What Causes Leg Pain?

Patient Presentation
A 13-year-old male came to clinic for his health supervision visit. He was a runner but had had no athletic injuries. He did complain of intermittent bilateral lower leg pain. It occurred mainly in the evenings after running. He wasn’t sure how long it lasted for but less than 1 hour usually. The pain did not awaken him when sleeping and did not occur during school. It occurred approximately 1x/week and wasn’t changing in location, radiation or intensity. It did not cause limping, but was achy with rest and brief massage helping. The pain was a generalized soreness. He was running track, but had not started other events such as jumping or throwing. He was running about the same mileage on grass or a rubber track. His coach would make them run counterclockwise during warm-ups to help decrease stress on the inside track leg. The past medical history was negative. The family history was positive for a benign bone tumor in a maternal adult cousin who currently had no other problems. The review of systems was negative for fevers, chills, night sweats, easy bruising or bleeding, joint swelling, myalgia, or arthralgias.

The pertinent physical exam showed a well-appearing male with growth parameters around 50% for age. He had normal weight gain compared to a sick visit 3 months previously. His physical examination was normal. The diagnosis of of a healthy male was made. The pediatrician felt that the symptoms were most consistent with growing pains of the legs. He recommended making sure that the patient was stretching adequately before, during and after practices in addition to drinking adequate fluids. The patient was having routine screening laboratory evaluations for his age completed that day, so the physician also ordered an erythrocyte sedimentation rate and C-reactive protein which were normal. The patient was to followup with a diary of the leg pain in 2 months or sooner if new symptoms occurred.

“Growing pains” of the legs are a common complaint in children. Heterogeneous studies from 1928-2004 have found prevalence rates of 2.6-49.4% in children ages 4-19. The studies are heterogeneous because of time, location, and especially definition of growing pains. A study of 1445, 4-6 year olds in 2004 using a validated tool showed a prevalence rate of 36.9%.

The definition of growing pains used by Peterson in the 2004 study is chronic “…intermittent (nonarticular) pains in both legs that generally occur late in the day or at night…” with a normal physical examination and laboratory testing (if any is done). The pain is in the thigh or calf muscles. The pain can occur over weeks or months. Patients should not have a history of trauma but because the time period over which the pains occur, patients and families will often relate histories of minor trauma. The cause of growing pains is not known but theories include muscle fatigue, anatomic differences such as flat feet or knock-knees or being part of a larger pain constellation such as headache or abdominal pain.

Leg pain that has different characteristics such as localized, persistent or intensifying pain, pain that occurs at different times of the day, obvious joint involvement, limb swelling or erythema or systemic symptoms demand a more extensive history and laboratory and/or radiological investigation. For many children and young adolescents, intermittent viral syndromes with myalgias or athletic overuse are common problems that may have similar presentations to growing pains.

Learning Point
The differential diagnosis of leg pain includes:

  • Infectious Disease
    • Arthritis, septic
    • Toxic synovitis
    • Lyme disease
    • Osteomyelitis
    • Rheumatic fever
    • Viral syndromes
  • Hematology/Oncology
    • Bone tumor
    • Leukemia
    • Muscle tumor
    • Neuroblastoma
  • Orthopaedic
    • Compartment syndrome
    • Entrapments
      • Arterial
      • Nerve
    • Fracture
      • Growth plate
      • Stress
        • Medial tibial stress syndrome (i.e. shin splints)
        • Osgood-Schlatter disease
      • Hypermobility
      • Legg-Calve-Perthes disease
      • Muscle cramps
      • Slipped capital femoral epiphysis
      • Soft tissue injuries
        • Bursitis
        • Condritis
        • Injections
        • Meniscus
        • Myositis including benign acute childhood myositis and rhabdomyolysis
        • Tendonitis
  • Rheumatology
    • Arthritis, reactive
    • Dermatomyositis
    • Henoch Schonlein purpura
    • Juvenile idiopathic arthritis
    • Systemic lupus erythematosus
  • Other
    • Deep vein thrombosis
    • Fibromyalgia
    • Growing pains
    • Psychiatry/psychological problems
      • Conversion reaction
      • Munchausen syndrome or by proxy
      • Stress
    • Radiation from other body area, i.e. hip, back
      • Spinal stenosis
    • Reflex sympathetic dystrophy

Questions for Further Discussion
1. If a child has both upper extremity and lower extremity pain, how does that change your differential diagnosis?
2. What are indications for radiographs for patients with leg pain?
3. What laboratory evaluations could be considered for patients with leg pain?
4. What are indications for orthotics or similar shoe devices for the treatment of leg pain?

Related Cases

    Symptom/Presentation: Pain

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Leg Injuries and Disorders

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Evans AM, Scutter SD. Prevalence of “growing pains” in young children. J Pediatr. 2004 Aug;145(2):255-8.

Pell RF 4th, Khanuja HS, Cooley GR. Leg pain in the running athlete. J Am Acad Orthop Surg. 2004 Nov-Dec;12(6):396-404.

Tse SM, Laxer RM. Approach to acute limb pain in childhood. Pediatr Rev. 2006 May;27(5):170-9.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.


    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital