Analysis of the characteristics of anticipatory postural adjustments in older adults using smartphones: Association between cognitive and balance functions.

Objectives: Using smartphones, we aimed to clarify the characteristics of anticipatory postural adjustments (APA) in older adults and examine the relationship between cognitive and balance functions.

Methods: The study participants were 10 young and 13 older adults. An accelerometer built into a smartphone was attached to the lower back (L5) of the participant, and acceleration in the mediolateral direction was measured using a one-leg stance (OLS).

New quantitative evaluation of anticipatory postural adjustments using a smartphone in patients with Parkinson's disease.

Objective: To investigate a smartphone-enabled quantitative evaluation of anticipatory postural adjustments (APA) during one-leg stance (OLS) movements among individuals with Parkinson's disease (PD).

Methods: This cross-sectional study included 10 young controls, 10 older individuals, and 13 individuals with PD. A smartphone and accelerometer were attached to the participants' lower back (L5), and the movements of the lower back toward the stance side during OLS were measured.

Clarify Sit-to-Stand Muscle Synergy and Tension Changes in Subacute Stroke Rehabilitation by Musculoskeletal Modeling.

Post-stroke patients exhibit distinct muscle activation electromyography (EMG) features in sit-to-stand (STS) due to motor deficiency. Muscle activation amplitude, related to muscle tension and muscle synergy activation levels, is one of the defining EMG features that reflects post-stroke motor functioning and motor impairment. Although some qualitative findings are available, it is not clear if and how muscle activation amplitude-related biomechanical attributes may quantitatively reflect during subacute stroke rehabilitation.

Organization of functional modularity in sitting balance response and gait performance after stroke.

Background: Recovery of postural adjustment, especially when seated, is important for performing activities of daily living after stroke. However, conventional clinical measures provide little insight into a common strategy for dynamic sitting balance and gait. We aimed to evaluate functional re-organization of posture and ambulatory performance after stroke.

Spatiotemporal modular organization of muscle torques for sit-to-stand movements.

The robustness of movement patterns is an essential factor for characterizing the adaptability of our daily motions; however, details of the mechanism underlying adaptive motion patterns are not well understood. Here, we utilized complex principal component analysis (CPCA) to examine the spatiotemporal structure of dynamic muscle torques during sit-to-stand (STS) movements. The motion of a three-link rigid body model in the sagittal plane was captured by a Vicon motion analysis system to compute the kinematics of the center of mass (COM), angular displacement, and joint torques.

Dynamic optimization of the sit-to-stand movement.

The purpose of this study was to clarify criteria that can predict trajectories during the sit-to-stand movement. In particular, the minimum jerk and minimum torque-change models were examined. Three patterns of sit-to-stand movement from a chair, i.