The Validity and Reliability of Motion Analysis in Patellar Tendon Reflex Assessment

Abstract

BackgroundThe deep tendon reflex assessments that are essential to the accurate diagnosis of neurological or neuromuscular disorders are conducted subjectively in clinical neurology. Our aim was to assess deep tendon reflexes objectively with a new reflex quantification method.Methodology/Principal FindingsThe present study used a motion analysis technique to collect quantitative measurements for both the input and output of normal patellar tendon reflex. Reflex responses were measured as knee angles. The patellar tendon reflexes of 100 healthy subjects were examined using 6 levels of tendon taps, where all the assessments were captured using motion capture system. A linear relationship was found between the experimental maximum tapping velocity and tapping angle (coefficient of determination = 0.989), which was consistent with the theoretical values. Tapping velocities were predictable according to tapping angles. The findings proved the reproducibility of tapping method in producing consistent input. The reflex amplitude was consistent between two randomly assigned groups, and linearly proportionate to the tapping velocity.Conclusions/SignificanceThe findings on reflex amplitude indicate that motion analysis is a valid and reliable method of assessing and measuring deep tendon reflexes.

Clinical availability of the deep tendon reflex test using a novel apparatus in healthy subjects

“…Because of the scarcity of measurement tools that can quantitatively evaluate the DTR test, results such as these that assess the reliability and validity of the DTR test are very rare. In a recent paper, the reliability and validity of DTR data were verified through motion analysis of the patellar tendon reflex; variation in percussion speed and angle were also incorporated into that study 8 ) . Consistent with our study, the authors found that the amplitude of the response increased linearly in accordance with increased percussion angle, and a concomitant motion analysis confirmed the high reliability of the DTR data 8 ) .…”

“…Many previous studies have sought to identify quantitative and objective measures for the DTR test 6 , 7 , 8 ) . Kuruoglu and Oh 6 ) conducted an electrophysiological study using an electric hammer as a more quantitative means of conducting the DTR test.…”

“…The authors attributed this low correlation coefficient to differences among examiners when striking a given part of the tendon 10 ) . In more recent studies, quantitative trials of the DTR test have been carried out using motion analysis, which examines angular velocity and acceleration of the relative joints 8 , 11 ) .…”

Implementation of a smartphone as a wireless gyroscope application for the quantification of reflex response

“…Through manually applied instrumented reflex hammers, the reflex response of the patellar tendon has been quantified by the force and torque features of the reflex response [3,4,22,23]. The reflex response has also been quantified through wired triaxial accelerometers and optical electronic systems [3,4,24,25,26,27]. Wireless accelerometer systems for quantifying reflex response possess clear advantages over these described sensor applications, such as simplified mounting and application, minimal mass encumbrance, and robust signal transmission without line of sight or tethering requirements [3,4,7,28].…”

Implementation of an iPod Wireless Accelerometer Application Using Machine Learning to Classify Disparity of Hemiplegic and Healthy Patellar Tendon Reflex Pair

“…incorporated an optical motion analysis system for quantifying the patellar tendon reflex response. Multiple forces settings for quantified reflex input were derived from a reflex hammer attached to a protractor [26,27]. During 2006, LeMoyne et al conducted a similar themed reflex modulation study.…”