Patellar Tendon Properties and Lower Limb Function in Rheumatoid Arthritis and Ankylosing Spondylitis versus Healthy Controls: A Cross-Sectional Study

Figure 1

Illustration of patellar (P) tendon (PT) elongation. PT elongation shown from a skin marker (vertical line) to the tendon insertion at the patella (star) using US at rest (a) and during contractions ((b) and (c)).

(a)

(b)

(c)