Limb stiffness and activity disorders are common in rheumatic diseases. Patients often feel stiffness and pain in the joints, limbs, waist and other affected parts when they wake up in the morning, when they start to move, or when they change to another posture after being in a certain posture for a long time. Rheumatic disease caused by the stiffness of the limbs of the examination items: a. Laboratory tests of rheumatic disease (1) routine examination: rheumatic disease is invasive of the whole body multi-system multi-organ disease, so the patient should be a comprehensive examination, blood, urine, stool, blood sedimentation, CRP, comprehensive biochemical examination (liver function, kidney function, muscle enzyme profile, etc.). (2) Serological examination: ① General: RF, C3, C4, CH50, CIC, IgG, IgA, IgM, IgE. ② Special: a. Antinuclear antibody profile is very important for the diagnosis and differential diagnosis of rheumatic diseases. ANA is usually done first, and if the titer > 1:40, other items should be further examined. b. HLA: Although HLA has close correlation with rheumatic diseases, not much is known about it. 26% and Dw14 47% in JRA, DR3 was only 2.7% in SLE and 5.6% in pSS. Behcet’s disease was positive for HLA B5 in only 3.3%. c, other: such as anti-keratin antibody (AKA), anti-histone antibody (Anti-histone antibody), antiphospholipid antibody, anti-perinuclear factor (ANCA), etc. have diagnostic reference value for some diseases. (3) joint fluid examination: fresh joint fluid is very important, should be routine, culture, serology and immunological examination. (2) imaging of rheumatic diseases (1) X-ray plain film: generally used frontal, lateral, both large and small joints, extremities, shoulders, spine, sacroiliac joints; according to different diseases and sites, there can be different requirements, for skeletal damage or hyperplasia lesions generally show clearly, but due to overlapping images, early small lesions are not easy to see; synovium, joint capsule, cartilage, meniscus, ligaments are not shown. (2) Computed tomography (CT): It can accurately display small differences in density of different tissues in one cross-section, and is an ideal method to observe small lesions of bone, joint and soft tissue. It is mostly used in the sacroiliac joint and spine of AS, cartilage and meniscal lesions of the knee, brain changes of SLE, and early interstitial lung changes. (3) Magnetic resonance imaging (MRI): For bone, joint and soft tissue lesions, it has higher resolution than X-ray and CT, and is better than CT for soft tissue visualization; it is mostly used for the diagnosis of bone, cartilage, meniscus and fascia; it is also useful for brain tissue and spinal cord disease. (4) Contrast imaging: ① Arthrography: generally using filtered air or organic iodine solution, or both, called double contrast imaging. It can show the articular cartilage, meniscus, synovial membrane and ligaments and other structures. It is useful for the diagnosis of intra-articular lesions and is mostly used for large joints of the extremities, but is now less commonly used. (2) Angiography: divided into arteriogram and venogram, which is useful for the diagnosis of aortitis or vasculitis. (5) Arthroscopy: It can directly observe the lesions of various tissues in the joint, especially for the diagnosis and differential diagnosis of synovitis, which has great significance. If necessary, synovial biopsy and surgical treatment can be taken. (6) Biopsy: In cases where diagnosis is difficult, such examination can assist in confirming the diagnosis. Such as skin, lip mucosa, kidney, liver, synovial membrane, blood vessels, muscle, bone, cartilage, etc.. Sometimes immunohistochemical staining is also performed. (7) Isotope bone scan: It is helpful to identify bone tumor (primary or secondary) and myeloma. (8) Ultrasound examination: It is useful to determine the thickness of joint capsule, cartilage, synovial membrane and fluid accumulation.