Three-dimensional Cinematography Research Articles

착지동작에서 착지높이, 양발간격, 디딤형태가 하지분절에 미치는 영향

Purpose: The purpose of this study is to analyze the kinematics and kinematic changes of the lower extremity in the landing height, landing stand width, and foot contact patterns, and to reveal the relationship between these factors and lower extremity injuries.<BR> Method: The subjects of this study were nine male college students. The experimental task was to perform drop landing with both feet on the jump platform. The landing procedures were to land in accordance with the conditions of the landing height (30, 50cm), the landing stand width (narrow, wide), and foot contact patterns(flatfoot, forefoot). Three-dimensional cinematography was performed to analyze the ground reaction force, loading rate, angle, moment, and joint stiffness of the lower extremity.<BR> Results: The peak vertical ground reaction force increased when the landing height was increased, but the loading rate did not differ in all factors. As the landing height was increased, flexion and abduction of the hip joint increased, and the extension moment of the hip joint increased at the same time. As the landing stand width increased, abduction of the hip joint and inversion of the ankle joint increased. The change in foot contact pattern resulted in differences in all factors except hip flexion angle, and in particular, increased plantar flexion moment along with dorsiflexion of the ankle joint during forefoot contact. Finally, there was no difference in joint stiffness of the lower extremity in all conditions.<BR> Conclusion: The landing height affected the hip and knee joints, but the ankle joint was affected by the foot contact patterns. An increase in ankle plantar flexion moment during forefoot contact could be considered an effective feature to reduce lower extremity injuries. The landing stand width resulted in opposite anatomical characteristics in the hip and ankle joints, and further studies are likely to be needed to clarify the results related to this factor.

Influence of Load Carriage on the Gait Characteristics of the Obese.

Background:Gait mechanism due to overloaded weight of the obese may be altered, but yet uncertain whether an added loaded weight on body weight can alter or not gait characteristics.Methods:We applied with 0 kg (no load), 5 kg, 10 kg, and 15 kg of the load carriage respectively on the obese (n=11) to grasp a mechanism on the control of impact types and dynamic stability during gait. Gait characteristics was analyzed with three-dimensional cinematography and ground reaction force system consisted of a length of 1 stride, mean velocity of center of gravity during supporting phase, breaking force, propulsive force, dynamic posture stability index (DPSI), and extrapolated centre of mass (XCoM) respectively. We performed repeated measures one-way analysis of variance (0 kg, 5 kg, 10 kg, and 15 kg) and performed the post hoc test (Duncan) at (P<0.05) in case of significant level respectively.Results:Onestride length and mean velocity were decreased according to gradual increase of a load carriage, but breaking and propulsive force were somewhat increased. Particularly a decrease of gait velocity and stride length kept the range for DPSI and XCoM theta of a level of no-load carriage.Conclusion:Usually load carriage during prolonged time of the obese is few case, but rather a load carriage of 5 kg may alter a gait posture potentially with prolonged time of load carriage.

A Kinematic Analysis of Upper Extremity during Squash Backhand Drop Shot

The kinematic variables of the squash backhand drop shot were analyzed through a three-dimensional cinematography. The displacements and velocities of trunk and racket, and the angular displacements and velocities of elbow and shoulder joints were compared between the expert and novice groups. The results were follows. First, The lap time of the expert group was longer than that of the novice group. Second, X(anterior-posterior), Y(vertical), and Z(lateral)-axis racket displacements of the expert group were significantly higher than those of the novice group during the DS(down swing) period. X(anterior-posterior)-axis racket displacements of the expert group during the FT(follow through) period was shown to be maintained longer in forward direction. Third, Racket speed of expert group was significantly lower than that of the novice group. Forth, the elbow joint angle of the expert group was maintained longer after the impact than the novice group. Fifth, the expert group showed elbow extension just prior to the impact while the novice group showed impact with pre-extended elbow joint. As a final conclusion, the racket should move fast during the down-swing period and move slowly during the follow-through period, and the shoulder joint should extend prior to the elbow joint extention for the efficient squash backhand dropshot motion.

