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elliptical trainer, also known as elliptical trainers or cross-training machine that combines a variety of the most popular home fitness equipment training action. "Oval" when the word comes from the oval shape of pedal movement, which is a kind of treadmill, stair climbing, cycling, skiing part of the action into one of the instruments. Elliptical machine allows you to exercise on the machine, as in the ski machine that glide, you can simply adjust the pedals to increase the slope to get more like climbing stairs or riding a bicycle pedaling sense.
THE COMPARISON OF MUSCLE ACTIATION USING DIFFERENT TRAJECTORY ELLIPTICAL C-L Cheng, R-W Smith and T-Y Shiang Institute of Sports Equipment Technology email: email@example.com INTRODUCTION During one step cycle, muscle activation of the rectus The elliptical training machine creates a different movement femoris primarily worked in the first and the third phase. trajectory when compared to the treadmill and cycling. EMG amplitude in Biceps femoris did not show a significant Muscle recruitment activity is different when using the difference. Tibialis anterior functioned in the stance phase, elliptical trainer, treadmill and cycling. More and more new and there was other evidence of activation in the third phase designs of elliptical trainers are being produced and we can (50%~75%). For the tibialis anterior, the largest increase in see that each elliptical trainer has a different movement EMG amplitude was in the forefront, and the differences trajectory because of the changing pedal positions. Lot’s of during the three positions were much more distinct than the papers discuss elliptical training and how it affects other three muscles. As for the gastrocnemius, the cardiopulmonary training as well as the mechanism design downward phase indicated the greatest activation. The but there’re no investigations conferring different tibialis and gastrocnemius activation sequences, moreover, trajectories. Therefore, the purpose of this investigation is to are a little different between subjects during elliptical trails. examine the kinematics and biomechanics of different movement trajectories by changing the pedal position. METHODS Five healthy male adults were recruited to train on the elliptical machine. Lower limb kinematics was obtained using 10-camera motion analysis system sampled at 100 Hz. Muscle electromyography (EMG) data were collected from rectus femoris, biceps femoris, tibialis anterior and gastrocnemius using 4 EMG amplifiers at 1000 Hz. The subjects performed a 2-minute warm-up to develop a consistent pedaling speed and pattern. Data were collected during a 30-second period following the warm-up. During Figure 2: Joint angle of the hip, knee and ankle at different the test, the subject maintained a constant velocity of positions through the step cycle. 20mile/hr without the handles, and was instructed to pedal at three different pedal positions. Subjects were tested with their own comfortable shoes. After gathering data, the subjects cooled down and rested. Comparisons of parameters across position were made with single factor ANOVA. The level of significance used in this study was p ≤ 0.05. RESULTS AND DISCUSSION Figure 3: EMG data during the positions of forefront, normal Figure 1 represents the pattern of elliptical movement profile and back (from the left to the right of upper pattern). trajectory for each position throughout the pedaling motion from the forefront (0°) to the forefront (360°). Three pedal CONCLUSIONS positions with identical stride length but different In comparison with the different pedal positions, the more vertical altitudes are equidistant. changes of joint angle occurred at the forefront position. Also, the magnitude of muscle activation was significantly higher. In addition, in this experiment we also fond that muscle activation would be greater in order to keep to posture. Lower limb motion that used handles resulted in smaller muscle activation than without handles, and the Figure 1: Elliptical movement trajectory sequences and magnitude were identical. Therefore, in this study we can see, different elliptical movement trajectories In figure 2, at the beginning of the step cycle, the hip and have different performance results in kinematics and knee joints begun extension and the ankle joint maintained biomechanics. plantar flexor. At the upward movement phase (25%~50%), the hip and knee joints reached full extension and began REFERENCES flexing throughout the pedaling cycle. The hip joint reached 1. Huilien, C. (2006). Unpublished master’s thesis, National peak flexion after the knee joint reached full flexion Taiwan University, Taipei, Taiwan. approximately at the top of the path (75%). The movement 2. Jialing, L. (2004). Unpublished master’s thesis, Chaoyang of the ankle joint into dorsi flexion was brought on by the University of Technology, Taipei, Taiwan. displacement of the pedal, with peak dorsi flexor occurring 3. Porcari Jp, Zedaker JM, NawerL, and Miller M. (1998) similarly to the phase of the knee joint (75%). Medicine & Science in Sports & Exercise, 30, pS1.
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