Background A few studies report limitations in upper and lower extremity mobility and muscle function in patients with systemic sclerosis (SSc). Little is known about to what extent skin involvement (lcSSc/dcSSc) and lung function (no-mild vs moderate-endstage lung disease) influence active range of motion (AROM) in the shoulder-arms and muscle function i patients with SSc.

Objectives We aim to examine shoulder-arm AROM, shoulder and hip muscle endurance as well as lower extremity muscle function in patients with SSc in comparision with reference values and also to explore possible differences in function depending on lung function and skin involvement.

Methods 205 patients, fulfilling the EUSTAR/ACR criteria for SSc, were recruited from the Karolinska University Hospital. AROM in shoulder-arms (Functional Shoulder Assessment, FSA), muscle endurance in shoulder and hip flexion (Functional Index 2, FI-2), and muscle function in the lower extremities (Timed-Stands Test, TST) were assessed and compared with reference values. Patients were classified as to lung disease severity using using sub-items from the SSc disease severity score for lung involvement. Patients with a score of 0–1 were classified as no-mild lung disease and a score of 2–4 as having moderate-endstage lung disease.

Results SSc-patients had overall more reduced muscle endurance (FI-2,% of predicted) in shoulders 53(27–100) and hips 40(23–90) when compared with reference values, 100(100–100) and 100(72–100) (p<0.001) and patients with moderate-endstage lung disease were more impaired, 39(21–71) and 35(20–70) than no-mild, 57(33–99) and 48(28–100) (p<0.05). No differences were found between dcSSc/lcSSc. All patients, regardless of subgrouping, had lower muscle strength when measured with TST, 21(17–29) seconds, when compared to reference values, 17(15–18) (p<0.001). The FSA-scores was overall lower on both right, 22(20–24) and left, 23(20–24) compared with reference values 23(22–24) and 23(22–24) (p<0.05), especially in patients aged 60 years or more. DcSSc-patients had lower FSA-score than lcSSc-patients (p<0.05). No differences were found between patients with no-mild and moderate-endstage lung disease.

Conclusions SSc-patients have markedly reduced muscle endurance and muscle function compared with reference values and patients with moderate-endstage lung disease have reduced lower extremity muscle function compared to patients with no-mild lung disease. SSc-patients have slightly less AROM than controls and dcSSc-patients are more restricted than lcSSc. This study highlights the importance of identifying patients with an enhanced risk of developing severe muscle impairments. We suggest that physiotherapists regularly assess muscle function using standardised tests and when needed initiate exercise to improve function

Disclosure of Interest None declared