라켓볼 백핸드와 스쿼시 백핸드 스트로크 동작의 운동학적 비교

The purpose of this study was to comparatively analyze the kinematic variables between the squash backhand and racquetball backhand strokes through three-dimensional cinematography. Three expert racquetball players and three expert squash players were involved in the data gathering process. The horizontal, vertical and lateral displacement of racket and trunk segment, intersegmental angular velocity of the wrist, elbow and shoulder joints, and the linear velocity of the racket were descriptively analyzed, and the followings were concluded. The racket of the squash backhand stroke showed an 'U' shaped movement where the racket moved rapidly downward and moved forward to make an impact and followed through to a front-top finish, while the racket of racquetball backhand stroke showed an 'O' shaped movement where the racket showed circular movement through the rear and bottom positions for the impact, and showed rotation through the lower-front and upper front to a upper-rear-ward finish during the follow-through. The peak velocity of racket was found before the impact point in the squash backhand stroke and at the impact point in the racquetball backhand stroke. For the final conclusion, for the squash backhand stoke, instructors might be better to make the racket move downward to make highest velocity before the impact and finished short follow-through, while for the racquetball backhand stroke, to make the racket move forward to make highest velocity at the impact and finished rather long follow-through.

태권도 뒤차기의 인체 관절과 분절사이의 협응 형태

The purpose of this study was to qualitatively analyze coordination pattern of joints and segments during Dwichagi in Taekwondo and present a point of difference as compared with the previous study on Dolryeochagi in Taekwondo. By the utilization of three-dimensional cinematography, the angles of individual joints and segments of six male Taekwondo experts during Dwichagi were calculated by using Euler's angle. The used coordination variables were angle vs. angle plots between adjacent joints and segments and angle vs. angular velocity plots of individual joints and segments, respectively. It was observed during Dwichagi that in-phase coordination and spring-like rotational control mechanism of the lower and upper trunk were transferred into straight spring-like control mechanism of lower leg passing through flexion-extension and the fixation of degree-of-freedom of lower trunk and hip joint alternatively. This comparative study that coordination variables were used seems to be more useful research direction to deeply understand basic control mechanisms of Taekwondo kicking techniques when compared with the previous studies that defined Dwichagi as a thrust movement pattern merely based on biomechanical variables of a kicking leg.

태권도 뒤후려차기의 인체분절 사이의 협응 형태

The purpose of this study was to qualitatively analyze coordination pattern of joints and segments during Dwihuryeochagi and present points of difference as compared with the previous studies on Dolryeochagi and Dwichagi in Taekwondo. By the utilization of three-dimensional cinematography, the angles of individual joint and segment of six male Taekwondo experts during Dwihuryeochagi were calculated. The used coordination variables were angle vs. angle plots and angle vs. angular velocity plots. It was observed during Dwihuryeochagi that in-phase coordination including a turning point synchronization and spring-like rotational control mechanism of the lower and upper trunk were transferred into both ballastic and spring-like control mechanism of the lower leg by utilizing the intervention of the fixation of degree-of-freedom, out of phase coordination and decoupled coordination of the lower trunk and the hip joint. This comparative study that used coordination variables seems to be more useful research direction to deeply understand basic control mechanisms of Taekwondo kicking techniques and to propose effective and efficient graded learning sequences among them.

에너지보행과 일반보행의 운동학적 비교

The purpose of this study was to compare kinematic characteristics on the limbs at 3 different walking speed during the energy and the normal walking. Eight subjects performed energy walking and normal walking at the slow speed(65 beats/min), the normal speed(115beats/min), the fast speed(160 beats/min). The 3-d angle was calculated by vector projected with least squares solution with three-dimensional cinematography(Motion Analysis corporation). The range of motion was calculated on the trunk, shoulder, elbow, hip, knee joint. The results showed that stride length was no difference of the two walking pattern. The duration of support phase was also no difference of the two walking pattern. The range of motion of shoulder joint significantly increased in the sagittal and frontal planes, and the range of motion of elbow joint significantly increased as the energy walking. The range of motion of hip joint had no significant difference in the any planes in changing of walking speed. But the most remarkable difference of the two walking patterns revealed at the trunk. The range of flexion/extension angle had significant increasing at normal speed, and the range of the right/left flexion angle had significant increasing below at the 3 walking speed, and The range of rotation angle had significant increasing , , respectively at the normal and slow speed. But there was no significant difference of range of motion at the hip and knee joints between energy walking and normal walking.

