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Pain2026-03-06•5 min read

Pes Anserine Bursitis: The Common Cause of Inner Knee Pain

What Is Pes Anserine Bursitis?

Pes anserine bursitis is inflammation of the bursa (fluid-filled sac) located on the inner side of your knee, about 2-3 inches below the joint line. The pes anserinus ("goose's foot" in Latin) is where three tendons attach to the tibia in a fan shape.

Anatomy

The pes anserine is formed by the tendons of three muscles:

  • Sartorius
  • Gracilis
  • Semitendinosus

    • A bursa sits between these tendons and the bone, reducing friction. When it becomes inflamed, that's pes anserine bursitis.

    Who Gets It?

    Common in

  • Runners
  • Cyclists
  • Swimmers (breaststroke)
  • Middle-aged and older adults
  • People with knee osteoarthritis
  • Overweight individuals
  • Women (more than men)

    • Risk Factors

  • Obesity
  • Knee osteoarthritis
  • Tight hamstrings
  • Overpronation of feet
  • Diabetes
  • Medial meniscus tear

    • Symptoms

    Classic Presentation

  • Pain on inner knee, below joint line
  • Tender to touch at pes anserine
  • Pain going up or down stairs
  • Pain with activity
  • Stiffness, especially in morning
  • May have slight swelling

    • What Makes It Worse

  • Stairs (especially going down)
  • Walking uphill
  • Running
  • Deep knee bending
  • Getting up from seated position

    • Different From Medial Meniscus

  • Meniscus pain is at the joint line
  • Pes anserine pain is below the joint line
  • Can coexist with meniscus problems

    • Diagnosis

    Physical Exam

  • Point tenderness at pes anserine
  • Pain with resisted knee flexion and internal rotation
  • No instability

    • Imaging

    X-rays:

  • Usually normal
  • May show associated arthritis

    • MRI:

  • Shows bursal inflammation if significant
  • Rules out other pathology
  • Often not needed for diagnosis

    • Ultrasound:

  • Can show fluid in bursa
  • Good for injection guidance

    • Treatment

    Rest and Activity Modification

  • Reduce aggravating activities temporarily
  • Avoid stairs when possible
  • Modify training (reduce mileage, avoid hills)

    • Ice

  • 15-20 minutes, several times daily
  • After activity
  • Reduces inflammation

    • Stretching

    Hamstring stretching:

  • Lying hamstring stretch with strap
  • Seated hamstring stretch
  • Hold 30 seconds, 3x daily

    • Hip adductor stretching:

  • Butterfly stretch
  • Side lunge stretch
  • 30 seconds, 3x daily

    • Strengthening

    Quadriceps:

  • Straight leg raises
  • Wall sits
  • Short arc quads

    • Hip strengthening:

  • Clamshells
  • Side-lying leg raises
  • Bridges

    • Addressing Contributing Factors

    If overweight:

  • Weight loss reduces knee stress
  • Significant impact on symptoms

    • If overpronation:

  • Consider orthotics
  • Appropriate footwear

    • If osteoarthritis:

  • Manage arthritis comprehensively

    • Medications

    NSAIDs:

  • Oral anti-inflammatories help
  • Topical NSAIDs can be effective
  • Follow dosing guidelines

    • Physical Therapy

  • Guided stretching and strengthening
  • Manual therapy
  • Modalities for pain relief
  • Address biomechanics

    • Injections

    Corticosteroid Injection

    When indicated:

  • Failed 4-6 weeks conservative treatment
  • Significant pain

    • What to expect:

  • Local anesthetic + corticosteroid
  • Relief often within days
  • May last weeks to months
  • Can be repeated if needed (limit of 3-4)

    • Effectiveness

  • High success rate
  • Often provides lasting relief when combined with exercise

    • Surgery

    Very Rarely Needed

    Almost all cases resolve with conservative treatment or injection.

    When Considered

  • Refractory cases despite extensive treatment
  • Typically involves bursa removal (bursectomy)

    • Prevention

    Stretching

  • Regular hamstring and adductor stretching
  • Before and after activity

    • Strengthening

  • Hip and quad strengthening
  • Core stability

    • Training Modifications

  • Gradual increases in activity
  • Avoid sudden mileage spikes
  • Cross-training

    • Footwear

  • Appropriate for your activity
  • Address overpronation if present

    • Timeline

    Typical Recovery

  • Mild cases: 2-4 weeks
  • Moderate cases: 4-8 weeks
  • With injection: often rapid improvement
  • Chronic cases: may take longer

    • Pes anserine bursitis is common and very treatable. Stretch the hamstrings, strengthen the hips and quads, address contributing factors, and it usually resolves. If not, a corticosteroid injection often does the trick. Surgery is almost never needed.

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