Balance and postural control are fundamental components of functional independence and quality of life in adults. Deficits in trunk stability and balance are strongly associated with increased fall risk, impaired mobility, and decreased ability to perform activities of daily living in sedentary individuals and clinical populations. Trunk muscles play a key role in stabilizing the spine and coordinating movement; their activation is essential for maintaining balance during static and dynamic tasks. Evidence suggests that targeted trunk training can significantly improve postural control and functional outcomes.

Inclusion Criteria:

• Participants with low physical activity level evaluated by the Arabic version of the International Physical Activity Questionnaire-Short Form.
• Their age between 18 and 30 years.
• Body mass index less than 30 kg/ m2
• Participants who did not engage in a physiotherapy program in the previous 6 months.
• Have the ability to stand independently on balance board.
• With good cognition.
• No prior experience with dual task training.
• Absence of visual impairments, injuries or medications (such as analgesics or muscle relaxants) that may affect the results of the study.

Exclusion Criteria:

• Any neurological diseases (such as; severe disc prolapse and radiating pain). - History of knee injury.
• Fracture or surgery in lower extremity or the spine.
• Congenital deformity.
• Orthopedic disorders such as patellofemoral pain syndrome.
• Vestibular disorders or severe balance impairment.
• Psychiatric problem.
• Any systemic disease.
• Cardiovascular complications.
• Pregnancy.

females will be included in this study to maintain a homogeneous sample as there is sex differences in neuromuscular control, balance performance, and hormonal influences that directly affect the study outcomes (e.g., postural stability, muscle activation, and fatigue responses).