볼링 투구동작의 운동역학적 연구

The general objective of this study was to investigate biomechanical characteristics of bowling swing using three-dimensional cinematography. This study focused specifically on movements of the upper body segments during a bowling swing. Eight elite female bowling players participated in this study. Subjects performed bowling swing and their performance was sampled at 60 frame/sec using two high-speed video cameras with a synchronizer. After digitizing images from two cameras, the two-dimensional coordinates were used to produce three-dimensional coordinates of the 12 body segments (20 joint reference makers). The obtained three-dimensional coordinates were fed to a custom-written kinematic and kinetic analyses program (LabView 6.1, National Instrument, Austin, TX, USA). The analyses determined the linear and angular kinematic variables of the body segments with which joint force and torque of the lower and upper trunks and the shoulder were estimated based on the Newton-Euler equations. It was found that during the bowling swing the peak linear velocities of the body segments were reached in sequence the trunk, the shoulder, the elbow, the wrist, and the bowl. This result indicates that linear momentum of the lower body and the trunk transmits to the arm segment during the bowling swing. The joint torques of the torso and the arm occurred almost simultaneously, indicating that bowling swing seem to be a push-like motion, rather than a proximal-distal sequence motion in which many of throwing motions are categorized. The ultimate objective of the bowling swing is to release a heavy-weight bowl with power and consistency. Therefore, the bowling swing observed in this study well agrees with that bowlers use the stepping to increase the linear velocity of the bowl, the simple pendulum system and the push-like segmental motion in the torso and the arm segment to enhance the power at the release of the bowl.

철봉 엔도 360°엘그립 동작의 기술분석

This study was attempted to Kinematical characteristics of the Endo <TEX>$360^{\circ}$</TEX>El-grip Swing on the horizontal bar. To do this, we selected and analyzed the performance of two athletes who did Endo <TEX>$360^{\circ}$</TEX>El-grip Swing in the horizontal bar competition of male artistic gymnastic in the 22nd Universiad Games 2003 Daegu. We drew the conclusions from the kinematical factors that were came out through analyzing three-dimensional cinematography of the athletes' movements, by using two video cameras. In point of analyzing the actual competition situation, it is expected that gymnastics and coaches have the effective informations, and the following conclusion had resulted. 1. When performing Endo <TEX>$360^{\circ}$</TEX>El-Grip, the average for entire required time was <TEX>$1.93{\pm}0.06sec$</TEX>. The average for descent phase time was <TEX>$0.24{\pm}0.02sec$</TEX>, ascent phase time was <TEX>0.22${\pm}0.07sec$</TEX>, connecting phase time was <TEX>$0.87{\pm}0.07sec$</TEX>, and El-Grip phase time was <TEX>$0.61{\pm}0.02sec$</TEX>. The descent phase need short period of time but however to have a stable performance, ensuring ascent and connecting phase time are needed. El-Grip phase need short period of time to have a stable re-grasp. 2. To have a convenient preparation for El-Grip in descent and ascent phase, lowering CM, and ease up in sway and plunge from the High Bar would make descent and ascent even more faster and would have increase effect in trunk rotation. 3. In descent and ascent phase, if shoulder angle and arm slope is dwindling then it would effect rotation angle so might risk it from hitting a Bar when putting legs in and out. 4. In connecting phase, it requires some time to show stable performance when El-Grip phase is continued by using hip angle which would make trunk rotation angle bigger and make descent and ascent time slower. 5. In El-Grip phase, when doing motions like hand standing. using hip angle more than maximum would make CM even faster and it is stable position while performing.

