Patterns of Impairment in Digit Independence After Subcortical Stroke

Raghavan, Preeti; Petra, Electra; Krakauer, John W.; Gordon, Andrew M.

doi:10.1152/jn.00873.2005

Cited by 69 publications

(68 citation statements)

References 57 publications

(66 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mechanically, the limitations on the independent movement of the thumb appear to be negligible compared to the fingers (Lang and Schieber 2004). Moreover, clinical studies of stroke patients suggest subtle differences in the neural architecture of the thumb compared to the fingers (Lang and Schieber 2003; but see also Raghavan et al 2006). Not surprisingly, the thumb emerged as a special digit in a number of our analyses.…”

Section: The Thumbmentioning

confidence: 66%

The statistics of natural hand movements

et al. 2008

View full text Add to dashboard Cite

Humans constantly use their hands to interact with the environment and they engage spontaneously in a wide variety of manual activities during everyday life. In contrast, laboratorybased studies of hand function have used a limited range of predefined tasks. The natural movements made by the hand during everyday life have thus received little attention. Here, we developed a portable recording device that can be worn by subjects to track movements of their right hand as they go about their daily routine outside of a laboratory setting. We analyse the kinematic data using various statistical methods. Principal component analysis of the joint angular velocities showed that the first two components were highly conserved across subjects, explained 60% of the variance and were qualitatively similar to those reported in previous studies of reachto-grasp movements. To examine the independence of the digits, we developed a measure based on the degree to which the movements of each digit could be linearly predicted from the movements of the other four digits. Our independence measure was highly correlated with results from previous studies of the hand, including the estimated size of the digit representations in primary motor cortex and other laboratory measures of digit individuation. Specifically, the thumb was found to be the most independent of the digits and the index finger was the most independent of the fingers. These results support and extend laboratory-based studies of the human hand.

show abstract

Section: The Thumbmentioning

confidence: 66%

The statistics of natural hand movements

et al. 2008

View full text Add to dashboard Cite

show abstract

“…When studying digit extension, subjects were instructed to extend all five digits together to avoid potentially confounding deficits in fractionating digit movements Schieber 2003, 2004;Raghavan et al 2006b). When studying grasping, the task required only a minimal amount of hand translation (Յ100 mm) to minimize any potentially confounding effects of reaching deficits on grasping performance (Lang et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Recovery of Thumb and Finger Extension and Its Relation to Grasp Performance After Stroke

Lang¹,

DeJong²,

Beebe³

2009

Journal of Neurophysiology

View full text Add to dashboard Cite

Lang CE, DeJong SL, Beebe JA. Recovery of thumb and finger extension and its relation to grasp performance after stroke. J Neurophysiol 102: 451-459, 2009. First published May 20, 2009 doi:10.1152/jn.91310.2008. This study investigated how the ability to extend the fingers and thumb recovers early after stroke and how the ability to extend all of the digits affects grasping performance. We studied 24 hemiparetic patients at 3 and 13 wk post stroke. At each visit, we tested the subjects' ability to actively extend all five digits of their contralesional, affected hand against gravity and to perform a grasp movement with the same hand. Three-dimensional motion analysis captured: 1) maximal voluntary extension excursion of each digit and 2) grasp performance variables of movement time, peak aperture, peak aperture rate, and aperture path ratio. We found that finger and thumb extension improved from 3 to 13 wk, with average improvements ranging from 12 to 19°across the five digits. Grasp performance improved on two of the four variables measured. Peak apertures and peak aperture rates improved from 3 to 13 wk, but self-selected movement time and aperture path ratio did not. Stepwise multiple regression models showed that the majority of variance in grasp performance at 13 wk could be predicted by the ability to extend the index or middle finger at 3 wk, plus the change in the ability to extend the index finger from 3 to 13 wk. R 2 values ranged from 0.55 to 0.89. Our data indicate that the amount of recovery in finger and thumb extension and grasping is small from 3 to 13 wk post stroke. In people with relatively pure motor hemiparesis, one important factor underlying deficits in hand shaping during grasping is the inability to extend the fingers and thumb. Without sufficient volitional control of finger and thumb extension, successful grasping of objects will not occur.

show abstract

“…There have been few quantitative studies of the thumb after stroke (Lang and Schieber 2003;Raghavan et al 2006) and limited investigations of the reflexes of the thumb (Marsden et al 1973(Marsden et al , 1976(Marsden et al , 1977a. The stretch reflex properties of most thumb flexors have not been characterized.…”

Section: Introductionmentioning

confidence: 99%

Lack of Hypertonia in Thumb Muscles After Stroke

Towles

Kamper

Rymer

2010

Journal of Neurophysiology

View full text Add to dashboard Cite

Towles JD, Kamper DG, Rymer WZ. Lack of hypertonia in thumb muscles after stroke. J Neurophysiol 104: 2139 -2146, 2010. First published June 28, 2010 doi:10.1152/jn.00423.2009. Despite the importance of the thumb to hand function, little is known about the origins of thumb impairment poststroke. Accordingly, the primary purpose of this study was to assess whether thumb flexors have heightened stretch reflexes (SRs) following stroke-induced hand impairment. The secondary purpose was to compare SR characteristics of thumb flexors in relation to those of finger flexors since it is unclear whether SR properties of both muscle groups are similarly affected poststroke. Stretch reflexes in thumb and finger flexors were assessed at rest on the paretic side in each of 12 individuals with chronic, severe, stroke-induced hand impairment and in the dominant thumb in each of eight control subjects also at rest. Muscle activity and passive joint flexion torques were measured during imposed slow (SS) and fast stretches (FS) of the flexors that span the metacarpophalangeal joints. Putative spasticity was then quantified in terms of the peak difference between FS and SS joint torques and electromyographic changes. For both the hemiparetic and control groups, the mean normalized peak torque differences (PTDs) measured in thumb flexors were statistically indistinguishable (P ϭ 0.57). In both groups, flexor muscles were primarily unresponsive to rapid stretching. For 10 of 12 hemiparetic subjects, PTDs in thumb flexors were less than those in finger flexors (P ϭ 0.03). Paretic finger flexor muscle reflex activity was consistently elicited during rapid stretching. These results may reflect an important difference between thumb and finger flexors relating to properties of the involved muscle afferents and spinal motoneurons.

show abstract

Patterns of Impairment in Digit Independence After Subcortical Stroke

Cited by 69 publications

References 57 publications

The statistics of natural hand movements

The statistics of natural hand movements

Recovery of Thumb and Finger Extension and Its Relation to Grasp Performance After Stroke

Lack of Hypertonia in Thumb Muscles After Stroke

Contact Info

Product

Resources

About