Characterization of the mechanical changes of adductor muscles in the lower extremities for patients with multiple sclerosis.

Abstract

It is important to know how the mechanical properties of the muscles change in the management of adductor spasticity in patients with Multiple Sclerosis (pwMS). This study was conducted by evaluating forty-two pwMS bilaterally. The Modified Ashworth Scale (MAS) was used to determine the hip adductor spasticity level, and pwMS were divided into four groups (MAS0, MAS1, MAS1+, MAS2) regarding the MAS grade. MyotonPro® (Myoton AS, Estonia) was used to determine mechanical properties (tone, stiffness, elasticity) of the muscle from the (i) belly, (ii) musculotendinous, and (iii) tendon sites of the muscle. The measurements obtained from the belly and musculotendinosus sites of the muscle were compared concerning the MAS, there was a difference in the tones and stiffness of the muscle (p < 0.05). There was no difference in elasticity values of belly and musculotendinosus sites (p > 0.05). Musculotendinosus sites' tone and stiffness were different between MAS0 and MAS2 (p < 0.05). All of the myotonometer values were differences in tendon sites regarding the MAS (p < 0.05). The relationship between elasticity and the MAS was only present in the tendon region, and a moderate negative correlation was observed between them (r = 0.358, p < 0.05). As spasticity progresses, the change in viscoelastic properties advances from contractile structures to non-contractile structures. Mechanical influence in the tendon area is not only confined to tone and stiffness, it also affects elasticity. In the techniques chosen for the management of spasticity, the regional characteristics of the muscle should be taken into consideration according to the severity of spasticity.