Table 1 Summary of inclusion and exclusion criteria

Study design

Observational, cross-sectional studies

Non-English language publication, published before 10thAugust 2022

Population

Younger adults (18 to 40 years old) and older adults (over 60 years old)

Animals, pregnant women, and participants with any diagnoses that affected balance such as a neurological or orthopedic disease, and metabolic or inflammatory disorders, were also excluded

Interventions

Anteroposterior perturbation (including unilateral arm movements, pendulum impact, tilt in force platform)

Gait initiation and any protocol wit exacerbated response

Comparators

Younger vs older adults

Pathological conditions

Setting

APAs assessments including onset, amplitude of muscle recruitment (electromyography) and/or COP parameters (force platform), and/or kinematics features

Exacerbated postural reaction after the disturbance (such as falls and the use of the step to return to initial position)

Outcome

APA onset and/or APA amplitude (any muscle)

COP onset and/or COP amplitude

None