Relationship between handgrip strength, peripheral muscle strength and respiratory muscle endurance in patients with Fibromyalgia Syndrome (FMS)?

Abstract

FMS is a rheumatic disease, which manifests itself primarily in the musculoskeletal system in the form of chronic and diffuse pain, and causes impairment in the quality of life. The FMS may have reduced muscle strength of upper and lower limbs, and of respiratory muscles. We investigated whether FMS commits in an equivalent manner the musculature of limbs and respiratory muscles. For this, we analyzed the upper limb strength (HS) through handgrip dynamometer, the strength of the lower limbs by the 5 repetitions Sit–to-Stand Test (SST), and respiratory muscle endurance, assessed using the spirometric maneuver MVV. The study included 41 women (52.9±8.52 years) with FMS. The results demonstrated the presence of significant reduction of HS, both in dominant upper limb (DUL) and in non-dominant upper limb (NDUL) in all age groups evaluated. Furthermore, reduced peripheral muscle strength in the lower limbs was observed, since, on average, participants exceeded the normative SST times stipulated for the age groups. About two-thirds of the sample had MVV values below the lower limit of normality. We detected: inverse and moderate correlation between peripheral muscle strength and HS NDUL (r=-0.472; p=0.002), and inverse and weak with the HS DUL (r=-0.374; p=0.016); weak correlations between respiratory muscle endurance and HS DUL (r=0.299; p=0.058), the HS NDUL (r =-0.317; p=0.043) and the peripheral muscle strength (r=-0.372, p=0.017 ); strong correlation between the HS of DUL and NDUL (r=0.899; p