Clinical Study

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

Table 3

Physiological data of RA ( ; 13 women) and AS ( ; 4 women) patients versus age- and sex-matched healthy controls. ACSA: anatomical cross-sectional area. Results are presented as mean ± SEM.

RA studyAS study
RA patients Healthy controls valueAS patients Healthy controls value
( = 18)( = 18)( = 12)( = 12)

Quadriceps force (N)3407 3013640 244 0.444887 4924922 4940.93
Quadriceps ACSA (cm2) 62.7 3.660.3 2.7 0.4077.4 5.374.6 4.90.62
Muscle quality (N/cm2)55.1 4.0 60.9 3.40.3061.6 3.365.4 4.20.34
Patella tendon stiffness (N/mm) 1017 122 1385 1580.041131 1331751 2120.01
Patella tendon CSA (mm2)91.4 4.5 91.3 2.6 0.89 111.8 5.8 96.9 3.90.04
Young’s modulus (GPa)0.59 0.070.74 0.080.130.49 0.040.90 0.10<0.001