How do you tell if your son was born missing the triceps muscle?

To determine if your son was born missing the triceps muscle, look for any visible abnormalities in his upper arms, such as an unusual shape or lack of muscle bulk. Notice if he has difficulty extending his elbow or performing activities that require arm strength, like pushing or lifting. A medical professional can perform a physical examination and possibly imaging tests to confirm the absence of the muscle. If you have concerns, consulting a pediatrician or a specialist in musculoskeletal disorders is recommended.