METHODS: Twenty-five young and healthy university students performed a triceps push-down exercise at 45% one repetition maximum (1RM) with and without CS until task failure, and the rate of fatigue (ROF), endurance time (ET) and number of repetitions (NR) for both exercises were analyzed. In addition, the first and last six repetitions of each exercise were considered non-fatiguing (NF) and fatiguing (Fa), respectively, and the root mean square (RMS), mean power frequency (MPF) and median frequency (MDF) for each exercise repetition were evaluated.
RESULTS: The lateral and long head showed significant differences (P<0.05) in the ROF between the two exercises, and all the heads showed significant (P<0.05) differences in the RMS between the two exercises under NF conditions. Only the long head showed a significant difference (P<0.05) in the MPF and MDF between the two exercises. CS increases the ET (24.74%) and NR (27%) of the exercise. The three heads showed significant differences (P<0.05) in the RMS, MPF and MDF under all exercise conditions.
CONCLUSION: A lower ROF was obtained with CS. In addition, the RMS was found to be better approximator of CS, whereas MPF and MDF were more resistant to the effect of CS. The results showed that the three heads worked independently under all conditions, and the non-synergist and synergist head pairs showed similar behavior under Fa conditions. The findings from this study provide additional insights regarding the functioning of each TB head.
Aim: To investigate the concurrent validity and reliability of the WBB for balance assessment in healthy young adults.
Methods: Thirty-two young adults participated in this study. Their ability to balance was tested while standing on a WBB and a laboratory-grade force platform, under three conditions: feet together with eyes open, feet together with eyes closed and semi-tandem standing with eyes open. They had 10 min resting period between tests. The agreement between the WBB and the laboratory-grade force platform was investigated, and the reliability of the WBB was determined.
Results: A poor agreement between the WBB and the laboratory-grade force platform was found for all standing conditions [intraclass correlation coefficient (ICC) = 0.03 to 0.07]. A moderate to high reliability was found for the WBB for balance assessment in healthy young adults (ICC = 0.66 to 0.76).
Conclusion: The WBB was found to be a reliable tool for static balance assessment in healthy young adults. However, it had poor validity compared to the laboratory-grade force platform.
METHODOLOGY: Twenty healthy adults (8 males, 12 females, age: 29±4.10years, BMI: 21.56±2.36kg/m2) participated in this study. Static and dynamic (levels 8 and 2) balance with single stance and double stance and dynamic (level 8 and levels 6-2) for risk of fall with double stance were tested with the Biodex Balance System with three self-selected feet positions: straight (13.8°), toe-out (35.6°) and toe-in (-11.9°) for each test condition. Additionally, TUG test was performed with toe-out and toe-in gait.
RESULTS: The results of repeated measures ANOVA showed significant differences (p<0.05) between straight and modified toe angles in balance at dynamic level 2 with both double and single stance conditions. Significant differences (p<0.001) were also found in TUG scores for the test conditions.
CONCLUSION: Toe-in and toe-out gait modifications have significant effects on balance at higher levels of platform tilt and functional balance. Further investigations with knee osteoarthritis patients and electromyography may provide insight in balancing strategies adopted by the body in toe-out and toe-in gait.