## 4 Discussion  
The use of lexical analysis allows extensive evaluation and speculation about the words used in the papers. For example, considering fibromyalgia, the strict association with the word \"tender\" may be related to the typical evaluation of fibromyalgia, which is based on the identification of specific tender points. Regarding rheumatoid arthritis, the strict association with the inflammation may be explained by the common impairment of the joints characterized by the peculiar inflammation. The association with the term \"serum\" is interesting, because it may be related to the high interest in the use of serum outcome measures for the evaluation of patients with rheumatoid arthritis. Besides these considerations, with the LENGTH approach, the words can be classified not only for their frequency but also for their importance in the whole literature about the topic. It can be promising support for a scoping review. In fact, the lexical analysis displays the formal characteristic of the current scientific production and can allow discussions about the ways in which the information is spread in the literature. Furthermore, it may help the selection of the papers, focusing attention on the works containing specific terms. Our analysis showed an important concern regarding the use of proper terminology. Indeed, by applying the lexical analysis method, only a few works, compared to the multitude of the initial results, included the researched keywords. Therefore, only 14 studies have been included in the scoping review. Moreover, due to the heterogeneity of the studies, regarding waters/mud content, treatment periods, protocols, and potential associations with other treatments, it is not possible to define with certainty the superiority of a combined BT and exercise program intervention in rheumatic diseases. However, the results showed some beneficial effects of BT treatments that could positively modify impairments and symptoms related to rheumatic diseases. These positive effects may probably be the result of a combination of mechanical (hydrostatic force), thermal (mineral water or mud temperature), and chemical (mineral water or mud composition) effects. Immersion in thermal water through increased buoyancy can lead to an unloading effect, which is protective in degenerated and/or inflamed joints. Hydrostatic pressure can have a positive effect on muscle tone, joint function, and pain intensity. Temperature, stimulating cortisol, adrenocortic hormone, prolactin and \(\beta\)-endorphin release, may have an important analgesic action and an immunosuppressive effect [28]. Studies carried out in cellular models of acute joint inflammation demonstrated that treatment with hydrogen sulphide donors reduced oxidant-induced mitochondrial dysfunction [29], and the production of pro-inflammatory mediators [30; 31]. Similar immunomodulatory properties were observed also after incubation with NaHS or thermal water of human OA chondrocytes or fibroblast-like synovioocytes [32; 33; 34; 35; 36]. In vivo experiments with mud therapy and bath treatments showed a significant reduction in TNF-\(\alpha\) and IL-1 serum levels and decreased leukocyte migration into the articular cavity in rat models of OA [37; 38]. In vitro and in vivo studies also showed a positive action of mineral waters on the oxidant/antioxidant system, especially after incubation in sulphurous mineral water [28]. An in vivo study performed on C57 BL/6N mice that spontaneously develop OA has demonstrated that mud-therapy potentiated the effect of chondro sulphate by reducing the serum level of nitric oxide (NO) [39]. Furthermore, mud therapy can have a protective effect on OA articular cartilage through an increase in chondrocyte number and collagen amount [40]. The positive effects described in OA patients after mud-bath therapy can also be linked to a decrease in adiponectin and resistin levels, involved in the development and progression of the disease [8].