Criterion validity of ActiGraph monitoring devices for step counting and distance measurement in adults and older adults: a systematic review.

Background: Wearable activity monitors such as ActiGraph monitoring devices are widely used, especially in research settings. Various research studies have assessed the criterion validity of ActiGraph devices for step counting and distance estimation in adults and older adults. Although several studies have used the ActiGraph devices as a reference system for activity monitoring, there is no summarized evidence of the psychometric properties.

Standing on a Double-Seesaw Device is an Easy Way to Modify the Coordination Between the Two Feet for Controlling Upright Stance: Assessment Through Weight-Bearing Asymmetry.

Healthy young subjects were instructed to modify their weight-bearing asymmetry when standing on a double-seesaw device. The results indicated decreased and unchanged amplitudes in the center-of-pressure movements under the unloaded and loaded legs, respectively. In addition, a concomitant increased contribution of the more loaded leg and a decreased contribution of the pressure distribution mechanism along the mediolateral axis were observed in the production of the resultant center of pressure, its amplitude remaining constant.

Upright stance on a single vs double seesaw: are automatic and voluntary components similarly involved in balance control?

The relevance of seesaw devices in postural evaluation and training is gathering growing evidence due to its sensory-motor specificity. Nonetheless, the physiological specificities resulting from the dissociation or not of the seesaws (single vs double) still need to be investigated, in particular by assessing the respective contribution of automatic and voluntary components in the postural control. A protocol based on attention disturbance through a dual-task paradigm was set to establish this contribution.

Undisturbed stance on a double seesaw: Interaction between asymmetries of the center-of-pressure patterns under each foot and weight-bearing.

Both center-of-pressure (CP) displacements under each foot and relative body-weight distribution intervene in the production of resultant CP movements. To better understand their respective involvement, a protocol was set up for young healthy individuals consisting in standing on a double seesaw, favoring pitch motions and laying on a dual-force platform. The postural control effects induced by two types of asymmetry, weight-bearing and the CP movement patterns, were investigated.