A different weak link

In an adult arm, the headline throwing injury is the torn ligament. In a child's arm, the story is different. Before the bones finish growing, the softest spot in the throwing arm is the growth plate, a zone of cartilage where the bone is still lengthening. That cartilage is weaker than the surrounding tendon and ligament, so under repeated throwing stress it tends to give first.1

This is why two of the most common throwing injuries in youth baseball have nothing to do with the UCL. They happen at the growth plates, and they have earned the nicknames Little League elbow and Little League shoulder.

Little League elbow

The medical name is medial epicondyle apophysitis. Every hard throw pulls on the growth center on the inside of the elbow, and repeated pulling irritates and inflames it.12 The growth center on the inner elbow typically appears around age 6 or 7 and fuses by about age 15, which defines the window of risk. It shows up most often in pitchers younger than 16.2

What you would notice: pain on the inner side of the elbow that comes on with throwing, tenderness right over that bony bump, and sometimes a drop in velocity or trouble fully straightening the arm.

Little League shoulder

The medical name is proximal humeral epiphysiolysis, a stress reaction of the growth plate at the top of the upper arm bone. It tends to appear in higher-volume pitchers between roughly 11 and 16, and the growth plate there does not fully fuse until the late teens or early twenties.3 The complaint is usually shoulder pain with throwing, often most noticeable during the acceleration phase, sometimes felt as a vague ache at the top of the arm.

Why these injuries get missed

Both often begin as a dull ache that arrives with throwing and quietly fades with a few days of rest. So the natural response is to shrug it off, ice it, and keep playing. A young pitcher who wants to compete will rarely volunteer the information, and sometimes the first visible clue is a loss of velocity or command rather than a complaint of pain.

Watch for

Treat a young pitcher's recurring elbow or shoulder ache as information, not weakness. Pain that returns every time they throw is the body reporting a problem, and it deserves a look from a sports medicine professional rather than another inning.

What to do about it

  1. Stop throwing. Rest is not optional with a growth-plate injury; it is the treatment.
  2. Get it evaluated. A sports medicine physician can examine the arm and may use imaging to confirm what is going on.
  3. Let it calm down fully before returning, which often takes weeks, not days.
  4. Come back through a gradual, structured throwing progression rather than straight back to the mound.
  5. Fix the cause. Look hard at the volume, the rest, and the year-round schedule that produced the injury in the first place.
Key idea

Here is the reassuring part. Caught early, growth-plate throwing injuries almost always heal completely with rest and a smart return. The cases that turn serious, including a fracture or a pulled-off piece of bone, are usually the ones that got pushed through.

Preventing them in the first place

The prevention playbook is the same one that protects the ligaments: respect age-based pitch counts and rest days, take a genuine off-season from throwing, watch for fatigue, and never let a child pitch through pain.4 Growth plates are forgiving when you give them time and unforgiving when you do not.

Education, not a medical diagnosis or treatment plan. If your pitcher has pain, consult a qualified sports-medicine professional.

Originally published on CritchPitch.