Wrist and Finger Torque Sensor for the quantification of upper limb motor impairments following brain injury

Background Extensive neuromotor development occurs early in human life, and the timing of brain injury may affect the resulting motor impairment. In part I of this paper series it was demonstrated that the distribution of weakness in the upper extremity depended on the timing of brain injury in individuals with childhood-onset hemiparesis. Objective The goal of this study was to characterize how timing of brain injury impacts joint torque synergies, or losses of independent joint control. Method Twenty-four individuals with hemiparesis were divided into three groups based on the timing of their injury: before birth (PRE-natal, n=8), around the time of birth (PERI-natal, n=8) and after 6 months of age (POST-natal, n=8). Individuals with hemiparesis, as well as 8 typically developing peers participated in maximal isometric shoulder, elbow, wrist, and finger torque generation tasks while their efforts were recorded by a multiple degree-of-freedom load cell. Motor output in 4 joints of the upper extremity were concurrently measured during 8 primary torque generation tasks to quantify joint torque synergies. Results There were a number of significant coupling patterns identified in individuals with hemiparesis that differed from the typically developing group. POST-natal differences were most noted in the coupling of shoulder abductors with elbow, wrist, and finger flexors, while the PRE-natal group demonstrated significant distal joint coupling with elbow flexion. Conclusion The torque synergies measured provide indirect evidence for the use of bulbospinal pathways in the POST-natal group, while those with earlier injury may utilize relatively preserved ipsilateral corticospinal motor pathways.

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“…5 Finger and wrist torques were measured by the single degree-of-freedom load cells located distally. 16 …”

Section: Methodsmentioning

confidence: 99%

Motor Impairments Related to Brain Injury Timing in Early Hemiparesis. Part II

Sukal-Moulton

Krosschell

Gaebler-Spira

et al. 2013

Neurorehabil Neural Repair

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“…The arm was positioned at a shoulder abduction angle of 75° and an elbow flexion angle of 90°. The fingers were secured to a custom hand piece at 0° wrist and finger (metacarpophalangeal) flexion/extension (Stienen et al 2011, Miller and Dewald 2012, Miller et al 2014 (figure 1).…”

Section: Experimental Apparatusmentioning

confidence: 99%

Impact of parameter selection on estimates of motoneuron excitability using paired motor unit analysis

et al. 2020

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Objective.-Noninvasive estimation of motoneuron excitability in human motoneurons is achieved through a paired motor unit analysis (ΔF) that quantifies hysteresis in the instantaneous firing rates at motor unit recruitment and de-recruitment. The ΔF technique provides insight into the magnitude of neuromodulatory synaptic input and persistent inward currents (PICs). While the ΔF technique is commonly used for estimating motoneuron excitability during voluntary contractions, computational parameters used for the technique vary across studies. A systematic investigation into the relationship between these parameters and ΔF values is necessary.Approach.-We assessed the sensitivity of the ΔF technique with several criteria commonly used in selecting motor unit pairs for analysis and methods used for smoothing the instantaneous motor 10

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“…A custom built device ( 52 ) was used to collect torques produced about the wrist and fingers. The device allows the experimenter to position the wrist and metacarpophalangeal (MCP) joints separately, in discrete 15° increments, while simultaneously collecting torques about each joint.…”

Section: Methodsmentioning

confidence: 99%

Passive Properties of the Wrist and Fingers Following Chronic Hemiparetic Stroke: Interlimb Comparisons in Persons With and Without a Clinical Treatment History That Includes Botulinum Neurotoxin

2021

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Background: Neural impairments that follow hemiparetic stroke may negatively affect passive muscle properties, further limiting recovery. However, factors such as hypertonia, spasticity, and botulinum neurotoxin (BoNT), a common clinical intervention, confound our understanding of muscle properties in chronic stroke.Objective: To determine if muscle passive biomechanical properties are different following prolonged, stroke-induced, altered muscle activation and disuse.Methods: Torques about the metacarpophalangeal and wrist joints were measured in different joint postures in both limbs of participants with hemiparetic stroke. First, we evaluated 27 participants with no history of BoNT; hand impairments ranged from mild to severe. Subsequently, seven participants with a history of BoNT injections were evaluated. To mitigate muscle hypertonia, torques were quantified after an extensive stretching protocol and under conditions that encouraged participants to sleep. EMGs were monitored throughout data collection.Results: Among participants who never received BoNT, no significant differences in passive torques between limbs were observed. Among participants who previously received BoNT injections, passive flexion torques about their paretic wrist and finger joints were larger than their non-paretic limb (average interlimb differences = +42.0 ± 7.6SEM Ncm, +26.9 ± 3.9SEM Ncm, respectively), and the range of motion for passive finger extension was significantly smaller (average interlimb difference = −36.3° ± 4.5°SEM; degrees).Conclusion: Our results suggest that neural impairments that follow chronic, hemiparetic stroke do not lead to passive mechanical changes within the wrist and finger muscles. Rather, consistent with animal studies, the data points to potential adverse effects of BoNT on passive muscle properties post-stroke, which warrant further consideration.

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Wrist and Finger Torque Sensor for the quantification of upper limb motor impairments following brain injury

Cited by 10 publications

References 17 publications

Motor Impairments Related to Brain Injury Timing in Early Hemiparesis. Part II

Motor Impairments Related to Brain Injury Timing in Early Hemiparesis. Part II

Impact of parameter selection on estimates of motoneuron excitability using paired motor unit analysis

Passive Properties of the Wrist and Fingers Following Chronic Hemiparetic Stroke: Interlimb Comparisons in Persons With and Without a Clinical Treatment History That Includes Botulinum Neurotoxin

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