Effect of binocular vision during target shooting in archery.

PurposeThis study aimed to evaluate the difference between binocular and monocular vision and eye movements during the competition using video-oculography (VOG).MethodsExperiment 1 included 14 participants to evaluate differences in arrow convergence. Then, seven participants in Experiment 1 were randomly selected and included in Experiment 2, which evaluated eye movements during archery using VOG. The target used an 80-cm waterproof target face and was set at a distance of 30 m. All players shot the target 36 times using their bows and arrows. Experiments 1 and 2 evaluated the distribution of arrows in each score and the number of focus points, respectively, between binocular and monocular conditions.ResultsThe arrows, which include the area of 9 points, were significantly greater in the binocular condition (11.85 ± 5.04 shots) than in the monocular condition (9.36 ± 5.41 shots) in Experiment 1 (P = 0.047). The players focused on the target under both binocular and monocular conditions, although the players were switching off fixation between the target and shooting sight under the binocular condition in Experiment 2.ConclusionThese behaviors indicated that the players were trying to accurately shoot the target by exploring the distance between themselves and the target as a cue for depth perception

Vibration acceleration promotes endochondral formation during fracture healing through cellular chondrogenic differentiation.

Vibration acceleration through whole body vibration has been reported to promote fracture healing. However, the mechanism responsible for this effect remains unclear. Purpose of this study was to determine whether vibration acceleration directly affects cells around the fracture site and promotes endochondral ossification. Four-week-old female Wistar Hannover rats were divided into two groups (vibration [V group] and control [C group]). The eighth ribs on both sides were cut vertically using scissors. From postoperative day 3 to 11, vibration acceleration using Power Plate® (30 Hz, low amplitude [30-Low], 10 min/day) was applied in the V group. Mature calluses appeared earlier in the V group than in the C group by histological analysis. The GAG content in the fracture callus on day 6 was significantly higher in the V group than in the C group. The mRNA expressions of SOX-9, aggrecan, and Col-II in the fracture callus on day 6 and Col-X on day 9 were significantly higher in the V group than in the C group. For in vitro analysis, four different conditions of vibration acceleration (30 or 50 Hz with low or high amplitude [30-Low, 30-High, 50-Low, and 50-High], 10 min/day) were applied to a prechondrogenic cell (ATDC5) and an undifferentiated cell (C3H10T1/2). There was no significant difference in cell proliferation between the control and any of the four vibration conditions for both cell lines. For both cell lines, alcian blue staining was greater under 30-Low and 50-Low conditions than under control as well as 30-High and 50-High conditions on days 7 and 14. Vibration acceleration under 30-L condition upregulated chondrogenic gene expressions of SOX-9, aggrecan, Col-II, and Col-X. Low-amplitude vibration acceleration can promote endochondral ossification in the fracture healing in vivo and chondrogenic differentiation in vitro

Vibration acceleration enhances proliferation, migration, and maturation of C2C12 cells and promotes regeneration of muscle injury in male rats

Abstract Vibration acceleration (VA) using a whole‐body vibration device is beneficial for skeletal muscles. However, its effect at the cellular level remains unclear. We aimed to investigate the effects of VA on muscles in vitro and in vivo using the C2C12 mouse myoblast cell line and cardiotoxin‐induced injury in male rat soleus muscles. Cell proliferation was evaluated using the WST/CCK‐8 assay and proportion of Ki‐67 positive cells. Cell migration was assessed using wound‐healing assay. Cell differentiation was examined by the maturation index in immunostained cultured myotubes and real‐time polymerase chain reaction. Regeneration of soleus muscle in rats was assessed by recruitment of satellite cells, cross‐sectional area of regenerated muscle fibers, number of centrally nucleated fibers, and conversion of regenerated muscle from fast‐ to slow‐twitch. VA at 30 Hz with low amplitude for 10 min promoted C2C12 cell proliferation, migration, and myotube maturation, without promoting expression of genes related to differentiation. VA significantly increased Pax7‐stained satellite cells and centrally nucleated fibers in injured soleus muscles on Day 7 and promoted conversion of fast‐ to slow‐twitch muscle fibers with an increase in the mean cross‐sectional area of regenerated muscle fibers on Day 14. VA enhanced the proliferation, migration, and maturation of C2C12 myoblasts and regeneration of injured rat muscles