Modifiability of abnormal isometric elbow and shoulder joint torque coupling after stroke

Ellis, Michael D.; Holubar, Bradley G.; Acosta, Ana Marı́a; Beer, Randall F.; Dewald, Julius P. A.

doi:10.1002/mus.20343

Cited by 120 publications

(107 citation statements)

References 33 publications

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“…Our group and others have previously quantified abnormal muscle coactivations and joint torque-coupling patterns in both static (Dewald et al 1995;Beer et al 1999;Dewald and Beer 2001;Lum et al 2003) and dynamic (Beer et al 2000(Beer et al , 2004 protocols reflecting constraints in the ability of individuals with stroke to generate certain joint torque combinations (Twitchell 1951;Brunnstrom 1970). The mutability of abnormal muscle coactivation and joint torque-coupling has been addressed recently in studies attempting to change or remediate the impairment through eight weeks of physical interventions (Lum et al 2004;Ellis et al 2005). In this report, we pose the question of whether these abnormal patterns are affected by altering afferent somatosensory feedback resulting from changes in static limb configuration.…”

Section: Introductionmentioning

confidence: 91%

Position-dependent torque coupling and associated muscle activation in the hemiparetic upper extremity

et al. 2006

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Previous studies have demonstrated abnormal joint torque coupling and associated muscle coactivations of the upper extremity in individuals with unilateral stroke. We investigated the effect of upper limb configuration on the expression of the well-documented patterns of shoulder abduction/ elbow flexion and shoulder adduction/elbow extension. Maximal isometric shoulder and elbow torques were measured in stroke subjects in four different arm configurations. Additionally, an isometric combined torque task was completed where subjects were required to maintain various levels of shoulder abduction/adduction torque while attempting to maximize elbow flexion or extension torque. The dominant abduction/elbow flexion pattern was insensitive to changes in limb configuration while the elbow extension component of the adduction/extension pattern changed to elbow flexion at smaller shoulder abduction angles. This effect was not present in control subjects without stroke. The reversal of the torque-coupling pattern could not be explained by mechanical factors such as muscle length changes or muscle strength imbalances across the elbow joint. Potential neural mechanisms underlying the sensitivity of the adduction/elbow extension pattern to different somatosensory input resultant from changes in limb configuration are discussed along with the implications for future research.

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Section: Introductionmentioning

confidence: 91%

Position-dependent torque coupling and associated muscle activation in the hemiparetic upper extremity

et al. 2006

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“…Weakness dependent on joint position in subjects with hemiparesis was largely described for upper extremity 3,6 . Despite a large number of studies considering this question for upper extremities [6][7][8][9] , less attention has been given to describing the effect of joint position on lower limb force production after stroke.…”

Section: Introductionmentioning

confidence: 99%

Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis

Michaelsen¹,

Ovando²,

Bortolotti³

et al. 2013

Braz. J. Phys. Ther.

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| Background: The extent to which muscle length affects force production in paretic lower limb muscles after stroke in comparison to controls has not been established. Objectives: To investigate knee flexor strength deficits dependent on hip joint position in adults with hemiparesis and compare with healthy controls. Method: a cross-sectional study with ten subjects with chronic (63±40 months) hemiparesis with mild to moderate lower limb paresis (Fugl-Meyer score 26±3) and 10 neurologically healthy controls. Isometric knee flexion strength with the hip positioned at 90° and 0° of flexion was assessed randomly on the paretic and non-paretic side of hemiparetic subjects and healthy controls. Subjects were asked to perform a maximal isometric contraction sustained for four seconds and measured by a dynamometer. The ratio of knee flexor strength between these two hip positions was calculated: Hip 0°/Hip 90°. Also, locomotor capacity was evaluated by the timed up and go test and by walking velocity over 10 meters. Results: In subjects with hemiparesis, absolute knee flexion torque decreased (p<0.001) with the hip in extension (at 0°). The ratio of knee flexor torque Hip 0°/Hip 90° on the paretic side in hemiparetics was lower than in controls (p=0.02). Conclusions: Weakness dependent on joint position is more significant in the paretic lower limb of adults with hemiparesis when compared to controls. More attention should be given to lower limb muscle strengthening exercises in individuals with stroke, with emphasis on the strengthening exercises in positions in which the muscle is shortened.Keywords: stroke; lower extremity; muscle weakness; physical therapy; rehabilitation. HOW TO CITE THIS ARTICLEMichaelsen SM, Ovando AC, Bortolotti A, Bandini B. Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis. Braz J Phys Ther. 2013 Jan-Feb; 17(1):86-91. http://dx

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“…The most studied abnormal neural synergy is the inability to simultaneously abduct the shoulder and extend the elbow [20][21][22][23]. While compensatory strategies (excessive trunk movement) can overcome this impairment, recovery of interjoint coordination is possible with a focused intervention [24]. Importantly, therapy strategies that promote relearning of normal interjoint coordination and movement kinematics may critically affect actual real-world use of the limb in ADLs [25], while therapies that allow use of compensatory strategies may impede this process [26][27].…”

Section: Introductionmentioning

confidence: 99%

Retraining of interjoint arm coordination after stroke using robot-assisted time-independent functional training

Brokaw¹,

Murray²,

Nef³

et al. 2011

JRRD

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Abstract-We have developed a haptic-based approach for retraining of interjoint coordination following stroke called time-independent functional training (TIFT) and implemented this mode in the ARMin III robotic exoskeleton. The ARMin III robot was developed by Drs. Robert Riener and Tobias Nef at the Swiss Federal Institute of Technology Zurich (Eidgenossische Technische Hochschule Zurich, or ETH Zurich), in Zurich, Switzerland. In the TIFT mode, the robot maintains arm movements within the proper kinematic trajectory via haptic walls at each joint. These arm movements focus training of interjoint coordination with highly intuitive real-time feedback of performance; arm movements advance within the trajectory only if their movement coordination is correct. In initial testing, 37 nondisabled subjects received a single session of learning of a complex pattern. Subjects were randomized to TIFT or visual demonstration or moved along with the robot as it moved though the pattern (time-dependent [TD] training). We examined visual demonstration to separate the effects of action observation on motor learning from the effects of the two haptic guidance methods. During these training trials, TIFT subjects reduced error and interaction forces between the robot and arm, while TD subject performance did not change. All groups showed significant learning of the trajectory during unassisted recall trials, but we observed no difference in learning between groups, possibly because this learning task is dominated by vision. Further testing in stroke populations is warranted.

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Modifiability of abnormal isometric elbow and shoulder joint torque coupling after stroke

Cited by 120 publications

References 33 publications

Position-dependent torque coupling and associated muscle activation in the hemiparetic upper extremity

Position-dependent torque coupling and associated muscle activation in the hemiparetic upper extremity

Strength deficit of knee flexors is dependent on hip position in adults with chronic hemiparesis

Retraining of interjoint arm coordination after stroke using robot-assisted time-independent functional training

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