Precision Vibration Therapy for Neuromuscular and Functional Improvement in Older Adults and Stroke Survivors

Inclusion Criteria: Older Adults: * Meet two or more criteria of the Study of Osteoporotic Fractures (SOF) frailty index * Willing to participate in the study and comply with all study procedures * Able to wear and safely use the vibration device * Normal cognitive function (Mini-Mental State Examination \[MMSE\] score ≥ 23) * Presence of knee joint pain in the lower limbs Stroke Survivors: * Clinical diagnosis of ischemic or hemorrhagic stroke confirmed by a physician * Clinically stable stroke condition (i.e., not in an acute or unstable phase) * Brunnstrom stage ≥ III for the affected limb * Cognitive ability sufficient to follow study procedures (MMSE score ≥ 23) * Modified Ashworth Scale (MAS) score \< 3 for the paretic limb * Able to sit safely and participate in vibration or rehabilitation sessions for up to 60 minutes per visit * Willing and able to comply with all study procedures and provide written informed consent Exclusion Criteria: Older Adults: * Acute or chronic neurological injury involving the upper or lower limbs within the past 6 months * Acute or chronic musculoskeletal injury involving the upper or lower limbs within the past 6 months * History of surgery on the upper or lower limbs within the past 6 months Stroke Survivors: * Recurrent stroke during the current episode (i.e., acute re-stroke) or otherwise clinically unstable stroke presentation * Markedly elevated spasticity preventing isolated voluntary movement of the target limb (MAS score ≥ 3) * Hemianopsia or severe hemineglect that significantly interferes with task execution * Concomitant vestibular or cerebellar disorders that severely impair motor performance * Orthopedic or traumatic comorbidities causing significant pain or limiting safe participation during evaluation or intervention * Cognitive impairment attributable to stroke that precludes effective communication or adherence to the study protocol * Other neurological or psychiatric disorders judged likely to interfere with motor performance or study outcomes