FORCE-VELOCITY RELATIONSHIP OF LEG MUSCLES ASSESSED BY MOTORIZED TREADMILL TESTS

We aimed to explore the properties of the F-V relationship of leg muscles exerting the maximum pulling F within a wide range of V set on a standard motorized treadmill. Subjects exerted maximum horizontally pulling F while walking on a treadmill set to 8 different V (1.4 - 3.3 m/s). The obtained F-V relationships proved to be linear and strong (all R \u3e 0.84), while their parameters depicting the leg muscle capacities for producing maximum F, V, and power (i.e., the maximum product of F and V) were highly reliable (0.84 \u3c ICC \u3c 0.97; 6.4 \u3c CV% \u3c 19.3). Moreover, when obtained from only the lowest and highest V the F-V relationships revealed virtually identical outcomes. We conclude that the evaluated procedure could be developed into an ecologically valid and reliable protocol for routine testing of the F, V, and P-producing capacities of leg muscles

A SIMPLE METHOD FOR ASSESSMENT OF MUSCLE MECHANICAL CAPACITIES FROM FUNCTIONAL MOVEMENT TASKS

The aim of the present study was to evaluate the level of agreement between the routinely used multiple-load method and a simple two-load method based on direct assessment of the F-V relationship from only 2 external loads applied. Twelve participants were tested on the maximum performance vertical jumps, cycling, bench press throws, and bench pull performed against a variety of different loads. All four tested tasks revealed both exceptionally strong relationships between the parameters of the 2 methods (median R = 0.98) and a lack of meaningful differences between their magnitudes (fixed bias below 3.4%). Therefore, addition of another load to the standard tests of various functional tasks typically conducted under a single set of mechanical conditions could allow for the assessment of the muscle mechanical properties, such as the muscle F, V, and P producing capacities

Force-velocity relationship of leg muscles assessed with motorized treadmill tests: two-velocity method

Author's manuscriptLinear regression models applied on force (F) and velocity (V) data obtained from loaded multi-joint functional movement tasks have often been used to assess mechanical capacities of the tested muscles. The present study aimed to explore the properties of the F-V relationship of leg muscles exerting the maximum pulling F at a wide range of V on a standard motorized treadmill. Young and physically active male and female subjects (N=13+15) were tested on their maximum pulling F exerted horizontally while walking or running on a treadmill set to 8 different velocities (1.4-3.3 m/s). Both the individual (median R=0.935) and averaged across the subjects F-V relationships (R=0.994) proved to be approximately linear and exceptionally strong, while their parameters depicting the leg muscle capacities for producing maximum F, V, and power (P; proportional to the product of F and V) were highly reliable (0.84<ICC<0.97). In addition, the same F-V relationship parameters obtained from only the highest and lowest treadmill V (i.e., the 'two-velocity method') revealed a strong relationship (0.89<R<0.99), and there were no meaningful differences regarding the magnitudes of the same parameters obtained from all 8 V’s of the treadmill. We conclude that the F-V relationship of leg muscles tested through a wide range of treadmill V could be strong, linear, and reliable. Moreover, the relatively quick and fatigue-free twovelocity method could provide reliable and ecologically valid indices of F, V, and P producing capacities of leg muscles and, therefore, should be considered for future routine testing.University of Delaware. Department of Kinesiology

Are family physical activity habits passed on to their children?

Studies of the familial association of physical activity (PA) and sedentary behaviour (SB) have increased in recent years. However, there is a lack of studies that have objectively examined the correlates between parents, grandparents, and childrens\u27 PA. Therefore, the purpose of this study was to measure PA using accelerometers to determine the extent to which PA and SB correlate among parents, grandparents, and children. A sample of 169 children between 11-14 years (77 boys and 97 girls), 225 parents (98 males and 127 females) and 52 grandparents (16 males and 36 females) were recruited for the current study. Accelerometers RM42 (UKK Terveyspalvelut Oy, Tampere, Finland) were used to determine PA levels of children, parents and grandparents. Epoch was set to 1 second. Mothers\u27 moderate-to-vigorous PA (MVPA) was associated with children\u27s MVPA (p 0.05) of children\u27s MVPA (total sample). In contrast, grandfathers\u27 sedentary behaviour was a significant predictor (% = 0.269p < 0.05) of children\u27s sedentary behaviour (total sample). The results of the current study suggest that parental involvement in PA, particularly by mothers, is important for children\u27s PA and, accordingly, healthy outcomes

