Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes joint inflammation and progressive joint destruction. Rheumatoid cachexia is one of the structural manifestations of RA, and consists of a reduction in muscle mass, due to an increased muscle protein catabolism induced by inflammatory cytokines. This muscle mass loss generates an impairment in physical function and functional capacity in RA patients. The aim of study was to verify neuromuscular and functional responses in middle-aged women with RA compared to paired healthy women.
Study Type
OBSERVATIONAL
Enrollment
70
The Timed Up and Go test; Maximal knee-extensor muscle strength (isometric and concentric tests) was measured with a Biodex System 3 dynamometer; A B-mode ultrasonography system with a linear-array probe (60 mm, 7.5 MHz) was used to determine VL and RF muscle thickness, pennation angle, fascicle length and tendon CSA. Measurements were obtained with the volunteer seated in the dynamometer, during isometric contraction at 90° of knee flexion. An 8-channel EMG system was synchronized with the dynamometer through a Windaq data acquisition system and used to evaluate the vastus lateralis and rectus femoris electrical activity during isometric knee-extensor tests.
Knee-Extensor Muscular Strength
Maximal knee-extensor muscle strength (isometric and concentric tests), in different angles and velocities were measured with a Biodex System 3 dynamometer (Biodex Medical Systems, Shirley, NY, USA). A 2-min interval was observed between contractions. We used the peak torque of each maximal test to analysis.
Time frame: Only one day.
Muscle architecture and tendon parameters
An ultrasonography system was used to determine VL and RF muscle thickness, pennation angle and fascicle length. Muscle architecture measurements were obtained with the volunteer seated in the dynamometer, during isometric contraction at 90° of knee flexion. Muscle thickness was considered the distance between deep and superficial aponeuroses. The best fascicle in each image was used for pennation angle and fascicle length analysis. Pennation angle was calculated as the angle between the muscle fascicle and the deep aponeurosis, whereas fascicle length was measured as the length of the fascicular path between the two aponeuroses. Furthermore, patellar tendon cross-section area was measured with probe perpendicular to tendon during isometric contractions.
Time frame: Only one day.
Functional Capacity
Timed Up and Go test
Time frame: Only one day.
Quadriceps muscle activation
Vastus Lateralis and Rectus Femoris muscle activation during strength tests
Time frame: Only one day.
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