Pelvic incidence–lumbar lordosis mismatch

Principle and interpretation

The abbreviation PI–LL is common. Measurement depends on the boundaries used for lordosis and should be interpreted with age and global parameters.

Indications, limitations and precautions

Mismatch can inform deformity surgery planning. In isolation, it is neither proof of pain nor an indication to correct posture using a device.

Points to consider

These parameters describe geometric relationships on standardized images. Standing position, framing and landmark selection can influence values. Interpretation considers age, compensation and the overall sagittal profile; one number is not a surgical indication.

Role of TAGMED care

At TAGMED, assessment aims to understand symptoms, history and functional limitations. Manual care and osteopathy, motorized spinal decompression, laser and shockwave have different indications. The term described in this entry is not enough to select any of these modalities. Their relevance, limitations and possible contraindications should be discussed in relation to diagnosis and individual goals.

Related concepts and distinctions

These concepts belong to the same field, but are not synonyms.

• Sagittal vertical axis — Measure of horizontal offset between a vertical line through C7 and a sacral landmark, used to assess global sagittal alignment.
• Sacral slope — Angle between the upper sacral endplate and horizontal, used to describe sagittal sacral orientation.
• Pelvic tilt — Angle describing pelvic orientation relative to vertical, measured using the sacral endplate and femoral-head axis.

Medical references

1. Legaye et al., original research indexed in PubMed. Pelvic incidence: a fundamental pelvic parameter for three-dimensional regulation of spinal sagittal curves.
2. Original research indexed in PubMed. Pelvic parameters: origin and significance.

References document the topic; their inclusion does not imply endorsement of TAGMED services by those organizations.