The flexor pronator is a group of five muscles in the forearm that attach to the bony bump on the inner side of the elbow. These muscles are responsible for flexing the wrist and rotating the forearm. A strain occurs when these muscle fibers or their tendons are stretched or torn due to repetitive stress or sudden forceful movements.
Tender Inner Elbow: Direct soreness over the muscle mass just below the medial epicondyle bone.
Pain with Wrist Motion: Discomfort when bending the wrist toward the palm or when turning the palm down toward the floor.
Weakened Grip: A noticeable loss of hand strength or pain when squeezing objects.
Activity Related Aching: Pain that intensifies during the acceleration or follow through phase of a throw.
Forearm Tightness: A feeling of constant tension or a "pulling" sensation in the upper forearm.
Accurate diagnosis is essential to differentiate this muscle strain from a ligament tear or ulnar nerve issue.
Physical Exam
X-ray: To evaluate for soft tissue calcifications or fractures
MRI or Ultrasound: While often diagnosed through a physical exam, imaging can confirm the grade of the strain and ensure the underlying ulnar collateral ligament is intact.
Most flexor pronator strains respond well to non-surgical care with activity modification and structured physical therapy. Platelet rich plasma (PRP) injections can be helpful as well.
Surgery for a flexor pronator injury is very rare and typically only considered if the tendon has completely detached from the bone or if there is significant associated damage to the elbow ligament. For most patients, a gradual return to play program ensures the muscle can handle the high forces of sports without re-injury.