Internal anal sphincter (IAS) tone plays an important role in rectoanal incontinence (RI). IAS tone may be compromised during aging, leading to RI in certain patients. We examined the influence of oxidative stress in the aging-associated decrease in IAS tone (AADI). Using adult (4-6 mo old) and aging (24-30 mo old) rats, we determined the effect of oxidative stress on IAS tone and the regulator...

A pseudo-strain energy function (pseudo-SEF) describing the biomechanical properties of large conduit arteries under the influence of vascular smooth muscle (VSM) tone is proposed. In contrast to previous models that include the effects of smooth muscle contraction through generation of an active stress, in this study we consider the vascular muscle as a structural element whose contribution to...

[Purpose] The aim of this study was to quantify the resistance to passive movement by measuring changes in muscle-tendon length and joint range of motion (ROM), before and after applying a standardized 5-kilogram tension force, and to correlate and compare these changes to muscle tone. [Subjects and Methods] Children with cerebral palsy (n=29) and typically developed children (n=12) participate...

Background/Aims Although bisacodyl is a widely administered laxative, its underlying mechanism of action remains generally unknown. This study focuses on investigating the effects of bisacodyl on the human colon muscle contraction, and elucidating its mechanism of action. Methods Sigmoid colon muscle strips (20 longitudinal and 18 circular muscles) were obtained from 20 subjects who underwent...

[Purpose] The aim of this study was to investigate the effect of lumbar lordosis assistive support (LLAS) on craniovertebral angle (CVA) and mechanical properties of the upper trapezius (UT) muscle in subjects with forward head posture (FHP). [Subjects and Methods] This study recruited 20 subjects with FHP. CVA and muscle tone, viscoelasticity, and stiffness of the UT were measured using Myoton...

Ipsilateral and contralateral stapedius muscle contractions were studied as functions of the sound pressure level (SPL) and duration of 2-kHz tone bursts. The study complemented a preceding study in which temporal summation of stapedius muscle contractions produced by pairs of short tone bursts was determined and analyzed. The muscle contractions were determined indirectly by measuring changes ...