ABSTRACT
The purpose of this study was to research the physical fitness of elderly weekly hill walkers by comparison with general average values for Japanese. The participants total 77 members (28 males and 49 females) of a mountaineering party who did a hill walking once a week for at least 1 year. The test of physical fitness consisted of muscle strength (knee extension strength, back strength, grip strength and sit ups), agility (reaction time), body flexion (long sitting forward reach), balance (one-leg balancing with eyes open) and ability of daily physical actions (10-times-reapeated sit-to-stand test and 5m maximal walking test). The general average values were taken from several previous studies considered to be highly appropriate as the general average. For statistical analysis, unpaired t-test using the number of subjects, means and standard deviations of previous studies was performed. As a result, the 4 muscle strength tests were significantly higher than the general average value (P<0.001). In addition, the agility test and 2 abilities of daily physical action’s tests were significantly faster than the general average value (P<0.001). Moreover, there was no relationship between the value of knee extension and ages, but it existed in between annual climbing number of days (male: r=0.40, P<0.05, female: r=0.35, P<0.05). In conclusion, it appears that elderly people who climb the low mountain weekly have the higher physical fitness than general average values, and it can be inferred that weekly hill walking in low mountains can potentially keep higher knee extension regardless of age.
ABSTRACT
In Japan, Nordic walking (NW) has two style walking method. For one thing, the poles are used to push against the ground towards the back of the body (diagonal style: DIA). The other one, the poles put on forward and using like a cane (defensive style: DEF). This study aims to clarify differences between the two Nordic walking (NW) styles. The subjects were 12 community-dwelling middle-aged and older adults (mean age: 62.4 ± 7.8 years). All of subjects were tested to perform NW in both style for 12 minutes walking around the park. Walking distance, speed, heart rate (HR), energy expenditure (EE) and electromyogram (EMG) amplitude of the upper and lower limbs using surface EMG were assessed. A pole with a built-in load cell measured force used to push the pole into the ground (pole force), pole contact time, and pole impulse. Distances and speed in DIA was significantly higher than DEF. Significant difference in muscle activity was observed between DIA and DEF in the triceps brachii only. EE of DEF was significantly higher than DIA. Poling force and pole impulse in DIA was significantly higher than DEF. These results indicate that when prescribing NW for health promotion, it should be done according to each characteristic in DIA or DEF.
ABSTRACT
This study aimed to elucidate how body composition, force-generating capacity and jump performances are associated with 50-m sprint velocity in circumpubertal boys, in relation to sprint phases and maturation. One hundred thirty four circumpubertal boys were allocated to preadolescent or adolescent group on basis of the height at the peak height velocity of Japanese boys (154 cm) reported in literature: those with body heights over 154 cm as adolescent group and others as preadolescent group. Body composition was determined by bioelectrical impedance analysis. In addition to maximal voluntary isometric knee extension torque, the performances of counter movement jump (CMJ), rebound jump (RJ), standing long jump (SLJ) and standing 5-step jump (SFJ) were also measured. RJ-index was calculated by dividing height by contact time. The time of 50-m sprint was determined at 10-m intervals. Multiple regression analysis showed that in preadolescent boys, SFJ become a predictor for the sprint speed during acceleration phases, and SFJ, RJ-index and CMJ as predictors for the sprint speeds during maximal speed and deceleration phases. In the adolescent boys, age, CMJ, SLJ, and SFJ become a predictor for the sprint speed during acceleration phases, and torque relative to body mass, CMJ and SFJ were selected as predictors for the sprint speeds during maximal speed and deceleration phases. Thus, the current results indicate that force-generating capacity and jumping ability are determinants for sprint performance in circumpubertal boys, but the relative contribution of each of the two factors differs between preadolescent and adolescent stages and among the sprint phases.
ABSTRACT
This study aimed to determine the relationships between the torque generating capacity of the lower extremity muscles and either running or jump performance in primary and junior high school boys. A total of 102 primary and junior high school boys participated in this study. Muscle thicknesses (MTs) of the knee extensors and plantar flexors were determined using ultrasonography. Muscle volumes (MVs) of the knee extensors and plantar flexors were estimated using MTs and limb lengths. The isometric joint torques (TQs) for knee extensors and ankle plantar flexors were measured using myometer. MV and TQ were divided by body mass (MV/BM and TQ/BM, respectively). Running velocity was measured using a non-motorized treadmill. The counter movement jump (CMJ) and squat jump (SJ) were performed on a matswitch system. The flight time was measured and used to calculate the heights of CMJ and SJ using the following equation; height (cm) = g × (flight time)<sup>2</sup> /8/10. As the result of multiple regression analysis, age, MV/BM and TQ/BM were selected as predictors of running velocity in the primary school boys, whereas TQ and lean body mass in junior high school boys. In the primary school boys, TQ/BM and body fat mass was selected as significant contributors for SJ and CMJ performances, whereas, in the junior high school boys, TQ and the percent of body fat for SJ performance and MV/BM and TQ for CMJ performance. Thus, the present results indicate that the relationships between torque generating capacity of the lower extremity muscles and either running or jump performance differ between primary and junior high school boys. It may be assumed that, for running and jump performances, muscle mass and strength become determinant factors in junior high school boys, whereas their values relative to body mass in primary school boys.
ABSTRACT
This study was performed to establish a simple method to evaluate knee joint proprioception by examining knee-bending angle, in which Lombard's Paradox phenomenon could be confirmed, in 8 extremities of 7 patients with ACL injured who were diagnosed with ACL rupture at a medical facility (ACL injured group) and 10 extremities of 10 healthy adults (control group). As a result, knee joint proprioception in the ACL injured group was significantly lower than that in the control group (P<0.05). Significantly more incidence of Lombard's Paradox phenomenon was confirmed at the knee-extension position in the ACL injured group (P<0.01), compared with the control group. Significant negative correlation was confirmed between the reproductive angle inaccuracy of joint position sensation, a marker of knee joint proprioception, and Lombard's Paradox phenomenon under the conditions of r=-0.58 and the risk rate of 5%. Based on the results of this study, it was suggested that the knee-bending angle, in which Lombard's Paradox phenomenon was confirmed, would be affected by knee joint proprioception through feedback from the ACL mechanoreceptors, and the angle might be used as a simple evaluation method for knee joint proprioception.