The Effect of Combined Versus Sequential Attentional Focus Instructions on Upper Extremity Function in Subacute Stroke Patients: An Assessor-Blinded Randomized Controlled Trial

Stroke is a major global cause of long-term disability. Upper extremity deficits are particularly common, affecting nearly 80% of individuals after stroke and manifesting as weakness, impaired selective motor control, abnormal muscle tone, sensory disturbances, and reduced coordination. These deficits cause substantial limitations in functional reach, grasp, and object manipulation, and they persist more severely compared with lower extremity impairments. Although most stroke survivors regain some degree of independent ambulation, only a minority recover meaningful functional use of the paretic upper limb, resulting in a disproportionately higher disability burden for the upper extremity.

Conventional rehabilitation often shows limited effectiveness in improving upper extremity outcomes because training intensity is typically insufficient, task specificity is restricted, and interventions do not consistently apply established motor learning principles. These challenges underscore the need for new therapeutic perspectives that more effectively harness neuroplasticity through high-intensity, task-oriented, and motor learning-based approaches tailored to the complex demands of upper extremity recovery.

Upper-extremity motor functions, which are often severely impaired in the acute phase of stroke, gradually begin to recover during the transition into the subacute period as spontaneous neurobiological repair processes become more active. Subacute stroke refers to the recovery phase that begins after the first week post-onset and extends through the early months, during which spontaneous biological recovery and neuroplasticity remain highly active. Although many frameworks define the core subacute window as the first 3 months, functional recovery and rehabilitation responsiveness continue meaningfully up to 6 months, which is widely accepted as the upper limit of the subacute period in clinical research and guideline-based stroke classification. Therefore, including patients within the first 6 months post-stroke ensures enrolment during a period of high rehabilitative potential.

In recent years, the integration of physical exercise and cognitive training has emerged as a promising strategy for enhancing both cognitive and motor functions in rehabilitation. One example of combining motor tasks with cognitive components is attentional focus training, which includes external and internal attentional focus strategies. External attentional focus directs the learner's attention to the effects of movement (e.g., "focus on the movement of the ball") and has been consistently shown to enhance movement efficiency and task performance. This effect is believed to occur through increased motor automaticity and reduced conscious interference. Conversely, internal attentional focus emphasizes the mechanical components of body movements (e.g.,'focus on your hand position') and can support the development of foundational motor control, particularly during the early stages of motor learning and recovery.

Recent evidence suggests that both internal and external attentional focus strategies can complement each other in therapeutic contexts. Internal focus (IF) supports early stroke rehabilitation by enhancing basic motor control, whereas external focus (EF) improves movement efficiency and functional parameters in later stages. EF has also been reported to outperform IF in improving upper extremity performance in stroke populations. These findings suggest that combining IF and EF-either simultaneously or in a structured progression-may better align with the evolving demands of stroke recovery.