Effect of Herbicide Clopyralid and Imazamox on Dehydrogenase Enzyme in Soil of Regenerated Pedunculate Oak Forests

Clopyralid and imazamox are successfully used for weed control during the first years of regeneration of pedunculate oak forests. Hence, the question that arises is how these herbicides affect microorganisms, especially the activity of dehydrogenase enzyme, when they reach the soil. Two study sites were selected in regenerated pedunculate oak forests, and the two herbicides were applied in two doses that are used for weed control (clopyralid, 100 g a.i. ha&minus;1 and 120 g a.i. ha&minus;1; imazamox, 40 g a.i. ha&minus;1 and 48 g a.i. ha&minus;1). The effect of the herbicides was evaluated 7, 14, 21, 30, and 60 days after application. A significant reduction in dehydrogenase activity was found on days 7 and 14 at both sites. However, after 14 days there was a recovery of dehydrogenase activity for all treatments such that the values obtained on day 21 did not differ from the control values. The effect of clopyralid and imazamox on dehydrogenase activity was not dose-dependent. Dehydrogenase activity also depended on soil properties, soil sampling time and climatic conditions during the investigation years. The results show that clopyralid and imazamox can reduce soil dehydrogenase activity, but this effect is transient. This can be attributed to the ability of microorganisms to overcome the stress caused by the herbicide by developing the capability to utilize herbicides as a nutrient source and proliferating in such an environment

Effects of Nonsurgical Periodontal Therapy on Salivary 8-Hydroxy-Deoxyguanosine Levels and Glycemic Control in Diabetes Mellitus Type 2 Patients

Diabetes and periodontitis are complex chronic diseases that are potentially interrelated, as well as associated with oxidative stress. Thus, the aim of the present study was to evaluate the influence of nonsurgical periodontal treatment on salivary 8-hydroxy-deoxyguanosine (8-OHdG) levels and glycemic control in patients suffering from both diabetes mellitus type 2 (DM2) and periodontitis. The study sample included 53 DM2 patients, while 31 systemically healthy patients served as controls. Participants in both groups suffered from periodontitis of comparable severity. Periodontal clinical parameters, namely plaque index (PI), gingival index (GI), papilla bleeding index (PBI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded, along with salivary 8-OHdG levels and glycated hemoglobin (HbA1c). Levels of 8-OHdG were analyzed by ELISA. All aforementioned parameters were evaluated prior to commencing the study and at 90-day follow-up upon nonsurgical periodontal therapy completion. At baseline, salivary levels of 8-OHdG in DM2 patients were significantly higher (1.17 ng/mL) than those measured for the control group (0.75 ng/mL) and showed significant positive correlation with GI and PPD (p &lt; 0.05). Three months after nonsurgical periodontal therapy, the salivary 8-OHdG levels were significantly reduced in DM2 patients (p &lt; 0.05). Analysis results also revealed statistically significant changes in all measured clinical parameters between baseline and three-month follow-up in both groups (p &lt; 0.05). Upon treatment completion, a decline in the HbA1c level was noted in DM group, but it did not reach statistical significance (p &gt; 0.05). It can be concluded that DM2 patients benefit from non-surgical periodontal therapy, as indicated by a marked reduction in their salivary 8-OHdG level and a modest improvement in glycemic control. Short-term clinical benefits noted in the DM group were similar to those observed in the non-diabetic periodontal patients

Die "STERNBERG-Originale" der Bayerischen Staatssammlung f\ufcr Pal\ue4ontologie und historische Geologie zu M\ufcnchen

Volume: 12Start Page: 105End Page: 11