Body & Balance Studio
Posture scan

Trunk Lean

Also known as: forward lean, trunk inclination.

What it is

Trunk lean is a forward or backward inclination of the torso from the vertical plumb line in a side view. A forward lean increases demand on the back extensors; it can reflect hip-flexor tightness or a postural habit.

How to spot it

From the side, the line from hip to shoulder angles forward of vertical. The scan reports the trunk angle from vertical.

Muscles involved

Muscles involved in Trunk Lean, front view — typically tight muscles in coral, typically weak in teal
Front (anterior) view
Muscles involved in Trunk Lean, back view — typically tight muscles in coral, typically weak in teal
Back (posterior) view

Coral = typically tight, teal = typically weak. Anatomical illustration from Z-Anatomy (derived from BodyParts3D), licensed under CC BY-SA 4.0.

Typically tight: hip flexors, erector spinae

Typically weak: deep abdominals, gluteals

How to correct it

  • Stretch the hip flexors.
  • Strengthen the deep core and glutes for an upright stack.
  • Cue tall, plumb-line standing.
Wall-Standing Postural Exerciseactivate · thoracicOne-Joint Hip Flexor Stretch (Supine, Knee to Chest)stretch · hipStanding Door-Frame Hip Flexor Stretch (Posterior Pelvic Tilt)stretch · hipAbdominal Trunk Curlstrengthen · core
hip flexorserector spinaedeep abdominalsgluteals

Educational wellness content — not a diagnosis. See a clinician for pain or concerns. Run a posture scan to check your own alignment.