The Use of Computerised Dynamometry to Quantify Functional Grip and Release in People Post Stroke: A Pilot Study

Abstract

Abstract:Purpose: To present a theoretical construct and pilot data from an analytic technique to simultaneously quantify positive and negative upper motor neuron (UMN) features.Method: Computerised hand dynamometry was used to measure hand contraction-relaxation cycles during a repetitive grasp and release task. Measurements of force, time, force velocity and 'grip work' were collected on a pilot sample of 5 post-stroke subjects and 5 matched controls. Within and between group differences were analysed.Results: Force, time and velocity dependent aspects of hand performance did not differ between the dominant and nondominant upper-limbs of control subjects. In contrast, the post-stroke group generated less grip force over longer cycle times with their affected limb, consistent with negative UMN features. In controls, 97% of grip work was task specific, with 3% associated with involuntary, non-task grip work. Conversely, the post-stroke group generated high levels of involuntary, non-task grip work (39%), a feature consistent with positive UMN features of muscle overactivity. Force velocity and maximal force were lower in the non-affected limbs of the stroke group than matched dominant limbs of the control group, supporting functional Magnetic Resonance Imaging data that the function of non-affected cerebral hemisphere is abnormal following stroke. Conclusions:The computerised dynamometry analysis paradigm was able to simultaneously quantitate aspects of hand performance affected by positive and negative UMN features within an individual and between groups. This approach uses a clinically relevant, functionally based assessment technique that appears to have greater ecological validity and fewer limitations than current measures of spasticity.

Test–retest reliability of computerised hand dynamometry in adults with acquired brain injury

“…The methods outlined above for evaluating the hand performance of adults with UMN syndrome present clinical and psychometric limitations, prompting the authors of this article to examine an alternate method proposed by Baguley, Nott and Barden (). In contrast with the Modified Ashworth Scale and the Tardieu Scale, Baguley et al .…”

“…In contrast with the Modified Ashworth Scale and the Tardieu Scale, Baguley et al . 's () protocol is based on the dynamic assessment of computerised hand dynamometry data, having the advantage of assessing both positive and negative features of the UMN simultaneously. Mechanical and computerised dynamometers are highly reliable methods for measuring hand grip strength (Hamilton, Balnave & Adams, ; Innes, ; Massy‐Westropp, Rankin, Ahern, Krishnan & Hearn, ; Mathiowetz, Weber, Volland & Kashman, ; Shechtman, Davenport, Malcolm & Nabavi, ).…”

“…Drawing from the strong results of the above studies, the authors hypothesised that similar levels of test–retest reliability will be achieved using Baguley et al . 's () DCD protocol. This study aims to examine the test–retest reliability of DCD for measuring force, time and velocity dependent features of hand performance during grasp and release over two test occasions in adults with and without ABI.…”

Computerised pinch dynamometry in the assessment of adult hand spasticity

“…(). Participants' consecutive pinch and release cycles yielded two data representations: the Force Curve and the Force Velocity Curve (Baguley et al ., ) (Fig. ).…”

Quantifying patterns of upper limb motor change following BTX-A injection in adult spasticity management

“…Alternative measures that attempt to measure spasticity dynamically during active UL use exist (e.g. Electromyography [16], Dynamic Computerized hand Dynamometry [17][18][19] and kinematics [20]); however, these measures require specialized equipment and data analysis methods, currently limiting them to research settings.…”