Introduction:
Clinical assessments of spasticity symptoms and muscle strength are often used to plan and monitor the progress and the physiotherapeutic treatment in patients after an incomplete spinal cord injury (iSCI). However, these assessments are subjective and may not provide detailed neurophysiological changes that appear following spinal trauma.

Aim:
In this study, we analyzed correlations between standard clinical assessments of spasticity and muscle strength and objective, and non-invasive neurophysiological measures of muscle activity in iSCI patients up to 2 months after injury.

Material and Methods:
We evaluated 19 iSCI patients (ASIA C=10, and D=9) after C5-Th1 spinal injuries using the Modified Ashworth Scale (MAS) and the Lovett Scale (Lovett), as well as surface electromyography (sEMG) recordings at rest (rsEMG) and during the attempt of maximal contraction (mcsEMG) performed in abductor pollicis brevis (APB) and rectus femoris (REC FEM) muscles bilaterally.

Results:
We have found significant positive correlations between MAS and rsEMG (rs=0.701, p=0.008 in APB recordings; rs=0.672, p=0.021 in REC FEM recordings), and Lovett and mcsEMG (rs=0.525, p=0.008 in APB recordings; rs=0.408, p=0.028 in REC FEM recordings) results, and negative correlations between rsEMG and mcsEMG scores (rs=-0.581, p=0.008 in APB recordings; rs=-0.487, p=0.032 in REC FEM recordings).

Conclusions:
Detected correlations between clinical assessments and the results of sEMG recordings reveal phenomenon of dependence on increased muscle tension causing a decrease in contractile properties of muscle motor units, which should be taken into account when formulating kinesiotherapeutic strategies in the rehabilitation of patients after iSCI at cervical levels.