This was a question from a patient who I had recently. She has knee osteoarthritis but not to the point that she needs surgery. She comes to see me whenever she has a flare-up. I help calm down her knee pain and she goes on her way. This time she had something a little different. She had her normal knee pain but also had pain a little lower into her shin bone. Her knee had a little more valgus to it than before – meaning that she was more knock-kneed. There was also noticeable swelling on the upper shin bone just where the pes anserine is located. Looks like pes anserine bursitis! To learn more about this condition, read on.  Let’s start with the anatomy.
The knee joint
The knee is the largest joint in the body. The knee is made up primarily by the tibiofemoral joint and patellofemoral joint. The tibiofemoral joint is what most of us think of as the knee. It is the joint made between the bottom of the femur (the thigh bone) and the top of the tibia (the shin bone). The patellofemoral joint is the joint made between the femur and the patella (the kneecap).
The bursa
Bursas are fluid filled sacs that are located all around the body. They reduce friction and act as cushions for structures such as bones, tendons, and muscles. The pes anserine bursa is located on the shin about 2-3 inches below the inner front knee. Three muscles attach to this area. These muscles are the gracilis, sartorius, and semitendinosis. Each of these muscles originate at a different area of the pelvis and then travel down the thigh to attach at the pes anserine. Together these muscles help to bend the knee and rotate it inwardly.  The pes anserine bursa decreases the friction between the tendons of the gracilis, sartorius, and semitendinosis.
Pes anserine bursitis
Bursitis occurs when the bursa becomes irritated and inflamed. This inflammation and pain typically build up over time rather than presenting suddenly. Pes anserine bursitis has several causes. These include:
- Repeatedly bending the knee and adducting the hip (moving the leg toward the other leg).
- Knee osteoarthritis
- Contusion or trauma to the area
- Knock-kneed positioning of the knees
Symptoms of pes anserine bursitis
There are several symptoms associated with pes anserine bursitis. These include:
- Pain and swelling at the area of the pes anserine on the inner shin bone 2 to 3 inches below the knee.
- Tenderness at the pes anserine area.
- Pain with bending or straightening the knee.
- Pain with getting up from sitting.
- Pain going up steps.
- Pain with crossing legs.
- Pain with walking or running.
- Pain with squatting.
Who gets pes anserine bursitis?
There are a few different groups of people that are more likely to develop pes anserine bursitis. These include:
- Young people that are active in sports
- Women ages 50-80
- Women have a wider pelvis which increases the likelihood of an inward rotation of the knees (knock-knee position).
- Those suffering from knee osteoarthritis
- About 75% of those with knee osteoarthritis will have pes anserine bursitis at some point.
- Type 2 diabetics
- About 1/3 of knee pain in type 2 diabetics is pes anserine bursitis.
What are the risk factors for pes anserine bursitis?
There are several risk factors for developing pes anserine bursitis. These include:
- Participating in certain sports or activities
- Swimming breaststroke
- Running
- Basketball
- Racquet sports
- Incorrect technique or form when training
- Obesity
- Knee osteoarthritis
- Type 2 diabetes
- Tight hamstrings
- Flat feet
Who should I see?
- Physical therapy – This would be my first stop. Physical therapy can help decrease pain and inflammation with techniques including manual therapy and dry needling. PT can evaluate and address abnormal joint mobility, muscle weakness, and flexibility. If you are an athlete, your PT can also assess your training schedule and technique to prevent the problem from happening again.
- Orthopedic or sport medicine physician – An orthopedist might be necessary if the condition is not responding to physical therapy.  Your physician can prescribe medication, give an injection, or order imaging if needed. Surgery is an option if your condition does not respond to any conservative treatment.
What can I do?
- Relative rest – Resting the area to decrease further pain and damage from occurring is one of the best ways to treat pes anserine bursitis. Basically, stay away from the activities that are causing pain. This gives the area time to rest and heal. This can include avoiding steps and any other activities that cause significant irritation and pain. You can perform non-irritating activities such as biking, swimming, or walking to maintain cardiovascular and muscle strength. Limit your walking distance if it begins to irritate the knee. Return to sport or normal activities slowly to prevent bursitis from reoccurring.
- Ice – Ice can help decrease pain and swelling in the area. Ice the painful area for 15 to 20 minutes at a time. I would recommend using an ice pack several times per day if the pain is constant or is preventing you from participating in an activity. Ice immediately after activity.
- Stretching – Stretching all the muscles around the hip is very important in helping to manage pes anserine bursitis. Increasing the mobility of the hip and knee will decrease the stress on this area.  See the videos below for instructions in how to stretch hamstrings, quadriceps, hip flexors, calves, and adductors.
- Strengthen the muscles around the hip and knee– It is important to strengthen the muscles around the hip and knee. This includes your gluteal muscles, quadriceps, and the hamstrings.   All these muscles will help take some of the load off the pes anserine area. The first 2 videos are isometrics and some non-weightbearing exercises that can be done at the beginning of your healing process. The next video is more mid-stage strengthening and should only be performed when the pain has subsided significantly. There should be minimal soreness when performing the exercises and no pain afterwards. Using loop resistance bands , resistance bands and ankle weights can increase strength and difficulty of the exercises. See the videos below.
In review
- Bursas are fluid filled sacs that are located all around the body.
- They reduce friction and act as cushions for structures such as bones, tendons, and muscles.
- The pes anserine bursa is located on the shin about 2-3 inches below the inner front knee.
- Three muscles attach to this area.
- These muscles are the gracilis, sartorius, and semitendinosis.
- Bursitis occurs when the bursa becomes irritated and inflamed.
- This inflammation and pain typically build up over time rather than presenting suddenly.
- Pes anserine bursitis can be caused by repetitive knee bending and hip adduction but is also associated with knee osteoarthritis, knock knee positioning, and direct trauma to the area.
- Pes anserine bursitis causes pain and swelling on the inner shin bone 2 to 3 inches below the knee.
- Pes anserine bursitis is more common with certain sports, females ages 50-80, those with knee osteoarthritis, and type 2 diabetics.
- Physical therapy is very successful in treating pes anserine bursitis.
- An orthopedist might be necessary if the condition is not improving with physical therapy.
- There are several things that you can do:
- Relative rest
- Ice
- Stretching
- Strengthening
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
Additional resources
https://www.physio-pedia.com/Pes_Anserinus_Bursitis
https://www.ncbi.nlm.nih.gov/books/NBK532941/
https://www.choosept.com/guide/physical-therapy-guide-pes-anserine-bursitis