric component. The popliteus works eccentrically to control tibial external rotation during activities like walking downhill, where the shin naturally wants to rotate outward with each step. Eccentric training, like slow, controlled step-downs where you resist the knee rotating outward on the way down, mimics this real-world demand and builds resilience against the type of strain injuries that commonly affect the popliteus in runners and field-sport athletes.

When Hands-On Treatment Has a Role

For people dealing with popliteus pain or tightness rather than pure weakness, manual therapy can complement a strengthening program. The popliteus is deep enough that it is difficult to reach with conventional massage, sitting underneath the gastrocnemius (calf muscle). One technique that has been studied is dry needling, in which a thin filament needle is inserted through the skin to the muscle. A validation study found that trained physiotherapists were able to reach the popliteus in 92% of attempts, at a mean needle depth of about 4.6 centimeters.⁹ That depth gives you a sense of how buried the muscle is and why superficial foam rolling over the back of the knee is unlikely to reach it directly.

Dry needling, soft-tissue mobilization, and targeted stretching can help reduce pain and improve tissue quality, but they do not replace strengthening. A muscle that hurts less but remains weak will simply become symptomatic again once you return to demanding activity. Consider manual therapy as a way to create a window of reduced pain in which you can do the strengthening work more effectively, not as a standalone solution.

1
PubMed. Anatomy, function, and rehabilitation of the popliteus musculotendinous complex
2
The Journal of Bone and Joint Surgery. British volume. THE POPLITEUS MUSCLE AND THE LATERAL MENISCUS
3
PubMed. The function of the popliteus muscle: An in vivo ultrasound shear wave elastography study
4
PubMed Central. Popliteus Tendon Morphology: Anatomical Classification and Clinical Implications—A Narrative Review – Section: Rehabilitation Following Popliteus Tendon Injury or Reconstruction
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PubMed Central. Popliteus Tendon Morphology: Anatomical Classification and Clinical Implications—A Narrative Review – Section: Biomechanics of the Popliteus Tendon
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PubMed. The distal semimembranosus complex: normal MR anatomy, variants, biomechanics and pathology
7
PubMed Central. POPLITEUS STRAIN WITH CONCURRENT DELTOID LIGAMENT SPRAIN IN AN ELITE SOCCER ATHLETE: A CASE REPORT
8
Arthroscopy: The Journal of Arthroscopic and Related Surgery. The popliteus as a retractor of the lateral meniscus of the knee
9
PubMed Central. Dry Needling of the Popliteus Muscle Validation by Ultrasound Imaging: A Cross-Sectional Observational Study