Anticipatory postural adjustment (APA) existed before a self-induced perturbation is an important motor control skill for balance and gait initiation, but cannot be easily monitored. During proactive balance test, a self-initiated weight shifting is produced. This might be an optimal paradigm for APA measurement. The purpose of this study was to investigate if APAs existed in the proactive balance test which consists of quantifiable weight shifting. The feature and reliability of the APAs were also evaluated. We firstly built a proactive balance test program on the commercially available Wii balance board. The program could generate adjustable target direction and distance for guiding subjects performing quantifiable weight shifting. The center of pressure (COP) was recorded and analyzed for balance-related variables (path length, path time, and direction error) and APA-related variables (APA time, APA distance, and APA correction). The results showed that APAs could be detected in every testing trial. Adequate to good reliability in both balance and APA-related variables were found. This study proved the feasibility of quantifying APA during proactive balance tests and its feasibility for clinical- and home-based measurements.
The strength of lower extremity is important for individuals to maintain balance and ambulation functions. The previous studies showed that individuals with Parkinson’s disease suffered from fatigue and strength loss of central origin. The purpose of this study was to investigate the effect of lower extremities’ cycling training on different components of force and fatigue in individuals with Parkinson’s disease. Twenty-four individuals (13 males, 11 females, mean age: 60.58 ± 8.21 years) diagnosed with idiopathic Parkinson’s disease were randomized into training and control groups. The maximum voluntary contraction (MVC) force, voluntary activation level (VA), and twitch force of knee extensors were measured using a custom-made system with surface electrical stimulation. The general, central, and peripheral fatigue indexes (GFI, CFI, and PFI) were calculated after a fatiguing cycling protocol. Subjects received 8 weeks of low resistance cycling training (training group) or self-stretching (control group) programs. Results showed that MVC, VA, and twitch force improved (p < 0.05) only in the training group. Compared to the baseline, central fatigue significantly improved in the training group, whereas peripheral fatigue showed no significant difference in two groups. The cycling training was beneficial for individuals with Parkinson’s disease not only in muscle strengthening but also in central fatigue alleviation. Further in-depth investigation is required to confirm the effect of training and its mechanism on central fatigue.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.