The research will make it possible to assess effects of rehabilitation of arm function with the use of biofeedback method and conventional therapies administered to patients at a chronic stage of recovery post-stroke, as part of the treatment in a health-resort setting.

: In accordance with the study design, the group will comprise 100 patients with hemiparesis after stroke, participating in a health-resort based rehabilitation program during their stay in the Health-Resort Rehabilitation Hospital in Iwonicz Zdrój, Poland. The minimum size of the sample was calculated based on the total annual number of patients after stroke receiving treatment in the Health-Resort Rehabilitation Hospital in Iwonicz Zdrój, i.e. approximately 200 patients, 100% of these being in a chronic stage of recovery. It was assumed that 50% of the patients would present stage 4-5 arm paresis according Brunnström scale. A fraction of 0.8 and a maximum error of 5% were applied and the sample size of 71 patients was obtained.

The patients meeting eligibility criteria will be randomly divided into two groups:

• the study group (50 patients), participating in a conventional rehabilitation program supplemented with additional biofeedback training;
• the control group (50 patients), participating in the conventional rehabilitation program only.

The patients in both groups will participate in a three-week rehabilitation program (from Monday to Friday), with the treatments and therapies continued for up to two hours per day. The program will include: group and individual exercise (active and assisted exercises, manipulation exercises, PNF-based practice, balance and breathing exercises), manual massage, physical treatments, such as: laser, whirlpool therapy, mud compress therapy, carbonic acid therapy, TENS therapy, BIO-V lamp, and localized cryotherapy. The patients in the study group will also receive biofeedback training aimed to improve motor function of the upper limb. The exercise will be performed using equipment manufactured by Biometrics. The device makes it possible to perform movements in all the planes of the joints in the upper limb. During the exercise, a visualisation of the movements is shown to the patient on the screen; this biofeedback makes it possible for them to regulate and increase the range of movement, to use greater muscle strength and to visually assess the accuracy of their performance. The training with the biofeedback function will be carried out for 30 minutes per day.

After the program is completed, the subjects from the control group will have an opportunity to also practice with the Biometrics device with the biofeedback function.

Examinations will be carried out three times: the baseline at the start of the rehabilitation program, a check-up at the end of the three-week program, and a follow-up two months after discharge from the hospital. The tests will be performed at the same time of day, and following the same conditions.

The patients' condition and the rehabilitation effects will be assessed using the following measures:

• hand grip strength and pinching strength of the fingers, to be tested with a dynamometer and pinch meter, respectively;
• ranges of motion in the joints of the upper limb, with R500 goniometer;
• manual skills, with Box and Blocks test;
• handgrip function, according Franchay scale;
• motor capacities of the upper limb, according to Fugl-Meyer Motor Assessment Scale;
• EMG test, with the Biometrics device;
• activities of daily living, with Barthel Index.

Inclusion Criteria:

• informed, voluntary consent of the patient;
• a single ischemic stroke experienced;
• hemiparesis;
• a minimum of 6 months from the stroke onset;
• age 45-75 years;
• elementary (basic) handgrip ability;
• stage 4-5 arm paresis according Brunnström scale;
• stage 3 disability according to Rankin scale;
• spasticity in the paretic arm up to 1 plus on the modified Ashworth scale;
• current health status, confirmed by a medical examination, allowing the person to take part in the study and in the exercise.

Exclusion Criteria:

• lack of informed and voluntary consent of the patient;
• two or more strokes experienced, haemorrhagic stroke, brain stem and cerebellar stroke;
• impairments in higher mental functions adversely affecting the ability to understand and perform the tasks during exercise;
• visual field impairment;
• mechanical and thermal injuries potentially limiting handgrip function;
• coexisting neurological, rheumatic and orthopaedic conditions, including fixed contractures potentially affecting gripping abilities;
• unstable health condition;
• failure to complete the three-week rehabilitation program.