철봉운동 Deff 동작의 운동학적 분석

The purpose of this study is to prove the kinematical characteristics of Deff motion, the high bar performance, in terms of flying phases so that we can provide basic sources for improving gymnastic performance. To do this, we selected and analyzed the performance of two athletes who did Deff motion in the high bar competition of male artistic gymnastic in the 22nd Universiade 2003 Daegu. We drew the conclusions from the kinematical factors that were came out through analyzing three-dimensional cinematography of the athletes` movements, by using a high speed video camera. To make a successful performance, a performer releases the bar at a height of a high bar vertically and at a height of 82cm horizontally, and the flying performance should be made without moving forward, as maintaining the proper balance, in order to rise over 118cm high during the flying phase. When the performer is releasing the bar, an increase of the vertical speed in the center of the body and extension of a knee joint and a hip joint contribute to increasing a flying height. And when the moving body is twisted, leaning to left side is caused by the winding movement of a knee joint, which causes an unstable bar grasp. To grasp the bar stably, just before releasing the performer should gain propulsive force from twisting rotation through increasing the speed of shoulder rotation. And before the peak point, the performer should make sure of a body rotation distance over so that he or she can do an aerial rotary performance smoothly. When grasping the high bar, the center of the body should be above the bar and the angle of shoulder rotation should be maintained close to simultaneously. he high point performance(S1) has more speed on an ascending phase and less speed on a descending phase than the low point performance (S2). At the peak point, both the rotation angle of the body and that of the shoulder in high point performance are big as well. In conclusion, it is shown that a performer can make a jump toward the high bar easily with the body straight because the performer can hold the upper part of the body erect early in a descending phase.

축구 페널티킥에서 초보자와 숙련자의 3차원 운동학적 비교

The purpose of this study was to compare kinematic data between experts and novices, and identify difference kinematic parameters changing direction to kick in penalty kick of soccer play. Novice subjects were 5 high school students Who has never been experienced a soccer player, and expert subjects were 5 competitive high school soccer players. The 3-d angle was calculated by Euler's Angle by inertial axis and local axis with three-dimensional cinematography. Kinematic parameters in this study consisted of angles of knee joints, hip joints, lower trunk and upper trunk when the support foot was contacted on ground and kicking foot impacted the ball. The difference of angle of knee joints in the flexion/extension was insignificantly showed below <TEX>$4{\sim}9^{\circ}$</TEX> in groups and directions of ball at the time of support and impact. But the difference of angle of hip joint was significant in groups and directions of ball at the time of support and impact. Specially the right hip joint of experts were more flexed about <TEX>$12^{\circ}$</TEX>(<TEX>$43.99{\pm}6.17^{\circ}$</TEX> at left side, <TEX>$31.87{\pm}4.49^{\circ}$</TEX> at right side), less abducted about <TEX>$10^{\circ}$</TEX> (<TEX>$-31.27{\pm}4.49^{\circ}$</TEX> at left side, <TEX>$-41.97{\pm}6.67^{\circ}$</TEX> at right side) at impact when they kicked a ball to the left side of goalpost. The difference of amplitude angle in the trunk was significantly shown at upper trunk not lower trunk. The upper trunk was external rotated about <TEX>$30^{\circ}$</TEX> (novice' angle was <TEX>$-16.3{\pm}17.08^{\circ}$</TEX>, expert's angle was <TEX>$-43.73{\pm}12.79^{\circ}$</TEX>) at impact. Therefore the significant difference of kinematic characteristics could be found at the right hip joint and the upper trunk at penalty kick depending on the direction of kicking.

높이뛰기의 바 넘기 동작을 위한 각운동량 분석

The purpose of this study was to analyze the angular momentum characteristics of the Fosbury Flop high jump and the role of the body segments for the production of 3 angular momentum components. The subjects were three male jumpers who were former Korean national team players. Their jumping motions were analyzed using the DLT method of three-dimensional cinematography. The conclusions were as follows. 1. All the forward angular momentum needed to clear the bar was created in the take-off phase. Take-off leg was the great contributor of the forward angular momentum. On the other hand, free leg produced large opposite angular momentum. 2. All subject had some lateral angular momentum before the take-off phase. Head and free leg had major contribution to the lateral angular momentum production. Take-off leg produced opposite angular momentum. 3. All subject had some twisting angular momentum, which make the back of the athlete him to the bar, before the take-off phase. Free leg was the major contributor of the twisting angular momentum. Head and trunk was the second contributor of the twisting angular momentum. 4. Total angular momentum needed to clear the bar had no significant correlation to the jumping height. 5. Subject who made excessive angular momentum showed different pattern of angular momentum production and had a poor record compared to other subject.

