Technology-assisted assessment of spasticity: a systematic review

Abstract

Background Spasticity is defined as “a motor disorder characterised by a velocity dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks”. It is a highly prevalent condition following stroke and other neurological conditions. Clinical assessment of spasticity relies predominantly on manual, non-instrumented, clinical scales. Technology based solutions have been developed in the last decades to offer more specific, sensitive and accurate alternatives but no consensus exists on these different approaches. Method A systematic review of literature of technology-based methods aiming at the assessment of spasticity was performed. The approaches taken in the studies were classified based on the method used as well as their outcome measures. The psychometric properties and usability of the methods and outcome measures reported were evaluated. Results 124 studies were included in the analysis. 78 different outcome measures were identified, among which seven were used in more than 10 different studies each. The different methods rely on a wide range of different equipment (from robotic systems to simple goniometers) affecting their cost and usability. Studies equivalently applied to the lower and upper limbs (48% and 52%, respectively). A majority of studies applied to a stroke population (N = 79). More than half the papers did not report thoroughly the psychometric properties of the measures. Analysis identified that only 54 studies used measures specific to spasticity. Repeatability and discriminant validity were found to be of good quality in respectively 25 and 42 studies but were most often not evaluated (N = 95 and N = 78). Clinical validity was commonly assessed only against clinical scales (N = 33). Sensitivity of the measure was assessed in only three studies. Conclusion The development of a large diversity of assessment approaches appears to be done at the expense of their careful evaluation. Still, among the well validated approaches, the ones based on manual stretching and measuring a muscle activity reaction and the ones leveraging controlled stretches while isolating the stretch-reflex torque component appear as the two promising practical alternatives to clinical scales. These methods should be further evaluated, including on their sensitivity, to fully inform on their potential.

Pendulum test parameters are useful for detecting knee muscle hypertonia and quantifying response to an intrathecal baclofen bolus injection

“…The participant was seated barefoot in an isokinetic dynamometer (System 3, Biodex Medical Systems, Inc. New York, New York, USA) in a semi-reclined position as the compromise between the supine and upright sitting position [27]. The knee joint angle was measured using a custom-made electrogoniometer consisting of two thermal plastic arms (305 mm length, 25 To commence a test, the experimenter held the heel and slowly raised the lower leg until the knee started to rise.…”

“…Psychometric properties of technology-based spasticity outcomes have rarely been examined, especially their sensitivity [25]. Similarly, a few studies have evaluated the validity and sensitivity of the pendulum test parameters.…”

Expert consensus on the surgical evaluation and management of upper extremity spasticity in adults

“…While several tools and classification systems have been described to objectively evaluate and standardize communication, there was no universally agreed metric for the assessment of spasticity among the members surveyed and a variety of outcome measures are currently used by the panel (Guo, 2022;Rekand, 2010). It is most critical to use the same metric before and after treatment, and have the same evaluator complete the assessment to ensure reliability.…”

An online method to monitor hand muscle tone during robot-assisted rehabilitation

“…Robotic devices can be used to accurately estimate changes in muscle tone (or its manifestation in terms of change in joint stiffness) during limb mobilization ( Artemiadis et al, 2010 ; Tucker et al, 2013 ; Dehem et al, 2017 ; Ranzani et al, 2019 ; Zou et al, 2021 ; van der Velden et al, 2022 ). Most frequently, to do this, position- or velocity-controlled perturbations are applied to the passive limb while force sensors measure the reaction force/torque of joint and muscles during the movement, which can be used to quantify muscle tone and limb biomechanics, as well as spasticity when different perturbation speeds are considered ( De-la-Torre et al, 2020 ; Guo et al, 2022 ). However, to date, no device for robot-assisted therapy allows to autonomously monitor the changes in patient’s muscle tone directly during rehabilitation exercises as a way to ensure safe conditions of use during unsupervised therapy sessions.…”

“…However, to date, no device for robot-assisted therapy allows to autonomously monitor the changes in patient’s muscle tone directly during rehabilitation exercises as a way to ensure safe conditions of use during unsupervised therapy sessions. Moreover, according to a recent review, only three percent of the studies focusing on technology-assisted assessment of spasticity focus on the hand ( Guo et al, 2022 ).…”