• 전기학회논문지
• /
• 제65권4호
• /
• pp.678-683
• /
• 2016

The study aim was to investigate a comparison of muscle activity fatigue between maximal and submaximal strength gains during the bench press in men. It was hypothesized that maximal voluntary contraction (%MVC) would similar gains between maximal and submaximal strength gains during the bench press, but median frequency (MDF) would increase in maximal compared with submaximal exercise. Employing a randomized, counterbalanced crossover design, 12 men were asked to perform maximal repetitions and submaximal repetitions (concentric: 1-s, eccentric: 1-s, 2-s/repetition) to failure with a load of 85% of 1RM for the bench press, with a 3-minute recovery between the sets. Each subject was tested for the number of repetitions and sets, total work in bench press. Surface electromyography (EMG) was recorded from the pectoralis major, deltoid anterior, and triceps brachii for %MVC and MDF. Total work was significantly higher in the submaximal repetition exercise than that the maximal repetition exercise (p<.05). Muscle fatigue of pectoralis major, deltoid anterior and triceps brachii were significantly smaller in the submaximnal repetition exercise than that the maximal repetition exercise (p<.05, respectively). However, muscle activity of pectoralis major, deltoid anterior, and triceps brachii were not significantly different between exercises. Our study showed that a smaller muscle fatigue in submaximal repetitions, despite higher in total work and a similar in muscle activity were observed. These results suggest that submaximal repetitions during the bench press would be enhanced intensity and/or volume compared with maximal repetitions exercise.

• 한국전문물리치료학회지
• /
• 제30권4호
• /
• pp.275-280
• /
• 2023

Background: Although warm-ups before exercise are widely accepted, research on sex differences in improving hamstring flexibility is limited. Differences in the physical and physiological characteristics between males and females may result in different responses to warm-ups. Objects: This study aimed to examine sex differences in the effects of specific warm-up on hamstring flexibility. Methods: This study included 24 young adults with hamstring tightness. The participants performed five maximal knee extensions and flexions at 90° flexion of the hip, and the maximal knee extension angle was measured in real-time using a smartphone clinometer application. Results: The groups did not significantly affect the maximal knee extension angle but showed a significant effect for repetition (p = 0.002) and group-repetition interaction (p = 0.002). Males had no significant change in hamstring flexibility; however, females showed a significant increase in flexibility in the 5^th trial compared with the 1^st trial (p = 0.041). These results demonstrated sex-specific differences in flexibility improvement over time. Conclusion: The findings of this study suggest that specific warm-up can successfully improve hamstring flexibility in females. This may be due to various factors, such as muscle stiffness of the lower extremity, estrogen levels, and temperature sensitivity. In clinical settings, specific warm-up might be helpful for females who participate in sports or activities, such as running or jumping, which require a full range of motion in the hip and knee joints.

• 한국운동역학회지
• /
• 제15권4호
• /
• pp.75-83
• /
• 2005

The purpose of this study was to determine the kinematic characteristics of the ankle joint and RPM(repetition per minutes) during the supra maximal training in cycling. For this study, 8 national representative cyclists, distance cyclists in track and road, were selected. During the super-maximum pedalling, kinematic data were collected using a six-camera(240Hz) Qualisys system. the room coordinate system was right-handed and fixed in the back of a roller for cycle, with right-handed orthogonal segment coordinate systems defined for the leg and foot. Lateral kinematic data were recorded at least for 3 minutes while the participants pedal on a roller. Two-dimensional Cartesian coordinates for each marker were determined at the time of recording using a nonlinear transformation technique. Coordinate data were low-pass filtered using a fourth-order Butterworth recursive filter with cutoff frequency of 15Hz. Variables analyzed in this study were compared using a one factor(time) ANOVA with repeated measures. The results of investigation suggest that the number of rotating pedal was decreased with time phase during the super-maximum pedaling. Maximum angle of the ankle joint showed little in change with time phase compared with minimum angle of that.

• 전기학회논문지P
• /
• 제66권4호
• /
• pp.247-251
• /
• 2017

This paper proposes a low power transmission technique for single-carrier modulation with frequency domain equalization. As time domain signals and frequency domain signals have unique corresponding functions, inserting zeros after each symbol causes a repetition in other domain, so maximal ratio combining technique using repetitive transmission can be applied in the frequency domain. In this paper, we configure transmit signals to insert zeros after each symbols for single-carrier modulation with frequency domain equalization and maximal ratio receive combining block in the receiver structures, propose a structure for transmitter and receiver and show that its performance is better than the traditional algorithm by simulations.

• 대한수학회논문집
• /
• 제35권1호
• /
• pp.83-116
• /
• 2020

Let G be a finite group. By a sequence over G, we mean a finite unordered sequence of terms from G, where repetition is allowed, and we say that it is a product-one sequence if its terms can be ordered such that their product equals the identity element of G. The large Davenport constant D(G) is the maximal length of a minimal product-one sequence, that is, a product-one sequence which cannot be factored into two non-trivial product-one subsequences. We provide explicit characterizations of all minimal product-one sequences of length D(G) over dihedral and dicyclic groups. Based on these characterizations we study the unions of sets of lengths of the monoid of product-one sequences over these groups.

