You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
Sensorimotor integration in human postural control.
Abstract 1:
It is generally accepted that human bipedal upright stance is achieved by feedback mechanisms that generate an appropriate corrective torque based on body-sway motion detected primarily by visual , vestibular , and proprioceptive sensory systems . Because orientation information from the various senses is not always available ( eyes closed ) or accurate ( compliant support surface ) , the postural control system must somehow adjust to maintain stance in a wide variety of environmental conditions . This is the sensorimotor integration problem that we investigated by evoking anterior-posterior ( AP ) body sway using pseudor and om rotation of the visual surround and /or support surface ( amplitudes 0.5 - 8 degrees ) in both normal subjects and subjects with severe bilateral vestibular loss ( VL ) .  AP rotation of body center-of-mass ( COM )  was measured in response to six conditions offering different combinations of available sensory information .  Stimulus-response data were analyzed using spectral analysis to compute transfer functions and coherence functions over a frequency range from 0.017 to 2.23 Hz . Stimulus-response data were quite linear for any given condition and amplitude . However , overall behavior in normal subjects was nonlinear because gain decreased and phase functions sometimes changed with increasing stimulus amplitude . " Sensory channel reweighting " could account for this nonlinear behavior with subjects showing increasing reliance on vestibular cues as stimulus amplitudes increased . VL subjects could not perform this reweighting , and their stimulus-response behavior remained quite linear . Transfer function curve fits based on a simple feedback control model provided estimates of postural stiffness , damping , and feedback time delay . There were only small changes in these parameters with increasing visual stimulus amplitude . However , stiffness increased as much as 60 % with increasing support surface amplitude . To maintain postural stability and avoid resonant behavior , an increase in stiffness should be accompanied by a corresponding increase in damping . Increased damping was achieved primarily by decreasing the apparent time delay of feedback control rather than by changing the damping coefficient ( i.e. , corrective torque related to body-sway velocity ) . In normal subjects , stiffness and damping were highly correlated with body mass and moment of inertia , with stiffness always about 1/3 larger than necessary to resist the destabilizing torque due to gravity . The stiffness parameter in some VL subjects was larger compared with normal subjects , suggesting that they may use increased stiffness to help compensate for their loss . Overall results show that the simple act of st and ing quietly depends on a remarkably complex sensorimotor control system


Title 2:
The effects of foam surface properties on standing body movement
Abstract 2:
Conclusion . The properties of a foam surface significantly affect  body movement variance . Therefore , studies where different kinds of foam have been used may not provide congruent results . Objectives . To investigate whether different properties of foam  affect body movement variance ( 32 subjects , mean age 22.5 years ) in terms of linear head , shoulder , hip and knee movements . Subjects repeated tests with eyes open and closed , to also determine the effect of vision on the different surfaces . Subjects and methods . Body movement was captured on three different foam surfaces and on a control solid surface over 2 min using a Zebris ™ ultrasound measuring system . The foam surfaces were categorized by their firmness as firm foam , medium foam and soft foam . Results . Body movement variance increased significantly when st and ing on all foam surfaces compared with the solid surface . However , movement variance was larger when st and ing on the firm foam compared with the softer foams , except in the anteroposterior total and low frequency ranges . We also found that the body movement pattern differed when st and ing on foam and firm surfaces , with greater reliance on movements at the knee to give postural stability on foam than on the solid surface . Vision clearly reduced all body movement variances , but particularly within the high frequency range
RESULTS Based on the present review ed findings , it is impossible to conclude that children with Down syndrome present significantly lower static postural control compared to TD children .
In contrast , findings showed that adolescents with Down syndrome tended to present significantly lower static postural control compared to TD adolescents when visual and plantar cutaneous inputs were disturbed separately or simultaneously .