Isokinetic strength differences in patients with mucopolysaccharidosis I, II, and VI

Abstract

The aim of this study was to examine muscular strength differences in patients with Mucopolysaccharidosis (MPS) I, II, or VI versus age- and sex-matched healthy controls. Isokinetic knee extension and flexion strength was measured at 90, 120, and 180 degrees/second (d/s) using a dynamometer in 30 subjects with MPS and 42 controls (9-16 years). MPS-IH (neuropathic), MPS-II, and MPS-VI exhibited significant strength decrements when compared to controls. MPS-IA (non-neuropathic) was not significantly different than controls. MPS-IH and MPS-II had significantly lower dominant leg extension average peak torque (DLEAPT) than controls at 90, 120, and 180d/s. MPS-VI had significantly lower DLEAPT than controls at 90 and 120d/s. At 180d/s, MPS-IH DLEAPT was significantly lower than that of MPS-IA. MPS-IA DLEAPT was not significantly different than controls at any angular velocity. Children with MPS-IH, II and VI have decreased skeletal muscle strength compared to children with MPS-IA.