The Centers for Advanced Orthopaedics
Maryland Orthopedic Specialists
A Division of The Centers for Advanced Orthopaedics
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Shoulder

Proximal Humerus Stress Fracture

Proximal humerus stress fractures are rare injuries that occur in overhead throwing athletes subjected to repetitive, high-intensity loading of the shoulder. Prompt recognition is critical — continued throwing through a stress fracture risks progression to a complete fracture. At Maryland Orthopedic Specialists, our sports medicine specialists have the expertise to distinguish this uncommon diagnosis from the more familiar Little Leaguer's Shoulder and guide athletes through safe, structured recovery.

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What is proximal humerus stress fracture?

A proximal humerus stress fracture is a small fatigue crack near the top of the upper arm bone, caused by repetitive overhead loading rather than a single injury. It is most common in throwing athletes and weightlifters, producing activity-related shoulder or upper-arm pain that eases with rest.

A stress fracture develops when repetitive submaximal loading overwhelms the bone's capacity for remodeling, creating a fatigue crack. In the proximal humerus of skeletally mature athletes, stress fractures occur most commonly at the surgical neck or through the proximal humeral metaphysis, subjected to the powerful torsional and tensile forces of the overhead throwing motion — particularly during the late cocking and acceleration phases.

Who Is Affected?

Proximal humerus stress fractures of this type occur in skeletally mature overhead athletes — typically collegiate or professional baseball pitchers, gymnasts, and volleyball players. This distinguishes them from Little Leaguer's Shoulder, which is a physeal injury (stress fracture through the open growth plate) in skeletally immature adolescent athletes.

In the skeletally mature athlete, the physis has closed; the fracture line runs through metaphyseal or diaphyseal bone rather than the growth plate.

Distinguishing from Little Leaguer's Shoulder

  • Skeletal maturity: Stress fracture — Mature (physis closed); Little Leaguer's Shoulder — Immature (physis open)
  • X-ray finding: Stress fracture — Cortical stress reaction or fracture line; Little Leaguer's Shoulder — Widening of proximal humeral physis
  • Age: Stress fracture — Typically ≥ 18 years; Little Leaguer's Shoulder — 11–16 years
  • Treatment: Stress fracture — Rest; return-to-throw protocol; Little Leaguer's Shoulder — Rest 3 months; return-to-throw protocol

Both conditions respond to rest; the key is accurate diagnosis so that continued throwing does not occur during healing.

Treatment options

Complete Rest from Throwing

The cornerstone of treatment is complete cessation of throwing until the athlete is pain-free at rest and with daily activities, and imaging demonstrates healing. This typically requires 6–12 weeks of throwing rest, though timelines vary with fracture grade. Return-to-throw before adequate healing risks progression to a complete fracture.

Gradual Return-to-Throw (RTT) Protocol

Once pain-free at rest and on clinical examination, athletes progress through a structured, interval return-to-throw program: - Begin with flat-ground tosses at short distances - Progressively increase distance, then velocity - Progress to off-mound throwing only after completing flat-ground phases without pain - Full return to competitive pitching typically 3–6 months from injury

Surgery

Surgery is rarely required. Surgical fixation may be considered for a complete or displaced fracture, which is an unusual complication of a missed or undertreated stress fracture.

Frequently Asked Questions

Can I keep throwing if I push through the pain?
No. Continuing to throw with a stress fracture risks progression to a complete fracture, which would require surgery and a substantially longer recovery. Rest is not optional.
How will we know it's healed?
Healing is confirmed by the absence of pain on clinical examination and resolution or stabilization of imaging findings. We use MRI and serial examination to confirm readiness before advancing the return-to-throw protocol.
Is this the same as Little Leaguer's Shoulder?
They are related conditions affecting the same region but in different age groups. Little Leaguer's Shoulder affects the open growth plate in adolescents; this stress fracture occurs through metaphyseal/diaphyseal bone in mature athletes with fused growth plates.
How long will I need to stop throwing because of a proximal humerus stress fracture?
Complete rest from throwing is typically required for 6–12 weeks, depending on the severity of the stress reaction and whether there is visible fracture on imaging. Healing is confirmed by follow-up MRI or X-ray showing resolution of the stress response before any throwing is initiated. A supervised interval throwing program then begins gradually, and most athletes reach full competitive throwing at 4–6 months from diagnosis. At MOS, we map out a precise return-to-throw progression and monitor your response at each stage to ensure the growth plate has fully recovered.
Are stress fractures of the shoulder common in young pitchers?
Proximal humerus stress fractures (Little Leaguer's Shoulder) are not rare in competitive youth pitchers, particularly those who throw year-round across multiple teams without adequate rest. The open growth plate of the upper humerus in adolescents is mechanically weaker than the surrounding bone and tendons, making it the weak link under the repetitive rotational forces of pitching. Surveys of high-level youth pitchers have identified significant rates of growth plate stress changes in those who exceed recommended pitch count and rest guidelines. This is why pitch count rules, mandatory rest days, and off-season breaks are so important — guidelines that your MOS team will reinforce as part of your child's care.

Meet the specialists

Christopher S. Raffo, MD

Christopher S. Raffo, MD

Orthopedic Surgery · Sports Medicine

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John J. Christoforetti, MD

John J. Christoforetti, MD

Orthopedic Surgery · Sports Medicine · Hip Preservation Surgery

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James S. Gardiner, MD

James S. Gardiner, MD

Orthopedic Surgery · Sports Medicine

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Related conditions

Little Leaguer's ShoulderClavicle Fracture
Medically reviewed by Christopher S. Raffo, MD
Last reviewed May 1, 2026

References

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  3. Osbahr DC, Kim HJ, Dugas JR. Little league shoulder. Curr Opin Pediatr. 2010;22(1):35–40. doi: 10.1097/MOP.0b013e328334909b.
  4. Dotter WE. Little leaguer's shoulder: a fracture of the proximal epiphyseal cartilage of the humerus due to baseball pitching. Guthrie Clin Bull. 1953;23:68–72.
  5. American Academy of Orthopaedic Surgeons. Little Leaguer's Shoulder. OrthoInfo. https://orthoinfo.aaos.org/en/diseases--conditions/little-leaguers-shoulder/
  6. Bencardino JT, Gyftopoulos S, Palmer WE. Imaging in anterior glenohumeral instability. Radiology. 2013;269(2):323–337. doi: 10.1148/radiol.13121926.