Evaluating the strength of spinal and proximal girdle muscles in patients with axial spondyloarthritis: Correlation...

To compare the muscle strength of muscle groups in axial spondyloarthritis (axSpA) patients with the muscle powers of healthy volunteers and to examine the relationship of muscle strengths with disease activity, functionality, and disability.

One hundred males (50 axSpA, 50 healthy) were included in the study. Bath Disease Activity Index (BASDAI), Functional Index (BASFI), and Health Assessment Questionnaire-Disability Index (HAQ-DI) scores were recorded. The maximum (max) and mean cervical flexion, extension, lateral flexion (CF, CE, CLF), truncal flexion, extension (TF, TE), root joint flexion, extension, abduction, internal and external rotation (SF, SE, SAB, SIR and SER for the shoulder; HF, HE, HAB, HIR and HER for the hip) muscle strengths of the patients in both groups were measured by a handheld dynamometer. Total muscle strength (CT, TT, ST, HT) was found according to the sum of the max and mean values for each region.

All muscle strengths were lower in the axSpA group compared to the healthy volunteers. The symptom duration was found to have a weak-moderate negative correlation with CT, TT, ST, HT and all individual muscle strengths except for the TE, CF, HIR, and HER. BASDAI and HAQ-DI had weak-moderate negative correlations with HIR and HER. BASFI had a weak-moderate negative correlation with cervical measurements, TE, TF, SF, SER, SIR, and hip measurements.

All muscle strengths were lower in patients compared to healthy volunteers. Strengthening specific muscle groups for the desired goal can be a reasonable strategy. The study is prospectively registered and available at www.clinicaltrials.gov (NCT04435860).