Illustration of a child's arm showing the humerus-elbow-wrist angle.

Is Your Child's Arm Straight? Understanding Elbow Alignment and Growth

Kai Mendoza in Health & Wellness June 2025 • 4 min read.

"A Comprehensive Guide to the Humerus-Elbow-Wrist Angle (HEWA) and Its Significance in Pediatric Orthopedics"

As parents, we're always on the lookout for anything that might affect our children's health and development. One area you might not have thought about is the alignment of their arms. Terms like cubitus valgus or varus might sound like something out of a medical textbook, but they refer to common alignment issues in the elbow that can affect a child's arm's appearance and function.

Doctors use various measurements to evaluate these conditions. Among them is the humerus-elbow-wrist angle (HEWA), an angle that provides insights into the alignment of the upper arm (humerus) relative to the forearm. Understanding HEWA can be crucial in assessing whether a child's elbow alignment falls within the normal range or requires attention.

This guide is designed to help you understand HEWA, why it's important, and what to do if you have concerns about your child's arm alignment. We'll break down the medical jargon, explain the measurement process, and provide practical advice to support your child's healthy development. Let's dive in!

What is the Humerus-Elbow-Wrist Angle (HEWA)?

Illustration of a child's arm showing the humerus-elbow-wrist angle.

The humerus-elbow-wrist angle (HEWA) is a specific measurement used in orthopedics to assess the alignment of the arm. It's defined as the angle between the longitudinal axis of the humerus (the upper arm bone) and a line that passes through the midpoints of two transverse lines across the forearm. Think of it as a way to quantify how straight or angled the arm is at the elbow.

Why is this angle important? Because it helps doctors determine if there's an unusual alignment that could indicate cubitus valgus (where the forearm angles outward, away from the body) or cubitus varus (where the forearm angles inward, toward the body). While some degree of angulation is normal, excessive angulation might need monitoring or correction.

Normal Range: A typical HEWA falls within a specific range. A study of healthy children showed an average HEWA of 12.1 degrees, with a range from 5 to 20 degrees. This range can vary slightly depending on age.
Age Matters: The HEWA naturally changes as children grow. Research indicates the angle increases with age, so what's considered normal for a toddler might be different for a preteen.
No Gender Difference: Interestingly, studies have found no significant difference in HEWA between boys and girls.
Side to Side Symmetry: The HEWA should be relatively similar on both arms. Significant differences between the left and right arms could be a sign of an issue.

HEWA is particularly useful after surgery to correct arm alignment issues. By measuring the angle, surgeons can assess the effectiveness of the procedure and ensure the arm is properly aligned. It provides an objective way to track progress and make any necessary adjustments during recovery.

Taking the Next Steps

Understanding HEWA is just one piece of the puzzle when it comes to your child's health. If you have any concerns about your child's arm alignment or notice anything unusual, it's always best to consult with a healthcare professional. They can perform a thorough evaluation, take appropriate measurements, and provide personalized guidance based on your child's specific needs. Regular check-ups and open communication with your pediatrician are key to ensuring your child's healthy growth and development.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1097/bpb.0000000000000553, Alternate LINK

Title: Normal Value And Range Of The Humerus–Elbow–Wrist Angle In A Sample Of Healthy Children With Even Distributions Of Age, Sex, And Laterality

Subject: Orthopedics and Sports Medicine

Journal: Journal of Pediatric Orthopaedics B

Publisher: Ovid Technologies (Wolters Kluwer Health)

Authors: Naoto Inaba, Taku Suzuki, Takuji Iwamoto, Noboru Matsumura, Satoshi Oki, Masao Nishiwaki, Masaya Nakamura, Morio Matsumoto, Kazuki Sato

Published: 2019-01-01

Everything You Need To Know

What exactly is the Humerus-Elbow-Wrist Angle (HEWA), and why is it used?

The Humerus-Elbow-Wrist Angle (HEWA) is a specific measurement used in pediatric orthopedics to assess arm alignment. It is the angle formed between the longitudinal axis of the humerus, which is the upper arm bone, and a line passing through the midpoints of two transverse lines across the forearm. Doctors use HEWA to determine if the arm alignment is within the normal range. It helps identify conditions like cubitus valgus (forearm angles outward) and cubitus varus (forearm angles inward), which are important for a child's arm function and appearance.

What is considered a 'normal' range for the Humerus-Elbow-Wrist Angle (HEWA) in children, and does it change?

A typical HEWA falls within a specific range, with an average of 12.1 degrees and a range from 5 to 20 degrees based on studies of healthy children. This range can change with age, as the HEWA naturally increases as children grow. Therefore, what is considered normal for a toddler may differ from what's normal for a preteen. It's crucial to understand that the normal range is age-dependent.

Are there any differences in the Humerus-Elbow-Wrist Angle (HEWA) based on a child's gender or arm side?

Studies have shown no significant difference in the Humerus-Elbow-Wrist Angle (HEWA) between boys and girls. However, there should be relatively similar measurements on both arms. A significant difference between the left and right arms could indicate an underlying issue that warrants medical attention. Symmetry in HEWA is an important factor in assessing overall arm health and alignment.

How is the Humerus-Elbow-Wrist Angle (HEWA) used after surgery, and why is it so important in the recovery process?

The Humerus-Elbow-Wrist Angle (HEWA) is a valuable tool after surgery to correct arm alignment issues. Surgeons use HEWA measurements to assess the effectiveness of the surgical procedure, ensuring that the arm is properly aligned. It provides an objective, quantifiable way to track progress during recovery. By monitoring HEWA, healthcare professionals can make necessary adjustments and ensure optimal healing and alignment restoration.

If I'm concerned about my child's arm alignment, what steps should I take, and why is it crucial to seek professional advice?

If you have any concerns about your child's arm alignment, it is best to consult with a healthcare professional. They can perform a thorough evaluation and take the appropriate measurements, including the Humerus-Elbow-Wrist Angle (HEWA). The healthcare professional will provide personalized guidance based on your child's specific needs. Regular check-ups and open communication with your pediatrician are key to ensuring your child's healthy growth and development. Seeking professional advice ensures timely intervention if any issues are identified, helping to prevent potential long-term complications and supporting optimal arm function.