“Why Is This Kid Limping?” A Detailed Evaluation of the Antalgic Gait in Children

By |September 9th, 2025|Orthopedics| Evaluating a limping child is a core skill in Pediatric Emergency Medicine, and it’s one of those presentations where your differential can expand quickly if you don’t anchor it with age, a careful exam, and a good sense of red flags. In this post, you’ll find a comprehensive overview of history-taking, physical exam, imaging, labs, and an age-based diagnostic framework, all designed to help you distinguish benign self-limited causes from those that demand urgent intervention. Age-Based Diagnostic Framework Your first anchor point is the child’s age. This helps you narrow the wide differential: In kids under 3, think trauma and congenital conditions. Between 3 and 10, transient synovitis reigns supreme. Over 10? Think SCFE, stress injuries, and systemic disease. [1–3] What to Ask: History Matters A high-yield history can shortcut your entire evaluation. Ask: Onset: Sudden vs gradual? Recent illness: URI or GI symptoms may point toward transient synovitis. Trauma: Even minor, unwitnessed trauma in toddlers matters. Systemic symptoms: Fever, rash, weight loss, malaise. Worse in the morning? Think inflammatory arthritis. Location of pain: Not always the joint they’re guarding. Video evidence: Parents’ videos of ambulation at home are gold. Also consider: Tick exposure or travel (→ Lyme arthritis or osteomyelitis) Prior episodes (→ JIA, reactive arthritis) Toileting regression (→ spinal pathology or pelvic issues) [2,4,5] Physical Exam Start by observing the child walk. Have them move across the room, not just take a few steps. Note: Antalgic gait (shortened stance phase) Stiff leg or Trendelenburg pattern Refusal to bear weight Your hands-on exam should include: Palpating each limb entirely, not just the “hurting” one. Testing passive and active range of motion. Log rolling the hip — pain suggests intra-articular pathology. Squeezing the calf or heel to localize pain in younger kids. Assessing abdominal tenderness and testicular exam in boys (torsion and appendicitis can masquerade as limp). Looking at the soles for splinters, puncture wounds, ingrown nails, or petechiae. [2,4] Imaging: Know What to Order Plain Films Always your first stop. Get two views, minimum. Focus on the symptomatic joint—but if the diagnosis isn’t clear, image from hip to toes. Toddler’s fractures and SCFE can be subtle. Don’t skimp. Ultrasound Great for detecting joint effusions, especially at the hip. Not diagnostic for septic arthritis. A small effusion could be transient synovitis or early infection. Normal ultrasound doesn’t rule out septic arthritis. Ultrasound is not part of the Kocher criteria — don’t let it falsely reassure you. MRI Best for osteomyelitis, discitis, or deep soft tissue infections. Useful when x-rays are unrevealing and you’re worried about infection or malignancy. May require sedation in younger children. [1,2,4,5] Labs: What and When to Send Tailor labs to the level of concern: CBC – look for leukocytosis or pancytopenia. ESR and CRP – both are inflammatory markers; CRP rises/falls faster. Blood culture – if febrile or concern for septic arthritis. Lyme serology – if exposure risk is high.If Lyme is your top diagnosis and the child has a classic rash, it’s reasonable to start treatment while labs are pending or equivocal [5]. ANA, RF – not useful in the ED unless the limp is chronic and you’re coordinating with Rheumatology. [1,2,4,5] The Kocher Criteria These prediction rules help estimate the likelihood of septic arthritis of the hip: Fever >38.5°C Non–weight bearing ESR > 40 mm/hr (CRP > 2.0 mg/dL can be used instead) WBC > 12,000/mm³ CRP and ESR are interchangeable in the Kocher criteria — CRP was not available when the original prediction rule was developed, but studies have shown similar performance when substituted [6]. Remember: Ultrasound isn’t part of the rule. The child in front of you matters more than the prediction model. [6] Don’t Miss These “Non-Limp” Limp Causes Appendicitis: Can cause psoas irritation and limp. Testicular torsion: Especially with abdominal or groin pain. Discitis: Refusal to sit or walk. Leukemia: Bone pain, limp, fatigue, pallor, bruising. Pelvic abscess or psoas abscess: May mimic hip pain. [1,2,4] Red Flags: When to Worry Child is ill-appearing or febrile. Pain is severe or progressive. Lab markers of inflammation are elevated. No diagnosis, but the kid still won’t walk. You suspect non-accidental trauma or infection. Don’t send these children home. If in doubt, admit and consult orthopedics. Final Thoughts The limping child is a diagnostic puzzle with serious implications if you miss something like septic arthritis, SCFE, or malignancy. Anchor your evaluation in the child’s age, start with a careful history and exam, use imaging and labs judiciously, and always watch the kid walk. And please, don’t forget to take off their shoes and check the feet. A Bonus Podcast References Terk MR, et al. Antalgic Gait in Children. StatPearls. 2023. Neuman MI, et al. Evaluation of limp in children. UpToDate. Accessed 2025. Bernard SA, et al. Differential diagnosis of limp in children. UpToDate. Accessed 2025. Schunk JE. Limping child. Pediatrics in Review. 2023;44(9):466-476. doi:10.1542/pir.2023-006052 Boutis K. The limping child: a systematic approach. Pediatric Annals. 2015;44(9):e217-e222. Kocher MS, et al. Differentiating septic arthritis from transient synovitis of the hip in children. J Bone Joint Surg Am. 1999;81(12):1662-1670. About the Author: Brad Sobolewski, MD, MEd Brad Sobolewski, MD, MEd is a Professor of Pediatric Emergency Medicine and the Associate Director of Physician and Team-Based Education at Cincinnati Children's Hospital Medical Center. He is on Twitter/X @PEMTweets, on Instagram @BradSobolewski, authors the Pediatric Emergency Medicine site PEMBlog and is the host and creator of PEM Currents: The Pediatric Emergency Medicine Podcast. All views are strictly my own and not official medical advice. Related Posts