Pes Anserinus Pain in Runners: Understanding Causes, Diagnosis & Recovery

Inner knee pain, especially just below the joint line, is a common complaint among runners. While medial meniscus or MCL injuries are often suspected, pes anserinus tendinopathy or bursitis is a frequently overlooked, but treatable condition affecting the tendons and bursa on the anteromedial tibia.

At Endurance Health Lab, we help runners in Chatswood recover from overuse injuries by targeting the root causes: movement inefficiencies, strength deficits, and training load errors.

What Is the Pes Anserinus?

The pes anserinus ("goose's foot") refers to the insertion of three muscles:

• Sartorius

• Gracilis

• Semitendinosus

These tendons attach just below the medial knee joint on the tibia. A bursa lies beneath them to reduce friction. Overload, poor biomechanics, or inflammation of the bursa or tendons results in pes anserinus syndrome (Aicale et al., 2024).

Why Runners Are Susceptible: The Biomechanics

1. Repetitive Stress and Flexion Cycles

Runners perform up to 1,500 strides per kilometre, subjecting the hamstrings and adductors to repetitive eccentric and concentric loads (Alvarez-Nemegyei, 2007; Homayouni et al., 2016).

2. Dynamic Valgus and Gluteal Weakness

Poor gluteus medius activation leads to hip adduction and internal rotation, causing the knee to collapse inward (valgus). This increases friction and tensile strain on the pes tendons (Aicale et al., 2024; Sarifakioglu et al., 2016).

3. Foot Mechanics

Excessive pronation causes tibial internal rotation, stressing the insertion point and increasing bursal compression (Alvarez-Nemegyei, 2007; Yoon et al., 2005).

4. Load Errors

A systematic review by Choi et al. (2021) identified training volume spikes and poor recovery as major contributors to overload-related tendon injuries in runners.

Symptoms and Clinical Presentation

• Pain 4–5 cm below the medial joint line

• Worse with stairs, kneeling, or getting out of a car

• Pain on resisted knee flexion, hip adduction or passive extension with valgus stress

• Occasional swelling or burning over the insertion (Rennie & Saifuddin, 2005)

Differential Diagnosis

Differentiating Pes Anserinus disorders from other medial knee pathologies is crucial:

Condition	Key Features
Pes Anserinus Bursitis	Pain localised below the joint line; tenderness over the pes anserinus area.
Medial Meniscus Tear	Joint line tenderness; possible locking or clicking sensations.
MCL Sprain	Pain over the medial collateral ligament; instability during lateral movements.

Imaging modalities like MRI or ultrasound can aid in diagnosis when clinical examination is inconclusive .

Diagnosis and Imaging

Clinical Testing

• Palpation: Focal tenderness at the pes insertion

• Pain reproduction: Resisted knee flexion or internal rotation, passive stretch, or valgus load

• Differential tests: McMurray's or valgus stress test to rule out meniscal or MCL involvement (Medscape, 2024)

  
  

Ultrasound

Reveals bursal distension, tendon thickening, and increased Doppler flow - useful for confirming diagnosis and guiding injections (Yoon et al., 2005).

MRI

Used in chronic or complex cases to rule out intra-articular involvement. Findings include soft tissue edema and peritendinous inflammation (Radiopaedia, 2024).

Diagnostic Injection

An anesthetic injection into the bursa that resolves symptoms confirms pes anserinus bursitis as the pain source (Medscape, 2024).

3-Phase Rehabilitation Plan: Pes Anserinus Pain

Phase I - Settle Symptoms (1–2 weeks)

Goals: Reduce pain and inflammation, protect from further aggravation

Interventions:

• Relative rest and activity modification (avoid stairs, deep squats)

• Ice and NSAIDs if needed

• Manual therapy to release hamstrings, adductors

• Isometric exercises

• Education on load management

Kinesiotaping plus isometrics reduced symptoms comparably to NSAIDs (Homayouni et al., 2016).

Phase II - Restore Strength and Mobility (2–4 weeks)

Goals: Restore normal movement patterns and build load tolerance

Interventions:

• Glute medius and glute max strengthening

• Hamstring and adductor eccentrics

• Hip mobility

• Gait retraining if valgus collapse or overstriding is present

• Introduce unilateral strengthening and proprioception

Physiotherapy was superior to corticosteroid injections over 6 weeks (Sarifakioglu et al., 2016).

Prolotherapy and corticosteroids showed varying timelines of effectiveness (Babaei-Ghazani et al., 2024).

Phase III - Return to Running (4–6+ weeks)

Goals: Safely reintroduce running and high loads

Interventions:

• Walk-run progression

• Introduce plyometrics

• Continue strength training (2x/week maintenance)

• Shoe and orthotic review for pronation control

Daily movement pattern modification helped reduce symptoms (Farsad et al., 2023).

