[Purpose] The purpose of this study was to investigate the concurrent validity and test-retest reliability of the recently introduced OPTOGait Photoelectric Cell System for the assessment of spatio-temporal parameters of gait. [Subjects] Twenty healthy young adults (mean age = 27.35, SD = 7.4) were asked to walk 3 times on walkway at a comfortable speed. [Methods] Concurrent validity was assessed by comparing data obtained using the OPTOGait and GAITRite systems, and reliability was assessed by comparing data from the first and third OPTOGait sessions. [Results] Concurrent validity, as identified by intra-class correlation coefficients (ICC (2, 1) = 0.929–0.998), coefficients of variation (CVME = 0.32–11.30%), and 95% limits of agreement, showed high levels of correlation. In addition, the test-retest reliability of the OPTOGait Photoelectric Cell System was demonstrated as showing a high level of correlation with all spatio-temporal parameters by intra-class correlation coefficients (ICC (3, 1) = 0.785–0.952), coefficients of variation (CVME = 1.66–4.06%), 95% limits of agreement, standard error of measurement (SEM = 2.17–5.96%), and minimum detectable change (MDC95% = 6.01–16.52%). [Conclusion] The OPTOGait Photoelectric Cell System has strong concurrent validity along with relative and absolute test-retest reliabilities. This portable system with easy-to-use features can be used for clinical assessments or research purposes as an objective means of assessing gait.

[Purpose] To date, core muscle activity detected using ultrasonography during prone bridge exercises has not been reported. Here we investigated the effects of core muscle thickness and balance on sling exercise efficacy by shoulder joint angle in healthy individuals. [Subjects and Methods] Forty-three healthy university students were enrolled in this study. Ultrasonography thickness of external oblique, internal oblique, and transversus abdominis during sling workouts was investigated. Muscle thickness was measured on ultrasonography imaging before and after the experiment. Dynamic balance was tested using a functional reaching test. Static balance was tested using a Tetrax Interactive Balance System. [Results] Different muscle thicknesses were observed during the prone bridge exercise with the shoulder flexed at 60°, 90° or 120°. Shoulder flexion at 60° and 90° in the prone bridge exercise with a sling generated the greatest thickness of most transversus abdominis muscles. Shoulder flexion at 120° in the prone bridge exercise with a sling generated the greatest thickness of most external oblique muscles. [Conclusion] The results suggest that the prone bridge exercise with shoulder joint angle is an effective method of increasing global and local muscle strength.

Objective: The purpose of this study was to analyze and compare vertical ground reaction forces during sit to stand (STS) and gait between female elderly and young individuals using the Wii Balance Board (WBB). Design: Cross-sectional study. Methods: Fifty-one female elderly people (age: 75.18±4.60 years), and 13 young people (age: 29.85±3.69 years) performed the five times STS test and gait respectively on the WBB. We analyzed time (s), vertical peak (%), integral summation (Int_SUM, %), and counter variables (%) in STS and 1st peak (body weight, BW%), 2nd peak (BW%), peak minimum (BW%), time (second), center of pressure (COP) path length (mm), and Int_SUM (BW%) in gait. The independent t-test was used to assess for differences in STS, gait ability, and general characteristics between the female elderly group and young adults group. With the first and last trials excluded, the mean value was obtained from the middle three of the five trials. Results: During STS, Int_SUM and time of young adults were significantly less than of the female elderly subjects. There were no significant differences in peak and counter variables. In gait, all variables (1st peak, 2nd peak, min, time, COP_path, and Int_SUM) showed significant differences between groups (p<0.05). This study demonstrated that the validity of vertical ground reaction forces occurring during STS and gait was significant in female elderly and young adults. Conclusions: Based on the measurement of vertical ground reaction forces in STS and gait using the WBB, it is possible to clinically improve the quality of geriatric physical therapy. Further studies are necessary to examine concurrent validity of elderly patients who have undergone total hip or knee replacement.