ISBS (International Society of Biomechanics in Sports): Conference Proceedings Archive
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BIOMECHANICS OF RUNNING WITH FOREFOOT-SPRING FOOTWEAR
Get PDFForefoot strikers have significantly lower rates of repetitive stress injury than rearfoot strikers. The purpose of this study was to design a forefoot-spring footwear to induce habitual rearfoot runners to adopt a forefoot strike pattern and to investigate the effect of this forefoot-spring footwear on lower extremity joints biomechanics during running. Our findings indicated that different lower limb energy absorption strategies were adopted for running with the forefoot-spring footwear, as compared to control footwear. A shift from hip-dominant to ankle-dominant energy absorption strategy may reduce the loading to the hip and knee joints and could be beneficial towards the prevention of running related injuries particularly at the knee joint
ACUTE EFFECTS OF SURFACE TYPE ON BIOMECHANICAL PARAMETERS OF RUNNING
Get PDFThe purpose of this study was to examine whether an acute bout of exercise on a compliant versus non-compliant surface could reveal biomechanical indicators of injury. Twelve college-aged seasoned cross-country runners performed two bouts of 20 minute runs, one on grass and one on asphalt, one week apart. Changes (pre vs. post) measures in contact time (s), impulse (Ns) and peak vertical force (N) showed no significant differences based on surface type. The results show that an acute bout of exercise on either surface will not be different in terms of potential for injury. However, the chronic effects of running on different surfaces should be examined using fatigue levels to determine
COMPARISON OF THE CATCHER’S TRADITIONAL THROW-DOWN VERSUS PITCH-OUT
Get PDFThe catcher is often the defensive leader on the field. With a plethora of assignments to manage during a game, one of the many responsibilities a catcher has is catching base runners that attempt to steal. Catchers throwing out base stealers at second base utilize two methodologies: a traditional throw-down or the pitch-out. The purpose of the study was to explore potential differences in joint kinematics between the two motions when throwing to second base and how performance is affected. Vicon cameras recorded the throwing motions of the catcher, providing data for kinematic analysis. The pitch-out showed higher ball velocities than the traditional throw-down, but similar pop times. Furthermore, elbow extension and trunk angular velocities were significantly different. With knowledge of the throwing kinematics of catchers, performance can be potentially improved and injury avoided
Diurnal Variation in Stretch Shortening Cycle and Non-Stretch Shortening Cycle Jumping Performance
Get PDFThis study assessed the diurnal variations, as well as the subjects’ perceptions of how time of day affects their jumping performance. Eighteen subjects participated in testing sessions at 7 a.m., noon, and 5 p.m., on the same day. Subjects performed squat jumps (SJ) and countermovement jumps (CMJ) on a force platform with peak ground reaction force (GRF), jump height, and reactive strength index-modified (RSImod) obtained for each jump. Diurnal differences for the CMJ were found for GRF (P = 0.048). Diurnal differences for the SJ were found in RSImod (P= 0.04). Subjective assessment of jumping explosiveness was significantly different across time of day (P = 0. 047). Lower body power training such as plyometrics, may be more effective at mid day than early morning or late afternoon
ACUTE EFFECTS OF BAREFOOT RUNNING ON LOWER LIMB KINEMATICS AND SPATIOTEMPORAL VARIABLES IN HABITUALLY SHOD MALES
Get PDFThe aim of this study was to examine the immediate effects of barefoot running on lower limb joint kinematics and stride patterns in a group of habitually shod runners. Ten male runners performed 1 minute bouts of treadmill running at 3 fixed velocities in both shod and barefoot conditions. 2D video kinematic data were recorded and 6 discrete markers were digitized in order to quantify ankle, knee and hip kinematics. Synchronous kinetic data were recorded from a force plate supporting the right posterior treadmill leg in order to quantify spatiotemporal variables. BF running resulted in significantly higher stride frequency and shorter ground contact times. In addition, BF running significantly reduced knee and hip but increased ankle range of motion during the absorptive phase of the stance. The results highlight that running mechanics can change in as little as 30 seconds of BF running
FINGER FORCES DURING BASEBALL PITCHING
Get PDFA 3D force transducer was installed in an official baseball to make a direct measurement of finger force imparting on the ball during pitching. Eight collegiate pitchers threw a 4- seam fastball at their maximal speed. Force was measured separately from each of the index, middle, and ring fingers, and the thumb. Peaks and peak occurrence time of computed resultant and shear forces were evaluated. Index and middle finger forces generally had a bimodal pattern with the first and second peaks appeared at about 80, and 96% of the stride foot contact period, respectively. Their force magnitude reached 90 N. and above. Magnitude of shear force was about half of the resultant force. Forces by the thumb and ring finger were less than those by the index and middle fingers. The findings indicated that the fingers were applying considerably large magnitude of force during pitching
KINEMATICS OF JUDO BREAKFALL FOR OSOTO-GARI
Get PDFThe purpose of this study was to identify kinematic parameters of breakfall for osoto-gari that can be distinguished between the experienced and the novice judokas. Eight experienced and four novice judukas volunteered to participate in the study. The motion data of the breakfall for osoto-gari were collected with a three-dimensional motion analysis technique. Our result demonstrated that there are significant differences in the hip movement pattern between the experienced and the novice judokas (
BIOMECHANICAL ANALYSIS OF ROTATION STRATEGY OF BACKWARD SOMERSAULT IN ARTISTIC GYMNASTICS
Get PDFThe purpose of this study was to examine the rotation strategy used by gymnasts to successfully land after a backward somersault. Nine male university gymnasts (1.66 ± 0.03 m, 61.2 ± 0.75 kg) performed a backward-tucked somersault from a box (0.3 m height). Three-dimensional coordinate data was collected by a Vicon MX+ system. We compared the trials in which the landing succeeded and trials in which the landing failed. There was a difference in the moment of inertia during the airborne phase and the phase time. The results of this study suggest that changing the moment of inertia during the airborne phase has a significant effect on the body rotation. In particular, it is considered that the timing at which the phase is switched by changing the moment of inertia determined the body rotation
GROUND REACTION FORCES DURING “POINTE” IN BALLET
Get PDFThe purpose of this study was to investigate the differences in ground reaction forces between right and left leg during pointe. Fifteen ballet dancers who have no lower limb injury participated in this study. Eight infrared cameras (Qualisys, Sweden) and two force plates (Kistler, Switzerland) were used for a three dimensional motion analysis. Ballet dancers were asked to perform 10 trials of “demi-plie en pointe”. The results showed significant differences in vertical ground reaction forces between right and left leg at maximum ankle extension (E3, ?
FOOT POSITION AFFECTS KNEE JOINT TORQUE IN ERGOMETER ROWING
Get PDFRecreational and competitive athletes use rowing ergometers for aerobic exercise. Little is known about the impact of foot position on knee joint loads during this exercise. The aim of this study was to investigate the effect of foot position on hip joint kinematics as well as knee adduction and knee rotation torques. It was hypothesized that altering the foot position to a more lateral placement on a rowing ergometer would mediate knee joint torques. Data supported the hypothesis that a significant change of knee adduction torque as well as reduced external rotation torques in the knee joint would accompany more lateral foot positioning. These results support the development of adjustable foot rests for rowing ergometers to better modulate knee forces