Increasing the Repertoire of Intermuscular Co-ordination Post Stroke Through EMG-Guided Human-Machine Interaction

Inclusion criteria for aged matched healthy group

* Male or female whose age range between 40 and 75
* no known neurological injuries

Exclusion criteria for aged matched healthy group

* have an orthopedic disorder involving upper limbs;
* have a history of any neurologic disease;
* have any history of epilepsy of the potential participants and/or their family members;
* are unable to consent;
* are pregnant.

Inclusion criteria for stroke group

* male or female hemiparetic chronic stroke survivors;
* age ranging between 40-75 year;
* with single unilateral ischemic or hemorrhagic middle cerebral artery stroke;
* neurologically stable for \>6 months;
* have an expectation that current medication will be maintained without changes for at least 3 months. Stable use of anti-spasticity medication (e.g., baclofen, diazepam, tizanidine) is accepted;
* without severe spasticity (Modified Ashworth (MA) \<4);
* have not received botulinum toxin on the impaired arm within 3 months.

Exclusion criteria for stroke group

* have an orthopedic disorder involving upper limbs;
* cognitive impairment sufficient to interfere with informed consent or successful completion of the protocol (Montreal Cognitive Assessment (MoCA) score \< 26);
* a history of another neurologic disease;
* anesthesia of joint position sense in upper limbs;
* are pregnant or have a chance that they might be (self-reported);