The objective of this before-after non-randomized trial study is to evaluate the efficacy of ultrasound therapy in combination with manual therapy in the management of systemic sclerosis patients with IDU. The main questions it intends to answer are:

• Is this combination of treatments effective in these patients in terms of improvement in hand functional ability, pain relief, injury healing, and quality of life?

Participants will receive rehabilitation treatment consisting of a combination of manual therapy (McMennel joint manipulation, pumping, and connective tissue massage) and US water immersion. The researchers will compare the group of participants, called the treatment group, with a control group to see if:

• Is the combined treatment of ultrasound therapy and manual therapy more effective in these patients than manual therapy alone?

Inclusion Criteria:

• diagnosis of SSc according to the ACR and EULAR criteria
• presence of IDU in active phase
• naïve to rehabilitation treatment for their hands and upper limbs
• written in-formed consent to participate in the study.

Exclusion Criteria:

• presence of skin lesions due to other conditions (e.g., trauma);
• pregnancy;
• infectious diseases (e.g. HIV, HBV, HCV);
• myositis;
• arthritis;
• other rheumatological diseases and immunodepression.