Positive effects of robotic exoskeleton training of upper limb reaching movements after stroke

This is for chronic so thats great, I think I'd prefer the Japanese one
 http://www.jneuroengrehab.com/content/pdf/1743-0003-9-36.pdf
Background
Impairment of upper limb function is one of the most common sequelae following stroke; in
particular arm function is found to be altered in 73% to 88% of first time stroke survivors
(infarctions only), and 55% to 75% still experience problems that impair their activities of
daily living for up to 3 to 6 months or more [1,2].
Impairments limit the patient’s autonomy in daily living and may lead to permanent disability
[3]. The deficits are typically characterized by weakness of specific muscles [4], lack of
mobility between structures at the shoulder girdle [5], incorrect timing of components within
a movement pattern [6,7] and loss of interjoint coordination [8]. Consequently goal directed
movements in hemiplegic patients are characterized by lower movement amplitude,
prolonged movement time, segmented trajectories and abnormal pattern of muscle activation.
Compensatory motor strategies, characterized by adaptations to muscle imbalance [9], are
commonly adopted by stroke patients in attempt to overcome these impairments.
Various rehabilitation interventions to improve skill reacquisition have shown promising
results in overcoming motor impairment after stroke [10].
High intensity and task specific upper limb treatment consisting of active, highly repetitive
movement is one of the most effective approaches to arm function post-stroke restoration
[11-13]. Recent studies moreover suggest that given appropriate training, motor
improvements of the upper limb can continue well into the chronic stage of stroke [14-16].
The use of robot devices in rehabilitation can provide high intensity, repetitive, task specific
and interactive treatment of the impaired upper limb and an objective, reliable mean of
monitoring patients progress. Systematic review confirms the potential for robotic assisted
devices to elicit improvements in upper limb function [17,18]. Moreover virtual reality
provided a unique medium where therapy can be provided within a functional, purposeful and
motivating context and can be readily graded and documented [19]. The cortical
reorganization and associated functional motor recovery after virtual reality in patient with
chronic stroke are documented also by fMRI [20].
 While several studies have already investigated the effects of robot assisted training in planar
movements performed in the horizontal plane [21], the effect of training on the control and
production of multi-joint and spatial functional arm movements, including movements
against gravity, in hemiparetic subjects has received less attention.
It has been already shown that stereotyped movement patterns [8] due to abnormal muscle
co-activation result in a reduced active range of motion against gravity. In particular
providing antigravity limb support, leads to a reduction of the abnormal coupling between
shoulder abduction/elbow flexion [22] and promising results have been found in the robotic
training of patients with antigravity vertical movements that involve shoulder elevation [23].
Moreover orthoses providing only passive gravity assistance to the arm in reaching
movements can induce comparable clinical improvements to those obtained with robotic
training [24].
In this study we have investigated the effects of robot aided training on the recovery of spatial
reaching movements, with a focus on point-to-point reaching movements performed in
different directions, analysing how muscle imbalance in stroke influences the process of
motor recovery in terms of regain of smooth movement, interjoint coordination and
agonistic/antagonistic muscle recruitment.
A robotic treatment was administered through the L-EXOS [25,26], a robotic exoskeleton for
the upper limb, in a group of nine patients with chronic hemiparetic stroke. Exoskeleton
robotic systems allow to execute full spatial multi-joint functional arm movements, including
elevation movements with shoulder abduction, providing either variable gravity support or
active assistance to the impaired arm [27].
To assess the carry-over of the observed improvements in movement during training into
improved function, changes in movement execution and smoothness of motion were analysed
through a kinesiologic assessment, consisting in the motion and dynamic electromyographic
analysis of reaching movements performed before and after training.
The kinesiologic performance (movement time, smoothness of motion) was then analysed in
relation to the changes in the EMG pattern of agonist–antagonist muscle co-activation and
shoulder-elbow interjoint coordination.