Patients diagnosed with rheumatoid arthritis had significantly impaired shoulder function compared to healthy participants when evaluated 1.5 years following diagnosis, according to recently published research.
Researchers studied 103 women with rheumatoid arthritis (RA) and 103 healthy women matched for age. The mean age was 47.1 years and patients had a mean disease duration of 20.3 months and a mean Disease Activity Score in 28 joints (DAS28) of 3.8.
Patients were evaluated for disease activity and blood samples were analyzed for markers of disease and disease activity. Muscle strength, active shoulder-arm movement and shoulder pain during movement were evaluated to determine shoulder function. An IsoBex dynamometer (Cursor AG) was used to measure the isometric muscle strength of the shoulder abductor muscles. A shoulder-arm impairment instrument was used to measure active shoulder-arm movement while participants raised hands to the opposite shoulder, behind the back and hand to seat. The Borg symptom scale was used to measure shoulder pain during shoulder and arm movements. A Grippit (AB Detektor) electronic dynamometer was used to measure hand grip force in Newtons, and limitations to activities were assessed with the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire.
Radiographs were obtained from all but four patients at a mean of 21.1 months following diagnosis and erosive damage was seen in 38% of patients’ hands or feet. Compared to 97% of the reference group, 73% were employed and for significantly fewer hours per week (24.3 hours vs. 36.8 hours). Unemployment, disability pension and sick leave were seen in 27% of the patients with RA and patients were not as physically active during leisure time, compared to the reference group.
Shoulder symptoms were seen in 53.4% of patients with RA compared to 20.4% of participants in the reference group. Unilateral symptoms were seen in 32% of patients with RA and 21.4% had bilateral symptoms. The mean isometric shoulder strength of the dominant arm was significantly lower in the patients with RA (3.7 kg) compared to the reference group (5.6 kg). Patients with RA had a mean lateral shoulder elevation of the dominant arm of 164.3° compared to 178.7° in the reference group. Patients with RA had a mean active shoulder-arm movement of the dominant hand score of 27.4 compared to 29.7 in the reference group. Patients with RA had shoulder pain scores of 7.6 compared to 0.9 in the reference group.
Dominant hand grip force was 159 N in patients with RA compared to 288 N in the reference group, and a difference in strength between hands was 10.9 N in the patient group compared to 22 N in the reference group.
Patients with RA reported more activity limitations compared to the reference group as seen in higher DASH scores, which were associated with shoulder muscle strength and pain. – by Shirley Pulawski
Disclosure: The researchers report no relevant financial disclosures.