Volume 5, Issue 2

The Effect of External Stimulus Produced by Vibration Stimulus Instrument on Body Sway
Original Research
This study aimed to examine the effect of right-left or front-back vibration stimulus during standing on body sway. Subjects were 10 healthy young male adults. They had no evidence or known history of a gait, posture or skeletal disorder. After a weak vibratory stimulus (20 Hz) for 1 min, subjects stood under the strong stimulus (70 Hz) of front-back or right-left vibratory for 1 min. The subjects were measured body sway for 1 min before and after the above vibratory stimulus. Four body-sway factors (unit time sway, front-back sway, left-right sway, and the high frequency band power) were used as evaluation parameters. A significant decrease was found only in a unit time sway factor after vibratory stimulus. A significant difference between front-back and right-left vibratory stimuli was found only in a left-right sway factor and the latter stimulus produced a large change. In conclusion, even in the vibratory stimulus with the same intensity, body sway decreases after front-back stimulus, but increases after right-left stimulus. In short, the effect of vibratory stimulus on posture control system may differ by the vibratory direction.
American Journal of Sports Science and Medicine. 2017, 5(2), 38-43. DOI: 10.12691/ajssm-5-2-4
Pub. Date: August 03, 2017
7490 Views2839 Downloads
Stretching Exercises to Prevent Work-related Musculoskeletal Disorders – A Review Article
Review Article
Background: Lower back, neck and shoulder pain, which affects the lumbar spine, are the most commonly reported Musculoskeletal Disorders (MSDs). Approximately 80 percent of the general population is affected by these disorders at a certain point during their lifetime, with some estimates being as high as 84 percent. The most commonly used approach for the treatment of MSDs is exercise therapy. Stretching provides several benefits for people at work, and may help improve morale and team cohesiveness. Another benefit of stretching is that participants may increase their range of motion compared to their counterparts who do not participate in stretching programs. Objective: The aim of this study is to synthesize the recent literature on workplace stretching exercise programs and their effects on reducing work-related MSDs in different occupational groups. Method: Specific keywords were identified and used in a systematic search to guide the discovery of relevant studies and data. Electronic databases including PubMed, ScienceDirect, and Google Scholar, were searched for the following combination of keywords: workplace, stretching, exercises, injury, work, prevention, safety, occupation, and ergonomics. Studies that do not focus on the benefits of stretching exercise were excluded simply because the present study examines prevention of work-related musculoskeletal disorders through stretching exercises. Results: Whilst majority of the literature examined in this study may not completely explain that stretching at the office will prevent work-related musculoskeletal accidental injuries, some studies have shown that performing stretching exercises can lead to reducing discomfort/pain and raising range of motion (ROM). Conclusion: Majority of the literature reviewed in this study might not fully explain that stretching at work prevents work-related musculoskeletal injuries. Some studies have shown that performing stretching exercises can contribute to reducing discomfort/pain and increasing range of motion (ROM). Particularly, construction workers who participated in stretching exercise programs reported significant positive effects including reduction in pains/disability, increase in muscle flexibility and endurance. These exercises are recommended to be performed during breaks throughout, depending on the type of occupation. All the exercises suggested could be performed at the workstation, and only require a few seconds to perform.
American Journal of Sports Science and Medicine. 2017, 5(2), 27-37. DOI: 10.12691/ajssm-5-2-3
Pub. Date: May 04, 2017
21214 Views4776 Downloads
Modified Reactive Strength Index in Adolescent Athletes Competing in Different Sports and Its Relationship with Force Production
Original Research
The modified reactive strength index (RSImod) is used as a measurement of reactive strength and explosiveness. The main purpose of the current study was to assess RSImod in young athletes competing in various sports and to examine the relationship between RSImod and eccentric and concentric force and vertical displacement. Two-way ANOVA showed a significant main effect for sport group, but not for age group. Soccer (0.47±0.09 m/s) and basketball players (0.49±0.1 m/s) had significantly higher values than handball players (0.36±0.07 m/s) and rowers (0.35±0.07 m/s). Among the independent variables, average eccentric force had the strongest relationship with RSImod. In conclusion, RSImod differs between athletes from different sports, but not between athletes from different age groups in the examined age period. Also, RSImod is strongly associated mainly with the average eccentric force and secondarily with the average concentric force during the countermovement jump.
American Journal of Sports Science and Medicine. 2017, 5(2), 21-26. DOI: 10.12691/ajssm-5-2-2
Pub. Date: April 26, 2017
15098 Views3427 Downloads
Wrist-Lagging Angle Impact on Both Golf Swing Distance and Accuracy
Original Research
The purpose of this study was to investigate the impact of wrist-lagging angle on both distance and accuracy in golf downswing among NCAA Division I female golfers. Seven female golfers from a university of the East Coast of the United States volunteered to participate in the study. While performing a full swing with 7-iron, a standardized Golf Simulator was used to obtain swing related data and Dartfish was utilized to measure the wrist angles in the downswing. Multivariate General Linear Regression (MGLR) analysis was conducted to determine predictor variables for hitting distance and accuracy. The results have shown that for irons wrist-lagging angle is a significant predictor for the accuracy, but not for the distance. Other variables such as club head speed, smash effect, sidespin and backspin were also found significant in MGLR model (p < .01). Future studies should gain a comprehensive understand of how wrist-lagging angle impact on male golfers.
American Journal of Sports Science and Medicine. 2017, 5(2), 15-20. DOI: 10.12691/ajssm-5-2-1
Pub. Date: April 20, 2017
6539 Views1915 Downloads