Background; Blood flow restriction training (BFRT) is a physical intervention that promotes many beneficial muscular activities and functions when low load/intensity is used in healthy and clinical populations.

Objectives: To determine the effect of BFRT on upper extremity motor function, strength, and Activity of daily living in chronic/acute stroke patients.

A cerebrovascular accident (CVA) is often known as a stroke and can be described as a localized neurological deficiency caused by various cardiovascular abnormalities that disrupt brain function. Stroke is the primary cause of death worldwide, it also leads to a substantial number of disability among the population.

There is no doubt that stroke is one of the most common causes of adult-onset disabilities. 70-85% of the first strokes are associated with hemiplegia which is usually followed by hemiparesis. Only 60% of patients suffering from hemiparesis need physical rehabilitation and have attained functional independence in basic activities of daily living (ADLs) such as using the restroom and short-distance walking. Patients with sensorimotor and visual-field loss are much more dependent on care than those with pure motor impairments.

Stroke patients require post-stroke rehabilitation and physical therapy procedures to improve their recovery and quality of life. A multidisciplinary approach that addresses each patient's unique physical, occupational, and speech deficits can assist optimize their functional abilities and encourage independence.

Hemiplegic stroke rehabilitation involves structured, interdisciplinary, supportive services that start 48 hours after the stroke starts for stable patients. Although patients and families generally benefit from inpatient and outpatient rehabilitation, each treatment modality's efficacy falls short of standards set by evidence-based therapy (reference). Rehabilitation has always been around teaching patients how to compensate with their unaffected arm or limb. The major goals of physical, occupational, and speech therapists are to modify the surroundings and develop new skills in order to keep patients at home with the least amount of care assistance. The removal of architectural impediments to movement, problem-solving techniques, supporting social and psychological services, braces and other orthotics, and equipment like wheelchairs and walkers all continue to be crucial in assisting patients in doing daily life tasks (Dobkin, 2004).

The goal of physical therapy rehabilitation modalities post-stroke is to enhance activities of daily living, enhance range of motion, reduce pain, and improving muscle tone. Previous studies on BFRT have focused on healthy populations, limited number of observational trials have been performed on BFRT in patients with neurological problems, such as Parkinson's disease, multiple sclerosis, spinal cord injury, and stroke.

BFRT involves partially restricting arterial blood flow into muscles as well as occluding the venous outflow during exercise. It was first introduced into the literature by a Japanese doctor Yoshiaki Sato in Japan in 1987 who used tourniquet ischemia to induce muscle fatigue. This technique was originally called "kaatsu training," meaning "training with added pressure." Kaatsu training is now performed all over the world and is more commonly referred to as "BFRT" and is achieved using a pneumatic tourniquet system.

In addition to physical rehabilitation, BFRT is used for physical training and performance in healthy individuals. There has been extensive research into its value as a training tool, including elite- and amateur-level athletes, untrained young and older adults, and hypertensive individuals.

In addition to reducing arterial blood flow to working muscles, blood flow restriction obstructs venous return. When active muscles are exposed to BFR conditions, they are subjected to ischemia, which increases the metabolic stress on them. In addition to BFR, venous occlusion increases muscle cell swelling, activates intracellular anabolic pathways, and recruits fast-twitch fibers, which are thought to be involved in muscle adaptation.

There were different Factors affecting exercise adaptations with BFR including pressure of occlusion (partial or complete), type of occlusion (continuous or intermittent), intensity of exercise, and volume of exercise with BFR.

BFR along with low-load resistance training, cardio endurance training, and other activities that are generally recommended to improve muscular mass/strength are also associated with these adaptations in muscles.

The combination of Low-load Resistance Exercise with Body-Focused Rehabilitation (BFR) promotes greater strength adaptations and hypertrophy than the combination of Low-Load Resistance Exercise with BFR alone. Exercises that combine low load resistance with BFR can promote comparable levels of hypertrophy to those that combine high load resistance.

The review done by Vinolo-Gil and colleagues revealed that treatment with blood flow restriction appears to be helpful for neurological conditions without having side effects. Improvements have been shown in gait, quality of life, endurance, muscle strength, and limb functions.

Many studies done on the effect of BFRT on the lower limb in stroke patients, for an example the randomized trial done to compare low-intensity resistance training with BFR (LIRT-BFR) and high-intensity resistance training in stroke patients, results revealed that BFRT produced a significant improvement in lower limb strength, balance, gait, and depression No previous studies done on the effect of BFRT on upper limbs in post-stroke patients so This study aims to study the effect of Blood Flow Restriction training on motor function, strength, and Activity of daily living in stroke patients.

Inclusion Criteria:

• 30 ≥ years of age.
• The diagnosis of stroke
• Confirmed by cranial CT and/or MRI
• Hemipaises (weakness of one side of the body ), clear consciousness, stable vital signs

Exclusion Criteria:

• Uncontrolled hypertension
• Coronary artery disease
• Deep vein thrombosis
• Severe osteoarthritis
• Cognitive impairment, inability to cooperate
• Any severe musculoskeletal problem that prevented the participants from doing resistance training
• unstable complications related to heart, lung, and kidney diseases.
• Serious cognitive or audio-visual impairment
• Mini-Mental Scale Examination score, <24)

the data could be used in future study

the participants will be allocated using the closed-envelop method with each envelop containing a card with a coded number. Particiants will be treated using these code numbers throughout the study. only the outcome assessor will not be allowed to have the interpritation of the coded numbers till the end of the study