높이뛰기의 도약 높이를 증가시키는 역학적 원리와 동작

This study was conducted to investigate the principles and motions for increasing the jumping height of Fosbury Flop. The subjects were three male jumpers who were former Korean national team players. Their jumping motions were analyzed using the DLT method of three-dimensional cinematography. The conclusions were as follows. 1. The horizontal velocity of approach run and decreasing of this velocity during the take off phase were increased as the jumping height was increased. Therefore, in order to increase the jumping height, the horizontal velocity of approachrun should be increased and decreased properly during the take-off phase. The average height of the analyzed Dials was 2.15m. The average horizontal velocity of approachrun was 7.49m/s and decreased to 4.16m/s at the instance of take-off. 2. The vertical velocity of the center of gravity was increased as the ascending height of the center of gravity during the take-off phase was increased. Therefore, the center of gravity at the instant of touch down should be lowered. This could be possible by increasing the length of the last stride and the backward lean angle of the body. The average length of the last stride was 111.1% of the standing height, the average height of the center of gravity was 46.6% of the standing height and the average backward lean angle of the body was 40.3 degrees.

Changes in angular momentum during the tennis serve

Three-dimensional cinematography and the direct linear transformation method were used to obtain the coordinates of the landmarks of five right-handed collegiate tennis players. A 15-segment model was used to calculate the total body angular momentum about three orthogonal axes (X, parallel to the baseline; Y, normal to baseline and pointing towards the net; and Z, pointing upwards) passing through the centre of mass and to obtain the segmental contribution of the trunk, arms and legs. Most of the clockwise angular momentum about the X-axis was concentrated in the trunk and the racket-arm. Between the events of maximum external rotation and ball impact, the clockwise angular momentum about the X-axis of rotation of most body segments was reduced and the racket-arm gained clockwise angular momentum. The body angular momentum about the Y-axis of rotation had two distinct patterns and was the result of the lateral rotation of the trunk as the racket shoulder was elevated in preparation for impact. This body angular momentum was clockwise from the event of maximum external rotation to impact for the players with the greatest ball speed, whereas it was counterclockwise for the other players. The angular momentum about the Z-axis of rotation was small and lacked a consistent pattern. The largest source of angular momentum in the tennis serve derives from the remote angular momentum about the X- and Y-axes of rotation, which are then transferred from the trunk to the racket-arm and finally to the racket. Near impact, most of the angular momentum (75.1%) was concentrated in the racket-arm. Of the angular momentum of the racket-arm, the largest percentages were concentrated in the racket (35.9%) and the forearm segment (25.7%).

The relationship between basketball shooting kinematics, distance and playing position

Three-dimensional cinematography (100 Hz) was used to establish the relationship between distance and the kinematics of shooting with respect to playing position in basketball. Fifteen subjects, divided into guards, forwards and centres (all n = 5), performed jump shots from each of three distances: 2.74, 4.57 and 6.40 m from the basket. Increases in mean release speed were found as shooting distance increased for all groups. This was due to increased angular velocities of both shoulder flexion and elbow extension and an increased speed of the centre of mass in the direction of the basket. Release angles for the two shorter distances (52-55 degrees) tended to provide the advantage of a steep angle of entry into the basket, whereas those at the longest distance (48-50 degrees) were closer to those requiring the minimum possible release speed. All groups exhibited an earlier timing of release as shooting distance increased, which gave rise to an earlier rotation of the shoulder axis. The more consistent changes in kinematic patterns with changes in shooting distance exhibited by guards as compared to centres would suggest that such adjustments are easier to make for those players who regularly shoot from long range.

