The purpose of the present study was to examine the importance of the agonist muscle activity of the post-impact 30 ms phase during drop jump (DJ) for effective rebound performance by comparing those of sprint runners and swimmers. The eight sprint runners (SPRINT) and twelve swimmers (SWIM) were participated in this study. They performed DJ from a 0.3-m height box with maximal rebound efforts. Electromyograms (EMG) of the lower leg muscles (medial gastrocnemius [MG], soleus [SOL] and tibialis anterior [TA]), and vertical ground reaction force together with kinematic data were measured simultaneously during DJ. In addition, the onsets of fascicle stretching of the MG and SOL muscles were measured by using high-speed ultrasonography (521Hz) during DJ. The onsets of the fascicle stretching of SOL during DJ were not significantly different between SPRINT and SWIM (15 ± 7 ms and 16 ± 6 ms, respectively). During DJ, SPRINT showed onset of the SOL EMG before the ground contact (-26 ± 19 ms). Meanwhile, SWIM showed the onset of the SOL EMG after the ground contact of DJ (16 ± 19 ms). These results suggest that the SOL muscles for SWIM cannot be fully-activated during the braking phase. Consequently, the rate of force development during the braking phase of DJ and subsequently rebound height could be reduced in SWIM.

BACKGROUND: Oral health is thought to be associated with diet quality, and socioeconomic status (SES) affects both oral health and diet. The aim of this study was to investigate the association between the number of teeth and dietary intake as well as nutritional biomarker, considering the subjects' SES. METHODS: We conducted a cross-sectional analysis of data from 2049 individuals aged ≥ 50 years from the National Integrated Project for Prospective Observation of Non-communicable Disease and its Trends in the Aged 2010. The number of remaining teeth was categorized into age-specific quartiles (Q1 to Q4). We assessed the adjusted means and 95% confidence intervals for dietary variables by the number of teeth using analysis of covariance. Stratified analyses by SES were also conducted. RESULTS: The intake of grain products was 31 g higher, and those of vegetables and meat were 30 g and 8 g lower, respectively, in Q1 (fewer teeth) than in Q4 (more teeth). Carbohydrate intake was higher whereas protein, minerals (potassium, magnesium, and zinc), vitamins (vitamins A, E, B, B, β-carotene, and folic acid), and dietary fiber intakes were lower among individuals with fewer teeth. Adjusted mean serum albumin levels were low in Q1. The associations between the number of teeth and dietary intake were more evident in individuals with a low SES. CONCLUSIONS Having few remaining teeth was associated with a low nutrient intake and low serum albumin levels in middle-aged and older Japanese adults, and these associations were more evident in individuals with low SES.
Aged ; Aged, 80 and over ; Carbohydrates ; Cross-Sectional Studies ; Diet ; Energy Intake ; physiology ; Female ; Humans ; Japan ; Male ; Middle Aged ; Nutrients ; Nutrition Surveys ; Nutritional Status ; Serum Albumin ; analysis ; Socioeconomic Factors ; Tooth ; Vegetables