Flexor-Pronator Strain

A flexor-pronator strain of the elbow is a common source of pain in the elbows of pitchers. The pain is

Flexor-pronator origin
The flexor-pronator muscle are a source of medial elbow pain in throwing athletes. Note the location of the flexor-pronator origin (orange arrow).
located on the medial side of the elbow (the inside of the elbow closest to the body). There are many causes of pain on the medial side of the elbow in pitchers and other throwing and overhead athletes, such as medial epicondylitis (“golfer’s elbow), ulnar neuritis or ulnar nerve compression, and ulnar collateral ligament injury. Therefore diagnosis of this injury can be difficult.

A flexor-pronator strain can either result from an acute event or can develop as a result of overuse. A pitcher who has an acute flexor-pronator strain will remember a specific throw where he felt sharp pain on the medial side of the elbow. His pain will usually be located just past the bony prominence on the inside of the elbow. He often will have pain flexing the wrist or pronating the forearm.

Evaluation by a sports medicine physician is important soon after the injury to try to determine the correct diagnosis quickly. X-rays are usually normal with this injury. In high-level athletes an MRI is often ordered to ensure that the pain is not coming from an underlying injury to the ulnar collateral ligament, also known as the Tommy John injury. Most of the time, a flexor-pronator strain is treated with rest from pitching for several weeks to give the tendons time to heal. Ice and physical therapy can also be helpful to decrease the athlete’s symptoms. As the pain improves, the pitcher will be started on a long toss program prior to returning to full pitching.

10 Responses to Flexor-Pronator Strain

  1. Injury while hitting in wiffle tournament. Am54 years young. MRI results arrived thus morning – see doc next week. Diagnosis is complete rupture of the pronator teres at the medial epicondyle. I like golf and wish to continue an active lifestyle. Generally speaking, what are the options for this type of issue?

    • Depending on the extent of the injury, the tendon can be repaired to bone surgically, or the surgeon may elect to allow it to heal without surgery.

  2. My son is 18 & plays college baseball. His primary position is shortstop. In highschool he was also a pitcher. He had started feeling pain in his throwing elbow and was diagnosed with a strain in his ucl. He was put on a PT program and rest. That was back in June. After still not feeling 100% his. College coach sent him to a surgeon where a second MRI showed no change or additional damage. He felt something in his elbow the other day while throwing and the surgeon said it was his floor pronator. Surgery not necessary. My question after rambling on is would PRP be a viable option and would you recommend it. Thx

    • PRP has been used for partial UCL injuries. I haven’t seen data on its use for flexor pronator injuries. There is generally little downside other than the cost and it might not work.

  3. I just started throwing with my kid after hurting my arm 20 years ago. Could never throw again after pitching years of tennis ball stick ball and finally 21 innings in 2 days did it. For a while I couldn’t shoot a basketball and roll it off the fingers, but could always still throw a football. The pain is right at this point on the elbow, right on the inside at the bone, like in that picture. I would think after 5 or 10 years btwn throws it would not come back on the first harder throw. Does this sound like the same injury or something else? Would love to throw again with my kids. Thanks

    • It could be, but it is hard to say without examining you. If it isn’t getting better, you might consider seeing a doctor.

  4. Hi Dr David
    I would like your opinion on a an injury I had about 2 weeks ago. I fell and hurt my wrist. Main difficulty is pronation of the forearm. i have a lot of pain at night especially when my arm does not rest in supination position. I have been strapping my wrist and forearm as this helps with the swelling. Xrays showed no fracture. I have difficulty changing the gears in my car, picking up heavier objects, and extention of the wrist. I am 59, an Occupational Therapist and do SI treatment with children. I am having difficulty with the handling if my apparatus, What should I do.

  5. I train boxing .. I was taking gym partner on the pads and he followed through with a punch that wipped my arm write back. Been in pain when wash face .. or anything while arms bent and pressure is needed. Sharp pain at boney inner elbow. 1 year and no improvement. MrI scan shows no damage. Do you have any ideas how to help

  6. Dr.David,

    I am a division 1 pitcher at West Virginia University, and I suffered a strain in my forearm pronator muscle throwing a two-seam fastball. I felt the sharp pain when I threw it and the ball did not even reach the plate. I had three doctors look at it, including a team doctor and surgeon for an MLB team and I also had an MRI with a dye shot. Everything came back fine, but it has been five months now of rehab, treatment. Rested it for about two and half months, and began a throwing program. I started throwing bullpens at 50%, 75% and two at 100% about 3 weeks ago until now. so 6 bullpens total. but i am still feeling that pain in my elbow after all that rest and rehab. There is nothing else i can think of to do, I have stopped drinking for 4 months now and haven’t been doing anything damaging to my body. I can’t fully wrap my head around why I am not 100 percent by now… This is a big year for me athletically and I can’t afford to miss out anymore. Do you have any suggestions, examples, advice?

Leave a reply

Please note: I cannot and will not provide specific medical information within these comments, just as I won't anywhere else. Also, I reserve the right to delete comments that are offensive, off-topic, or spam. If you have questions, please read My Comments Policy.

david-headshot I am an orthopaedic surgeon and sports medicine specialist in Charleston, South Carolina.

On this blog, on my podcast, and in articles for numerous publications and in media interviews, I aim to provide you leading commentary and education on injury treatment and prevention to keep you performing at your best! Learn more about me >>


I'm excited to help with information and interviews for print, radio, television, and online media. Media information >>


Writing I write articles and columns for a number of publications and organizations. Writing information >>
Sports Medicine Simplified: A Glossary of Sports Injuries, Treatments, Prevention and Much More

Learn more about the glossary >>
© 2017 Dr. David Geier Enterprises, LLC

Site Designed by Launch Yourself