Three-Dimensional Kinematic Analysis of Baseball Pitching in Acceleration Phase

To examine the relationships of pitching performance to maximum external rotation of the shoulder and to time in the acceleration phase, 3 male baseball pitchers were tested using three-dimensional cinematography. Analysis indicated that increasing maximum external rotation of the shoulder at the very beginning of the acceleration phase would help to generate a higher pitching ball velocity since a greater linear and angular displacement could be used to accelerate the throwing forearm. Slowing the wrist action just before ball-release may be a key technique to increasing pitching velocity of the ball.

Predicting muscle forces in gait from EMG signals and musculotendon kinematics

An EMG-driven muscle model for determining muscle force-time histories during gait is presented. The model, based on Hill's equation (1938), incorporates morphological data and accounts for changes in musculotendon length, velocity, and the level of muscle excitation for both concentric and eccentric contractions. Musculotendon kinematics were calculated using three-dimensional cinematography with a model of the musculoskeletal system. Muscle force-length-EMG relations were established from slow isokinetic calibrations. Walking muscle force-time histories were determined for two subjects. Joint moments calculated from the predicted muscle forces were compared with moments calculated using a linked segment, inverse dynamics approach. Moment curve correlations ranged from r = 0.72 to r = 0.97 and the root mean square (RMS) differences were from 10 to 20 Nm. Expressed as a relative RMS, the moment differences ranged from a low of 23% at the ankle to a high of 72% at the hip. No single reason for the differences between the two moment curves could be identified. Possible explanations discussed include the linear EMG-to-force assumption and how well the EMG-to-force calibration represented excitation for the whole muscle during gait, assumptions incorporated in the muscle modeling procedure, and errors inherent in validating joint moments predicted from the model to moments calculated using linked segment, inverse dynamics. The closeness with which the joint moment curves matched in the present study supports using the modeling approach proposed to determine muscle forces in gait.

A new technique of three-dimensional cinematography

A new technique of three-dimensional cinematography

Three-Dimensional Interactions in a Two-Segment Kinetic Chain. Part II: Application to the Throwing Arm in Baseball Pitching

Fastball pitches of eight collegiate baseball pitchers were filmed using the Direct Linear Transformation (DLT) method of three-dimensional (3D) cinematography. Coordinate data were obtained, and the model developed by Feltner and Dapena (1989) was used to fractionate the 3D angular acceleration of the upper arm and distal segment (the forearm, the hand, and prior to release, the baseball) of the throwing arm into terms associated with the joint torques exerted on the segments and the kinematic variables used to define the motions of the segments. The findings indicated that the extreme external rotation of the upper arm during the pitch was due mainly to the sequential actions of the horizontal adduction and abduction muscles at the shoulder. The study also found that the rapid elbow extension prior to ball release was due primarily to the counterclockwise angular velocity of the upper arm and trunk (viewed from above) that occurred during the pitch, and not to the elbow extensor muscles.

A biomechanical analysis of the sticking region in the bench press

The performance of ten elite powerlifters were analyzed in a simulated competition environment using three-dimensional cinematography and surface electromyography while bench pressing approximately 80% of maximum, a maximal load, and an unsuccessful supramaximal attempt. The resultant moment arm (from the sagittal and transverse planes) of the weight about the shoulder axis decreased throughout the upward movement of the bar. The resultant moment arm of the weight about the elbow axis decreased throughout the initial portion of the ascent of the bar, recording a minimum value during the sticking region, and subsequently increased throughout the remainder of the ascent of the bar. The electromyograms produced by the prime mover muscles (sternal portion of pectoralis major, anterior deltoid, long head of triceps brachii) achieved maximal activation at the commencement of the ascent phase of the lift and maintained this level essentially unchanged throughout the upward movement of the bar. The sticking region, therefore, did not appear to be caused by an increase in the moment arm of the weight about the shoulder or elbow joints or by a minimization of muscular activity during this region. A possible mechanism which envisages the sticking region as a force-reduced transition phase between a strain energy-assisted acceleration phase and a mechanically advantageous maximum strength region is postulated.