Key Takeaways

• Common in runners due to repetitive valgus stress, poor hip control, and overuse.

• Presents with localised medial knee pain below the joint line, worsened by stairs, running, or resisted knee flexion.

• Clinical exam is primary; ultrasound and MRI assist in complex or persistent cases.

• Often linked to weak glutes, poor hip stability, excessive foot pronation, and altered running mechanics.

• Treatment involves load management, hip/core strengthening, gait retraining, and gradual return to sport.

• Prognosis is excellent with comprehensive rehab addressing the kinetic chain.

• Biomechanical corrections (hip, foot, gait) are key to preventing recurrence.

When to See a Physiotherapist at Endurance Health Lab

You should consider seeing a physiotherapist if you experience:

• Localised pain on the inside of the knee or upper shin that worsens with running

• Pain during walking, stairs, or hopping

• Persistent symptoms despite rest, footwear changes, or self-management

• A recent increase in running distance, speed, or hill training

• Difficulty returning to sport due to recurring knee discomfort

📅 Book an assessment with Endurance Health Lab. We’ll guide you through accurate diagnosis, imaging referral if needed, and a personalised return-to-running program that ensures long-term recovery.

Book Now

Located in Chatswood, 2067

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📚 References 

Aicale, R., Pellegrino, R., Di Iorio, A., Mottola, R., Saggini, R., Ruosi, C., & Tarantino, D. (2024). Comprehensive review of pes anserinus syndrome: Etiology, diagnosis, and management. European Journal of Musculoskeletal Diseases, 13(3), 60–69.

Alvarez-Nemegyei J. (2007). Risk factors for pes anserinus tendinitis/bursitis syndrome: a case control study. Journal of clinical rheumatology : practical reports on rheumatic & musculoskeletal diseases, 13(2), 63–65. 

Babaei-Ghazani, A., Eftekharsadat, B., Soleymanzadeh, H., & ZoghAli, M. (2024). Ultrasound-Guided Pes Anserine Bursitis Injection Choices: Prolotherapy or Oxygen-Ozone or Corticosteroid: A Randomized Multicenter Clinical Trial. American journal of physical medicine & rehabilitation, 103(4), 310–317. 

Choi, H. J., Back, H. K., Kim, Y. J., Oh, D. Y., Park, C. W., & Namgoong, J. (2021). A review of randomized controlled trials of pes anserinus tendinitis/bursitis syndrome in the China National Knowledge Infrastructure database. Journal of Acupuncture Research, 38(4), 284–292.

Farsad, F., Moghimi, J., Mirmohammadkhani, M., Gholami, E., & Moazeni, M. (2023). The effect of modifying the sitting and getting up method on pain intensity in patients with pes anserine tendinitis bursitis: A randomized clinical trial study [Preprint]. Research Square.

Homayouni, K., Foruzi, S., & Kalhori, F. (2016). Effects of kinesiotaping versus non-steroidal anti-inflammatory drugs and physical therapy for treatment of pes anserinus tendino-bursitis: A randomized comparative clinical trial. The Physician and sportsmedicine, 44(3), 252–256. 

Khosrawi, S., Taheri, P., & Ketabi, M. (2017). Investigating the Effect of Extracorporeal Shock Wave Therapy on Reducing Chronic Pain in Patients with Pes Anserine Bursitis: A Randomized, Clinical- Controlled Trial. Advanced Biomedical Research, 6, 70. 

Medscape. (2024). Pes anserine bursitis – Clinical presentation. Medscape Reference. https://emedicine.medscape.com/article/308694-clinical

Radiopaedia. (2024). Pes anserine bursitis. Radiopaedia.org. https://radiopaedia.org/articles/pes-anserinus-bursitis-1

Rennie, W. J., & Saifuddin, A. (2005). Pes anserine bursitis: incidence in symptomatic knees and clinical presentation. Skeletal radiology, 34(7), 395–398.

Sarifakioglu, B., Afsar, S. I., Yalbuzdag, S. A., Ustaömer, K., & Bayramoğlu, M. (2016). Comparison of the efficacy of physical therapy and corticosteroid injection in the treatment of pes anserine tendino-bursitis. Journal of physical therapy science, 28(7), 1993–1997. 

Yoon, H. S., Kim, S. E., Suh, Y. R., Seo, Y. I., & Kim, H. A. (2005). Correlation between ultrasonographic findings and the response to corticosteroid injection in pes anserinus tendinobursitis syndrome in knee osteoarthritis patients. Journal of Korean medical science, 20(1), 109–112.