Differential Diagnosis for Arm Pain after Exercise

The patient's symptoms of pain along the trapezius and tricep that radiates down the arm to the elbow after performing pushups and chest-related exercises can be approached by considering the following differential diagnoses:

• Single Most Likely Diagnosis

  • Muscle Strain: This is the most likely diagnosis given the history of recent exercise, particularly pushups and chest-related activities that engage the trapezius and tricep muscles. Muscle strain can cause pain and stiffness in the affected muscles, which can radiate along the path of the muscle.

• Other Likely Diagnoses

  • Tendinitis: Inflammation of the tendons around the shoulder or elbow could cause pain that radiates down the arm. Given the patient's recent exercise history, tendinitis is a plausible diagnosis, especially if the exercises involved repetitive movements that could irritate the tendons.
  • Thoracic Outlet Syndrome (TOS): This condition involves compression, injury, or irritation of the nerves and/or blood vessels (arteries and veins) in the thoracic outlet area, which lies between your collarbone (clavicle) and first rib. It could cause pain in the shoulders and neck and numbness in the fingers, but the symptoms can sometimes radiate down the arm.
  • Cervical Radiculopathy: Although the physical exam is reassuring, cervical radiculopathy (nerve root irritation or compression in the cervical spine) could cause pain that radiates down the arm. The pain pattern can vary depending on which nerve root is affected.

• Do Not Miss Diagnoses

  • Myocardial Infarction (MI): Although less likely given the context of recent exercise and the specific location of pain, it's crucial not to miss an MI, especially if the patient has risk factors. Atypical presentations of MI can include arm pain without chest pain.
  • Pulmonary Embolism: While rare and less directly related to the symptoms described, a pulmonary embolism could potentially cause referred pain in the arm, especially if it leads to a myocardial infarction or other complications affecting the arm indirectly.

• Rare Diagnoses

  • Brachial Plexus Injury: Direct injury to the brachial plexus, which is a network of nerves that conducts signals from the spinal cord to the shoulder, arm, and hand, could cause pain and numbness in the arm. However, this would typically be associated with more significant trauma than pushups.
  • Osteonecrosis or Bone Tumors: Although very rare in this context, conditions affecting the bones of the arm or shoulder could cause pain. These would typically have additional symptoms or findings on physical examination or imaging.