Humerus Lateral (Recumbent) is a radiography positioning projection of the Upper Extremity. Supine, arm internally rotated, palm down. SID 40". The centering point is located at the midpoint of the humerus in the lateral position. supine position with shoulder raised.. The central ray is perpendicular to ir, typically horizontal when patient is supine.. Image-quality criteria include entire humerus visible in true lateral position., greater tuberosity projected posteriorly.. Standard exposure ranges from 70 to 80 kVp, 3 to 6 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Humeral head, neck, and shaft in lateral projection.
- Greater tuberosity projected posteriorly.
- Lesser tuberosity visible medially.
- Shoulder joint space open.
- Distal humerus and trochlea.
- Proximal radius and ulna.
Patient preparation
- Verify patient identity using two identifiers.
- Remove watches, bracelets, and radiopaque items from the arm.
- Position patient supine on the table.
- Internally rotate the arm with palm facing down.
- Raise the shoulder for lateral positioning on the IR.
Position & centering point
At the midpoint of the humerus in the lateral position. Supine position with shoulder raised.
Central ray
Perpendicular to IR, typically horizontal when patient is supine.
Exposure / technique
- kVp
- 70–80
- mAs
- 3–6
- SID
- 40" (102 cm)
- Notes
- Grid recommended. Horizontal CR for supine positioning.
Image-quality criteria
- Entire humerus visible in true lateral position.
- Greater tuberosity projected posteriorly.
- Lesser tuberosity projected medially.
- Shoulder articulation open and clearly defined.
- Distal humerus and proximal elbow included.
- Collimation: 1 inch above shoulder, 1 inch below elbow.
Common errors / ARRT traps
- 1 Insufficient internal rotation leaves humerus off true lateral.
- 2 Forward shift of the shoulder rotates the arm.
- 3 Off-center CR clips the proximal humerus or elbow.
- 4 Inadequate shoulder elevation changes the lateral angle.
Clinical indications
- Severe humeral trauma or fracture.
- Shoulder dislocation when patient cannot sit or stand.
- Proximal humerus fracture assessment in recumbent patients.
- Post-operative follow-up of shoulder or humerus fixation.
Aligned to the 2025 ARRT Content Specifications.