The pes anserine is where three tendons — sartorius, gracilis, and semitendinosus — insert on the inner shin, just below the knee joint. A small fluid-filled sac (bursa) sits between these tendons and the underlying bone. When irritated, this bursa creates a distinct pain pattern on the inner side of the knee, below the joint line.
Classic presentation
- Pain on the inner side of the knee, 2-3 inches below the joint line (not right at the joint)
- Localized tenderness at the pes anserine
- Worse with climbing stairs, getting up from sitting, or running
- Sometimes swelling in the area
- Often confused with medial meniscus or MCL pain
Common contributors
- Overuse from running or repetitive knee flexion
- Weak glutes and hip abductors — leads to knee collapse inward and increased pes anserine load
- Tight hamstrings or hip adductors
- Poor running form or footwear
- Underlying knee osteoarthritis (common in older patients with pes anserine involvement)
Treatment
Load management — reduce aggravating activity while the bursa calms down. Substitute low-impact activities.
Soft tissue therapy — the involved tendons and the surrounding musculature.
Hip and glute strengthening — the primary long-term fix. If the hip stabilizes better, the pes anserine doesn't get overloaded.
Manual therapy — joint mobilization for the knee, hip, and lumbar spine as needed.
Shockwave therapy — for chronic cases that haven't responded to standard care.
Class IV laser therapy for symptom management.
Home protocol
- Glute bridges, clam shells, and single-leg squats to progression
- Gentle hamstring and hip adductor stretching
- Ice after activity during acute phases
- Foam roll the medial thigh and hip
When to get it seen
Persistent inner knee pain, especially with weakness or swelling, deserves an assessment. Many patients have been treated for "knee arthritis" without addressing a pes anserine component that's actually driving most of their symptoms.