• 한국전문물리치료학회지
• /
• 제2권1호
• /
• pp.51-61
• /
• 1995

In general, research in isokinetic exercise has focussed on studies of peak torque. However, peak torque is not always sufficient to assess the real amount of motion or to determine endurance. In this study, the subjects were 54 healthy students who performed continuous maximal isokinetic knee flexion and extension until their total work per time reached 50% of their maximal total work. Isokinetic curves were then plotted. Total work sums, exercise durations in seconds, and the numbers of repetitions were compared with reference to subject gender, angular velocity and muscle group. The relationship between total work sum, duration and number of repetition and thigh circumference plus leg length was computed. In addition, the characteristics of total work per second and total work per time were calculated. Results showed the total work sums differed greatly from muscle group to muscle group and with different angular velocities. The duration in seconds and the numbers of repetition differed only at higher angular velocity. Males achieved higher levels in every category except for some duration in seconds and some numbers of repetitions. Thigh circumference and leg length were deciding fators in every case, but duration in seconds and number of repetitions were not. These results suggest that measures of endurance should be included along with measures of total work when isokinetic studies are done. Measures of endurance in seconds are more accurate when isokinetic exercise is performed at lower angular velocities and numbers of repetitions at higher angular velocities.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2008년도 하계종합학술대회
• /
• pp.155-156
• /
• 2008

This paper provides a general and compact expression for the probability density function (pdf) and the moment-generating function (MGF) of the maximal ratio combiner output over Rayleigh fading channels. It is then used to derive closed form expression outage probability for repetition code problem. A variety of simulations is performed and shows that they match exactly with analytic ones.

• Annals of Clinical Neurophysiology
• /
• 제5권2호
• /
• pp.197-201
• /
• 2003

Background: The aim of this study is to present the basic reference data of kinematic gait analysis of normal Korean adults with 3 dimensional electrogoniometer, $Domotion^{(R)}$. Method: The basic kinematic gait parameters of hip, knee and ankle joints on the sagittal plane were obtained from 10 healthy adults with 5 repetition for each. Three-dimensional gait analysis was performed with $Domotion^{(R)}$ electrogoniometer in 10 meters long flat floor. Each data collected was processed with IBM PC equipped with gait analysis program. Results: Mean maximal hip flexion was $23.05^{\circ}{\pm}4.62^{\circ}$and mean maximal hip extension was $6.46^{\circ}{\pm}1.30^{\circ}$. Knee flexion was observed with two peak values. The first peak knee flexion was $6.50^{\circ}{\pm}2.07^{\circ}$ at 20.4% of gait cycle and the second peak flexion was $50.34^{\circ}{\pm}2.23^{\circ}$ at 75.8% of gait cycle. Mean maximum ankle dorsiflexion was $5.57^{\circ}{\pm}1.19^{\circ}$ at 44% of gait cycle and mean maximum ankle plantar flexion was $15.51^{\circ}{\pm}1.73^{\circ}$ at 68.5% of gait cycle. Conclusion: We concluded three dimensional gait analysis with electrogoniometer $Domotion^{(R)}$ offers a valid and reliable kinematic data and the application of this tools for clinical gait evaluation will be helpful in management of pathological gait.

• 한방비만학회지
• /
• 제2권1호
• /
• pp.73-82
• /
• 2002

Objectives: The purpose of this study is to investigate the effect of the aerobic exercise and weight training combined with VLCD(very low calorie diet) and chegameuyiin-tang(體減薏苡仁湯) on the change of the body composition during 15 days of hospitalization treatment. Methods: Twenty four female obese patients were observed. Exercise regimen was composed with aerobic exercise and weight training program, and the intensity of aerobic exercise were 50% HRmax(maximal heart rate) twice time a day and weight training were 50% 1RM(one repetition maximum) a day. All subjects diet regimen was VLCD of 600kcal/day. Results & Conclusions. 1. There was no significant difference between the aerobic exercise and the weight training groups in the change of body weight, fat mass, and percent body fat, waist-hip ratio, body mass index and resting metabolic rate. 2. In the comparison of the change rate of FFM(fat free mass), weight training group preserved FFM better than aerobic-exercise-only-group with no statistical significance.

• The Korean Journal of Physiology and Pharmacology
• /
• 제18권5호
• /
• pp.441-446
• /
• 2014

Ursolic acid (UA), a type of pentacyclic triterpenoid carboxylic acid purified from natural plants, can promote skeletal muscle development. We measured the effect of resistance training (RT) with/without UA on skeletal muscle development and related factors in men. Sixteen healthy male participants (age, $29.37{\pm}5.14$ years; body mass index=$27.13{\pm}2.16kg/m^2$) were randomly assigned to RT (n=7) or RT with UA (RT+UA, n=9) groups. Both groups completed 8 weeks of intervention consisting of 5 sets of 26 exercises, with 10~15 repetitions at 60~80% of 1 repetition maximum and a 60~90-s rest interval between sets, performed 6 times/week. UA or placebo was orally ingested as 1 capsule 3 times/day for 8 weeks. The following factors were measured pre-and post-intervention: body composition, insulin, insulin-like growth factor-1 (IGF-1), irisin, and skeletal muscle strength. Body fat percentage was significantly decreased (p<0.001) in the RT+UA group, despite body weight, body mass index, lean body mass, glucose, and insulin levels remaining unchanged. IGF-1 and irisin were significantly increased compared with baseline levels in the RT+UA group (p<0.05). Maximal right and left extension (p<0.01), right flexion (p<0.05), and left flexion (p<0.001) were significantly increased compared with baseline levels in the RT+UA group. These findings suggest that UA-induced elevation of serum irisin may be useful as an agent for the enhancement of skeletal muscle strength during RT.