Table 9 Bath Ankylosing Spondylitis Metrology Index (BASMI) linear function20
S = (21.1 cm−A)/2.1 cmLateral lumbar flexion (mean right/left)
S = (A−8 cm)/3 cmTragus to wall distance (mean right/left)
S = (7.4 cm−A)/0.7 cmLumbar flexion (modified Schober)
S = (124.5 cm−A)/10 cmMaximal intermalleolar distance
S = (89.3°−A)/8.5°Cervical rotation angle (mean right/left)
  • The average score of the five assessments gives the BASMI linear result. The additional condition 0⩽S⩽10 is always applied.

  • A, result of assessment.