Use of a hand-held dynamometer and a Kin-Com dynamometer for evaluating spastic hypertonia in children: a reliability...

Area of Science:

• Neurology
• Biomedical Engineering
• Pediatric Rehabilitation

Background:

• Spastic hypertonia in cerebral palsy (CP) involves both hyperactive stretch reflexes and muscle-tendon unit changes.
• Accurate measurement of these components is crucial for effective treatment planning.

Purpose of the Study:

• To compare the test-retest reliability of hand-held dynamometry (myometer) and isokinetic dynamometry (Kin-Com) for evaluating non-reflex and reflex-mediated resistive forces in pediatric spastic CP.
• To assess the suitability of these methods for differentiating reflex and non-reflex components of spasticity.

Main Methods:

• Ten children (2-7 years) with spastic CP underwent passive ankle dorsiflexion tests at low and high velocities using both myometer and Kin-Com, with a 1-month interval between tests.
• Electromyography (EMG) of soleus and tibialis anterior muscles was recorded during Kin-Com testing to identify reflex responses and unwanted muscle activity.

Main Results:

• Both myometer and Kin-Com demonstrated high test-retest reliability, with intraclass correlation coefficients (ICCs) ranging from .79 to .90.
• Coefficients of variation for force measurements were comparable between the two devices, indicating similar precision over a 1-month period.

Conclusions:

• The hand-held myometer offers comparable reliability to the Kin-Com for measuring spastic hypertonia in children with CP.
• The myometer is a simpler, more affordable, and time-efficient clinical tool for assessing spasticity.
• Differentiating reflex and non-reflex components by using varied velocities is essential for guiding treatment decisions in spastic CP.